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ObjectiveTo investigate the relationship between the degenerative mechanisms of lumbar intervertebral disc (LID) and apoptosis.MethodsThe total RNAs were isolated from human LID tissues. Both the mRNAs from the degeneration and normal LID were reversely transcribed to the cDNAs. The cDNAs were labeled with the incorporations of fluorescent dUTP, for preparing the hybridization probes. The mixed probes were then hybridized to the cDNA microarray. After high-stringent washing, the cDNA microarray was scanned for the fluorescent signals and analyzed by computer image analysis. The apoptotic status and the expression of Bcl-2 and Bax in 12 cases of degenerative LID and 10 cases of normal LID were detected with TdT-mediated dUTP-biotin nick end labeling (TUNEL) and immunohistochemistry methods.ResultsAmong the 4096 targets, there were 10 genes related to apoptosis. The expression related to Bax protein gene was up-regulated and it was down-regulated for Bcl-2 protein. In group of normal LID, the average apoptotic index (AI) was (24.897±3.620); percentage of Bcl-2 positive cells was (31.440±4.150)%; percentage of Bax positive cells was (29.372±2.588)%, average optical density (OD) values of positive particles were (0.183± 0.010 ), ( 0.203 ±0.012) and (0.169±0.005) respectively. In group of degenerative LID, the average AI was (49.232±3.440); percentage of Bcl-2 positive cells was (18.239±2.470)%; percentage of Bax positive cells was (52.349±3.764)%; average OD values of positive particles were (0.152±0.003), (0.310±0.008) and (0.262±0.014) respectively. There were significantly differences in AI and expressions of Bcl-2 and Bax proteins between normal LID and degenerative LID (P<0.05).ConclusionCell apoptosis plays an important role in the process of LID degeneration. Both Bcl-2 and Bax take part in the occurrence and progression of LID.

BACKGROUND: The investigation of culturing, passaging and establishing human limbal stem cells can strengthen the recognition of the stem cells and provide the enough cellular reserve for the basic and clinical research of limbal stem cell transplantation.OBJECTIVE: To explore a method of pessaging and establishing cell line of human limbal stem cells cultured in vitro.DESIGN: Randomized controlled observation.SETTING: Gannan Medical College.MATERIALS: The experiment was performed at Scientific Center of Gannan Medical College and the National Key Laboratory of Ophthalmology Hospital Affiliated to Sun Yat-Sen University from June 2003 to April 2004. Fresh human limbus corneae were isolated from two healthy donors. Procedures were performed according to the informed consent of the donors. Main reagents contained RPMI-1640 (Sigma R8755, containing L-glutamine) and 200 g/L fetal calf serum (FCS) (Gibco 16140-071). DMEM medium, chondroitin sulfatase and human epidermal growth factor (hEGF) were purchased from Sigma Co. USA; HEPES and DMSO were bought from Gibco, USA; 100% glycerinum was purchased from Yunjia Huangpu Pharmaceutical Product Limited Company, PRC; glutaraldehyde was bought from E.Merk, Germany; Alcohol, chlorhydric acid, acetone and methyl aldehyde were purchased from Beijing Chemical Agent Company, PRC; 0.25% parenzyme was bought from Shanghai Xinhua Pharmaceutical Factory, PRC.Above-mentioned reagents were analytical pure grade.METHODS: After digestion, human limbal tissues in limbal basilar part with an abundant pigment were cultured in the culture flask containing RPMI-1640 and 200 g/L FCS and in culture dish containing amniotic extracellular matrix (AECM) as the cultural supporter. Primary and passage cells were observed under light microscope and scanning electron microscope (SEM). The revival ratio of stem cell refrigeration of every generation was calculated by the trypanblau exclusion experiment.MAIN OUTCOME MEASURES: ① Observational results of limbal stem cells during the primary culture and serial subcultivation in vitro, and ② revival ratio of stem cell refrigeration.RESULTS: ①Findings of primary culture: Most limbal stem cells in the culture flask had the adherence and were arrayed uniformly sparsely to form monolayer and adhered to the bottom of culture flask under the inverted phase contrast microscope after 1-day culture. ② Findings of serial subcultivation: After human epidermal growth factor (hEGF) was added into the second passage, cells were scattered into the monolayer and adhered to grow quickly.Morphological variability of all the cells increased obviously when passage the 30th generation. The cellular volume was obviously increasing, and the round or irregular round cells gathered together. The 33rd generation human limbal stem cells still could vigorously differentiate, proliferate and grow in ACEM. ③ The revival ratio of stem cell refrigeration was 82.2%.CONCLUSION: The human limbal stem cell lines were preliminarily established by culturing and freezing the cells of 33 generations in vitro. The human limbal stem cell lines preferred to grow in the culture dish containing AECM as the cultural supporter.

Purpose: The poor retention and ambiguous differentiation of stem cells (SCs) within corpus cavernosum (CC) limit the cell application in erectile dysfunction (ED). Herein, the effects and mechanism of microRNA-145 (miR-145) gene modification on modulating the traits and fate of bone marrow-derived mesenchymal stem cells (BMSCs) were investigated. Materials and Methods: The effects of miR-145 on cell apoptosis, proliferation, migration, and differentiation were determined by flow cytometry, cell counting kit-8, transwell assays and myogenic induction. Then, the age-related ED rats were recruited to four groups including phosphate buffer saline, BMSC, vector-BMSC, overexpressed-miR-145-BMSC groups. After cell transplantation, the CC were harvested and prepared to demonstrate the retention and differentiation of BMSCs by immunofluorescent staining. Then, the target of miR-145 was verified by quantitative real-time polymerase chain reaction and immunohistochemical. After that, APTO-253, as an inducer of Krüppel-like factor 4 (KLF4), was introduced for rescue experiments in corpus cavernosum smooth muscle cells (CCSMCs) under the co-culture system. Results: In vitro, miR-145 inhibited the migration and apoptosis of BMSCs and promoted the differentiation of BMSCs into smooth muscle-like cells with stronger contractility. In vivo, the amount of 5-ethynyl-2′-deoxyuridine (EdU)+cells within CC was significantly enhanced and maintained in the miR-145 gene modified BMSC group. The EdU/CD31 co-staning was detected, however, no co-staining of EdU/α-actin was observed. Furthermore, miR-145, which secreted from the gene modified BMSCs, dampened the expression of KLF4. However, the effects of miR-145 on CCSMCs could be rescued by APTO-253. Conclusions Overall, miR-145 modification prolongs the retention of the transplanted BMSCs within the CC, and this effect might be attributed to the modulation of the miR-145/KLF4 axis. Consequently, our findings offer a promising and innovative strategy to enhance the local stem cell-based treatments.

Age-dependent loss of skeletal muscle mass and function is a feature of sarcopenia, and increases the risk of many aging-related metabolic diseases. Here, we report phenotypic and single-nucleus transcriptomic analyses of non-human primate skeletal muscle aging. A higher transcriptional fluctuation was observed in myonuclei relative to other interstitial cell types, indicating a higher susceptibility of skeletal muscle fiber to aging. We found a downregulation of FOXO3 in aged primate skeletal muscle, and identified FOXO3 as a hub transcription factor maintaining skeletal muscle homeostasis. Through the establishment of a complementary experimental pipeline based on a human pluripotent stem cell-derived myotube model, we revealed that silence of FOXO3 accelerates human myotube senescence, whereas genetic activation of endogenous FOXO3 alleviates human myotube aging. Altogether, based on a combination of monkey skeletal muscle and human myotube aging research models, we unraveled the pivotal role of the FOXO3 in safeguarding primate skeletal muscle from aging, providing a comprehensive resource for the development of clinical diagnosis and targeted therapeutic interventions against human skeletal muscle aging and the onset of sarcopenia along with aging-related disorders.
Animals ; Humans ; Sarcopenia/metabolism* ; Forkhead Box Protein O3/metabolism* ; Muscle, Skeletal/metabolism* ; Aging/metabolism* ; Primates/metabolism*