Tea plant(Camellia sinensis(L.)O.Kuntze)is a cold-sensitive leaf-harvesting crop whose growth,yield,and processed tea quality are all inhibited by low temperatures.Therefore,identifying the regulatory genes involved i...Tea plant(Camellia sinensis(L.)O.Kuntze)is a cold-sensitive leaf-harvesting crop whose growth,yield,and processed tea quality are all inhibited by low temperatures.Therefore,identifying the regulatory genes involved in tea plant growth and freezing tolerance is crucial for genetic improvement.WRKY transcription factors regulate various plant processes,including growth and development,stress responses,and metabolite biosynthesis.However,the molecular network through which WRKY coordinates these pathways in tea plants remains unclear.In this study,we revealed that CsWRKY57L,a cold-inducible WRKY IIc subfamily member,positively regulated freezing tolerance by directly promoting flavonoid accumulation in tea plants.Transient suppression of CsWRKY57L weakened the freezing tolerance of tea plants by reducing flavonoid content and suppressing the C-repeat-binding factor(CBF)-cold-responsive(COR)gene pathway.In contrast,heterologous overexpression of CsWRKY57L in Arabidopsis had the opposite effect.Additionally,overexpression of CsWRKY57L inhibited reproductive development and accelerated senescence in Arabidopsis.Interaction analysis revealed that CsWRKY57L directly binds to the promoters of CsSWEET1a,CsSWEET15,and AtSWEET15,which encode sugar transporters essential for plant reproductive development,and inhibits their transcription.Overall,the study revealed a dual role of CsWRKY57L in promoting freezing tolerance via flavonoid biosynthesis and inhibiting reproductive development by regulating SWEETs expression.This study uncovers a novel mechanism whereby CsWRKY57L coordinately regulates both stress responses and growth in tea plants,providing a molecular basis for breeding low-temperature-tolerant varieties with restricted reproductive development.展开更多
Objective This study aimed to comprehensively investigate the potential protective effects and underlying mechanisms of taurine against dihydrotestosterone(DHT)-induced androgenetic alopecia(AGA)in male C57BL/6 mice,w...Objective This study aimed to comprehensively investigate the potential protective effects and underlying mechanisms of taurine against dihydrotestosterone(DHT)-induced androgenetic alopecia(AGA)in male C57BL/6 mice,with a focus on hair follicle cycle modulation,cellular proliferation/apoptosis,and key related signaling pathways.Methods Six-week-old female C57BL/6 mice were initially used to assess the hair growth-promoting potential of taurine.After acclimatization,they were randomly assigned to three groups(n=8):control(regular drinking water),taurine(drinking water containing 1%taurine),and minoxidil(topical 2%minoxidil,positive control).For the AGA study,male C57BL/6 mice were randomly divided into five groups(n=8):control(physiological saline),DHT(model group,1 mg/d DHT),DHT+low-dose taurine(1 mg/d DHT+2 mg/d taurine),DHT+high-dose taurine(1 mg/d DHT+10 mg/d taurine),and DHT+minoxidil(positive control,1 mg/d DHT+topical 2%minoxidil).One day before treatment initiation,dorsal hair was shaved with scissors,and residual hair was removed using a depilatory cream.DHT and taurine were administered via daily intraperitoneal injection.Hair regrowth was assessed by photographing the depilated area at regular intervals and quantified using a four-point grading system(0-3).Dorsal skin samples were collected on day 14 for histological analysis(H&E staining),immunofluorescence staining(Ki67 for proliferation,TUNEL for apoptosis),ELISA(DHT quantification),RT-qPCR,and Western blot analysis to evaluate the expression of key genes and proteins(androgen receptor(AR),transforming growth factor(TGF)‑β1,TGF‑β2,Dickkopf-1(DKK1)).Results In female mice,taurine supplementation significantly accelerated hair growth,with effects comparable to minoxidil.This was evidenced by an earlier transition from pink(telogen)to black(anagen)skin and increased hair growth scores.Histological analysis showed that taurine increased hair follicle count and dermal thickness.Immunofluorescence confirmed enhanced keratinocyte proliferation in the hair matrix.In the DHTinduced AGA model,DHT significantly extended the telogen phase,inhibited hair growth,increased skin DHT content,and induced hair follicle miniaturization.Taurine treatment,particularly at the high dose,effectively counteracted these effects:it promoted the telogen-to-anagen transition and improved hair growth scores.Histomorphometric analysis showed that taurine significantly restored DHT-induced reductions in dermal thickness,hair follicle count,hair bulb depth,and follicle size.Taurine treatment also reduced apoptosis and promoted the proliferation of hair follicle cells,as demonstrated by Ki67 and TUNEL assays.Crucially,RT-qPCR and Western blot analyses revealed that DHT significantly up-regulated the expression of AR,TGF‑β1,TGF‑β2,and DKK1 at both mRNA and protein levels in dorsal skin.Taurine administration markedly down-regulated the expression of these pathogenic factors,bringing them closer to the levels observed in the control group.Conclusion Taurine demonstrates significant efficacy in alleviating DHT-induced AGA in male C57BL/6 mice.Its protective effects are mediated through multi-faceted mechanisms.(1)Promoting hair follicle cycle progression:it accelerates the transition from telogen to anagen,counteracting DHT-induced prolongation of the telogen phase.(2)Modulating cellular dynamics:it stimulates the proliferation of hair matrix keratinocytes and reduces DHT-induced apoptosis within hair follicle cells.(3)Suppressing androgen-driven pathogenic pathways:it downregulates the expression of critical molecules in the AGA pathway,including AR,the cytokines TGF-β1 and TGF-β2,and the Wnt pathway inhibitor DKK1.Given its favorable safety profile and multi-targeted action,taurine emerges as a promising novel therapeutic candidate or adjunct for treating AGA.Further investigation into its clinical potential and precise molecular mechanisms is warranted.This study provides a robust preclinical foundation for considering taurine supplementation or topical application in hair loss management strategies.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.32072630,32372774,and U22A20499)the earmarked fund for CARS(Grant No.CARS-19-01A).
文摘Tea plant(Camellia sinensis(L.)O.Kuntze)is a cold-sensitive leaf-harvesting crop whose growth,yield,and processed tea quality are all inhibited by low temperatures.Therefore,identifying the regulatory genes involved in tea plant growth and freezing tolerance is crucial for genetic improvement.WRKY transcription factors regulate various plant processes,including growth and development,stress responses,and metabolite biosynthesis.However,the molecular network through which WRKY coordinates these pathways in tea plants remains unclear.In this study,we revealed that CsWRKY57L,a cold-inducible WRKY IIc subfamily member,positively regulated freezing tolerance by directly promoting flavonoid accumulation in tea plants.Transient suppression of CsWRKY57L weakened the freezing tolerance of tea plants by reducing flavonoid content and suppressing the C-repeat-binding factor(CBF)-cold-responsive(COR)gene pathway.In contrast,heterologous overexpression of CsWRKY57L in Arabidopsis had the opposite effect.Additionally,overexpression of CsWRKY57L inhibited reproductive development and accelerated senescence in Arabidopsis.Interaction analysis revealed that CsWRKY57L directly binds to the promoters of CsSWEET1a,CsSWEET15,and AtSWEET15,which encode sugar transporters essential for plant reproductive development,and inhibits their transcription.Overall,the study revealed a dual role of CsWRKY57L in promoting freezing tolerance via flavonoid biosynthesis and inhibiting reproductive development by regulating SWEETs expression.This study uncovers a novel mechanism whereby CsWRKY57L coordinately regulates both stress responses and growth in tea plants,providing a molecular basis for breeding low-temperature-tolerant varieties with restricted reproductive development.
基金supported by grants from The National Natural Science Foundation of China(31772690)the Natural Science Foundation of Shanxi Province(201701D121106)PhD Research Startup Foundation of Changzhi Medical College(BS202308)。
文摘Objective This study aimed to comprehensively investigate the potential protective effects and underlying mechanisms of taurine against dihydrotestosterone(DHT)-induced androgenetic alopecia(AGA)in male C57BL/6 mice,with a focus on hair follicle cycle modulation,cellular proliferation/apoptosis,and key related signaling pathways.Methods Six-week-old female C57BL/6 mice were initially used to assess the hair growth-promoting potential of taurine.After acclimatization,they were randomly assigned to three groups(n=8):control(regular drinking water),taurine(drinking water containing 1%taurine),and minoxidil(topical 2%minoxidil,positive control).For the AGA study,male C57BL/6 mice were randomly divided into five groups(n=8):control(physiological saline),DHT(model group,1 mg/d DHT),DHT+low-dose taurine(1 mg/d DHT+2 mg/d taurine),DHT+high-dose taurine(1 mg/d DHT+10 mg/d taurine),and DHT+minoxidil(positive control,1 mg/d DHT+topical 2%minoxidil).One day before treatment initiation,dorsal hair was shaved with scissors,and residual hair was removed using a depilatory cream.DHT and taurine were administered via daily intraperitoneal injection.Hair regrowth was assessed by photographing the depilated area at regular intervals and quantified using a four-point grading system(0-3).Dorsal skin samples were collected on day 14 for histological analysis(H&E staining),immunofluorescence staining(Ki67 for proliferation,TUNEL for apoptosis),ELISA(DHT quantification),RT-qPCR,and Western blot analysis to evaluate the expression of key genes and proteins(androgen receptor(AR),transforming growth factor(TGF)‑β1,TGF‑β2,Dickkopf-1(DKK1)).Results In female mice,taurine supplementation significantly accelerated hair growth,with effects comparable to minoxidil.This was evidenced by an earlier transition from pink(telogen)to black(anagen)skin and increased hair growth scores.Histological analysis showed that taurine increased hair follicle count and dermal thickness.Immunofluorescence confirmed enhanced keratinocyte proliferation in the hair matrix.In the DHTinduced AGA model,DHT significantly extended the telogen phase,inhibited hair growth,increased skin DHT content,and induced hair follicle miniaturization.Taurine treatment,particularly at the high dose,effectively counteracted these effects:it promoted the telogen-to-anagen transition and improved hair growth scores.Histomorphometric analysis showed that taurine significantly restored DHT-induced reductions in dermal thickness,hair follicle count,hair bulb depth,and follicle size.Taurine treatment also reduced apoptosis and promoted the proliferation of hair follicle cells,as demonstrated by Ki67 and TUNEL assays.Crucially,RT-qPCR and Western blot analyses revealed that DHT significantly up-regulated the expression of AR,TGF‑β1,TGF‑β2,and DKK1 at both mRNA and protein levels in dorsal skin.Taurine administration markedly down-regulated the expression of these pathogenic factors,bringing them closer to the levels observed in the control group.Conclusion Taurine demonstrates significant efficacy in alleviating DHT-induced AGA in male C57BL/6 mice.Its protective effects are mediated through multi-faceted mechanisms.(1)Promoting hair follicle cycle progression:it accelerates the transition from telogen to anagen,counteracting DHT-induced prolongation of the telogen phase.(2)Modulating cellular dynamics:it stimulates the proliferation of hair matrix keratinocytes and reduces DHT-induced apoptosis within hair follicle cells.(3)Suppressing androgen-driven pathogenic pathways:it downregulates the expression of critical molecules in the AGA pathway,including AR,the cytokines TGF-β1 and TGF-β2,and the Wnt pathway inhibitor DKK1.Given its favorable safety profile and multi-targeted action,taurine emerges as a promising novel therapeutic candidate or adjunct for treating AGA.Further investigation into its clinical potential and precise molecular mechanisms is warranted.This study provides a robust preclinical foundation for considering taurine supplementation or topical application in hair loss management strategies.
