Liver fibrosis is a significant health burden,marked by the consistent deposition of collagen.Unfortunately,the currently available treatment approaches for this condition are far from optimal.Lysyl oxidase-like prote...Liver fibrosis is a significant health burden,marked by the consistent deposition of collagen.Unfortunately,the currently available treatment approaches for this condition are far from optimal.Lysyl oxidase-like protein 2(LOXL2)secreted by hepatic stellate cells(HSCs)is a crucial player in the cross-linking of matrix collagen and is a significant target for treating liver fibrosis.Mesenchymal stem cell-derived small extracellular vesicles(MSC-sEVs)have been proposed as a potential treatment option for chronic liver disorders.Previous studies have found that MSC-sEV can be used for microRNA delivery into target cells or tissues.It is currently unclear whether microRNA-4465(miR-4465)can target LOXL2 and inhibit HSC activation.Additionally,it is uncertain whether MSC-sEV can be utilized as a gene therapy vector to carry miR-4465 and effectively inhibit the progression of liver fibrosis.This study explored the effect of miR-4465-modified MSC-sEV(MSC-sEVmiR-4465)on LOXL2 expression and liver fibrosis development.The results showed that miR-4465 can bind specifically to the promoter of the LOXL2 gene in HSC.Moreover,MSC-sEVmiR-4465 inhibited HSC activation and collagen expression by downregulating LOXL2 expression in vitro.MSC-sEVmiR-4465 injection could reduce HSC activation and collagen deposition in the CCl4-induced mouse model.MSC-sEVmiR-4465 mediating via LOXL2 also hindered the migration and invasion of HepG2 cells.In conclusion,we found that MSC-sEV can deliver miR-4465 into HSC to alleviate liver fibrosis via altering LOXL2,which might provide a promising therapeutic strategy for liver diseases.展开更多
Non-myeloablative regimens for host conditioning have been widely used in clinical hematopoietic stem cell transplantation due to their reduced toxicity on the recipients. But a milder conditioning regimen may require...Non-myeloablative regimens for host conditioning have been widely used in clinical hematopoietic stem cell transplantation due to their reduced toxicity on the recipients. But a milder conditioning regimen may require a higher engrafting ability of donor stem cells in competing with endogenous stem cells. Thus, new strategies for enhancing the competitiveness of donor stem cells in non-myeloablative recipients would have important implications for current clinical stem cell trans- plantation. It is known that the absence of p18INK4C (p18) gene can enhance the self-renewal potential of hematopoietic stem cells (HSCs). We applied the approach of competitive bone marrow trans- plantation to evaluate the impact of p18 gene deletion on long-term engraftment of HSCs in sub- lethally irradiated hosts. We found that p18?/? HSCs had a significant advantage over wild-type HSCs during long-term engraftment in the mouse recipients that received a sub-lethal irradiation (5-Gy). The engraftment efficiency of p18?/? HSCs in the sub-lethally irradiated recipients was similar to that in the lethally irradiated (10-Gy) recipients. Our current study demonstrates that enhanced engraftment of donor HSCs in the absence of p18 does not strictly depend on the dose of irradiation used for host conditioning. Therefore, p18 might serve as a potential drug target for increasing the efficacy of stem cell transplant in the patients that are preconditioned with either a myeloablative or non-myeloablative regimen.展开更多
Establishment of a hematopoietic stem cell（HSC）pool depends on the appropriate formation,maturation and mobilization of HSCs in vertebrates.In mice,the aorta-gonad-mesonephros（AGM）is a prominent site for the forma...Establishment of a hematopoietic stem cell（HSC）pool depends on the appropriate formation,maturation and mobilization of HSCs in vertebrates.In mice,the aorta-gonad-mesonephros（AGM）is a prominent site for the formation of definitive HSCs from endothelial cells,although the placenta and yolk sac also give rise to HSCs（Mikkola and Orkin,2006;Chen et al.,2009）.After formation,AGM-derived HSCs migrate to the fetal liver（FL）,and ultimately to the bone marrow （BM）, two definitive hematopoietic organs （Cumano and Godin, 2007）.展开更多
Radioprotection was previously considered as a function of hematopoietic stem cells(HSCs).However,recent studies have reported its activity in hematopoietic progenitor cells(HPCs).To address this issue,we compared the...Radioprotection was previously considered as a function of hematopoietic stem cells(HSCs).However,recent studies have reported its activity in hematopoietic progenitor cells(HPCs).To address this issue,we compared the radioprotection activity in 2 subsets of HSCs(nHSC1 and 2 populations)and 4 subsets of HPCs(nHPC1–4 populations)of the mouse bone marrow,in relation to their in vitro and in vivo colony-forming activity.Significant radioprotection activity was detected in the nHSC2 population enriched in lymphoid-biased HSCs.Moderate radioprotection activity was detected in nHPC1 and 2 populations enriched in myeloid-biased HPCs.Low radioprotection activity was detected in the nHSC1 enriched in myeloid-biased HSCs.No radioprotection activity was detected in the nHPC3 and 4 populations that included MPP4(LMPP).Single-cell colony assay combined with flow cytometry analysis showed that the nHSC1,nHSC2,nHPC1,and nHPC2 populations had the neutrophils/macrophages/erythroblasts/megakaryocytes(nmEMk)differentiation potential whereas the nHPC3 and 4 populations had only the nm differentiation potential.Varying day 12 spleen colony-forming units(day 12 CFU-S)were detected in the nHSC1,nHSC2,and nHPC1–3 populations,but very few in the nHPC4 population.These data suggested that nmEMk differentiation potential and day 12 CFU-S activity are partially associated with radioprotection activity.Reconstitution analysis showed that sufficient myeloid reconstitution around 12 to 14 days after transplantation was critical for radioprotection.This study implied that radioprotection is specific to neither HSC nor HPC populations,and that lymphoid-biased HSCs and myeloid-biased HPCs as populations play a major role in radioprotection.展开更多
Hematopoietic stem cells (HSCs) are tissue-specific cells giving rise to all mature blood cell types regulated by a diverse group of hematopoietic cytokines and growth factors that influences the survival & prolif...Hematopoietic stem cells (HSCs) are tissue-specific cells giving rise to all mature blood cell types regulated by a diverse group of hematopoietic cytokines and growth factors that influences the survival & proliferation of early progenitors and differentiation mechanisms by modulating the functional activities of HSCs. In this study, the functional yet distinctive role of three novel combinations of gene pairs RRAGC & PSMC2;CKAP4 & MANF;and CTR9 & CNTNAP2 have been newly identified. These novel combinations of genes were confirmed and expressed in K562 human leukemic cell line in the presence of cytokine combination (IL-3, FLT-3 and SCF) using RT-PCR and siRNA-mediated gene knock down strategy. This study signifies the synergistic role of gene pairs in different molecular activities like ubiquitination or proteasomal degradation, calcium mobilization, dopamine signaling.展开更多
基金supported by the National Natural Science Foundation of China(No.82272421)the Jiangsu Provincial Key Research and Development Program(No.BE2021690)+2 种基金the Changzhou's 14th Five-year Plan Project to Train Highlevel Health Professionals(No.2022CZLJ027)the Scientific Project of Jiangsu Health Commission(No.Z2020038)the Changzhou Sci&Tech Program(No.CJ20220164),China.
文摘Liver fibrosis is a significant health burden,marked by the consistent deposition of collagen.Unfortunately,the currently available treatment approaches for this condition are far from optimal.Lysyl oxidase-like protein 2(LOXL2)secreted by hepatic stellate cells(HSCs)is a crucial player in the cross-linking of matrix collagen and is a significant target for treating liver fibrosis.Mesenchymal stem cell-derived small extracellular vesicles(MSC-sEVs)have been proposed as a potential treatment option for chronic liver disorders.Previous studies have found that MSC-sEV can be used for microRNA delivery into target cells or tissues.It is currently unclear whether microRNA-4465(miR-4465)can target LOXL2 and inhibit HSC activation.Additionally,it is uncertain whether MSC-sEV can be utilized as a gene therapy vector to carry miR-4465 and effectively inhibit the progression of liver fibrosis.This study explored the effect of miR-4465-modified MSC-sEV(MSC-sEVmiR-4465)on LOXL2 expression and liver fibrosis development.The results showed that miR-4465 can bind specifically to the promoter of the LOXL2 gene in HSC.Moreover,MSC-sEVmiR-4465 inhibited HSC activation and collagen expression by downregulating LOXL2 expression in vitro.MSC-sEVmiR-4465 injection could reduce HSC activation and collagen deposition in the CCl4-induced mouse model.MSC-sEVmiR-4465 mediating via LOXL2 also hindered the migration and invasion of HepG2 cells.In conclusion,we found that MSC-sEV can deliver miR-4465 into HSC to alleviate liver fibrosis via altering LOXL2,which might provide a promising therapeutic strategy for liver diseases.
基金partially supported by the Outstanding Award for Chinese Oversea Scholar by the National Natural Science Foundation of China(Grant No.30228011)the General Award of National Natural Science Foundation of China(Grant No.39970709).
文摘Non-myeloablative regimens for host conditioning have been widely used in clinical hematopoietic stem cell transplantation due to their reduced toxicity on the recipients. But a milder conditioning regimen may require a higher engrafting ability of donor stem cells in competing with endogenous stem cells. Thus, new strategies for enhancing the competitiveness of donor stem cells in non-myeloablative recipients would have important implications for current clinical stem cell trans- plantation. It is known that the absence of p18INK4C (p18) gene can enhance the self-renewal potential of hematopoietic stem cells (HSCs). We applied the approach of competitive bone marrow trans- plantation to evaluate the impact of p18 gene deletion on long-term engraftment of HSCs in sub- lethally irradiated hosts. We found that p18?/? HSCs had a significant advantage over wild-type HSCs during long-term engraftment in the mouse recipients that received a sub-lethal irradiation (5-Gy). The engraftment efficiency of p18?/? HSCs in the sub-lethally irradiated recipients was similar to that in the lethally irradiated (10-Gy) recipients. Our current study demonstrates that enhanced engraftment of donor HSCs in the absence of p18 does not strictly depend on the dose of irradiation used for host conditioning. Therefore, p18 might serve as a potential drug target for increasing the efficacy of stem cell transplant in the patients that are preconditioned with either a myeloablative or non-myeloablative regimen.
基金supported by the National Natural Science Foundation of China (No. 81200340)Team Program of Guangdong Natural Science Foundation (No. 2014A030312002)+2 种基金Talent Recruitment fundingExcellent Young Teacher funding of Guangdong Higher Education Institutes (No. Yq2013025)Peal River S&T Nova Program of Guangzhou (No. 2013J2200032)
文摘Establishment of a hematopoietic stem cell（HSC）pool depends on the appropriate formation,maturation and mobilization of HSCs in vertebrates.In mice,the aorta-gonad-mesonephros（AGM）is a prominent site for the formation of definitive HSCs from endothelial cells,although the placenta and yolk sac also give rise to HSCs（Mikkola and Orkin,2006;Chen et al.,2009）.After formation,AGM-derived HSCs migrate to the fetal liver（FL）,and ultimately to the bone marrow （BM）, two definitive hematopoietic organs （Cumano and Godin, 2007）.
基金the National Key Rescarch and Development Program of China Stem Cell and Translational Research(2017YFA0104900,2016YFA0100600,and 2019YFA0110203)CAMS Initiative for Innovative Medi-cine(CAMS-12M)(2016-I2M-1-017 and 2017-I2M-1-015)+1 种基金CAMS Fundamental Rescarch Funds for Central RescarchInstitutes(2019PT320017)the National Natural ScienceFoundation of China(81670105,81970119,and 81421002).
文摘Radioprotection was previously considered as a function of hematopoietic stem cells(HSCs).However,recent studies have reported its activity in hematopoietic progenitor cells(HPCs).To address this issue,we compared the radioprotection activity in 2 subsets of HSCs(nHSC1 and 2 populations)and 4 subsets of HPCs(nHPC1–4 populations)of the mouse bone marrow,in relation to their in vitro and in vivo colony-forming activity.Significant radioprotection activity was detected in the nHSC2 population enriched in lymphoid-biased HSCs.Moderate radioprotection activity was detected in nHPC1 and 2 populations enriched in myeloid-biased HPCs.Low radioprotection activity was detected in the nHSC1 enriched in myeloid-biased HSCs.No radioprotection activity was detected in the nHPC3 and 4 populations that included MPP4(LMPP).Single-cell colony assay combined with flow cytometry analysis showed that the nHSC1,nHSC2,nHPC1,and nHPC2 populations had the neutrophils/macrophages/erythroblasts/megakaryocytes(nmEMk)differentiation potential whereas the nHPC3 and 4 populations had only the nm differentiation potential.Varying day 12 spleen colony-forming units(day 12 CFU-S)were detected in the nHSC1,nHSC2,and nHPC1–3 populations,but very few in the nHPC4 population.These data suggested that nmEMk differentiation potential and day 12 CFU-S activity are partially associated with radioprotection activity.Reconstitution analysis showed that sufficient myeloid reconstitution around 12 to 14 days after transplantation was critical for radioprotection.This study implied that radioprotection is specific to neither HSC nor HPC populations,and that lymphoid-biased HSCs and myeloid-biased HPCs as populations play a major role in radioprotection.
文摘Hematopoietic stem cells (HSCs) are tissue-specific cells giving rise to all mature blood cell types regulated by a diverse group of hematopoietic cytokines and growth factors that influences the survival & proliferation of early progenitors and differentiation mechanisms by modulating the functional activities of HSCs. In this study, the functional yet distinctive role of three novel combinations of gene pairs RRAGC & PSMC2;CKAP4 & MANF;and CTR9 & CNTNAP2 have been newly identified. These novel combinations of genes were confirmed and expressed in K562 human leukemic cell line in the presence of cytokine combination (IL-3, FLT-3 and SCF) using RT-PCR and siRNA-mediated gene knock down strategy. This study signifies the synergistic role of gene pairs in different molecular activities like ubiquitination or proteasomal degradation, calcium mobilization, dopamine signaling.
