Acta Biochimica et Biophysica Sinica•2025•DOI: 10.3724/abbs.2025060
Type 2 diabetes mellitus (T2DM) is an endocrine metabolic disorder characterized by insulin secretion dysfunction and/or insulin resistance. Osteocalcin (OC), or bone γ-carboxyglutamic acid protein (BGP), is a bone matrix protein predominantly produced by osteoblasts. Vitamin K-dependent carboxylation converts OC into gamma-carboxyglutamic acid (Gla)-rich carboxylated osteocalcin (cOC), which binds to hydroxyapatite and can be decarboxylated to undercarboxylated osteocalcin (ucOC) under acidic conditions. While cOC influences bone formation and mineralization, ucOC regulates energy metabolism. This study aimed to explore the associations between T2DM, serum OC levels (including cOC and ucOC), and OC gene polymorphisms in the Chinese Han population. T2DM patients and a healthy cohort, all of Han ethnicity, were categorized into a T2DM group (n = 456) and a control group (n = 224). Serum levels of cOC and ucOC were determined via ELISA. Insulin sensitivity was assessed via HOMA-IR, and pancreatic β-cell function via HOMA-β. Nine SNPs in the OC gene were genotyped via SNaPshot. Compared with controls, T2DM patients presented significantly lower levels of ucOC, cOC, and ucOC/cOC ratio. Additionally, T2DM subjects had elevated BMI, HbA1c, HOMA-IR, ALP, TG, HDL, and LDL levels, with decreased HOMA-β, ALT, AST, hsCRP, and FFA levels. In terms of bone metabolism, T2DM patients presented increased blood phosphorus, ICTP, P1NP, and 25(OH)D levels and decreased blood calcium, N-MID, PTH, and β-CTX levels. Associations between serum cOC and ucOC and various factors were analyzed. In the T2DM group, cOC was inversely correlated with HbA1c and P1NP, and positively correlated with ALP, LDL, and N-MID. ucOC was positively associated with N-MID. In controls, cOC was positively correlated with HDL, N-MID, and PINP, while ucOC correlated with PINP. The study also examined SNPs in the OC gene and their relationships with serum cOC and ucOC.
Acta Biochimica et Biophysica Sinica•2025•DOI: 10.3724/abbs.2024198
Signal regulatory protein α (SIRPα) is recognized as a significant transmembrane protein within the glomeruli that is specifically localized in podocytes, where it plays a role in modulating downstream signaling pathways through phosphorylation. Upon tyrosine phosphorylation of the immunoreceptor tyrosine-based inhibitory motif (ITIM) within SIRPα, protein tyrosine phosphatases are recruited to facilitate the dephosphorylation of downstream signals. Nevertheless, the specific downstream signaling pathways affected by this mechanism have yet to be elucidated. In this study, phosphoproteomic analysis is conducted on podocytes with SIRPα deficiency to identify proteins whose phosphorylation is regulated by SIRPα and the associated signaling pathways in human podocytes. The results reveal significant alterations in biological processes related to cytoskeleton arrangement and cytoskeleton protein binding. Specifically, an increase in FAK tyrosine phosphorylation at Y576 is identified as a potentially crucial signal of the influence of SIRPα on the podocyte cytoskeleton. Our study suggests that SIRPα may facilitate podocyte cytoskeleton rearrangement and migration through the Src/FAK/p38 MAPK signaling pathway. For the first time, we discover increased level of SIRPα, which is strongly linked to urinary protein, in the urine of patients with nephrotic syndrome (NS). Additionally, an increase in urinary FAK level is observed in NS patients, which is positively correlated with both urinary protein level and urinary SIRPα level. These findings suggest that SIRPα and FAK may serve as promising biomarkers for podocytopathies.
Acta Biochimica et Biophysica Sinica•2025•DOI: 10.3724/abbs.2024158
Mechanical cues play an important role in regulating cellular activities. Cells are able to sense and respond to the mechanical cues present in the extracellular physical microenvironment via mechanotransduction, which can ultimately shape the functions and behaviors of the cells themselves as well as their microenvironments during numerous developmental, physiological and pathological processes. The development of human diseases such as cancer is generally accompanied by unique changes in the mechanical properties of cells and their physical microenvironments, and discoveries in the field of physical oncology are beginning to be translated into new therapeutic strategies for cancer. Delineating the mechanical properties of biological tissues in various dimensions from individual cells to organs is therefore fundamental for dissecting the mysteries of life and advancing human healthcare. In particular, atomic force microscopy (AFM)-based force spectroscopy has become a powerful, standard and multifunctional toolbox for characterizing the various mechanical properties of single cells at the micro/nanoscale. However, current studies of AFM-based single-cell mechanical measurements rely mainly on the experience of the experimental operator to move the AFM probe to the target cells for subsequent force measurements, which often results in a time-consuming and laborious experimental process. In addition, cell coculture has been widely used in the field of life sciences to examine intercellular interactions. Nevertheless, in current cell coculture studies, cells are commonly labelled with fluorescent molecules so that one can visually identify the specific cell types in the coculture, which can affect the behaviors of the fluorescently labelled cells. Consequently, developing a method that allows AFM to measure the mechanical properties of cells under coculture conditions in an efficient and fluorescence-independent way will significantly benefit the applications of AFM in the field of mechanobiology. Previously, we presented a method based on the combination of AFM and deep learning optical image recognition, which can precisely move the AFM probe to individual targeted cells to perform mechanical measurements under low-density co-culture conditions (nearly no contact between different cell types in the co-culture). Here, we present a study of deep learning image recognition-assisted AFM to rapidly probe the mechanical properties of single living cells grown in high-density co-culture conditions (with different cell types in contact with each other in the co-culture) without the need for fluorescent labelling. In this work, AFM experiments were performed with a commercial JPK NanoWizard AFM (Bruker, Santa Barbara, USA), which was mounted on an inverted optical microscope (Nikon, Tokyo, Japan). Three types of cells, MGC-803 (a human gastric cancer cell line), HGC-27 (a human undifferentiated gastric cancer cell line), and HMrSV5 (a human peritoneal mesothelial cell line), were used. All three types of cells were cultured in RPMI-1640 medium supplemented with 10% fetal bovine serum (FBS) and 1% penicillin-streptomycin at 37°C (5% CO2 and 95% air) in Petri dishes. During the experiments, the RPMI-1640 medium was replaced by CO2-independent Leibovitz’s L-15 medium, and the AFM experiments were performed at 37°C (the commercial AFM used here has a heater system). MGC-803 cells (stained with the DiI dye) were co-cultured with HGC-27 cells (stained with the DiO dye). Both optical bright-field images and corresponding fluorescent images of co-cultured cells were recorded. The YOLOX deep learning neural network was used for directly recognizing cell types from optical bright-field images. The fluorescent images were used to assist in the preparation of the training datasets (Supplementary Figure S1) and to verify the detection results of the deep learning image recognition model. In a previous study under low-density co-culture conditions, we reduced the complexity of the YOLOX neural network to improve the detection speed without reducing the detection accuracy. Under high-density co-culture conditions, where cell recognition becomes much more difficult, we found that reducing the complexity of the YOLOX model resulted in decreased detection accuracy. We examined the recognition performances of four YOLO series neural networks (YOLOX, YOLOv5, YOLOv7, and YOLOv8), and the experimental results revealed that the YOLOX model had the highest detection precision (89.25%) (Supplementary Table S1) and the best detection result (Supplementary Figure S2) and could meet the experimental requirements. Hence, the YOLOX neural network was used here. The AFM spherical probe (a microsphere attached to the tipless cantilever) was used in the indentation assay to measure the Young’s modulus of the cells, and the AFM single-cell probe (a living HMrSV5 cell attached to the tipless cantilever) was used in the single-cell force spectroscopy (SCFS) assay to measure the adhesion force of the cells. More experimental details (e.g., cell sample
Acta Biochimica et Biophysica Sinica•2024•DOI: 10.3724/abbs.2024083
LncRNA PRR34-AS1 overexpression promotes the proliferation and invasion of hepatocellular carcinoma (HCC) cells, but whether it affects HCC energy metabolism remains unclear. Mitochondrial division and glycolytic reprogramming play important roles in tumor development. In this study, the differential expression of PRR34-AS1 is explored via TCGA analysis, and higher levels of PRR34-AS1 are detected in patients with liver cancer than in healthy individuals. A series of experiments, such as CCK-8, PCR, and immunofluorescence staining, reveal that the proliferation, invasion, glycolysis, and mitochondrial division of PRR34-AS1-overexpressing hepatoma cells are significantly promoted. TCGA analysis and immunohistochemistry reveal high expression of the mitochondrial dynamin MIEF2 in liver cancer tissues. Dual-luciferase reporter assays confirm that miR-498 targets and binds to mitochondrial elongation factor 2 (MIEF2). In addition, we show that PRR34-AS1 can sponge miR-498. Therefore, we further investigate the effects of the lncRNA PRR34-AS1/miR-498/MIEF2 axis on the growth, glucose metabolism, and mitochondrial division in hepatocellular carcinoma cells. A series of experiments are performed on hepatocellular carcinoma cells after different treatments. The results show that the proliferative activity, invasive ability, and glycolytic level of hepatocellular carcinoma cells are decreased in HCC cells with low PRR34-AS1 expression, and the miR-498 expression level is increased in these cells. Inhibition of miR-498 or overexpression of MIEF2 restored the proliferative activity, invasive ability, glycolysis, and mitochondrial division in hepatocellular carcinoma cells. Thus, PRR34-AS1 regulates MIEF2 by sponging miR-498, thereby promoting mitochondrial division, mediating glycolytic reprogramming and ultimately driving the growth and invasion of HCC cells. Furthermore, in vivo mouse experiments yield results similar to those of the in vitro experiments, verifying the above results.
Chinese Journal of Tissue Engineering Research•2026•DOI: 10.12307/2026.21330
BACKGROUND: Studies showed that multiple myeloma microenvironment has the function of inducing mesenchymal stem cells to become senescent phenotype, while the effect of senescent bone marrow mesenchymal stem cells on multiple myeloma cells is rarely reported. OBJECTIVE: To investigate the effect of senescent bone marrow mesenchymal stem cells on the proliferation of multiple myeloma cells through paracrine galectin-3. METHODS: Bone marrow blood was collected from healthy donors, and bone marrow mesenchymal stem cells were extracted by Ficoll density gradient centrifugation and adherent purification. The third-generation bone marrow mesenchymal stem cells were taken and induced with 200 µmol/L hydrogen peroxide solution for 2 h, then cultured with L-DMEM complete medium for 24 h to construct a senescent bone marrow mesenchymal stem cell model. The model was identified by β-galactosidase staining and senescence gene P21 expression. RT-qPCR was used to detect the expression of galectin-3 in senescent bone marrow mesenchymal stem cells. The supernatant of senescent bone marrow mesenchymal stem cells was collected and concentrated by centrifugation to prepare conditioned medium, which was used to culture multiple myeloma cell line U266 for 24 h. CCK-8 was used to detect U266 cell proliferation, flow cytometry was used to detect U266 cell apoptosis, and RT-qPCR and western blot were used to detect BCL-2 protein and mRNA expression in U266 cells. Bone marrow from multiple myeloma patients and healthy individuals was collected, and galectin-3 levels were detected by ELISA. RESULTS AND CONCLUSION: After hydrogen peroxide induction, the number of β-galactosidase positive cells significantly increased, and the mRNA expression of P21 and galectin-3 was upregulated (P < 0.01). Compared with the control group, after culturing U266 cells with senescent bone marrow mesenchymal stem cell conditioned medium for 24 h, cell proliferation increased (P < 0.05), apoptosis rate decreased (P < 0.05), and BCL-2 protein and mRNA expression levels increased (P < 0.05). The level of galectin-3 in bone marrow of multiple myeloma patients was significantly higher than that of healthy individuals (P < 0.05). The results indicate that senescent bone marrow mesenchymal stem cells may promote the proliferation of multiple myeloma cells by upregulating BCL-2 expression through paracrine galectin-3.
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: 10.12307/2026.21583
BACKGROUND: Hydrogel cardiac patches, with their excellent biocompatibility and tunable mechanical properties, demonstrate significant potential in treating acute myocardial infarction, especially when combined with stem cell technology. Hydrogels modified with active components of traditional Chinese medicine (TCM) can promote the proliferation, differentiation, migration, and homing of stem cells. This synergistic effect provides a new approach for stem cell transplantation therapy based on hydrogel cardiac patches.
OBJECTIVE: To focus on the application scenarios of novel biomaterial hydrogel cardiac patches combined with TCM in the treatment of myocardial infarction, and to discuss their development prospects.
METHODS: PubMed and CNKI databases were searched for literature on TCM combined with hydrogel cardiac patches for the treatment of acute myocardial infarction from January 2010 to January 2025. English search terms included "hydrogel, cardiac patch, myocardial infarction, Chinese medicine, stem cell, drug delivery system"; Chinese search terms included "水凝胶, 心脏贴片, 心肌梗死, 中药, 干细胞, 递药系统". According to inclusion and exclusion criteria, 99 articles were finally included for review.
RESULTS AND CONCLUSION: Hydrogel cardiac patches, with their excellent biocompatibility, tunable mechanical properties, and drug-loading capacity, provide ideal mechanical support and microenvironment for myocardial repair. As a hydrophilic polymer biomaterial, the three-dimensional network structure of hydrogel cardiac patches can highly mimic the physical properties of the natural cardiac extracellular matrix, providing a microenvironment for loaded biological cells to proliferate or maintain activity, and helping cell migration, adhesion, spreading, differentiation, and intercellular connection formation. Hydrogels modified with TCM can load stem cells, fully induce and regulate them, and more effectively perform cell regeneration therapy in the myocardial infarction area to achieve better repair. Therefore, the combined application of TCM and hydrogel cardiac patches has great development potential and prospects. Currently, the combined application mainly focuses on the following aspects: precise sustained-release therapy of TCM active ingredients via hydrogel cardiac patch loading; cell regeneration therapy via induced pluripotent stem cells delivered by TCM-modified hydrogel patches; and repair of cardiac electrophysiological function via TCM combined with conductive hydrogels. In future research, it is necessary to deeply understand the characteristics of hydrogels made from different materials and methods, and the therapeutic effects and mechanisms of TCM monomers and compound extracts, to achieve more combined applications of TCM and hydrogel cardiac patches.
Acta Biochimica et Biophysica Sinica•2025•DOI: 10.3724/abbs.2025060
Type 2 diabetes mellitus (T2DM) is an endocrine metabolic disorder characterized by insulin secretion dysfunction and/or insulin resistance. Osteocalcin (OC), or bone γ-carboxyglutamic acid protein (BGP), is a bone matrix protein predominantly produced by osteoblasts. Vitamin K-dependent carboxylation converts OC into gamma-carboxyglutamic acid (Gla)-rich carboxylated osteocalcin (cOC), which binds to hydroxyapatite and can be decarboxylated to undercarboxylated osteocalcin (ucOC) under acidic conditions. While cOC influences bone formation and mineralization, ucOC regulates energy metabolism. OC enhances adiponectin production and insulin sensitivity; however, its relationship with diabetes incidence and glucose levels remains controversial. This study aimed to explore the associations between T2DM, serum OC levels (including cOC and ucOC), and OC gene polymorphisms in the Chinese Han population. T2DM patients and a healthy cohort, all of Han ethnicity, were categorized into a T2DM group (n = 456) and a control group (n = 224). Serum levels of cOC and ucOC were determined via enzyme-linked immunosorbent assay. Insulin sensitivity was assessed via homeostatic model assessment of insulin resistance (HOMA-IR). Pancreatic β-cell function was evaluated with HOMA-β. Nine SNPs in the OC gene were selected from the International HapMap Project database: rs12563631, rs2241106, rs2277872, rs2758605, rs1543294, rs1800247, rs2842880, rs759330, and rs933489. Genotyping was conducted via the SNaPshot technique. Pearson correlation and multiple linear regression analyses were performed. Compared with controls, T2DM patients presented significantly lower levels of ucOC (0.82 ng/mL), cOC (12.19 ng/mL), and ucOC/cOC ratio (0.07) (1.17 ng/mL, 14.47 ng/mL, and 0.09, respectively). Additionally, T2DM subjects had elevated BMI (25.06 kg/m2), HbA1c (8.95%), HOMA-IR (0.61), ALP (79.00 U/L), and TG (1.50 mM). Notably, cOC levels exhibit a significant inverse correlation with HbA1c, whereas no such correlation was observed for ucOC. The CC genotype at rs933489 is associated with lower ucOC levels in Chinese Han T2DM patients. These findings provide novel perspectives on the role of OC in T2DM pathophysiology.