AIM To clarify the mechanisms involved in the critical endoplasmic reticulum(ER) stress initiating unfolded protein response pathway modified by melatonin.METHODS Hepatoma cells, Hep G2, were cultured in vitro. Flow c...AIM To clarify the mechanisms involved in the critical endoplasmic reticulum(ER) stress initiating unfolded protein response pathway modified by melatonin.METHODS Hepatoma cells, Hep G2, were cultured in vitro. Flow cytometry and TUNEL assay were used to measure Hep G2 cell apoptosis. Western blotting and quantitative reverse transcription-polymerase chain reaction methods were used to determine the protein and messenger RNA levels of ER stress and apoptosis related genes' expression, respectively. Tissue microarray construction from patients was verified by immunohistochemical analysis.RESULTS In the present study, we first identified that melatoninselectively blocked activating transcription factor 6(ATF-6) and then inhibited cyclooxygenase-2 (COX-2) expression, leading to enhanced liver cancer cell apoptosis under ER stress condition. Dramatically increased CCAAT-enhancer-binding protein homologous protein level, suppressed COX-2 and decreased Bcl-2/Bax ratio by melatonin or ATF-6 si RNA contributed the enhanced Hep G2 cell apoptosis under tunicamycin (an ER stress inducer) stimulation. In clinical hepatocellular carcinoma patients, the close relationship between ATF-6 and COX-2 was further confirmed.CONCLUSION These findings indicate that melatonin as a novel selective ATF-6 inhibitor can sensitize human hepatoma cells to ER stress inducing apoptosis.展开更多
To evaluate blood concentration of melatonin and urinary excretion of its metabolite, 6-sulfatoxymelatonin （6-OHMS）, in functional dyspepsia （FD）. METHODS： Ninety individuals were enrolled in the study： 30 in ea...To evaluate blood concentration of melatonin and urinary excretion of its metabolite, 6-sulfatoxymelatonin （6-OHMS）, in functional dyspepsia （FD）. METHODS： Ninety individuals were enrolled in the study： 30 in each study group： patients with postprandial distress syndrome （PDS）, epigastric pain syndrome （EPS）, and controls. Blood samples were drawn at 02：00 and 09：00 h and 24-h urine collection was performed. Serum melatonin and urinary 6-OHMS concentrations were measured by enzyme-linked immunosorbent assay. RESULTS： Serum melatonin concentration at night and in the morning was significantly （P 〈 0.001） higher inPDS patients [at 02：00 h-93.3 pg/mL, quartile range （QR）： 79.8-116.2; at 09.00 h-14.3 pg/mL, QR： 7.06-19.0] than in EPS （57.2 pg/mL, QR： 42.6-73.1, 8.1 pg/mL, QR： 4.2-9.3） and control patients （57.7 pg/mL, QR： 51.2-62.5; 8.1 pg/mL, QR： 5.4-10.3）. A similar relationship was observed for urinary 6-OHMS excretion. Patients with severe PDS symptoms had a higher melatonin concentration than these with moderate syndromes, whereas patients with severe EPS had a lower urinary 6-OHMS excretion than patients with moderate symptoms.CONCLUSION： Evaluation of melatonin serum concentrations and 24-h urinary 6-OHMS excretion are useful methods for differential diagnosis of various clinical forms of FD.展开更多
Normal spermatogenic processes require the scrotal temperature to be lower than that of the body as excessive heat affects spermatogenesis in the testes,reduces sperm quality and quantity,and even causes infertility.E...Normal spermatogenic processes require the scrotal temperature to be lower than that of the body as excessive heat affects spermatogenesis in the testes,reduces sperm quality and quantity,and even causes infertility.Endoplasmic reticulum stress(ERS)is a crucial factor in many pathologies.Although several studies have linked ERS to heat stress,researchers have not yet determined which ERS signaling pathways contribute to heat-induced testicular damage.Melatonin activates antioxidant enzymes,scavenges free radicals,and protects the testes from inflammation;however,few studies have reported on the influence of melatonin on heat-induced testicular damage.Using a murine model of testicular hyperthermia,we observed that heat stress causes both ERS and apoptosis in the testes,especially in the spermatocytes.These observations were confirmed using the mouse spermatocyte cell line GC2,where the Atf6 and Perk signaling pathways were activated during heat stress.Knockout of the above genes effectively reduced spermatocyte damage caused by heat stress.Pretreatment with melatonin alleviated heat-induced apoptosis by inhibiting the Atf6 and Perk signaling pathways.This mitigation was dependent on the melatonin receptors.In vivo experiments verified that melatonin treatment relieved heat-induced testicular damage.In conclusion,our results demonstrated that ATF6 and PERK are important mediators for heat-induced apoptosis,which can be prevented by melatonin treatment.Thus,our study highlights melatonin as a potential therapeutic agent in mammals for subfertility/infertility induced by testicular hyperthermia.展开更多
Vascular calcification and vascular ageing are“silent”diseases but are highly prevalent in patients with end stage renal failure and type 2 diabetes,as well as in the ageing population.Melatonin(MT)has been shown to...Vascular calcification and vascular ageing are“silent”diseases but are highly prevalent in patients with end stage renal failure and type 2 diabetes,as well as in the ageing population.Melatonin(MT)has been shown to induce cardiovascular protection effects.However,the role of MT on vascular calcification and ageing has not been well-identified.In this study,the aortic transcriptional landscape revealed clues for MT related cell-to-cell communication between endothelial cells(ECs)and vascular smooth muscle cells(VSMCs)in vascular calcification and vascular ageing.Furthermore,we elucidated that it was exosomes that participate in the information transportation from ECs to VSMCs.The exosomes secreted from melatonin-treated ECs(MT-ECs-Exos)inhibited calcification and senescence of VSMCs.Mechanistically,miR-302d-5p was highly enriched in MT-ECs-Exos,while depletion of miR-302d-5p blocked the ability of MT-ECs-Exos to suppress VSMC calcification and senescence.Notably,Wnt3 was a bona fide target of miR-302d-5p and modulated VSMC calcification and senescence.Furthermore,we found that maturation of endothelial derived exosomal miR-302d-5p was promoted by WTAP in an N^(6)-methyladenosine(m^(6)A)-dependent manner.Interestingly,MT alleviated vascular calcification and ageing in 5/6-nephrectomy(5/6 NTP)mice,a chronic kidney disease(CKD)induced vascular calcification and vascular ageing mouse model.MT-ECs-Exos was absorbed by VSMCs in vivo and effectively prevented vascular calcification and ageing in 5/6 NTP mice.ECs-derived miR-302d-5p mediated MT induced anti-calcification and anti-ageing effects in 5/6 NTP mice.Our study suggests that MT-ECs-Exos alleviate vascular calcification and ageing through the miR-302d-5p/Wnt3 signaling pathway,dependent on m^(6)A methylation.展开更多
Background:It is imperative to identify potential biomarkers for early diagnosis and intervention of severe sepsis.This study investigated the relationship between melatonin secretion and outcome of sepsis after 28-da...Background:It is imperative to identify potential biomarkers for early diagnosis and intervention of severe sepsis.This study investigated the relationship between melatonin secretion and outcome of sepsis after 28-day admission.Methods:Patients with sepsis were randomly divided into an eye mask group and a control group.Blood and urine samples were collected from day 0 to 4.Relevant clinical data and 28-day survival data were obtained.Serum melatonin and urine 6-hydroxy sulfate melatonin(6-SMT)levels were measured.Results:The outcome of sepsis did not differ between the eye mask and control groups.Acute Physiology and Chronic Health Evaluation(APACHE)II and Sequential Organ Failure Assessment(SOFA)scores were significantly higher and monocyte human leukocyte antigen-DR(mHLA-DR),serum melatonin,nocturnal urine 6-SMT,and 24-hour urine 6-SMT levels were significantly lower in the nonsurvivors than in the survivors.The outcome at day 28 after admission was significantly associated with APACHE II and SOFA scores and mHLA-DR,nocturnal urine 6-SMT,and 24-hour urine 6-SMT levels.The areas under the receiver operating characteristic curve were 0.785,0.740,0.774,and 0.858 for APACHE II score,SOFA score,mHLA-DR expression,and nocturnal urine 6-SMT amount,respectively.The optimal thresholds for mHLA-DR and nocturnal urine 6-SMT were 30.13%and 43.60%,respectively.Nocturnal urine 6-SMT level was significantly and positively correlated with mHLA-DR expression.Conclusion:Nocturnal urine 6-SMT level may be a feasible biomarker to predict the outcome of patients with sepsis.The use of a night-time eye mask has no significant effect on the outcome of sepsis.Clinical trials:This study was registered at clinicaltrials.gov(NCT02304224).展开更多
基金grants from the National Natural Science Foundation of China,No.81572430 and No.81272739
文摘AIM To clarify the mechanisms involved in the critical endoplasmic reticulum(ER) stress initiating unfolded protein response pathway modified by melatonin.METHODS Hepatoma cells, Hep G2, were cultured in vitro. Flow cytometry and TUNEL assay were used to measure Hep G2 cell apoptosis. Western blotting and quantitative reverse transcription-polymerase chain reaction methods were used to determine the protein and messenger RNA levels of ER stress and apoptosis related genes' expression, respectively. Tissue microarray construction from patients was verified by immunohistochemical analysis.RESULTS In the present study, we first identified that melatoninselectively blocked activating transcription factor 6(ATF-6) and then inhibited cyclooxygenase-2 (COX-2) expression, leading to enhanced liver cancer cell apoptosis under ER stress condition. Dramatically increased CCAAT-enhancer-binding protein homologous protein level, suppressed COX-2 and decreased Bcl-2/Bax ratio by melatonin or ATF-6 si RNA contributed the enhanced Hep G2 cell apoptosis under tunicamycin (an ER stress inducer) stimulation. In clinical hepatocellular carcinoma patients, the close relationship between ATF-6 and COX-2 was further confirmed.CONCLUSION These findings indicate that melatonin as a novel selective ATF-6 inhibitor can sensitize human hepatoma cells to ER stress inducing apoptosis.
基金Supported by The Ministry of Science and Higher Education of Poland,project NN 402481937
文摘To evaluate blood concentration of melatonin and urinary excretion of its metabolite, 6-sulfatoxymelatonin （6-OHMS）, in functional dyspepsia （FD）. METHODS： Ninety individuals were enrolled in the study： 30 in each study group： patients with postprandial distress syndrome （PDS）, epigastric pain syndrome （EPS）, and controls. Blood samples were drawn at 02：00 and 09：00 h and 24-h urine collection was performed. Serum melatonin and urinary 6-OHMS concentrations were measured by enzyme-linked immunosorbent assay. RESULTS： Serum melatonin concentration at night and in the morning was significantly （P 〈 0.001） higher inPDS patients [at 02：00 h-93.3 pg/mL, quartile range （QR）： 79.8-116.2; at 09.00 h-14.3 pg/mL, QR： 7.06-19.0] than in EPS （57.2 pg/mL, QR： 42.6-73.1, 8.1 pg/mL, QR： 4.2-9.3） and control patients （57.7 pg/mL, QR： 51.2-62.5; 8.1 pg/mL, QR： 5.4-10.3）. A similar relationship was observed for urinary 6-OHMS excretion. Patients with severe PDS symptoms had a higher melatonin concentration than these with moderate syndromes, whereas patients with severe EPS had a lower urinary 6-OHMS excretion than patients with moderate symptoms.CONCLUSION： Evaluation of melatonin serum concentrations and 24-h urinary 6-OHMS excretion are useful methods for differential diagnosis of various clinical forms of FD.
基金supported by the National Natural Science Foundation of China(32072815)General Project of the Key R&D Plan of Shaanxi Province(2019NY-091)+1 种基金Program of Shaanxi Province Science and Technology Innovation Team(2019TD-036)Fundamental Research Funds for the Central Universities(2452020157)。
文摘Normal spermatogenic processes require the scrotal temperature to be lower than that of the body as excessive heat affects spermatogenesis in the testes,reduces sperm quality and quantity,and even causes infertility.Endoplasmic reticulum stress(ERS)is a crucial factor in many pathologies.Although several studies have linked ERS to heat stress,researchers have not yet determined which ERS signaling pathways contribute to heat-induced testicular damage.Melatonin activates antioxidant enzymes,scavenges free radicals,and protects the testes from inflammation;however,few studies have reported on the influence of melatonin on heat-induced testicular damage.Using a murine model of testicular hyperthermia,we observed that heat stress causes both ERS and apoptosis in the testes,especially in the spermatocytes.These observations were confirmed using the mouse spermatocyte cell line GC2,where the Atf6 and Perk signaling pathways were activated during heat stress.Knockout of the above genes effectively reduced spermatocyte damage caused by heat stress.Pretreatment with melatonin alleviated heat-induced apoptosis by inhibiting the Atf6 and Perk signaling pathways.This mitigation was dependent on the melatonin receptors.In vivo experiments verified that melatonin treatment relieved heat-induced testicular damage.In conclusion,our results demonstrated that ATF6 and PERK are important mediators for heat-induced apoptosis,which can be prevented by melatonin treatment.Thus,our study highlights melatonin as a potential therapeutic agent in mammals for subfertility/infertility induced by testicular hyperthermia.
基金supported by National Key Research&Development Program(No.2021YFC2501701 to LQY and FX)the National Natural Science Foundation of China(No.82370892 and 82070910 to LQY,No.82100494 to FX,No.82100944 and No.82470927 to XL,No.82200869 to FW)+3 种基金National Clinical Key Specialties Main Research Projects(2023026 to LQY)the Natural Science Foundation of Hunan Province(No.2022JJ40721 to FX)the Health Research Project in Hunan Province(No.20231696 to XL)the Scientific Research Launch Project for new employees of the Second Xiangya Hospital of Central South University(No.7673 to FX).
文摘Vascular calcification and vascular ageing are“silent”diseases but are highly prevalent in patients with end stage renal failure and type 2 diabetes,as well as in the ageing population.Melatonin(MT)has been shown to induce cardiovascular protection effects.However,the role of MT on vascular calcification and ageing has not been well-identified.In this study,the aortic transcriptional landscape revealed clues for MT related cell-to-cell communication between endothelial cells(ECs)and vascular smooth muscle cells(VSMCs)in vascular calcification and vascular ageing.Furthermore,we elucidated that it was exosomes that participate in the information transportation from ECs to VSMCs.The exosomes secreted from melatonin-treated ECs(MT-ECs-Exos)inhibited calcification and senescence of VSMCs.Mechanistically,miR-302d-5p was highly enriched in MT-ECs-Exos,while depletion of miR-302d-5p blocked the ability of MT-ECs-Exos to suppress VSMC calcification and senescence.Notably,Wnt3 was a bona fide target of miR-302d-5p and modulated VSMC calcification and senescence.Furthermore,we found that maturation of endothelial derived exosomal miR-302d-5p was promoted by WTAP in an N^(6)-methyladenosine(m^(6)A)-dependent manner.Interestingly,MT alleviated vascular calcification and ageing in 5/6-nephrectomy(5/6 NTP)mice,a chronic kidney disease(CKD)induced vascular calcification and vascular ageing mouse model.MT-ECs-Exos was absorbed by VSMCs in vivo and effectively prevented vascular calcification and ageing in 5/6 NTP mice.ECs-derived miR-302d-5p mediated MT induced anti-calcification and anti-ageing effects in 5/6 NTP mice.Our study suggests that MT-ECs-Exos alleviate vascular calcification and ageing through the miR-302d-5p/Wnt3 signaling pathway,dependent on m^(6)A methylation.
基金funded by the National Natural Science Foundation of China(No.81000024).
文摘Background:It is imperative to identify potential biomarkers for early diagnosis and intervention of severe sepsis.This study investigated the relationship between melatonin secretion and outcome of sepsis after 28-day admission.Methods:Patients with sepsis were randomly divided into an eye mask group and a control group.Blood and urine samples were collected from day 0 to 4.Relevant clinical data and 28-day survival data were obtained.Serum melatonin and urine 6-hydroxy sulfate melatonin(6-SMT)levels were measured.Results:The outcome of sepsis did not differ between the eye mask and control groups.Acute Physiology and Chronic Health Evaluation(APACHE)II and Sequential Organ Failure Assessment(SOFA)scores were significantly higher and monocyte human leukocyte antigen-DR(mHLA-DR),serum melatonin,nocturnal urine 6-SMT,and 24-hour urine 6-SMT levels were significantly lower in the nonsurvivors than in the survivors.The outcome at day 28 after admission was significantly associated with APACHE II and SOFA scores and mHLA-DR,nocturnal urine 6-SMT,and 24-hour urine 6-SMT levels.The areas under the receiver operating characteristic curve were 0.785,0.740,0.774,and 0.858 for APACHE II score,SOFA score,mHLA-DR expression,and nocturnal urine 6-SMT amount,respectively.The optimal thresholds for mHLA-DR and nocturnal urine 6-SMT were 30.13%and 43.60%,respectively.Nocturnal urine 6-SMT level was significantly and positively correlated with mHLA-DR expression.Conclusion:Nocturnal urine 6-SMT level may be a feasible biomarker to predict the outcome of patients with sepsis.The use of a night-time eye mask has no significant effect on the outcome of sepsis.Clinical trials:This study was registered at clinicaltrials.gov(NCT02304224).
