Brain functional impairment after stroke is common;however,the molecular mechanisms of post-stroke recovery remain unclear.It is well-recognized that age is the most important independent predictor of poor outcomes af...Brain functional impairment after stroke is common;however,the molecular mechanisms of post-stroke recovery remain unclear.It is well-recognized that age is the most important independent predictor of poor outcomes after stroke as older patients show poorer functional outcomes following stroke.Mounting evidence suggests that axonal regeneration and angiogenesis,the major forms of brain plasticity responsible for post-stroke recovery,diminished with advanced age.Previous studies suggest that Ras-related C3 botulinum toxin substrate(Rac)1 enhances stroke recovery as activation of Rac1 improved behavior recovery in a young mice stroke model.Here,we investigated the role of Rac1 signaling in long-term functional recovery and brain plasticity in an aged(male,18 to 22 months old C57BL/6J)brain after ischemic stroke.We found that as mice aged,Rac1 expression declined in the brain.Delayed overexpression of Rac1,using lentivirus encoding Rac1 injected day 1 after ischemic stroke,promoted cognitive(assessed using novel object recognition test)and sensorimotor(assessed using adhesive removal tests)recovery on days 14–28.This was accompanied by the increase of neurite and proliferative endothelial cells in the periinfarct zone assessed by immunostaining.In a reverse approach,pharmacological inhibition of Rac1 by intraperitoneal injection of Rac1 inhibitor NSC23766 for 14 successive days after ischemic stroke worsened the outcome with the reduction of neurite and proliferative endothelial cells.Furthermore,Rac1 inhibition reduced the activation of p21-activated kinase 1,the protein level of brain-derived neurotrophic factor,and increased the protein level of glial fibrillary acidic protein in the ischemic brain on day 28 after stroke.Our work provided insight into the mechanisms behind the diminished plasticity after cerebral ischemia in aged brains and identified Rac1 as a potential therapeutic target for improving functional recovery in the older adults after stroke.展开更多
The“gut-skin”axis has been proved and is considered as a novel therapy for the prevention of skin aging.The antioxidant efficacy of oligomannonic acid(MAOS)makes it an intriguing target for use to improve skin aging...The“gut-skin”axis has been proved and is considered as a novel therapy for the prevention of skin aging.The antioxidant efficacy of oligomannonic acid(MAOS)makes it an intriguing target for use to improve skin aging.The present study further explored whereby MAOS-mediated gut-skin axis balance prevented skin aging in mice.The data indicated the skin aging phenotypes,oxidative stress,skin mitochondrial dysfunction,and intestinal dysbiosis(especially the butyrate and HIF-1a levels decreased)in aging mice.Similarly,fecal microbiota transplantation(FMT)from aging mice rebuild the aging-like phenotypes.Further,we demonstrated MAOS-mediated colonic butyrate-HIF-1a axis homeostasis promoted the entry of butyrate into the skin,upregulated mitophagy level and ultimately improving skin aging via HDAC3/PHD/HIF-1a/mitophagy loop in skin of mice.Overall,our study offered a better insights of the effectiveness of alginate oligosaccharides(AOS),promised to become a personalized targeted therapeutic agents,on gut-skin axis disorder inducing skin aging.展开更多
Pulmonary fibrosis(PF)is a lethal lung disease that predominantly affects older adults;however,whether and how aging triggers fibrosis remains unclear.To pinpoint the predominant initiating factors of PF,we first anal...Pulmonary fibrosis(PF)is a lethal lung disease that predominantly affects older adults;however,whether and how aging triggers fibrosis remains unclear.To pinpoint the predominant initiating factors of PF,we first analyzed single-cell RNA sequencing(scRNA-seq)data from the lung tissues of 45 normal donors and 51 PF patients and found that aging might serve as the primary catalyst for PF development.To further investigate the influence of aging on PF formation,we conducted a comprehensive and thorough study employing a natural aging mouse model.We found that dynamic alterations in the quantity and types of collagen fibers during aging-induced PF progression,especially in collagenous(Col)I,emerged as the predominant driver of PF.We then investigated the regulation of Col I synthesis during aging using primary alveolar type 2(AT2)cells and A549 cells line through conditioned media and Transwell cocul-ture,and found that secretions—particularly plasminogen activator inhibitor(PAI)-1—from aged AT2 cells promoted fibrosis and enhanced collagen type I alpha 1(Col1al)production via the transforming growth factor(TGF)-b/small mother against decapentaplegic(Smad)2/3 pathway.Furthermore,scRNA-seq and a histological analysis of human lung tissue demonstrated a significant upregulation of SERPINE1(the gene encoding PAI-1)and PAI-1 expression in both aging lung tissue and AT2 cells,which was consistent with our findings from animal experiments,providing additional evidence for the pivotal role of PAI-1 during aging and the development of PF.Our research demonstrates that PAI-1,a crucial factor secreted by aging AT2 cells,exerts a pivotal role in promoting the synthesis of Col1a1 in fibroblasts,subsequently leading to Col I deposition,and in driving the progression of PF by mediating the TGF-b/Smad2/3 pathway.Our find-ings offer critical evidence for the involvement of epithelial dysfunction in age-related PF and provides potential novel therapeutic targets for clinical intervention.展开更多
Introduction: Infant and child mortality is a worldwide concern, but developing countries such as Mali are more affected. The aim of this study was to investigate morbidity and factors associated with mortality in chi...Introduction: Infant and child mortality is a worldwide concern, but developing countries such as Mali are more affected. The aim of this study was to investigate morbidity and factors associated with mortality in children aged 1 month to 15 years. Methodology: This was a cross-sectional study which took place from January 1 to December 31, 2020 covering children aged 1 month to 15 years hospitalized at the Kalaban-Coro CSRéf. Data were entered into Excel and analyzed using SPSS version 20 software. Results: Five hundred children aged 1 months to 15 years were included. The age range 1 to 5 years (53.6%) and male sex (58.2%) were the most represented. Malaria (72.2%), acute respiratory infections (6.2%) and diarrhea/dehydration (3%) were the main morbidities. Mortality was estimated at 10.6%, and the two main causes of death were malaria (56.6%) and acute respiratory infections (7.54%). Univariate analysis revealed a statistically significant association between the dependent variable (death) and age (p Conclusion: This study confirms the high rate of infant and child morbidity and mortality in our health facilities. Strengthening human resources and intensifying behavior-change communication can help reverse the trend.展开更多
基金supported by NIH grants RF1 AG069466(to JL and LDM),R01 NS099628(to JL),and AG069466(to JL and LDM)the American Heart Association award 20POST35180172(to FB)。
文摘Brain functional impairment after stroke is common;however,the molecular mechanisms of post-stroke recovery remain unclear.It is well-recognized that age is the most important independent predictor of poor outcomes after stroke as older patients show poorer functional outcomes following stroke.Mounting evidence suggests that axonal regeneration and angiogenesis,the major forms of brain plasticity responsible for post-stroke recovery,diminished with advanced age.Previous studies suggest that Ras-related C3 botulinum toxin substrate(Rac)1 enhances stroke recovery as activation of Rac1 improved behavior recovery in a young mice stroke model.Here,we investigated the role of Rac1 signaling in long-term functional recovery and brain plasticity in an aged(male,18 to 22 months old C57BL/6J)brain after ischemic stroke.We found that as mice aged,Rac1 expression declined in the brain.Delayed overexpression of Rac1,using lentivirus encoding Rac1 injected day 1 after ischemic stroke,promoted cognitive(assessed using novel object recognition test)and sensorimotor(assessed using adhesive removal tests)recovery on days 14–28.This was accompanied by the increase of neurite and proliferative endothelial cells in the periinfarct zone assessed by immunostaining.In a reverse approach,pharmacological inhibition of Rac1 by intraperitoneal injection of Rac1 inhibitor NSC23766 for 14 successive days after ischemic stroke worsened the outcome with the reduction of neurite and proliferative endothelial cells.Furthermore,Rac1 inhibition reduced the activation of p21-activated kinase 1,the protein level of brain-derived neurotrophic factor,and increased the protein level of glial fibrillary acidic protein in the ischemic brain on day 28 after stroke.Our work provided insight into the mechanisms behind the diminished plasticity after cerebral ischemia in aged brains and identified Rac1 as a potential therapeutic target for improving functional recovery in the older adults after stroke.
文摘The“gut-skin”axis has been proved and is considered as a novel therapy for the prevention of skin aging.The antioxidant efficacy of oligomannonic acid(MAOS)makes it an intriguing target for use to improve skin aging.The present study further explored whereby MAOS-mediated gut-skin axis balance prevented skin aging in mice.The data indicated the skin aging phenotypes,oxidative stress,skin mitochondrial dysfunction,and intestinal dysbiosis(especially the butyrate and HIF-1a levels decreased)in aging mice.Similarly,fecal microbiota transplantation(FMT)from aging mice rebuild the aging-like phenotypes.Further,we demonstrated MAOS-mediated colonic butyrate-HIF-1a axis homeostasis promoted the entry of butyrate into the skin,upregulated mitophagy level and ultimately improving skin aging via HDAC3/PHD/HIF-1a/mitophagy loop in skin of mice.Overall,our study offered a better insights of the effectiveness of alginate oligosaccharides(AOS),promised to become a personalized targeted therapeutic agents,on gut-skin axis disorder inducing skin aging.
基金supported by the Young Elite Scientist Sponsorship Program by CAST(2022QNRC001)the 111 project of the Education Ministry of China(B18053).
文摘Pulmonary fibrosis(PF)is a lethal lung disease that predominantly affects older adults;however,whether and how aging triggers fibrosis remains unclear.To pinpoint the predominant initiating factors of PF,we first analyzed single-cell RNA sequencing(scRNA-seq)data from the lung tissues of 45 normal donors and 51 PF patients and found that aging might serve as the primary catalyst for PF development.To further investigate the influence of aging on PF formation,we conducted a comprehensive and thorough study employing a natural aging mouse model.We found that dynamic alterations in the quantity and types of collagen fibers during aging-induced PF progression,especially in collagenous(Col)I,emerged as the predominant driver of PF.We then investigated the regulation of Col I synthesis during aging using primary alveolar type 2(AT2)cells and A549 cells line through conditioned media and Transwell cocul-ture,and found that secretions—particularly plasminogen activator inhibitor(PAI)-1—from aged AT2 cells promoted fibrosis and enhanced collagen type I alpha 1(Col1al)production via the transforming growth factor(TGF)-b/small mother against decapentaplegic(Smad)2/3 pathway.Furthermore,scRNA-seq and a histological analysis of human lung tissue demonstrated a significant upregulation of SERPINE1(the gene encoding PAI-1)and PAI-1 expression in both aging lung tissue and AT2 cells,which was consistent with our findings from animal experiments,providing additional evidence for the pivotal role of PAI-1 during aging and the development of PF.Our research demonstrates that PAI-1,a crucial factor secreted by aging AT2 cells,exerts a pivotal role in promoting the synthesis of Col1a1 in fibroblasts,subsequently leading to Col I deposition,and in driving the progression of PF by mediating the TGF-b/Smad2/3 pathway.Our find-ings offer critical evidence for the involvement of epithelial dysfunction in age-related PF and provides potential novel therapeutic targets for clinical intervention.
文摘Introduction: Infant and child mortality is a worldwide concern, but developing countries such as Mali are more affected. The aim of this study was to investigate morbidity and factors associated with mortality in children aged 1 month to 15 years. Methodology: This was a cross-sectional study which took place from January 1 to December 31, 2020 covering children aged 1 month to 15 years hospitalized at the Kalaban-Coro CSRéf. Data were entered into Excel and analyzed using SPSS version 20 software. Results: Five hundred children aged 1 months to 15 years were included. The age range 1 to 5 years (53.6%) and male sex (58.2%) were the most represented. Malaria (72.2%), acute respiratory infections (6.2%) and diarrhea/dehydration (3%) were the main morbidities. Mortality was estimated at 10.6%, and the two main causes of death were malaria (56.6%) and acute respiratory infections (7.54%). Univariate analysis revealed a statistically significant association between the dependent variable (death) and age (p Conclusion: This study confirms the high rate of infant and child morbidity and mortality in our health facilities. Strengthening human resources and intensifying behavior-change communication can help reverse the trend.
