Stem Cell Research & Therapy•2024•DOI: 10.1186/s13287-024-03908-9
Background The formation of stem cell clones enables close contact of stem cells inside. The gap junctions in such clone spheres establish a microenvironment that allows frequent intercellular communication to maintain self-renewal and functions of stem cells. Nevertheless, the essential gap junction protein for molecular signaling in clones is poorly known. Methods Primary human airway basal cells (hBCs) were isolated from brushing samples through bronchoscopy and then cultured. A tightly focused femtosecond laser was used to excite the local Ca2+ in an individual cell to initiate an internal Ca2+ wave in a clone to screen gap junction proteins. Immunoflourescence staining and clonogenicity assay were used to evaluate self-renewal and functions. RNA and protein levels were assessed by PCR and Western blot. Air–liquid interface assay was conducted to evaluate the differentiation potential. A Naphthalene injury mouse model was used to assess the regeneration potential. Results Herein, we identify Connexin 25 (Cx25) dominates intercellular Ca2+ communications in clones of hBCs in vitro to maintain the self-renewal and pluripotency of them. The self-renewal and in vitro differentiation functions and in vivo regeneration potential of hBCs in an airway damage model are both regulated by Cx25. The abnormal expression of Cx25 is validated in several diseases including IPF, Covid-19 and bronchiectasis. Conclusion Cx25 is essential for hBC clones in maintaining self-renewal and functions of hBCs via gap junctions.
Acta Biochimica et Biophysica Sinica•2025•DOI: 10.3724/abbs.2025063
Homologous recombination (HR) is crucial for the high-fidelity repair of DNA double-strand breaks (DSBs), ensuring the maintenance of genome stability. In this study, we show that FOXD3 interacts with poly (ADP-ribose) polymerase 1 (PARP1) and is recruited to DSBs in a PARP1-dependent manner. FOXD3 directly binds to the DSB repair protein MRE11 and promotes its recruitment to DSB sites, ensuring proper end resection. Inhibition of FOXD3 expression compromises HR-mediated DSB repair and chromosome stability and sensitizes cancer cells to ionizing radiation. Collectively, our findings demonstrate that FOXD3 promotes HR-mediated DSB repair and genome stability.
Chinese Journal of Tissue Engineering Research•2026•DOI: 10.12307/2026.21291
BACKGROUND: ABL1 is involved in the regulation of multiple cellular processes, yet its functions within the cardiovascular system remains largely unexplored. In particular, its role in cardiac ischemia/reperfusion injury and necroptosis has not been reported. OBJECTIVE: To investigate the role of ABL1 in cardiac ischemia/reperfusion injury and myocardial necroptosis, as well as the underlying molecular mechanisms. METHODS: (1) Animal experiment: C57BL/6J mice were randomly divided into four groups: sham surgery group, ischemia/reperfusion group, ABL1 knockdown + ischemia/reperfusion group, and ABL1 negative control + ischemia/reperfusion group. Lentiviral vectors targeting ABL1 were injected in situ into the myocardium. One week later, ischemia/reperfusion injury was induced by ligation of the left anterior descending coronary artery followed by reperfusion. ABL1 protein expression, cardiac function, myocardial fibrosis, and cardiomyocyte surface area were assessed. (2) Cell experiment: H9c2 cells were divided into four groups: negative control cell line + PBS, ABL1 knockdown cell line + PBS, negative control cell line + H2O2 500 µmol/L, and ABL1 knockdown cell line + H2O2 500 µmol/L. Additionally, H9c2 cells were divided into five groups: negative control cell line + PBS, negative control cell line + H2O2 500 µmol/L, ABL1 knockdown cell line + H2O2 500 µmol/L, ABL1 knockdown cell line + Parkin overexpression adenovirus + H2O2 500 µmol/L, and ABL1 knockdown cell line + Parkin negative control adenovirus + H2O2 500 µmol/L. Cell viability, necroptosis, reactive oxygen species levels, and mitochondrial membrane potential were measured. Expression of ABL1, Parkin, and cyclophilin D was detected, and the interaction between ABL1 and Parkin was examined. RESULTS AND CONCLUSION: (1) ABL1 protein expression was significantly downregulated in the mouse cardiac ischemia/reperfusion model. (2) Knockdown of ABL1 exacerbated ischemia/reperfusion-induced cardiac dysfunction, as evidenced by decreased left ventricular ejection fraction and fractional shortening, and increased left ventricular end-systolic and end-diastolic diameters. (3) Knockdown of ABL1 promoted ischemia/reperfusion-induced myocardial fibrosis and aggravated ventricular remodeling. (4) ABL1 protein expression was significantly downregulated in the cardiomyocyte oxidative stress model. (5) Knockdown of ABL1 exacerbated oxidative stress-induced cell viability loss, necroptosis, and reactive oxygen species accumulation. (6) ABL1 regulated mitochondrial membrane permeability, modulated the expression of Parkin and cyclophilin D, and regulated cellular oxidative stress levels by targeting Parkin. (7) These results indicate that ABL1 expression is significantly downregulated in both in vivo ischemia/reperfusion and in vitro oxidative stress models, and knockdown of ABL1 aggravates cardiac ischemia/reperfusion injury and cardiomyocyte oxidative stress injury, acting through the Parkin-CypD pathway.
Chinese Journal of Tissue Engineering Research•2026•DOI: 10.12307/2026.21424
BACKGROUND: A combination of subjective and objective evaluation criteria is often required to more accurately and comprehensively assess knee function in patients undergoing anterior cruciate ligament reconstruction. OBJECTIVE: To review the evolving trends in effectiveness and safety evaluation criteria after anterior cruciate ligament reconstruction and analyze the dynamic shift in the use of subjective and objective assessment tools. METHODS: A systematic search of PubMed and Embase was conducted up to August 22, 2023 to identify studies assessing knee function after anterior cruciate ligament reconstruction. A total of 136 eligible studies meeting the inclusion criteria were included. The frequency of each evaluation standard was extracted and analyzed over time using Origin 2025 software. RESULTS AND CONCLUSION: (1) Between 1990 and 2005, objective measures were widely applied. Since 2005, subjective scoring systems, particularly patient-reported outcome measures, have increased sharply, surpassing objective standards in frequency from 2009 onward. (2) Early use was dominated by the Lysholm scale and Tegner activity score, while the International Knee Documentation Committee-Subjective Knee Form, Knee Injury and Osteoarthritis Outcome Score, and anterior cruciate ligament–return to sport after injury gradually emerged as the main tools in later years. (3) In contrast, objective assessments such as the KT1000/2000 arthrometer, Lachman test, and hop test remained relatively stable but showed an overall declining trend. (4) These findings indicate a paradigm shift from objective knee stability to patient-centered subjective experience in evaluating ACL reconstruction outcomes. (5) This study is the first to quantitatively reveal the dynamic evolution of mainstream evaluation tools, highlighting the current emphasis on combining subjective and objective criteria. The recommended combination is the International Knee Documentation Committee-Subjective Knee Form or Knee Injury and Osteoarthritis Outcome Score plus anterior cruciate ligament–return to sport after injury plus KT1000/2000 or hop test, to comprehensively reflect knee function recovery and patient perception, providing an evidence base for future comprehensive assessment approaches.
Acta Biochimica et Biophysica Sinica•2025•DOI: 10.3724/abbs.2025063
Homologous recombination (HR) is the high-fidelity pathway for repairing DNA double-strand breaks (DSBs) during S/G2 phases, and its dysfunction drives genomic instability and cancer progression. The MRN complex (MRE11/RAD50/NBS1) initiates DNA end resection, a critical step for HR, but how MRE11 recruitment and activity are regulated remains incompletely defined. Here we identify FOXD3 as a novel HR factor that interacts with PARP1 and is recruited to DSB sites in a PARP1-dependent manner. FOXD3 directly binds MRE11 and promotes its recruitment to DSBs, ensuring proper end resection. Depletion of FOXD3 impairs HR-mediated DSB repair, reduces chromosome stability, and sensitizes cancer cells to ionizing radiation. These findings establish FOXD3 as a key regulator of MRE11-mediated end resection and suggest that FOXD3 expression levels could serve as a biomarker for HR proficiency and as a therapeutic target to induce synthetic lethality with PARP inhibitors or radiotherapy. The study provides mechanistic insight into the early steps of HR and highlights the clinical potential of targeting FOXD3 in cancers with HR defects.