AIM:This study aims to investigate the mechanisms underlying skeletal muscle mitochondrial damage associated with decline in exercise function during high-altitude de-adaptation,using a mouse model.METHODS:Twen-ty-four healthy male C57BL/6J mice were randomly assigned to two groups:a high-altitude de-adaptation group and a plain control group.The model group was exposed to a low-pressure,low-oxygen chamber simulating an altitude of 7 000 meters for two weeks,followed by eight days of rearing in a plain environment.The control group was maintained in a plain envi-ronment for the same duration.Grip strength and pole-climbing tests were conducted on the 1st,3rd,and 5th days post-re-turn to assess muscle strength and motor coordination.Treadmill exercises were performed on the 4th and 8th days to eval-uate exercise endurance.After the treadmill exercise on the 8th day,serum,liver,and skeletal muscle tissues were col-lected.Levels of lactic acid(LA),glucose(GLU),creatine kinase(CK),lactate dehydrogenase(LDH),alanine trans-aminase(ALT),and aspartate aminotransferase(AST)in serum,as well as glycogen levels in the liver and muscle,were analyzed.Additionally,the expression of proteins related to mitochondrial biogenesis,fission,fusion,and oxidative phos-phorylation in muscle tissues was assessed using Western blot.RESULTS:(1)The model group exhibited significant re-ductions in grip strength,increased pole-climbing T-turn and total times,and decreased total time and distance in the ex-haustion running test.(2)Serum levels of LA,CK,LDH,ALT,and AST were elevated,while GLU levels decreased,and glycogen levels in both the liver and muscle were reduced in the model group following the treadmill exercise.(3)Ab-normal indicators in the model group did not return to normal by the end of the de-adaptation period.(4)Western blot analysis revealed decreased expression of mitochondrial oxidative phosphorylation proteins(ATP6V1A and Mt-CO2)and mitochondrial biogenesis proteins(PGC-1α and FGF21),increased levels of mitochondrial fusion proteins(OPA1 and MFN1),and no significant changes in fission protein expression(FIS1 and DRP1)in muscle tissue from the model group.CONCLUSION:Exercise capacity in mice during the high-altitude de-adaptation period significantly declined,particu-larly in terms of muscle strength,motor coordination,and endurance.This decline is closely associated with abnormal pro-tein expression related to skeletal muscle mitochondrial energy metabolism and production.

AIM:This study aims to investigate the mechanisms underlying skeletal muscle mitochondrial damage associated with decline in exercise function during high-altitude de-adaptation,using a mouse model.METHODS:Twen-ty-four healthy male C57BL/6J mice were randomly assigned to two groups:a high-altitude de-adaptation group and a plain control group.The model group was exposed to a low-pressure,low-oxygen chamber simulating an altitude of 7 000 meters for two weeks,followed by eight days of rearing in a plain environment.The control group was maintained in a plain envi-ronment for the same duration.Grip strength and pole-climbing tests were conducted on the 1st,3rd,and 5th days post-re-turn to assess muscle strength and motor coordination.Treadmill exercises were performed on the 4th and 8th days to eval-uate exercise endurance.After the treadmill exercise on the 8th day,serum,liver,and skeletal muscle tissues were col-lected.Levels of lactic acid(LA),glucose(GLU),creatine kinase(CK),lactate dehydrogenase(LDH),alanine trans-aminase(ALT),and aspartate aminotransferase(AST)in serum,as well as glycogen levels in the liver and muscle,were analyzed.Additionally,the expression of proteins related to mitochondrial biogenesis,fission,fusion,and oxidative phos-phorylation in muscle tissues was assessed using Western blot.RESULTS:(1)The model group exhibited significant re-ductions in grip strength,increased pole-climbing T-turn and total times,and decreased total time and distance in the ex-haustion running test.(2)Serum levels of LA,CK,LDH,ALT,and AST were elevated,while GLU levels decreased,and glycogen levels in both the liver and muscle were reduced in the model group following the treadmill exercise.(3)Ab-normal indicators in the model group did not return to normal by the end of the de-adaptation period.(4)Western blot analysis revealed decreased expression of mitochondrial oxidative phosphorylation proteins(ATP6V1A and Mt-CO2)and mitochondrial biogenesis proteins(PGC-1α and FGF21),increased levels of mitochondrial fusion proteins(OPA1 and MFN1),and no significant changes in fission protein expression(FIS1 and DRP1)in muscle tissue from the model group.CONCLUSION:Exercise capacity in mice during the high-altitude de-adaptation period significantly declined,particu-larly in terms of muscle strength,motor coordination,and endurance.This decline is closely associated with abnormal pro-tein expression related to skeletal muscle mitochondrial energy metabolism and production.

ObjectiveTo explore the activating effects of ten important effective components in seven medicinal and edible substances on human pregnane X receptor （PXR）， including Glycyrrhizae Radix et Rhizoma （liquiritin and glycyrrhizic acid）， Houttuyniae Herba （quercetin and houttuyfonate）， Prunellae Spica （rosmarinic acid）， Cassiae Semen （aurantio-obtusin）， Poria （pachymic acid）， Lilii Bulbus （Lilium brownii saponin and colchicine）， and Lycii Fructus （Lycium barbarum polysaccharide） and screen potentially toxic components. MethodCell counting kit-8 （CCK-8） assay was used to investigate the cytotoxic effect of liquiritin， glycyrrhizic acid， quercetin， houttuyfonate， rosmarinic acid， pachymic acid， aurantio-obtusin， and colchicine （10， 20， and 50 μmol·L^-1）， and L. brownii saponin and L. barbarum polysaccharide （10， 20， and 50 mg·L^-1） on normal human hepatocyte cell line （L02）. The release of lactate dehydrogenase （LDH） in L02 cells after drug treatments was detected by the biochemical analyzer. The apoptosis induced by ten effective components was explored by Hoechst 33342 staining. The secreted luciferase reporter system was used to co-transfect the PXR expression vector and reporter gene vector containing cytochrome P450 3A4 （CYP3A4） transcriptional regulatory region into L02 cells， with 10 μmol·L^-1 rifampicin （RIF） as a positive control. After treated with liquiritin， glycyrrhizic acid， quercetin， houttuyfonate， rosmarinic acid， aurantio-obtusin， pachymic acid， and colchicine （5， 10， and 20 μmol·L^-1） and L. brownii saponin and L. barbarum polysaccharide （5， 10， and 20 mg·L^-1） for 24 h， the cells were tested for secreted luciferase activity. ResultCompared with the control group， colchicine， L. brownii saponin， and quercetin decreased the cell viability （P<0.05， P<0.01）. Compared with the control group， quercetin， rosmarinic acid， glycyrrhizic acid， colchicine， aurantio-obtusin， and pachymic acid increased the release rate of LDH in L02 cells （P<0.05， P<0.01）. The proportion of hyperchromatic nuclei increased gradually after rosmarinic acid， liquiritin， and L. barbarum polysaccharide treatments as compared with the control group （P<0.05， P<0.01）. In terms of co-transfection of pcDNA3.1-PXR and pGLuc-CYP3A4 into L02 cells， compared with the control group， aurantio-obtusin and pachymic acid showed activating effects on PXR （P<0.05）， whereas liquiritin and glycyrrhizic acid showed inhibitory effects （P<0.05）. ConclusionThe findings suggest that when medicinal and edible substances are taken for a long time， attention should be paid to their influence on drug-metabolizing enzymes and possible interactions， so as to improve their safety.

【Objective】 To investigate the establishment of a competitive performance evaluation management program for blood centers to ensure the blood supply. 【Methods】 A competitive performance evaluation system for Blood Donor Service Department of blood centers in eastern Shenzhen was established. The data concerning blood collection after (May to October 2021, the experiment group) and before (the corresponding period in 2020, the control) the launch of evaluation system was compared, including the proportion of total/novel blood donors in fixed donation sites, the donation rate of 400 mL and pre-collection deferral rate; collected units per shift, the average collection volume of staff, and the growth rate of per capita donation; the proportion of first-time/repeated/double-dose platelet apheresis donors; the proportion of transfer-in/transfer-out of red blood cells; the ratio of group to street blood donors. 【Results】 The proportion of total/novel blood donors in fixed donation sites(81.13% vs 75.87%), the donation rate of 400 mL(58.14% vs 57.91%) and pre-collection deferral rate(76.55% vs 65.92%) in the experimental group was higher than that of the control, while the proportion of pre-collection deferral was lower(18.87% vs 24.13%) (P<0.05). Compared by the control, the units collected per shift, the average collection volume of staff and the blood donation per capita at fixed sites in the experiment group increased by 54.29%, 52.21%, and 3.36% (P<0.05). The proportion of first-time platelet donors was greater than that in the control(43.90% vs 19.61%), while the proportion of repeated platelet donors was lower (56.10% vs 80.39%). The proportion of double-dose platelet donors was lower than that in the control(12.62% vs 22.19%) (P<0.05). The amount of red blood cells transfer-in was 0%, lower than 2.38% in the control group(P<0.05), while the amount of red blood cell transfer-out was 1.86%, higher than 0% in the control group (P<0.05). The proportion of group blood donors decreased from 24% to 15.19%, while street blood donors increased from 76% to 84.81% (P<0.05). 【Conclusion】 Proper competitive performance evaluation system can effectively mobilize employee motivation, improve the efficacy of blood collection and internal management, and ensure clinical blood supply.

Objective:To lay a foundation for the continuous improvement of the birth cohort management in the future, and provides references for other hospitals in establishing the birth cohort through sharing the practice, experience and reflection of the establishment and management of the birth cohort of 500, 000 pregnant women.Methods:The present situation and data of the establishment and management of the birth cohort of 500, 000 pregnant women were summarized to describing the practice, experience and reflection.Results:The specific work regarding the establishment and management of the cohort include personnel investment, standards development, implementation process and quality control. Three phases of the management experiences were summarized which including explorative process implementation; standardize project implementation, and quality improvement along with the fast development of the birth cohort. Generally, the attention of leadership was one of the most important factors for the establishment and management of birth cohort in each research site.Conclusions:It is important that comprehensive considerations of factors including the personnel, standards, practical management process, quality control and the attention of leadership plays important role in improving the quality and efficiency of birth cohort establishment and management.

Doxorubicin (DOX) is a highly effective chemotherapeutic agent; however, the dose-dependent cardiotoxicity associated with DOX significantly limits its clinical application. In the present study, we investigated whether Rb1 could prevent DOX-induced apoptosis in H9C2 cells via aryl hydrocarbon receptor (AhR). H9C2 cells were treated with various concentrations (−μM) of Rb1. AhR, CYP1A protein and mRNA expression were quantified with Western blot and real-time PCR analyses. We also evaluated the expression levels of caspase-3 to assess the anti-apoptotic effects of Rb1. Our results showed that Rb1 attenuated DOX-induced cardiomyocytes injury and apoptosis and reduced caspase-3 and caspase-8, but not caspase-9 activity in DOX-treated H9C2 cells. Meanwhile, pre-treatment with Rb1 decreased the expression of caspase-3 and PARP in the protein levels, with no effects on cytochrome c, Bax, and Bcl-2 in DOX-stimulated cells. Rb1 markedly decreased the CYP1A1 and CYP1A2 expression induced by DOX. Furthermore, transfection with AhR siRNA or pre-treatment with AhR antagonist CH-223191 significantly inhibited the ability of Rb1 to decrease the induction of CYP1A, as well as caspase-3 protein levels following stimulation with DOX. In conclusion, these findings indicate that AhR plays an important role in the protection of Ginsenoside Rb1 against DOX-triggered apoptosis of H9C2 cells.
Apoptosis* ; Blotting, Western ; Cardiotoxicity ; Caspase 3 ; Caspase 8 ; Caspase 9 ; Cytochrome P-450 CYP1A1 ; Cytochrome P-450 CYP1A2 ; Cytochromes c ; Doxorubicin ; Myocytes, Cardiac ; Real-Time Polymerase Chain Reaction ; Receptors, Aryl Hydrocarbon* ; RNA, Messenger ; RNA, Small Interfering ; Transfection

Tanshinone IIA (Tan IIA) is a pharmacologically active substance extracted from the rhizome of Salvia miltiorrhiza Bunge (also known as the Chinese herb Danshen), and is widely used to treat atherosclerosis. The pregnane X receptor (PXR) is a nuclear receptor that is a key regulator of xenobiotic and endobiotic detoxification. Tan IIA is an efficacious PXR agonist that has a potential protective effect on endothelial injuries induced by xenobiotics and endobiotics via PXR activation. Previously numerous studies have demonstrated the possible effects of Tan IIA on human umbilical vein endothelial cells, but the further mechanism for its exerts the protective effect is not well established. To study the protective effects of Tan IIA against hydrogen peroxide (H₂O₂) in human umbilical vein endothelial cells (HUVECs), we pretreated cells with or without different concentrations of Tan IIA for 24 h, then exposed the cells to 400 μM H₂O₂ for another 3 h. Therefore, our data strongly suggests that Tan IIA may lead to increased regeneration of glutathione (GSH) from the glutathione disulfide (GSSG) produced during the GSH peroxidase-catalyzed decomposition of H₂O₂ in HUVECs, and the PXR plays a significant role in this process. Tan IIA may also exert protective effects against H₂O₂-induced apoptosis through the mitochondrial apoptosis pathway associated with the participation of PXR. Tan IIA protected HUVECs from inflammatory mediators triggered by H₂O₂ via PXR activation. In conclusion, Tan IIA protected HUVECs against H₂O₂-induced cell injury through PXR-dependent mechanisms.
Apoptosis ; Asian Continental Ancestry Group ; Atherosclerosis ; Endothelial Cells* ; Glutathione ; Glutathione Disulfide ; Human Umbilical Vein Endothelial Cells ; Humans ; Hydrogen Peroxide ; Inflammation ; Oxidative Stress ; Regeneration ; Rhizome ; Salvia miltiorrhiza ; Triacetoneamine-N-Oxyl ; Xenobiotics

OBJECTIVE To study the cardiotoxicity of ophiopogonin D′(OPD′) for rat H9c2 cardio? myocytes. METHODS H9c2 cells were exposed to OPD′ 0.1, 1, 5, 10, 20, 25 and 50 μmol·L-1 for 24 h. Cell viability was examined by MTS assay, and the morphological changes in H9c2 cells were quanti? fied. The cell nucleus injury was examined by high content immune fluorescence screening and the morphological changes were observed under a fluorescence microscope. After treatment with OPD′ 0.1, 1, 5 and 10 μmol·L- 1 for 24 h, the effect on reactive oxygen species (ROS), mitochondrial mem? brane potential(MMP) and apoptosis was detected by flow cytometry. RESULTS The viability was sig? nificantly reduced following exposure to OPD′ 0.1, 1, 5, 10, 20, 25 and 50 μmol·L- 1 (P<0.05,P<0.01). The IC50 value was 9.9 μmol ·L- 1 and cell shrinkage and apoptosis occurred. The levels of ROS and apoptosis rate of H9c2 cells were significantly increased after exposure to OPD′ 0.1, 1, 5 and 10 μmol·L-1 for 24 h (P<0.05,P<0.01) and MMP markedly declined (P<0.05,P<0.01). CONCLUSION OPD′ has significent cytotoxicity on H9c2 cells. It may be related to inducing apopotsis pathways.

OBJECTIVE To investigate the hepatotoxicity mechanisms of ethanol extract of Radix Polygoni Multiflori (RPM) and Radix Polygoni Multiflori Praeparata (RPMP) by high-content screen assay.METHODS HepG2 cells were treated with RPM (10,25,50,100,200 and 300 mg·L-1) and RPMP (10,50,100,300,600 and 1200 mg· L-1) for 3-24 h,respectively.The cell viability was detected by a CellTiter-GloTM luminescent cell viability assay kit.Cell count,reactive oxygen species (ROS),mitochondrial membrane potential (MMP),glutathione (GSH),superoxide dismutase 2 (SOD2),activating transcription factor 4 (ATF4),apoptosis,and cell cycles were investigated by high-content screen assay.Besides,SOD2 and ATF4 levels were confirmed by Western blotting.RESULTS RPM 300 mg· L-1 showed nearly 48 ％ reduction in cell viability compared with cell control (P＜0.01),while RPMP had no significant effect at the same concentration.Both RPM and RPMP decreased the level of MMP (P＜0.05) but incresed levels of GSH,ROS,SOD2 and ATF4 significantly (P＜0.05).Besides,RPM 200 mg· L-1 significantly increased the expression of SOD2 (P＜0.05) at 3 h by high-content screen assay,and the enhanced expression of ATF4 was shown at 6 h (P＜0.05).RPMP 300 mg· L-1 markedly increased the expression of ATF4 at 6 h (P＜0.05),while the expression of SOD2 significantly increased at 24 h (P＜0.05).CONCLUSION Both RPM and RPMP have some cytotoxicity,and the cytotoxicity of RPM is stronger than that of RPMP.The hepatotoxicity mechanisms of RPM and RPMP may be related to cell apoptosis caused by long-term oxidative stress and endoplasmic reticulum stress.