Objective To observe the effect of a heavy load exercise on the ultrastructure,function and fission of skeletal muscle mitochondria in rats,and to analyze the changes of the phosphorylation expression of mitochondrial fission protein and upstream kinase at different times postexercise,and to explore the effect of acute heavy load exercise on mitochondrial fission in skeletal muscle of rats and its possible mechanism.Methods Forty-eight adult male Sprague-Dawley rats were randomly divided in-to a quiet control group(C,n=8)and an exercise group(E,n=40).Rats in the E group exercised on a treadmill down a 16° decline at 16 m/min for 90 min and were further divided into 0 h,12 h,24 h,48 h,and 72 h postexercise subgroups.Soleus muscle was isolated and mitochondria were ex-tracted at the corresponding time points after exercise.The ultrastructure of mitochondria in the soleus muscle was observed using transmission electron microscopy,and mitochondrial quantity and morphomet-ric analysis were conducted.Moreover,the colocalization and quantity of dynamin-related protein 1(Drp1)and cytochrome C oxidease subunit Ⅳ(COXⅣ)in the soleus muscle were detected using im-munofluorescence double-labeling techniques.Meanwhile,protein levels of soleus musclep-Drp1Ser616,p-Drp1Ser637,p-extracellular regulatory protein kinaseThr202/Tyr204(p-ERKThr202/Tyr204),p-protein kinaseAThr197(p-PKAThr197),and mitochondrial NADH of ubiquinone oxidoreductase subunit B8(NDUFB8)and ubiqui-nol-cytochrome C reductase core protein 2(UQCRC2)were determined by using Western blotting.An-other twenty-four rats were randomly divided into a DMSO group(CD),a U0126 group(CU),an Ex-ercise+DMSO group(ED),and an Exercise+U0126 group(EU).Six mice in each group were giv-en a single intra-bitoneal injection of DMSO or ERK inhibitor U0126 20 min before acute downhill running.Then,their phosphorylated expressions of ERKThr202/Tyr204 and Drp1Ser616 in soleus muscle were de-tected by Western blotting.Results(1)From 0 h to 48 h after exercise,the soleus muscle mitochon-dria showed swelling,rounding,and uneven distribution of mitochondria,among which the degree of mitochondrial damage was the most serious at 12 h and 24 h after exercise.Moreover,the protein ex-pression of NDUFB8 and UQCRC2 in the mitochondria fractions from soleus muscle was significantly lower at 12 h post-exercise(P<0.05).(2)The co-localization of Drp1 and COXⅣ in the skeletal muscle increased significantly at 12 h to 24 h after a heavy load exercise compared with group C and group E0(P<0.01).Moreover,the mitochondrial area,circumference,aspect ratio and Ferret diameter in the skeletal muscle were significantly lower at 12 h to 24 h postexercise(P<0.05).Meanwhile,the number of mitochondria was significantly higher at 24 h after exercise(P<0.01).(3)The phosphoryla-tion of ERKThr202/Tyr204,PKAThr197 and Drp1Ser616 was significantly higher at 24 h after exercise(P<0.01),while that of Drp1Ser637 was significantly lower at 48 h and 72 h post-exercise(P<0.01).However,the phosphorylated expressions of ERKThr202/Tyr204 and Drp1Ser616 were significantly down-regulated by U0126 treatment before exercise.Conclusion A session of heavy load exercise caused mitochondrial structure and function damage and induced mitochondrial fission in the skeletal muscle,and then to maintain the homeostasis of skeletal muscle cells by cleaving damaged mitochondria.The mechanism of promot-ing skeletal muscle repair may be related to the positive and negative regulation of Drp1 activity by the phosphorylation of Drp1Ser616 and Drp1Ser637,respectively.Among them,the activation of ERKThr202/Tyr204 mediates the phosphorylation activation of Drp1Ser616,but PKAThr197 is not an upstream kinase that medi-ates the inactivation of Drp1Ser637 phosphorylation.

Objective To observe the effect of a heavy load exercise on the ultrastructure,function and fission of skeletal muscle mitochondria in rats,and to analyze the changes of the phosphorylation expression of mitochondrial fission protein and upstream kinase at different times postexercise,and to explore the effect of acute heavy load exercise on mitochondrial fission in skeletal muscle of rats and its possible mechanism.Methods Forty-eight adult male Sprague-Dawley rats were randomly divided in-to a quiet control group(C,n=8)and an exercise group(E,n=40).Rats in the E group exercised on a treadmill down a 16° decline at 16 m/min for 90 min and were further divided into 0 h,12 h,24 h,48 h,and 72 h postexercise subgroups.Soleus muscle was isolated and mitochondria were ex-tracted at the corresponding time points after exercise.The ultrastructure of mitochondria in the soleus muscle was observed using transmission electron microscopy,and mitochondrial quantity and morphomet-ric analysis were conducted.Moreover,the colocalization and quantity of dynamin-related protein 1(Drp1)and cytochrome C oxidease subunit Ⅳ(COXⅣ)in the soleus muscle were detected using im-munofluorescence double-labeling techniques.Meanwhile,protein levels of soleus musclep-Drp1Ser616,p-Drp1Ser637,p-extracellular regulatory protein kinaseThr202/Tyr204(p-ERKThr202/Tyr204),p-protein kinaseAThr197(p-PKAThr197),and mitochondrial NADH of ubiquinone oxidoreductase subunit B8(NDUFB8)and ubiqui-nol-cytochrome C reductase core protein 2(UQCRC2)were determined by using Western blotting.An-other twenty-four rats were randomly divided into a DMSO group(CD),a U0126 group(CU),an Ex-ercise+DMSO group(ED),and an Exercise+U0126 group(EU).Six mice in each group were giv-en a single intra-bitoneal injection of DMSO or ERK inhibitor U0126 20 min before acute downhill running.Then,their phosphorylated expressions of ERKThr202/Tyr204 and Drp1Ser616 in soleus muscle were de-tected by Western blotting.Results(1)From 0 h to 48 h after exercise,the soleus muscle mitochon-dria showed swelling,rounding,and uneven distribution of mitochondria,among which the degree of mitochondrial damage was the most serious at 12 h and 24 h after exercise.Moreover,the protein ex-pression of NDUFB8 and UQCRC2 in the mitochondria fractions from soleus muscle was significantly lower at 12 h post-exercise(P<0.05).(2)The co-localization of Drp1 and COXⅣ in the skeletal muscle increased significantly at 12 h to 24 h after a heavy load exercise compared with group C and group E0(P<0.01).Moreover,the mitochondrial area,circumference,aspect ratio and Ferret diameter in the skeletal muscle were significantly lower at 12 h to 24 h postexercise(P<0.05).Meanwhile,the number of mitochondria was significantly higher at 24 h after exercise(P<0.01).(3)The phosphoryla-tion of ERKThr202/Tyr204,PKAThr197 and Drp1Ser616 was significantly higher at 24 h after exercise(P<0.01),while that of Drp1Ser637 was significantly lower at 48 h and 72 h post-exercise(P<0.01).However,the phosphorylated expressions of ERKThr202/Tyr204 and Drp1Ser616 were significantly down-regulated by U0126 treatment before exercise.Conclusion A session of heavy load exercise caused mitochondrial structure and function damage and induced mitochondrial fission in the skeletal muscle,and then to maintain the homeostasis of skeletal muscle cells by cleaving damaged mitochondria.The mechanism of promot-ing skeletal muscle repair may be related to the positive and negative regulation of Drp1 activity by the phosphorylation of Drp1Ser616 and Drp1Ser637,respectively.Among them,the activation of ERKThr202/Tyr204 mediates the phosphorylation activation of Drp1Ser616,but PKAThr197 is not an upstream kinase that medi-ates the inactivation of Drp1Ser637 phosphorylation.

Objective To explore the effect of 4-week repetitive downhill treadmill running on the mi-tochondrial structure,function,and autophagy in skeletal muscle of rats,so as to analyze the role of FKBP8-mediated mitophagy in exercise-induced mitochondrial damage in their skeletal muscles.Meth-ods Thirty-two male adult Sprague-Dawley rats were randomly divided into a 2-week quiet control group(2C group,n=8),a 4-week quiet control group(4C group,n=8),a 2-week exercise group(2E group,n=8)and a 4-week exercise group(4E group,n=8).Rats in 2E and 4E groups performed dai-ly 90-minute downhill treadmill running(-16°,16 m/min)5 days a week for two and four weeks,re-spectively.Then,they rested for 24 hours and received an exhaustive exercise test.Running distance and blood lactate were measured prior to and at the time of exercise cessation.Moreover,mitochondri-al ultrastructural changes in soleus muscles were observed by using a transmission electron microscope.The protein expression of mitochondrial succinate dehydrogenase subunit B(SDHB),cytochrome C oxi-dase subunit 1(MTCO1),FK506 binding protein 8(FKBP8)and microtubule associated protein 1 light chain 3(LC3)in the soleus muscle were measured using Western blotting.Meanwhile,the co-localiza-tion of FKBP8 with LC3 and cytochrome C oxidase subunit Ⅳ(COXⅣ)with LC3,lysosomal associat-ed membrane protein 2(LAMP2)were detected by the immunofluorescence double labeling technique.Results(1)The running distance of one exhaustive exercise and the blood lactate before and after the test in 2E group were significantly higher than 2C and 4E groups(P<0.05 or P<0.01),and the run-ning distance of 4E group was significantly higher than 4C group(P<0.01).However,there was no sig-nificant difference between 4E and 4C groups in the blood lactate before and after the exhaustive exer-cise test(P>0.05).(2)In both 2E and 4E groups,significant mitochondrial swelling and accumulation under cell membrane,as well as a number of mitophagosomes and mitophagolysosomes were observed,together with a significant reduce in the number of mitochondria(P<0.05),which was more severe in 2E group than 4E group.(3)The protein expression of mitochondrial SDHB and MTCO1 in 2E and 4E groups were lower than 2C and 4C groups,respectively,with significantly greater changes of these proteins in 4E group than 2E group(P<0.05 or P<0.01).(4)The protein expression of mitochondrial FKBP8 and LC3,as well as the co-localization of FKBP8 with LC3 and COXⅣ with LC3,LAMP2 in 2E and 4E groups were higher than 2C and 4C groups,respectively,with significantly greater changes in 4E group than 2E group(P<0.05 or P<0.01).Conclusion After 4-week downhill treadmill running,the structure,quantity and function of mitochondria in skeletal muscle are impaired.FKBP8-mediated mitophagy is activated,but is insufficient to degrade the damaged mitochondria,leading to muscular damage,as well as the increasing and falling down of running capacity.

Objective To explore the effects of monocular deprivation(MD)on the expression of astrocytes in the superior colliculus,hippocampus,and visual cortex in mice during the critical period of visual development.Methods Eighteen C57BL/6J mice were randomly divided into the normal control group(CON group)and the MD group,with 9 mice in each group.Mice were bred under the 12 h/12 h dark/light conditions.Mice in the CON group received no treat-ment,while mice in the MD group underwent MD of the right eye on postnatal day 27,and the tissue was removed after 7 days.The mRNA and protein expression levels of glial fibrillary acidic protein(GFAP)in the superior colliculus,hippo-campus and visual cortex of mice in the two groups were detected using the real-time reverse transcription quantitative pol-ymerase chain reaction(RT-qPCR)and Western blot,respectively.The number of astrocytes labeled by GFAP and central nervous system specific protein β(S100β)in the superior colliculus,hippocampus and visual cortex of mice in the two groups was detected using the immunofluorescence staining.Results RT-qPCR and Western blot results showed that compared with the CON group,the mRNA and protein expression levels of GFAP in the superior colliculus,hippocampus(CA1,CA3 and dentate gyrus)and visual cortex of mice in the MD group decreased,and the differences were statistically significant(all P＜0.05).The immunofluorescence staining results showed that compared with the CON group,the number of GFAP and S1OOβ co-labeled astrocytes in the superior colliculus,hippocampus(CA1,CA3 and dentate gyrus)and visual cortex of mice in the MD group decreased,and the differences were statistically significant(all P＜0.05).Conclusion MD of mice during the critical period of visual development can result in a decrease in the number of astrocytes in the supe-rior colliculus,hippocampus and visual cortex.

Objective To investigate the effect of blue light on the dioptric development of the eyes of lens-induced myopia(LIM)guinea pigs.Methods Three-week-old trichromatic guinea pigs were randomly divided into three groups:control group,white light LIM(WL)group,and blue light LIM(BL)group(420 nm LED light,with an illuminance of 700 lx);guinea pigs in the latter two groups wore-10.00 D lenses in their right eyes to induce myopia.All guinea pigs under-went a 12 h light/12 h dark treatment cycle.Before and 2,4 weeks after the intervention,the diopter,axial length,retinal thickness and choroidal thickness were measured in all groups.After 4 weeks of intervention,the corneal fluorescent stai-ning and retinal Hematoxylin and Eosin(HE)staining were conducted.Results Compared with the control group,from week 0 to week 2 of the intervention(changes in weeks 0-2),the eyes in the WL group drifted(-2.22±1.28)D towards myopia,the axial length lengthened by(0.40±0.05)mm,and the retinal and choroidal thicknesses reduced by(-7.42± 7.04)μm and(-6.29±4.66)μm,respectively;compared with the WL group,in the BL group,the eyes drifted toward hyperopia by(0.48±1.16)D,the axial length increased by(0.20±0.10)mm,and retinal and choroidal thicknesses in-creased by(1.36±7.46)μm and(8.05±8.08)μm,respectively(all P＜0.05).From week 2 to week 4(changes in weeks 2-4),compared with the control group,the diopter in the WL and BL groups progressed towards myopia,with changes of(-4.64±0.50)D and(-2.11±2.02)D,respectively(both P＜0.05);the axial length lengthened,and reti-nal and choroidal thicknesses reduced in the WL group,with changes of(0.44±0.06)mm,(-7.35±5.87)μm and(-4.84±2.61)μm,while the choroidal thickness and the retinal thickness decreased in the BL group,with changes of(-0.33±5.95)μm and(-4.78±4.96)μm,respectively.Observations of corneal fluorescence staining and retinal HE staining indicated that prolonged blue light exposure could lead to damage to corneal and retinal cells.Conclusion Blue light may influence the development of myopia through choroid-related mechanisms,but its inhibitory effect is not positive-ly correlated with time.Prolonged exposure to blue light can damage the cornea and retina,thereby reducing the inhibitory effect.

The complex function of the brain depends on the interaction of its intrinsic neurons and neural network systems,in which glutamatergic projection neurons and GABAergic inhibitory interneurons play an important role.There is a critical period in the postnatal development of the visual system when it is susceptible to the external environment,which may affect visual plasticity.Changes in the visual environment can lead to adaptive adjustment in neural connections and synaptic structures among visual cortexes,and the perineural network in the extracellular matrix has been proven to play an essential role in this process.The parvalbumin-positive inhibitory interneurons(PV+INs)contained in the perineural net-works are also involved in regulating plasticity during the critical period of visual development.PV+INs are a kind of inter-neurons that express the parvalbumin found in various parts of the brain.Recent studies have demonstrated that specific modulation of these neurons not only reveals some potential therapeutic mechanisms for disorders such as amblyopia,de-pression and autism but also provides a more precise treatment for these diseases.In this paper,various regulatory factors of PV+INs from their origin to the end of the critical period of visual development and their involvement in visual develop-mental plasticity were reviewed,with the aim of providing some guidance for basic research on visual cortical plasticity.

Ketone bodies have beneficial metabolic activities, and the induction of plasma ketone bodies is a health promotion strategy. Dietary supplementation of sodium butyrate (SB) is an effective approach in the induction of plasma ketone bodies. However, the cellular and molecular mechanisms are unknown. In this study, SB was found to enhance the catalytic activity of 3-hydroxy-3-methylglutaryl-CoA synthase 2 (HMGCS2), a rate-limiting enzyme in ketogenesis, to promote ketone body production in hepatocytes. SB administrated by gavage or intraperitoneal injection significantly induced blood ß-hydroxybutyrate (BHB) in mice. BHB production was induced in the primary hepatocytes by SB. Protein succinylation was altered by SB in the liver tissues with down-regulation in 58 proteins and up-regulation in 26 proteins in the proteomics analysis. However, the alteration was mostly observed in mitochondrial proteins with 41% down- and 65% up-regulation, respectively. Succinylation status of HMGCS2 protein was altered by a reduction at two sites (K221 and K358) without a change in the protein level. The SB effect was significantly reduced by a SIRT5 inhibitor and in Sirt5-KO mice. The data suggests that SB activated HMGCS2 through SIRT5-mediated desuccinylation for ketone body production by the liver. The effect was not associated with an elevation in NAD⁺/NADH ratio according to our metabolomics analysis. The data provide a novel molecular mechanism for SB activity in the induction of ketone body production.
Mice ; Animals ; Butyric Acid/metabolism* ; Ketone Bodies/metabolism* ; Liver/metabolism* ; Hydroxybutyrates/metabolism* ; Down-Regulation ; Sirtuins/metabolism* ; Hydroxymethylglutaryl-CoA Synthase/metabolism*

The transcription factor nuclear factor of kappa-light-chain-enhancer of activated B cells (NF-κB) is expressed in brown adipocytes, but its role remains largely unknown in the cells. This issue was addressed in current study by examining NF-κB in brown adipocytes in vitro and in vivo. NF-κB activity was increased by differentiation of brown adipocytes through elevation of p65 (RelA) expression. The transcriptional activity of NF-κB was induced by the cold stimulation with an elevation in S276 phosphorylation of p65 protein. Inactivation of NF-κB in brown adipocytes made the knockout mice [uncoupling protein 1 (Ucp1)-CreER-p65^f/f, U-p65-KO] intolerant to the cold environment. The brown adipocytes exhibited an increase in apoptosis, a decrease in cristae density and uncoupling activity in the interscapular brown adipose tissue (iBAT) of p65-KO mice. The alterations became severer after cold exposure of the KO mice. The brown adipocytes of mice with NF-κB activation (p65 overexpression, p65-OE) exhibited a set of opposite alterations with a reduction in apoptosis, an increase in cristae density and uncoupling activity. In mechanism, NF-κB inhibited expression of the adenine nucleotide translocase 2 (ANT2) in the control of apoptosis. Data suggest that NF-κB activity is increased in brown adipocytes by differentiation and cold stimulation to protect the cells from apoptosis through down-regulation of ANT2 expression.

Objective To investigate the expression of proline rich tyrosine kinase 2 (Pyk2) in non-muscle invasive bladder cancer,and analyze its correlation to clinicopathologic features and prognosis of non-muscle invasive bladder cancer.Methods 114 surgical specimens and 50 normal bladder mucosa specimens were collected from 114 non-muscle invasive bladder cancer patients who underwent TURBT at our hospital,from June 2013 to March 2018.Of the 114 patients,63 were male and 51 were female,aged 42-87 years,average age of (63.6 ± 13.8) years,73 cases of tumor ＜3 cm,41 cases of tumor ≥3 cm,83 cases were single and 31 cases were multiple tumor,53 cases were high grade and 61 cases were low grade,59 cases were Ta and 55 cases were T1 stage.Pyk2 protein expression was detected by immunohistochemistry and western blot.The correlation of the expression of Pyk2 with clinicopathologic features,including gender,age,tumor size,the number of tumors,histological grade and clinical stage were analyzed.Survival analysis was calculated by using the Kaplan-Meier method,and the difference in survival curve was analyzed by using the log-rank test.Association of Pyk2 expression with prognosis of non-muscle invasive bladder cancer analyzed by using the Cox proportional hazards regression model.Results Compared with normal bladder tissues,expression of Pyk2 protein was increased in bladder cancer tissue significantly(0.571 ±0.230 vs.0.253 ± 0.152,P ＜0.01).The expression of Pyk2 protein was closely related to clinical stage(P =0.027) and grade(P =0.010),rather than gender (P =0.275),age (P =0.419),tumor size (P =0.317),and tumor number(P =0.208).The recurrence rate in the Pyk2 positive group and negative group were 46.1％ (35/76)and 28.9％ (11/38)respectively.The progression rate in the Pyk2 positive group and negative group were 35.5％ (27/76) and 10.5 ％ (4/38) respectively.Survival analysis suggested expression of Pyk2 in non-muscle invasive bladder cancer had a significant relation to recurrence-free survival rate(P ＜0.001) and progression-free survival rate(P =0.003).In the multivariable Cox analysis,we found that Pyk2 protein was an independent predictor of recurrence-free survival rate(HR 0.245,95％ CI 0.078-0.768,P =0.016) and progression-free survival rate (HR 0.095,95％ CI 0.012-0.764,P =0.027).Conclusions The expression of Pyk2 in non-muscle invasive bladder cancer was significantly increased.The expression of Pyk2 has a significant relation to recurrence and progression of non-muscle invasive bladder cancer.High Pyk2 expression is an independent prognostic factor in non-muscle invasive bladder cancer.

Objective To investigate the clinical therapeutic effect of sigmoid neobladder after laparoscopic radical cystectomy in the treatment of invasive bladder cancer .Methods 21 patients with invasive bladder cancer accepted sigmoid neobladder after laparoscopic radical cystectomy and pelvic lymphadenectomy .The postoperative complications and clinical therapeutic effect were analyzed .Results All surgeries were completed successfully .The operation time was (245 ±125) min,blood lost was (98 ±45) mL.All the 21 patients were followed up for 3-24 months,mean of 12 months.Both side mild hydronephrosis in 6 cases (28.6%) and unilateral hydronephrosis in 1 case(0.5%).Average bladder reservoir was (548.8 ±221.6)mL,the maximum bladder pressure during the new bladder urine storage period was (2.26 ±0.24) kPa,the maximum bladder pressure during voiding period was (6.18 ±0.29) kPa,volume of residual urine was (87 ±52) mL.The mean maximum uroflow rate was (83.2 ± 5.6)mL/s.The continence of micturition was 90.4% in day-time and 76.1% in night-time.1 case had urethral stricture and got better after the urethral dilatation .Conclusion The sigmoid neobladder after laparoscopic radical cystectomy has more reliable results,without serious postoperative complications and patients with high quality of life after operation.This operation may be applied in clinical practice .