Stem Cell Research & Therapy•2025•DOI: 10.1186/s13287-025-04788-3
End-stage liver disease (ESLD) is one of the predominant diseases contributing to high morbidity and mortality worldwide, with etiologies including alcoholic liver disease, viral hepatitis, non-alcoholic fatty liver disease, and metabolic-associated liver disease. Currently, liver transplantation remains the only effective treatment, however, its clinical application is significantly limited by donor shortages, immune rejection, and high medical costs. Among the five types of stem cells that have been experimentally applied to liver diseases, mesenchymal stem cells (MSCs) have emerged as the most extensively studied, with the largest number of experimental and clinical research platforms worldwide. This review compiles findings from 25 preclinical and clinical studies on MSCs in the treatment of ESLD, aiming to elucidate the core mechanisms of action and then outline both the challenges in MSC clinical translation and the novel opportunities arising from cutting-edge research.
Stem Cell Research & Therapy•2025•DOI: 10.1186/s13287-025-04203-x
Background Mesenchymal stem cell (MSC) -derived exosomes, especially adipose-derived mesenchymal stem cell exosomes (ADSC-Exos), have emerged as a promising alternative for skin damage repair with anti-inflammatory, angiogenic and cell proliferation effects while overcoming some of the limitations of MSC. However, the mechanism by which ADSC-Exos regulates inflammatory cells during wound healing remains unclear. This study investigated how ADSC-Exos regulate macrophages to promote wound healing. Methods ADSC-Exos were isolated using ultracentrifugation, with subsequent quantification of exosomes particle number. To investigate their role in wound healing, the effects of ADSC-Exos on inflammation, angiogenesis, collagen deposition and macrophage polarization were evaluated through immunohistochemical staining, immunofluorescence and western blotting. Changes in gene expression associated with ADSC-Exos-induced macrophage polarization were analyzed using qPCR. RNA sequencing was performed to identify differentially expressed genes affected by ADSC-Exos. The critical role of IL-33 in the wound healing process was further confirmed using Il33−/− mice. Additionally, co-culture experiments were conducted to explore the effects of IL-33 on keratinocyte proliferation, collagen deposition and epithelialization. Results ADSC-Exos inhibited the expression of TNF-α and IL-6, induced M2 macrophage polarization, promoted collagen deposition and angiogenesis, and accelerated wound healing. RNA sequencing identified IL-33 as a key mediator in this process. In Il33−/− mice, impaired wound healing and decreased M2 macrophage polarization were observed. The co-culture experiments showed that IL-33 enhanced keratinocyte function through activation of the Wnt/β-catenin signaling pathway. These findings highlight the therapeutic potential of ADSC-Exos in wound healing by modulating IL-33. Conclusions ADSC-Exos promote wound healing by regulating macrophage polarization and enhancing IL-33 release which drives keratinocyte proliferation, collagen deposition and epithelialization via the Wnt/β-catenin
Stem Cell Research & Therapy•2024•DOI: 10.1186/s13287-024-03660-0
Background Premature ovarian failure (POF) has a profound impact on female reproductive and psychological health. In recent years, the transplantation of umbilical cord-derived mesenchymal stem cells (UC-MSCs) has demonstrated unprecedented potential in the treatment of POF. However, the heterogeneity of human UC-MSCs remains a challenge for their large-scale clinical application. Therefore, it is imperative to identify specific subpopulations within UC-MSCs that possess the capability to improve ovarian function, with the aim of reducing the uncertainty arising from the heterogeneity while achieving more effective treatment of POF. Methods 10× Genomics was performed to investigate the heterogeneity of human UC-MSCs. We used LRP1 as a marker and distinguished the potential therapeutic subpopulation by flow cytometry, and determined its secretory functions. Unsorted UC-MSCs, LRP1high and LRP1low subpopulation was transplanted under the ovarian capsules of aged mice and CTX-induced POF mice, and therapeutic effects was evaluated by assessing hormone levels, estrous cycles, follicle counts, and embryo numbers. RNA sequencing on mouse oocytes and granulosa cells after transplantation was performed to explore the mechanism of LRP1high subpopulation on mouse oocytes and granulosa cells. Results We identified three distinct functional subtypes, including mesenchymal stem cells, multilymphoid progenitor cells and trophoblasts. Additionally, we identified the LRP1high subpopulation, which improved ovarian function in aged and POF mice. We elucidated the unique secretory functions of the LRP1high subpopulation, capable of secreting various chemokines, cytokines, and growth factors. Furthermore, LRP1 plays a crucial role in regulating the ovarian microenvironment, including tissue repair and extracellular matrix remodeling. Consistent with its functions, the transcriptomes of oocytes and granulosa cells after transplantation revealed that the LRP1high subpopulation improves ovarian function by modulating the extracellular matrix of oocytes, NAD metabolism, and mitochondrial function in granulosa cells. Conclusion Through exploration of the heterogeneity of UC-MSCs, we identified the LRP1high subpopulation capable of improving ovarian function in aged and POF mice by secreting various factors and remodeling the extracellular matrix. This study provides new insights into the targeted exploration of human UC-MSCs in the precise treatment of POF.
Acta Biochimica et Biophysica Sinica•2025•DOI: 10.3724/abbs.2025048
As a classic tumor suppressor gene, p53 has been extensively studied since its discovery in the mid-1980s. Research findings have revealed that p53 protein expression is suppressed in various cancers [1]. For example, in cervical cancer, p53 predominantly exists in a wild-type form to maintain its biological function [2]. Nevertheless, its tumor-suppressive activity is significantly impaired because of rapid protein degradation, short half-life, and low levels. Post-translational modifications (PTMs) of p53, such as ubiquitination, acetylation, phosphorylation and methylation, are critical regulators of its stability, activity, conformation, localization, and interactions with cofactors [3]. Among these, ubiquitination and acetylation play central roles in controlling p53 protein stability and activity [4]. Therefore, targeting p53 PTMs to modulate its ubiquitination and acetylation levels represents an effective strategy to increase its stability and tumor-suppressive function, offering a promising avenue for cervical cancer drug development. In 99% of cervical cancers (high-risk human papillomavirus-positive), E3 ubiquitin ligase E6-associated protein (E6AP) mediates the ubiquitination degradation of p53 [5], whereas histone deacetylase 6 (HDAC6) deacetylates p53. In this study, we explored the possibility of combining the natural product withferin A (WA) with the HDAC6 inhibitor ricolinostat (RIC) to treat cervical cancer cells, with a focus on the ubiquitination and acetylation of p53 and the consequences for its stability. These results suggested that the combination of WA and RIC is more effective than either treatment alone in inhibiting the degradation and increasing the stability of p53, thereby synergistically slowing the onset and progression of cervical cancer.
Acta Biochimica et Biophysica Sinica•2026•DOI: 10.3724/abbs.2025170
Cryptococcus gattii causes cryptococcosis and life-threatening cryptococcal meningitis. Currently, the pathogenic virulence mechanisms of C. gattii remain a significant area of ongoing research with considerable unexplored aspects. On the basis of our established research, a sub-cluster of strains with independent evolutionary relationships from WM276 in the phylogenetic analysis of VGI-type strains is identified. In vivo infection experiments on this sub-branch of strains reveal that there are hypervirulent strains and hypovirulent strains among these strains, and the virulence differences are significant (P < 0.001). Bioinformatic interrogation of differentially expressed genes reveals that the catalase-encoding gene CGB_J0620W, CAT2, is a pivotal virulence-associated gene. The hypervirulent clinical isolate G4 (G4-WT) is selected as the parental strain, from which an isogenic CAT2-knockout mutant (cat2Δ) is constructed via homologous recombination, which shows increased sensitivity to oxidative stress, as well as growth defects in response to hyperosmosis, 5-fluorocytosine, fluconazole and amphotericin B. The cat2Δ::CAT2 strain exhibits phenotypic restoration to wild type (WT). In the mouse experiments, significant differences in survival (P < 0.001), pulmonary fungal burden (P < 0.01), and alveolar structural damage are observed between the WT and cat2Δ strains, which are completely different from C. neoformans. Moreover, comparative transcriptome analysis is performed on the WT and cat2Δ strains, which reveals that enzymes encoded by CAT2 may be involved in oxidative stress, metabolism and sugar transport. In conclusion, this study may explain the differences in virulence among different genetic evolutionary processes of a sub-cluster of the VGI geneotype of C. gattii and provide a theoretical basis for targeted therapy in a specific genotype population in the future.
Acta Biochimica et Biophysica Sinica•2026•DOI: 10.3724/abbs.2025150
Rapid identification of pathogens responsible for bloodstream infection is critical for early intervention and effective treatment. Reporter phages, which are known for their exceptional sensitivity and specificity in pathogen detection, have garnered significant interest. In this study, we systematically evaluate phage genome editing strategies that combine homologous recombination with the CRISPR-Cas9 system. We investigate the impacts of homologous arm length, sgRNA activity, target site, and plasmid interactions on editing efficiency. Our results demonstrate that successful genome editing depends on both sufficient cleavage pressure and optimal homologous arm length, particularly when using low-activity sgRNAs. On the basis of these findings, we develop a highly efficient gene editing strategy TPMSR (triple-plasmid-mediated synchronous recombination) that overcomes the limitations of conventional methods that rely on high-activity sgRNA and restricted editing sites. Using the TPMSR strategy, we integrate the Nluc gene into phage T7, generating the reporter phage T7::Nluc, which is then incorporated into a microfluidic chip. Validation with 51 clinical isolates demonstrates outstanding sensitivity, specificity, and accuracy in detecting Escherichia coli in blood within 1.5 h at concentrations less than 30 CFU/mL. This study presents a robust strategy for phage genome engineering and develops a promising method for the rapid diagnosis of bloodstream infections caused by E. coli.
Acta Biochimica et Biophysica Sinica•2025•DOI: 10.3724/abbs.2024200
This is a corrigendum to the original article published in Acta Biochim Biophys Sin 2020, 52(2): 116–124. The authors correct an error in Figure 4 of the original manuscript. The correct figure is provided, and the authors apologize for the error.
Acta Biochimica et Biophysica Sinica•2024•DOI: 10.3724/abbs.2024024
Myocardial ischemia/reperfusion (I/R) injury is a classic type of cardiovascular disease characterized by injury to cardiomyocytes leading to different types of cell death. The degree of irreversible myocardial damage is closely related to age, and ferroptosis is involved in cardiomyocyte damage. However, the mechanisms underlying ferroptosis regulation in aging myocardial I/R injury are still unclear. The present study aims to explore the underlying mechanism of piRNA regulation in ferroptosis. Using left anterior descending coronary artery ligation in an aging rat model and a D-galactose-induced rat cardiomyocyte line (H9C2) to construct an aging cardiomyocyte model, we investigate whether ferroptosis occurs after reperfusion injury in vitro and in vivo. This study focuses on the upregulation of piR-000699 after hypoxia/reoxygenation treatment in aging cardiomyocytes by observing hypoxia/reoxygenation (H/R) injury indicators and ferroptosis-related indicators and clarifying the role of piR-000699 in H/R injury caused by ferroptosis in aging cardiomyocytes. Bioinformatics analysis reveals that SLC39A14 is a gene that binds to piR-000699. Our data show that ferroptosis plays an important role in I/R injury both in vivo and in vitro. Furthermore, the results show the potential role of piR-000699 in regulating SLC39A14 in ferroptosis in aging cardiomyocytes under hypoxia/reoxygenation conditions. Together, our results reveal that the mechanism by which piR-000699 binds to SLC39A14 regulates ferroptosis in aging myocardial I/R injury.
Acta Biochimica et Biophysica Sinica•2025•DOI: 10.3724/abbs.2024179
The ubiquitin-proteasome pathway is a highly selective protein degradation pathway that is capable of efficiently degrading intracellular proteins and plays an important role in various life processes. Dysfunction of this pathway has been associated with numerous problems, including cancer and neurodegenerative diseases. Targeted protein degradation (TPD) technologies have emerged as promising tools for use in a number of different areas, including biological research and clinical interventions. Recently, a technology named Trim-Away was developed for the rapid degradation of proteins in mammalian cells. Briefly, an antibody is designed against a target protein, and the E3 ligase TRIM21 is used to recognize the Fc region of the antibody and subsequently mediate antibody-dependent protein degradation via the proteasome. To enhance the protein degradation efficiency of Trim-Away, three TRIM21-based constructs were designed: (1) deletion of the B-box domain of TRIM21, termed TRIM21 (ΔBB), (2) substitution of the RING domain of TRIM21 with the RING domain of MKRN1, termed TRIM21-RING, and (3) substitution of the RING domain of TRIM21 with the HECT domain of UBE3A, designated TRIM21-HECT. The antibody was designed as a human IgG Fc region-fused nanobody. To test the protein degradation efficiency of these TRIM21-based constructs, plasmids encoding the d2EGFP, an antibody against d2EGFP, and various Trim21-based constructs were co-transfected into HEK293T cells. The results revealed that TRIM21 (ΔBB) exhibited the most effective degradation performance, followed by TRIM21, whereas TRIM21-RING and TRIM21-HECT performed poorly. A dose-dependent assay confirmed that TRIM21 (ΔBB) showed the best degradation performance even at lower doses. Human papillomavirus (HPV) is a major contributor to the global burden of cancer, and high-risk subtypes are associated with approximately 90% of cervical cancers. Two viral oncoproteins, E6 and E7, play a role in carcinogenesis. Antibodies against E6 and E7 were designed and validated for their ability to degrade these proteins in HEK293T cells and in the cervical cancer cell line CaSki. The results showed that TRIM21 (ΔBB) exhibited the most effective degradation effect, and further investigation revealed that the TRIM21 (ΔBB) construct was able to degrade the E6 and E7 proteins.
Acta Biochimica et Biophysica Sinica•2025•DOI: 10.3724/abbs.2025096
Ferroptosis, a novel form of regulated necrosis, has drawn the attention of the scientific community. Nevertheless, few studies have focused on the impact of ferroptosis on MC3T3-E1 cells in the context of steroid-induced osteonecrosis of the femoral head (SONFH). In this study, we explore the relationship between the degree of ferroptosis induced by dexamethasone (Dex) and the expression of silent information regulatory protein 1 (Sirt1). The results indicate that the ferroptosis level induced by Dex is mediated by the downregulation of Sirt1. Overexpression of Sirt1 increases the levels of the ferroptosis-related proteins SLC7A11 and GPX4 in MC3T3-E1 cells following Dex exposure. Moreover, the effect of Dex on Sirt1 expression is regulated by hypermethylation of the Sirt1 promoter, which is catalyzed by DNA methyltransferase 3a (DNMT3a). In summary, this study reveals that Dex can trigger ferroptosis by promoting DNMT3a-mediated DNA methylation and downregulating Sirt1 expression. Our findings provide an additional new mechanism for Dex-induced ferroptosis in MC3T3-E1 cells.
Acta Biochimica et Biophysica Sinica•2025•DOI: 10.3724/abbs.2024104
Carfilzomib (CFZ) is the second-generation proteasome inhibitor that is approved by Food and Drug Administration (FDA) of USA for the treatment of relapsed and refractory multiple myeloma. Although the preclinical and clinical efficacy of CFZ is obvious, the mechanism by which CFZ leads to cell death has not been fully elucidated. Since CFZ primarily functions as a proteasome inhibitor, profiling CFZ-induced changes in protein turnover at the systematic level is sufficient and necessary. In this study, we characterize the effects of CFZ on the stability of 15,000 human proteins using Protein Turnover Assay (ProTA). CFZ affects fundamental cellular glycolysis, nitric oxide production and proteasome subunit homeostasis in multiple myeloma cells. In addition, LY294002 or KU-0063794 has synergistic effects with CFZ in multiple myeloma treatment. A profound understanding of how cells respond to chemotherapeutic agents provides insights into the basic mechanism of drug function and the rationale for CFZ combination therapy.
Acta Biochimica et Biophysica Sinica•2024•DOI: 10.3724/abbs.2024047
The linear ubiquitin chain assembly complex (LUBAC) is the only known E3 ligase complex in which the ubiquitin-like (UBL) domains of SHARPIN and HOIL-1L interact with HOIP to determine the structural stability of LUBAC. The interactions between subunits within LUBAC have been a topic of extensive research. However, the impact of the LTM motif on the interaction between the UBL domains of SHARPIN and HOIL-1L with HOIP remains unclear. Here, we discover that the absence of the LTM motif in the AlphaFold2-predicted LUBAC structure alters the HOIP-UBA structure. We employ GeoPPI to calculate the changes in binding free energy (ΔG) caused by single-point mutations between subunits, simulating their protein-protein interactions. The results reveal that the presence of the LTM motif decreases the interaction between the UBL domains of SHARPIN and HOIL-1L with HOIP, leading to a decrease in the structural stability of LUBAC. Furthermore, using the AlphaFold2-predicted results, we find that HOIP (629‒695) and HOIP-UBA bind to both sides of HOIL-1L-UBL, respectively. The experiments of Gromacs molecular dynamics simulations, SPR and ITC demonstrate that the elongated domain formed by HOIP (629‒695) and HOIP-UBA, hereafter referred to as the HOIP (466‒695) structure, interacts with HOIL-1L-UBL to form a structurally stable complex. These findings illustrate the collaborative interaction between HOIP-UBA and HOIP (629‒695) with HOIL-1L-UBL, which influences the structural stability of LUBAC.
Chinese Journal of Tissue Engineering Research•2026•DOI: 10.12307/2026.21239
BACKGROUND: Estrogen deficiency can lead to a decrease in skeletal muscle mass and muscle strength in postmenopausal women, thereby affecting their quality of life. Muscle mass is maintained by satellite cells, which are regulated by estrogen. Regular exercise, especially high impact exercise (such as resistance training and high-intensity interval training), can induce muscle hypertrophy, but the role and mechanism of estrogen are still unclear. OBJECTIVE: To explore the effects of high-intensity interval training combined with estrogen therapy on skeletal muscle hypertrophy in ovariectomized rats and reveal its possible mechanism. METHODS: Sixty 8-week-old female Sprague-Dawley rats were divided into five groups using a random number table method: sham operation, model sedentary group, model exercise group, model hormone group, or model combined group. Bilateral ovariectomy was used to establish an estrogen deficiency model. Twelve weeks after operation, the model exercise and model combined group performed high-intensity interval training for 8 weeks (3 times/week), and hormone treatment groups received abdominal subcutaneous injection of 17β-estradiol (once a day for 8 weeks). Seventy-two hours after the last training, the grip force of the forelimb was measured by an electronic grip force meter. The gastrocnemius muscle was separated, and muscle mass index was calculated as muscle mass/body mass ratio. Hematoxylin-eosin staining was used to obtain cell cross-sectional area. Immunofluorescence staining was used to classify muscle fiber types and obtain myonuclear number, myonuclear domain size, and activated satellite cell number. BCA method was used to determine total protein concentration. Trizol method was used to extract total RNA. Western blot was used to detect ribosomal protein S6 expression. Real-time quantitative PCR was used to detect ribosomal RNA expression. RESULTS AND CONCLUSION: Compared with the sham operation group, the model sedentary group showed increased body mass and myosin heavy chain type I fiber proportion (P < 0.05), while uterine mass index, gastrocnemius mass index, grip strength, cell cross-sectional area, myosin heavy chain type IIa proportion, satellite cell and myonuclear number, myonuclear domain size, total protein and RNA content, and ribosomal protein S6, 18S rRNA and 28S rRNA expression decreased (P < 0.05). Compared with the model sedentary group, the model exercise group showed decreased body mass and myosin heavy chain type IIb proportion (P < 0.05), while uterine mass index, gastrocnemius mass index, grip strength, cell cross-sectional area, myosin heavy chain type IIa proportion, satellite cell number, myonuclear domain size, total protein and RNA content, and ribosomal protein S6 and 28S rRNA expression increased (P < 0.05). Compared with the model exercise group and model hormone group, the model combined group showed higher gastrocnemius mass index, grip strength, cell cross-sectional area, satellite cell number, myonuclear domain size, total protein and RNA content, and ribosomal protein S6 and 28S rRNA expression (P < 0.05). These results indicate that estrogen can enhance the skeletal muscle hypertrophy response induced by high-intensity interval training in ovariectomized rats, and the mechanism may be related to satellite cell activation, increased myonuclear domain and ribosome biogenesis, and improved ribosome function.
Chinese Journal of Tissue Engineering Research•2026•DOI: 10.12307/2026.21317
BACKGROUND: Existing animal models of knee osteoarthritis predominantly focus on mechanical injury factors but fail to simulate and observe the "cold-dampness obstruction" syndrome characteristics in traditional Chinese medicine. OBJECTIVE: To construct a traditional Chinese medicine-Western medicine integrated knee osteoarthritis model for cold-dampness obstruction syndrome and validate its efficacy via a multidimensional assessment. METHODS: Twenty-four male Sprague-Dawley rats (SPF-grade) were randomly divided into sham-operated, model, and cold-dampness obstruction groups. The latter two groups underwent anterior cruciate ligament transection of the right hind knee. The cold-dampness obstruction group received artificial cold-damp environment intervention (temperature 10.5 °C, humidity 90%, 4 h/day, for 4 weeks) starting 14 days post-surgery. The sham-operated group had skin incision and immediate closure. Before modeling and at 1, 2 weeks post-modeling, and 4 weeks after cold-damp intervention, traditional Chinese medicine syndrome scores and CatWalk gait analysis were performed. Right hind knee joint tissues were harvested for histopathological observation and Mankin scoring. RESULTS AND CONCLUSION: (1) Traditional Chinese medicine syndrome scores: The cold-dampness obstruction group showed significant mental fatigue, reduced activity, loose stools, dark purple tongue, dull fur, decreased food intake, and slower weight gain (P < 0.01). (2) CatWalk gait parameters: At 1 week post-modeling, compared with the sham-operated group, the model and cold-dampness obstruction groups showed decreased maximum contact intensity, print length, maximum intensity, average intensity of 15 maximum pixels, and increased swing phase of the right hind paw (all P < 0.01). The cold-dampness obstruction group also showed significantly decreased swing speed (P < 0.05). After 4 weeks in the artificial climate chamber, compared with the sham-operated group, the cold-dampness obstruction group showed significantly decreased maximum contact intensity, maximum intensity, average intensity of 15 maximum pixels (P < 0.01), increased swing phase (P < 0.01), and decreased swing speed (P < 0.05). (3) Histopathology: Mankin scores in the model and cold-dampness obstruction groups were significantly higher than in the sham-operated group (P < 0.01), and the cold-dampness obstruction group had significantly higher scores than the model group (P < 0.01). These results indicate that anterior cruciate ligament transection combined with cold-damp environment can successfully construct a cold-dampness obstruction type early knee osteoarthritis rat model. CatWalk gait parameters and traditional Chinese medicine syndrome scores provide an objective evaluation system for studying the mechanisms of traditional Chinese medicine in knee osteoarthritis.
Chinese Journal of Tissue Engineering Research•2026•DOI: 10.12307/2026.21394
BACKGROUND: Systemic fatigue increases injury risk in individuals with functional ankle instability, while stop-jump cutting is a high risk for ankle injuries. The biomechanical mechanisms underlying non-anticipated stop-jump cutting during systemic exercise fatigue in this population remain unclear. OBJECTIVE: To quantify differences in kinematic and kinetic characteristics during non-anticipated stop-jump cutting before and after exercise fatigue between individuals with functional ankle instability and healthy controls, revealing the impact of exercise fatigue on stop-jump cutting in individuals with functional ankle instability. METHODS: Fifteen male participants with unilateral functional ankle instability and 15 healthy male controls were recruited. Kinematic (peak angles of ankle dorsiflexion, plantarflexion, inversion, knee flexion, knee varus, knee valgus, hip flexion, and hip abduction) and kinetic (joint stiffness of hip, knee, and ankle) parameters were collected during non-anticipated stop-jump cutting before and after exercise fatigue. Two-way repeated measures ANOVA was used to analyze peak joint angles and joint stiffness. Statistical parametric mapping (SPM) was further used to analyze the effects of fatigue on time-series data of ankle angle and ground reaction forces. RESULTS AND CONCLUSION: Kinematic results: Two-way ANOVA revealed significant main effects of fatigue and group-by-fatigue interactions for peak ankle inversion, knee flexion, knee valgus, and hip flexion angles (P < 0.05). Compared with pre-fatigue, peak ankle inversion increased in the functional ankle instability group after fatigue (P < 0.05), peak knee flexion increased in both groups (P < 0.05), and peak hip flexion increased in the healthy control group (P < 0.05). After fatigue, the functional ankle instability group showed smaller peak ankle inversion and hip flexion angles but larger peak knee valgus and knee flexion angles than the healthy control group (P < 0.05). SPM analysis revealed that ankle inversion/eversion angle was greater during 4%-18% of the cutting movement after fatigue in the functional ankle instability group (P < 0.05). Kinetic results: Two-way ANOVA revealed significant main effects of fatigue and group-by-fatigue interactions for hip, knee, and ankle joint stiffness (P < 0.05). Compared with pre-fatigue, hip and ankle stiffness decreased in the healthy control group (P < 0.05), while knee and ankle stiffness decreased in the functional ankle instability group (P < 0.05). SPM analysis showed that vertical ground reaction force was greater during 5%-16% of the cutting movement, and mediolateral ground reaction force was greater during 35%-49% of the movement after fatigue in the functional ankle instability group (P < 0.05). CONCLUSION: Exercise fatigue alters kinematic and kinetic characteristics during non-anticipated stop-jump cutting in individuals with functional ankle instability, particularly affecting knee and ankle stability and shock absorption. Fatigue reduces joint stiffness and control, increasing injury risk, especially during the initial and transitional phases of the cutting movement.
Chinese Journal of Tissue Engineering Research•2026•DOI: 10.12307/2026.21380
BACKGROUND: Oxidative stress is a primary factor accelerating the progression of intervertebral disc degeneration. Mitophagy plays a crucial role in mitigating oxidative stress and preventing mitochondrial dysfunction and associated diseases. Prior investigations have demonstrated that kaempferol enhances the proliferative capacity of degenerating nucleus pulposus cells, diminishes inflammation, and decelerates the progression of intervertebral disc degeneration in rat models. OBJECTIVE: To investigate the effects of kaempferol on mitophagy in degenerated intervertebral disc tissue. METHODS: Fifteen Sprague-Dawley rats were randomly allocated into five intervention groups: a blank group (n=3), a model group (n=3), a low-dose kaempferol group (n=3), a medium-dose kaempferol group (n=3), and a high-dose kaempferol group (n=3). A coccygeal disc degeneration model was established in all groups except the blank group via full-thickness annulus fibrosus puncture. Commencing 4 weeks post-surgery, the blank and model groups received normal saline via gavage, while the low-dose, medium-dose, and high-dose kaempferol groups were administered 25, 50, and 100 mg/kg kaempferol via gavage, respectively, once daily for 8 consecutive weeks. Following the final administration, samples were collected for serum inflammatory cytokine level measurement, MRI imaging, and hematoxylin-eosin staining. In cell experiments, second-passage rat nucleus pulposus cells were divided into five groups: blank group (no treatment), model group (H2O2-induced oxidative stress), kaempferol group (H2O2 for 24 h then 10 μmol/L kaempferol), autophagy inhibitor group (H2O2 for 24 h then 3-methyladenine), and kaempferol + autophagy inhibitor group (H2O2 for 24 h then 10 μmol/L kaempferol plus 3-methyladenine). After 24 h of further culture, cell viability was assessed by CCK-8 assay, protein expression of inflammatory cytokines and autophagy markers by western blot, gene expression by RT-qPCR, type II collagen expression by immunofluorescence staining, and reactive oxygen species levels by DCFH-DA fluorescent probe. RESULTS AND CONCLUSION: In animal experiments, compared with the blank group, serum levels of interleukin-1β, interleukin-6, and tumor necrosis factor-α were elevated in the model group (P < 0.05), while kaempferol treatment at all doses reduced these levels (P < 0.05), with the medium dose showing the most pronounced effect. MRI and hematoxylin-eosin staining revealed that kaempferol treatment significantly ameliorated the pathological features of disc degeneration, with clearer and more continuous nucleus pulposus contours and increased cell numbers, particularly in the medium-dose group. In cell experiments, compared with the model group, kaempferol increased cell viability, type II collagen expression, and the gene and protein expression of PTEN-induced putative kinase 1 and Parkin (P < 0.05), while decreasing reactive oxygen species levels and the expression of inflammatory cytokines (P < 0.05). Kaempferol also increased the LC3-II/LC3-I ratio and LC3B mRNA expression (P < 0.05). 3-Methyladenine inhibited these effects of kaempferol. These findings indicate that kaempferol may alleviate oxidative stress injury and delay intervertebral disc degeneration by regulating mitophagy.
Chinese Journal of Tissue Engineering Research•2026•DOI: 10.12307/2026.21483
BACKGROUND: Oxidative stress is one of the potential factors contributing to muscle atrophy following anterior cruciate ligament injury. Alleviating skeletal muscle fatigue facilitates proprioceptive recovery, thereby accelerating rehabilitation after anterior cruciate ligament injury. Improving mitochondrial function helps mitigate skeletal muscle fatigue-related damage. OBJECTIVE: To verify that electroacupuncture at different frequencies alleviates skeletal muscle oxidative stress damage and improves mitochondrial function in rabbits, thereby reducing skeletal muscle fatigue, restoring proprioceptive function, and accelerating rehabilitation following anterior cruciate ligament injury. METHODS: Twenty-four healthy New Zealand rabbits were randomly divided into blank group, model group, low-frequency electroacupuncture group, and high-frequency electroacupuncture group, with 6 rabbits in each group. The model group, low-frequency electroacupuncture group, and high-frequency electroacupuncture group were used to construct a knee anterior cruciate ligament injury model. In the low-frequency and high-frequency electroacupuncture groups, electroacupuncture was applied to the acupoints Xuehai and Liangqiu on the affected knee joint 7 days after modeling. The blank and model groups were only grasped and fixed without electroacupuncture intervention, once daily for 21 consecutive days. After intervention, ELISA was used to detect the levels of superoxide dismutase, succinate dehydrogenase, and malondialdehyde in the quadriceps femoris; western blot was used to detect the protein expression levels of silent information regulator 2-related enzyme 1, peroxisome proliferator-activated receptor gamma coactivator 1 alpha, and mitochondrial transcription factor A in skeletal muscle tissue, as well as the mRNA expression of silent information regulator 2-related enzyme 1, peroxisome proliferator-activated receptor gamma coactivator 1 alpha, nuclear respiratory factor 1, and mitochondrial transcription factor A. RESULTS AND CONCLUSION: After anterior cruciate ligament injury, the level of superoxide dismutase in the quadriceps femoris of rabbits increased, the level of succinate dehydrogenase decreased, and the concentration of malondialdehyde increased; the protein expressions of silent information regulator 2-related enzyme 1, peroxisome proliferator-activated receptor gamma coactivator 1 alpha, and mitochondrial transcription factor A decreased; the mRNA expressions of silent information regulator 2-related enzyme 1, peroxisome proliferator-activated receptor gamma coactivator 1 alpha, nuclear respiratory factor 1, and mitochondrial transcription factor A were significantly downregulated. After electroacupuncture intervention, the concentration of malondialdehyde in the affected quadriceps femoris decreased, the activities of superoxide dismutase and succinate dehydrogenase increased, and the protein expressions of silent information regulator 2-related enzyme 1, peroxisome proliferator-activated receptor gamma coactivator 1 alpha, and mitochondrial transcription factor A increased; the mRNA expressions of mitochondrial biogenesis-related genes such as silent information regulator 2-related enzyme 1, peroxisome proliferator-activated receptor gamma coactivator 1 alpha, nuclear respiratory factor 1, and mitochondrial transcription factor A increased, and the low-frequency electroacupuncture group was superior to the high-frequency electroacupuncture group. These results indicate that electroacupuncture can reduce oxidative stress damage in skeletal muscle after anterior cruciate ligament injury by increasing the contents of superoxide dismutase and succinate dehydrogenase and decreasing the content of malondialdehyde; and improve mitochondrial function by regulating the expression of proteins related to the silent information regulator 2-related enzyme 1/peroxisome proliferator-activated receptor gamma coactivator 1 alpha signaling pathway and mitochondrial biogenesis-related genes, thereby accelerating rehabilitation after anterior cruciate ligament injury.
Chinese Journal of Tissue Engineering Research•2026•DOI: 10.12307/2026.21484
BACKGROUND: In sarcopenic osteoporosis, muscle loss and osteoporosis often coexist, leading to a significant increase in the risk of falls and fractures. Gushukang Granules are clinically used for the treatment of osteoporosis; however, the mechanism of action on myogenic and osteogenic factors in muscle and bone remains unclear.
OBJECTIVE: To investigate the effects of Gushukang Granules on myogenic and osteogenic factors in the muscles and bones of rats.
METHODS: Thirty-six healthy Sprague-Dawley rats were randomly divided into control, model, and Gushukang groups (n=12 per group). Osteoporosis was induced in the latter two groups by ovariectomy. Four weeks after surgery, the Gushukang group received 1.05 mL/kg Gushukang Granules solution by gavage, while the other groups received an equal volume of saline, once daily for 12 weeks. General conditions were observed. Hematoxylin-eosin staining was used to assess morphological changes in muscle and bone tissues. RT-qPCR was performed to detect mRNA expression of interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-alpha) in muscle, and osteocalcin (OCN) and insulin-like growth factor 1 (IGF-1) in bone. Immunohistochemistry was used to observe the expression of IL-6, TNF-alpha, IGF-1, and OCN in muscle and bone tissues. Western blot was used to detect protein expression levels of these factors.
RESULTS AND CONCLUSION: Compared with the control group, the model group exhibited typical sarcopenic osteoporosis phenotype: muscle fibers were sparse, disordered, and atrophic; bone trabeculae were reduced, sparse, and disconnected. mRNA and protein expression of IL-6 and TNF-alpha were significantly increased (P < 0.01), while IGF-1 and OCN were significantly decreased (P < 0.01). Compared with the model group, the Gushukang group showed significant improvement: muscle fiber arrangement became more orderly with interstitial fibrosis; bone trabeculae increased and connectivity improved (though still loose). IL-6 and TNF-alpha expression were significantly decreased (P < 0.01), while IGF-1 and OCN were significantly increased (P < 0.01). Western blot results were consistent with immunohistochemistry. These findings suggest that Gushukang Granules can improve muscle atrophy and bone trabecular thinning in ovariectomized rats by downregulating the abnormal high expression of IL-6 and TNF-alpha, and upregulating IGF-1 and OCN, possibly through regulating muscle-bone crosstalk signaling pathways and balancing inflammatory and growth factor levels, providing experimental support for the clinical treatment of sarcopenic osteoporosis.
Chinese Journal of Tissue Engineering Research•2026•DOI: 10.12307/2026.21599
OBJECTIVE: Romosozumab is a novel biologic agent currently being used to treat osteoporosis in postmenopausal women at high risk of fracture. This meta-analysis aims to systematically evaluate the efficacy and safety of romosozumab compared with placebo, alendronate sodium, teriparatide, and denosumab in the treatment of osteoporosis in adults. METHODS: The medical keywords “anti-sclerostin antibody,” “romosozumab,” “AMG 78500,” and “osteoporosis” were used to search PubMed, CNKI, Web of Science, and the Cochrane Central Register of Controlled Trials (CENTRAL) for randomized controlled trials comparing the safety and efficacy of romosozumab with alendronate, teriparatide, denosumab, or placebo in adult patients with osteoporosis. Two researchers independently screened studies, assessed risk of bias, and extracted data. The Cochrane Collaboration's risk of bias tool was used for quality assessment, and meta-analysis was performed using RevMan 5.4. The primary outcome was the percentage change from baseline in bone mineral density (BMD) at 6 and 12 months; secondary outcomes were the incidence of adverse events and cardiovascular complications during treatment. RESULTS: A total of 10 randomized controlled trials involving 12,570 patients were included. Compared with placebo, alendronate, and teriparatide, romosozumab significantly increased BMD at the lumbar spine, total hip, and femoral neck at 6 and 12 months. Compared with denosumab, romosozumab significantly increased lumbar spine BMD at 6 and 12 months (MD=3.68, 95%CI: 0.34-7.01, P=0.03; MD=5.20, 95%CI: 3.19-7.21, P<0.00001), while no significant differences were found in total hip and femoral neck BMD. In terms of safety, romosozumab had a lower incidence of adverse events compared with alendronate (RR=0.96, 95%CI: 0.93-0.99, P=0.02) but a higher incidence compared with teriparatide (RR=1.13, 95%CI: 1.01-1.25, P=0.03). No significant differences were found versus placebo or denosumab (RR=0.98, 95%CI: 0.96-1.00, P=0.11; RR=2.64, 95%CI: 0.74-9.36, P=0.13). Importantly, romosozumab did not significantly increase the risk of cardiovascular complications compared with other treatments (RR=1.25, 95%CI: 0.94-1.67, P=0.12). CONCLUSION: Romosozumab rapidly improves lumbar spine BMD with an overall manageable safety profile, particularly suitable for adult osteoporosis patients at high fracture risk who require rapid bone mass increase and have no cardiovascular contraindications. This meta-analysis is based on limited data and has certain limitations; more high-quality, longer-duration follow-up studies are needed to confirm the results.
Acta Biochimica et Biophysica Sinica•2025•DOI: 10.3724/abbs.2025096
Steroid-induced osteonecrosis of the femoral head (SONFH) is a progressive bone disorder driven by prolonged glucocorticoid exposure, with limited therapeutic options. Ferroptosis, a regulated form of necrosis, has emerged as a potential contributor to SONFH pathogenesis, yet its mechanistic link to osteoblast dysfunction remains poorly defined. This study investigates the relationship between dexamethasone (Dex)-induced ferroptosis and silent information regulator 1 (Sirt1) in MC3T3-E1 osteoblastic cells. Dex treatment downregulated Sirt1 expression and increased ferroptosis markers, while Sirt1 overexpression elevated the ferroptosis-related proteins SLC7A11 and GPX4 following Dex exposure. Mechanistically, Dex promoted hypermethylation of the Sirt1 promoter via DNA methyltransferase 3a (DNMT3a), leading to Sirt1 suppression. These findings establish a novel epigenetic axis—DNMT3a-mediated Sirt1 promoter hypermethylation—that drives Dex-induced ferroptosis in osteoblasts. The study was conducted exclusively in vitro, and the pathophysiological relevance requires validation in animal models. Nevertheless, this work provides a foundation for understanding the epigenetic regulation of osteoblast ferroptosis and suggests potential therapeutic avenues for preventing SONFH.
Acta Biochimica et Biophysica Sinica•2025•DOI: 10.3724/abbs.2025062
p62/SQSTM1 is the archetypal selective autophagy receptor, bridging ubiquitinated cargo to LC3 on phagophores. Its abundance is a critical determinant of autophagic flux, yet the E3 ligase governing its turnover remained incompletely defined. Using Flag-p62 Co-IP coupled to mass spectrometry in HEK293T cells, we identified the E3 ligases TRIM25 and ITCH as highest-confidence interactors. Endogenous and ectopic p62 formed complexes with both ligases; GST pull-down confirmed direct binding, and mCherry-TRIM25 co-localized with GFP-p62 in HeLa cytoplasm. In vitro ubiquitination demonstrated that TRIM25, but not ITCH, efficiently ubiquitinates p62. A reconstituted E. coli system mapped fifteen lysine residues, with K7 and K189 validated as the dominant TRIM25-mediated ubiquitination sites. Functionally, TRIM25 destabilized wild-type p62 but not the K7/189R mutant; TRIM25 knockdown stabilized p62 in HeLa and Caski cells. Degradation proceeded primarily via the lysosomal pathway, as bafilomycin (20 nM) but not bortezomib (1 μM) blocked p62 loss. TRIM25 knockdown enhanced GFP-LC3 puncta formation (P < 0.01) and elevated autophagic markers, whereas TRIM25 overexpression suppressed p62-mediated GFP-LC3 puncta (P < 0.05) and autophagy. These data establish TRIM25 as the principal E3 ligase targeting p62 for lysosomal degradation, defining a negative feedback node in selective autophagy with therapeutic implications for cancers and neurodegenerative disorders characterized by p62 accumulation.