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Biomedical subjects

Chunyan Zhou

Publications and source records attributed to Chunyan Zhou.

10 recordsLinked to original sources

Accurately Deciphering Tissue Heterogeneity From Spatial Multi-Modal and Multi-Omics With STransformer.

Advances in spatially resolved technologies enable the simultaneous acquisition of diverse data modalities within a tissue slice while preserving critical spatial context, which presents unprecedented opportunities to decipher intricate tissue heterogeneity. However, existing computational approaches lack the intrinsic flexibility to universally process both spatial multi-modal and multi-omics data. Here, we introduce STransformer, a unified deep learning framework designed to seamlessly accommodate a comprehensive landscape of spatial data. By simultaneously capturing short-range cellular interactions and tissue-wide semantic patterns, it extracts robust representations to accurately dissect complex tissue heterogeneity. Systematic evaluations across diverse species, tissue types, and data modalities highlight its profound versatility. For spatial multi-modal data, STransformer delineates intricate anatomical structures in the human cortex, uncovers pathological mechanisms in Alzheimer's disease, and characterizes dynamic spatiotemporal developmental trajectories during chicken cardiogenesis. Scaling to spatial multi-omics data, STransformer synergizes spatial transcriptomic and proteomic profiles to decipher intricate immune microenvironments within the human tonsil, and jointly analyzes spatial epigenomic and transcriptomic data to infer regulatory mechanisms in the mouse embryonic brain. Consequently, STransformer serves as a highly versatile and robust analytical framework for advancing our understanding of tissue heterogeneity and disease pathogenesis.

Multiomics↗

Adenovirus-mediated transfer of siRNA against Runx2/Cbfa1 inhibits the formation of heterotopic ossification in animal model.

The heterotopic ossification of muscles, tendons, and ligaments is a common problem faced by orthopaedic surgeons. Runx2/Cbfa1 plays an essential role during the osteoblast differentiation and is considered as a molecular switch in osteoblast biology. RNA interference technology is a powerful tool for silencing endogenous or exogenous genes in mammalian cells. In this study, we investigated the effect of Runx2/Cbfa1-specific siRNA on osteoblast differentiation and mineralization in osteoblastic cells, and then constructed adenovirus containing siRNA against Runx2/Cbfa1 (Ad-Runx2-siRNA) to inhibit the formation of heterotopic ossification induced by BMP4, demineralized bone matrix, and trauma in animal model. Our results showed that the Runx2/Cbfa1-specific siRNA could inhibit the expression of Runx2/Cbfa1 at the level of mRNA and protein. Analysis of the expression of osteoblast maturation genes including type I collagen, osteopontin, bone sialoprotein, and osteocalcin, alkaline phosphatase activity, and matrix mineralization (von kossa) revealed that osteoblast differentiation was inhibited in cultured primary mouse osteoblasts transduced with Ad-Runx2-siRNA. Furthermore, adenovirus-mediated transfer of siRNA against Runx2/Cbfa1 could inhibit the formation of heterotopic ossification induced by BMP4, demineralized bone matrix, and trauma in animal model. It is likely that the inhibition of Runx2/Cbfa1 by RNAi could be developed as a powerful approach to prevent or treat heterotopic ossification.

Adenoviridae↗

Cartilage-derived stromal cells: is it a novel cell resource for cell therapy to regenerate infarcted myocardium?

Human cartilage is reported to contain multipotent stromal cells. We evaluated the effect of human cartilage-derived stromal cells (CDSCs) on heart function when transplanted into the infarcted myocardium of rats. CDSCs were isolated and cultured from human articular cartilage and subjected to fluorescence-activated cell sorting (FACS) analysis. The CDSCs were consistently negative for CD14, CD34, CD38, CD45, CD49f, CD104, CD105, CD106, CD117, HLA-DR, and ABCG-2, and positive for CD10, CD44, CD71, CD73, CD90, CD147, and HLA-A, -B, and -C by FACS analysis. Myocardial infarction (MI) was created in rats by ligation of the left anterior descending artery. Three weeks after MI, the CDSCs labeled with Hoechst stain were injected into the infarct and border zone. Echocardiography, histological examination, and reverse transcription-polymerase chain reaction (RT-PCR) were performed 4 weeks after cell transplantation. Echocardiography indicated that CDSC transplantation could improve heart function. The number of capillaries increased in the injection regions in the transplantation group. Histological examination showed that Hoechst-labeled CDSCs in islands within the infarcted region were stained positively for desmin and smooth muscle actin but negatively for alpha-sarcomeric actin and troponin-I. RT-PCR results indicated the expression level of collagen I, collagen III, tissue inhibitor of metalloproteinase-1, transforming growth factor-beta1, and vascular endothelia growth factor were much higher in the scar tissue in the transplantation group than in the medium and control groups. Our findings suggested that CDSCs might promote angiogenesis, prevent left ventricular remodeling, and improve the heart function when transplanted into injured heart in the rat model of myocardial infarction.

Animals↗

Increased heme oxygenase-1 expression in infarcted rat hearts following human bone marrow mesenchymal cell transplantation.

Heme oxygenase-1 (HO-1) plays an important role in oxidative stress and recent studies indicate that it is a graft survival protein in cardiac and liver transplant models. In this study, we investigated the relation between the expressions of HO-1 and the effects of human bone marrow mesenchymal cells (MSCs) transplantation to xenogenic rat hearts with experimental myocardial infarction (MI). A total of 5 x 10(6) cells in 100 microl PBS or equal volume PBS alone were injected into the ischemic zones immediately post-MI. At 1, 3, and 7 days post-MI, cardiac function was evaluated by echocardiography, the expression of HO-1 was assessed by real-time PCR and Western blot, the localization of HO-1 protein was determined under immunofluorescence microscopy. The infarct size was examined by histology. The numbers of Hoechst-33342 positive MSCs were evaluated under immunofluorescence microscopy and also by flow cytometry after isolation from the host hearts. The results indicated that the HO-1 expressions were markedly increased at both mRNA and protein levels in comparison with injection of PBS at each time point post MSCs transplantation (P < 0.01). HO-1 was revealed both in transplanted MSCs and recipient cardiomyocytes by immunofluorescence. Up-regulated HO-1 expression was accompanied by increase of the numbers of Hoechst-33342 positive MSCs, the reduction of infarct size, and the improvement of cardiac function. Transplantation of human MSCs could up-regulate HO-1 expression in infarct rat hearts, which might play an important role in protecting transplanted MSCs, cardiomyocytes survival, and cardiac function improvement during the early stage after MI.

Adult↗

Purified human bone marrow multipotent mesenchymal stem cells regenerate infarcted myocardium in experimental rats.

Recent findings suggest the feasibility of cardiac repair by transplantation of bone marrow mesenchymal stem cell (MSCs). However, it remains controversial regarding which cell type is the best source for transplanting into the ischemic heart because of lack of well-defined cell markers. In this study, we investigated the in vitro and in vivo effects of the novel multipotent marrow mesenchymal stem cells (MMSCs) from human bone marrow. Pluripotent markers (Oct4, Bmi1, and Abcg2) and vascular endothelial growth factor (VEGF) were detected by RT-PCR and immunofluorescence in MMSCs. Myocardial differentiation was induced in the expanded MMSC cultures by treatment with 5-azacyline. Expressions of VEGF in the animals transplanted with MMSCs were markedly increased in comparison with the animals injected with fibroblasts or saline at both mRNA and protein levels. VEGF expression was observed in both transplanted MMSCs and recipient cardiomyocytes by immunofluorescence. Confocal immunofluorescence microscopy revealed the specific markers for cardiomyocytes and endothelial cells in transplanted MMSCs 14 days after transplantation. Vessel count was increased and left ventricular function improved post-MMSC transplantation. These results indicate that transplantation of purified MMSCs from human bone marrow upregulated VEGF expression, enhanced angiogenesis, and improved the functional recovery following myocardial infarction in rats.

ATP Binding Cassette Transporter, Subfamily G, Mem↗

Long-term effects of bone marrow mononuclear cell transplantation on left ventricular function and remodeling in rats.

This study was performed to evaluate the long-term effect on left ventricular function and remodeling in a rat model of bone marrow cell transplantation (BMT) into acute infarcted myocardium. After myocardial infarction was induced in inbred Lewis rats by left anterior descending artery ligation, the ischemic area was directly injected with saline, peripheral blood mononuclear cells (PB-MNCs) or bone marrow mononuclear cells (BM-MNCs). Cardiac function and structure were evaluated by echocardiography before the operation, and on day 1 and 2 months post-infarct. The collagen content, the number of vessels and the vasculogenesis were examined by histology and immunohistochemistry. We found at 2 months post-infarct, BMT significantly improved cardiac systolic function and recovered diastolic function. Transplantation of BM-MNCs, but not PB-MNCs, reversed remodeling and reduced collagen density. Vessel counts showed greater angiogenesis occurred in the animals transplanted with BM-MNCs. Furthermore, a vascular endothelial cell-specific marker was detected in the transplanted bone marrow cells. Our data suggest that BM-MNC transplantation results in long-term improvement in left ventricular function-especially diastolic function- and remodeling, possibly related with the reduction of the amount of the collagen and enhancement of neovascularization.

Animals↗

Enhanced cytoprotection and angiogenesis by bone marrow cell transplantation may contribute to improved ischemic myocardial function.

OBJECTIVES: Heat shock proteins (HSPs) are cytoprotective proteins. Vascular endothelial growth factor (VEGF) is the most potent angiogenic factor. This study aimed to elucidate the possible role of cytoprotection and angiogenesis on cardiac function after bone marrow cell transplantation (BMT). METHODS: Myocardial infarction was induced in inbred Lewis rats by left anterior descending artery ligation. A total of 5 x 10(6) bone marrow-mononuclear cells were transplanted into the ischemic zone by direct injection. At 1, 3, 7, 14 and 28 days post-transplantation, cardiac function was evaluated by echocardiography. The expressions of HSP32, HSP70 and VEGF were assessed by immunofluorescence and RT-PCR. The number of vessels was examined by immunohistochemistry. The differentiation of the transplanted cells was determined by immunofluorescence. RESULTS: Echocardiography showed BMT led to sustained improvement in cardiac function, as assessed by left ventricle ejection fraction and fraction of shortening. Immunofluorescence revealed that the expressions of HSP32, HSP70 and VEGF were promoted in both transplanted bone marrow cells and recipient cardiomyocytes. RT-PCR showed that the mRNA expression levels of HSP32, HSP70 and VEGF in the BMT group were markedly higher in comparison with injection of peripheral blood cells or saline (P<0.01) by day 7. Seven days later, the vessel count showed that angiogenesis had been induced to a significantly greater degree in the BMT groups. Fourteen days later, specific markers for myocardial or vascular endothelial cells were detected in the transplanted bone marrow cells. CONCLUSIONS: BMT upregulated the expressions of HSP32, HSP70 and VEGF in both transplanted bone marrow cells and recipient endogenous cardiomyocytes in the early phase post-transplantation. This enhanced cytoprotection and angiogenesis, and contributed to the functional recovery following cardiac infarction. In the late phase, the transplanted bone marrow cells might differentiate into both myocardial and vascular endothelial cells that enhanced the ischemic cardiac function further.

Animals↗

Bone marrow mononuclear cell transplantation into heart elevates the expression of angiogenic factors.

The expression of angiogenic factors was measured to elucidate the mechanism of angiogenesis after bone marrow stem cells transplantation. The left anterior descending coronary (LAD) artery was ligated in male Lewis rats to induce an acute myocardial infarction (AMI); of which, some rats received bone marrow mononuclear cells transplantation (BMT). The expression of cytokines and their receptors was assessed by RT-PCR. The expression of c-met was upregulated in the AMI animals and was further increased when the animals received BMT (P < 0.01). The other cytokines and their receptors remained unchanged after BMT compared with AMI samples. Normal bone marrow mononuclear cells have higher expression level of hepatocyte growth factor (HGF) than those in normal hearts. In conclusion, BMT could increase the expression of c-met. Not all angiogenic cytokines and their receptors were upregulated after BMT. The higher expression of hepatocyte growth factor in bone marrow may contribute to the upregulation of c-met.

Angiogenesis Inducing Agents↗

[Transplantation of bone marrow cells upregulated vascular endothelial growth factor and its receptor and improved ischemic myocardial function].

OBJECTIVE: To investigate the possible mechanisms of improving ischemic myocardial function by transplantation of bone marrow cells in a rat ischemic heart model. METHODS: Myocardial infarction was induced in inbred Lewis rats by left anterior descending artery ligation. Bone marrow cells were injected into an ischemic zone (BMI group). On days 1, 3, 7, 14 and 28 post-transplantation, the expressions of vascular endothelial growth factor (VEGF) and its receptor (Flk-1) and the differentiation of transplanted cells were determined by immunofluorescence and RT-PCR. The number of vessels was examined by immunohistochemistry. The cardiac function was evaluated by hemodynamics. RESULTS: Immunofluorescence microscopy of hearts from BMI group revealed that expressions of VEGF and Flk-1 were promoted within cardiomyocytes in the infarction zone, the peri-infarct zone and in some transplanted bone marrow cells. RT-PCR also showed that mRNA expression levels of VEGF and Flk-1 in BMI group were significantly higher than those of the control group, reached the highest level on days 3 and 14 post-transplantation, and then gradually declined. On days 7, 14 and 28, the vessel count showed the number of blood vessels in the BMI group was greater than that of the control group at the same time, and the cardiac function in the BMI group was improved more significantly than that of the control group. After day 14, the specific markers for myocardium or vascular endothelial cells were detected in the transplanted bone marrow cells. CONCLUSIONS: BMI improved the acute ischemic cardiac function by both upregulating the expressions of VEGF and Flk-1 in transplanted BMCs and recipient endogenous cardiomyocytes that enhanced angiogenesis.

Animals↗

[Transplantation of bone marrow cells up-regulated the expressions of HSP32 and HSP70 in the acute ischemic myocardium].

OBJECTIVE: To clarify the role of Heat shock proteins (HSPs) on the cardiac function during acute myocardial infarction (AMI) after bone marrow cell implantation (BMT), we examined the expression of HSP32 and HSP70 in a rat model of myocardial infarction. METHODS: Myocardial infarction model was induced in the inbred Lewis rats by left anterior descending artery ligation, and 5 x 10(6) of bone marrow-mononuclear cells (BM-MNCs) were injected into an ischemic zone. On days 1, 3, 7 and 14 post-infarct, the differentiations of transplanted cells and the expressions of HSP32 and HSP70 were determined by immunofluorescence or RT-PCR. The cardiac function was evaluated by echocardiography. RESULTS: Immunofluorescence microscopy of hearts from BMT group revealed that expressions of HSP32 and HSP70 were promoted within cardiomyocytes in the infarction zone and the peri-infarct zone, and expressed within some transplanted bone marrow cells as well. RT-PCR also showed the mRNA expression levels of HSP32 and HSP70 in BMT group were significantly higher than those of the control group, peaked on day 3 post-infarct (5.0-fold and 2.9-fold, respectively, P < 0.01), and then gradually reduced. On day 7 post-infarct, cardiac function (EF and FS) was improved, more than that of the control group (14% and 22%, P < 0.05). On day 14 post-infarct, the specific markers for myocardium or vascular endothelial cells were detected in the transplanted bone marrow cells. The cardiac function was further improved in the BMT group (P < 0.01). CONCLUSION: At the early phase after BMT, the expressions of HSP32 and HSP70 were upregulated in both transplanted cells and recipient endogenous cardiomyocytes, which improved the acute ischemic cardiac function.

Animals↗