4-Hydroxycinnamic acid attenuates neuronal cell death by inducing expression of plasma membrane redox enzymes and improving mitochondrial functions

Many approaches to neurodegenerative diseases that focus on amyloid-βclearance and gene therapy have not been successful.Some therapeutic applications focus on enhancing neuronal cell survival during the pathogenesis of neurodegenerative diseases,including mitochondrial dysfunction.Plasma membrane(PM)redox enzymes are crucial in maintaining cellular physiology and redox homeostasis in response to mitochondrial dysfunction.Neurohormetic phytochemicals are known to induce the expression of detoxifying enzymes under stress conditions.In this study,mechanisms of neuroprotective effects of 4-hydroxycinnamic acid(HCA)were examined by analyzing cell survival,levels of abnormal proteins,and mitochondrial functions in two different neuronal cells.HCA protected two neuronal cells exhibited high expression of PM redox enzymes and the consequent increase in the NAD^(+)/NADH ratio.Cells cultured with HCA showed delayed apoptosis and decreased oxidative/nitrative damage accompanied by decreased ROS production in the mitochondria.HCA increased the mitochondrial complexes I and II activities and ATP production.Also,HCA increased mitochondrial fusion and decreased mitochondrial fission.Overall,HCA maintains redox homeostasis and energy metabolism under oxidative/metabolic stress conditions.These findings suggest that HCA could be a promising therapeutic approach for neurodegenerative diseases.

Effect of Mitochondrial Function of Ovarian Granulosa Cells on In Vitro Fertilization and Embryo Transfer Outcomes in Obese Polycystic Ovary Syndrome Patients

Objective:To investigate the effect of abnormal ovarian granulosa cell metabolism on in vitro fertilization and embryo transfer(IVF-ET)outcomes in obese polycystic ovary syndrome(PCOS)patients.Methods:Patients with PCOS who met the study criteria were screened according to the inclusion criteria.A total of 32 patients with obese PCOS were recruited into the study group,and 39 patients with non-obese PCOS were recruited into the control group.The general data(age,body mass index,and years of infertility),insulin resistance index(HOMA-IR),follicle-stimulating hormone(FSH),luteinizing hormone(LH),granulosa cell mitochondrial function,and IVF-ET outcome of patients in the study group and control group were retrospectively analyzed.Results:The differences in age and years of infertility between the study group and the control group were insignificant(P>0.05),and the body mass index(BMI)of the study group and control group was 30.5±1.24 kg/m2 and 22.3±1.12 kg/m2,respectively,in which the difference was statistically significant(P<0.05);the HOMA-IR of the study group was significantly higher than that of the control group(P<0.05);the reactive oxygen species(ROS)in the study group was significantly higher than that in the control group(P<0.05),and the ATP content in the study group was significantly lower than that in the control group(P<0.05);comparing the FSH and LH levels between the two groups,the difference was not statistically significant(P>0.05);the rate of IVF-ET failure was significantly higher in the study group than in the control group.Conclusion:PCOS is a complex endocrine disorder,and obesity is one of the independent risk factors for the development of PCOS.

Effects of dietary tributyrin on intestinal mucosa development,mitochondrial function and AMPK-mTOR pathway in weaned pigs

Background:The objective of this experiment was to investigate the influence of dietary tributyrin on intestinal mucosa development,oxidative stress,mitochondrial function and AMPK-mTOR signaling pathway.Methods:Seventy-two pigs were divided into two treatments and received either a basal diet or the same diet supplemented with 750 mg/kg tributyrin.Each treatment has six replicates of six pigs.After 14 days,6 pigs from each treatment were selected and the jejunal samples were collected.Results:Results showed that supplemental tributyrin increased(P<0.05)villus height and villus height:crypt depth of weaned pigs.Pigs fed tributyrin had greater(P<0.05)RNA/DNA and protein/DNA ratios than pigs on the control group.The mRNA levels of sodium glucose transport protein-1 and glucose transporter-2 in the jejunum were upregulated(P<0.05)in pigs fed the tributyrin diet.Dietary tributyrin supplementation lowered(P<0.05)the malondialdehyde and hydrogen peroxide(H2O2)content in jejunum,enhanced(P<0.05)the mitochondrial function,as demonstrated by decreased(P<0.05)reactive oxygen species level and increased(P<0.05)mitochondrial membrane potential.Furthermore,tributyrin increased(P<0.05)mitochondrial DNA content and the mRNA abundance of genes related to mitochondrial functions,including peroxisomal proliferator-activated receptor-γcoactivator-1α,mitochondrial transcription factor A,nuclear respiratory factor-1 in the jejunum.Supplementation with tributyrin elevated(P<0.05)the phosphorylation level of AMPK and inhibited(P<0.05)the phosphorylation level of mTOR in jejunum compared with the control group.Conclusions:These findings suggest that dietary supplementation with tributyrin promotes intestinal mucosa growth,extenuates oxidative stress,improves mitochondrial function and modulates the AMPK-mTOR signal pathway of weaned pigs.

Regulation of mitochondrial function and endoplasmic reticulum stress by nitric oxide in pluripotent stem cells

Mitochondrial dysfunction and endoplasmic reticulum stress(ERS) are global processes that are interrelated and regulated by several stress factors. Nitric oxide(NO) is a multifunctional biomolecule with many varieties of physiological and pathological functions, such as the regulation of cytochrome c inhibition and activation of the immune response, ERS and DNA damage; these actions are dose-dependent. It has been reported that in embryonic stem cells, NO has a dual role, controlling differentiation, survival and pluripotency, but the molecular mechanisms by which it modulates these functions are not yet known. Low levels of NO maintain pluripotency and induce mitochondrial biogenesis. It is well established that NO disrupts the mitochondrial respiratory chain and causes changes in mitochondrial Ca^(2+) flux that induce ERS. Thus, at high concentrations, NO becomes a potential differentiation agent due to the relationship between ERS and the unfolded protein response in many differentiated cell lines. Nevertheless, many studies have demonstratedthe need for physiological levels of NO for a proper ERS response. In this review, we stress the importance of the relationships between NO levels, ERS and mitochondrial dysfunction that control stem cell fate as a new approach to possible cell therapy strategies.

REAL-TIME MONITORING OF MITOCHONDRIAL FUNCTION AND CEREBRAL BLOOD FLOW FOLLOWING FOCAL ISCHEMIA IN RATS

Focal ischemia due to reduction of cerebral blood flow(CBF),creates 2 zones of damage:the core area,which suffers severe damage,and penumbra area,which surrounds the core and suffers intermediate levels of injury.Objectives:A novel method is introduced,which evaluates mitochondrial function in the core and in the penumbra,during focal cerebral ischemia.Methods:Wistar rats underwent focal cerebral ischemia by middle cerebral artery occlusion(MCAO)for 60 minutes,followed by 60 minutes of reperfusion.Mitochondrial function was assessed by a unique Multi-Site—Multi-Parametric(MSMP)monitoring system,which measures mitochondrial NADH using fluorometric technique,and CBF using Laser Doppler Flowmetry(LDF).Results:At the onset of occlusion,CBF dropped and NADH increased significantly only in the right hemisphere.CBF levels were significantly lower and NADH significantly higher in the core than in the penumbra.After reperfusion,CBF and NADH recovered correspondingly to the intensity of ischemia.Conclusion:Application of the MSMP system can add significant information for the understanding of the cerebral metabolic state under ischemic conditions,with an emphasis on mitochondrial function.

Sirtuin 3 regulation:a target to alleviateβ-hydroxybutyric acid-induced mitochondrial dysfunction in bovine granulosa cells

Background During the transition period,the insufficient dry matter intake and a sharply increased in energy consumption to produce large quantities of milk,high yielding cows would enter a negative energy balance(NEB)that causes an increase in ketone bodies(KBs)and decrease in reproduction efficiency.The excess concentrations of circulating KBs,represented byβ-hydroxybutyric acid(BHBA),could lead to oxidative damage,which potentially cause injury to follicular granulosa cells(fGCs)and delayed follicular development.Sirtuin 3(Sirt3)regulates mitochondria reactive oxygen species(mitoROS)homeostasis in a beneficial manner;however,the molecular mechanisms underlying its involvement in the BHBA-induced injury of fGCs is poorly understood.The aim of this study was to explore the protection effects and underlying mechanisms of Sirt3 against BHBA overload-induced damage of fGCs.Results Our findings demonstrated that 2.4 mmol/L of BHBA stress increased the levels of mitoROS in bovine fGCs.Further investigations identified the subsequent mitochondrial dysfunction,including an increased abnormal rate of mitochondrial architecture,mitochondrial permeability transition pore(MPTP)opening,reductions in mitochondrial membrane potential(MMP)and Ca^(2+)release;these dysfunctions then triggered the caspase cascade reaction of apoptosis in fGCs.Notably,the overexpression of Sirt3 prior to treatment enhanced mitochondrial autophagy by increasing the expression levels of Beclin-1,thus preventing BHBA-induced mitochondrial oxidative stress and mitochondrial dysfunction in fGCs.Furthermore,our data suggested that the AMPK-mTOR-Beclin-1 pathway may be involved in the protective mechanism of Sirt3 against cellular injury triggered by BHBA stimulation.Conclusions These findings indicate that Sirt3 protects fGCs from BHBA-triggered injury by enhancing autophagy,attenuating oxidative stress and mitochondrial damage.This study provides new strategies to mitigate the fGCs injury caused by excessive BHBA stress in dairy cows with ketosis.

Synergistic activation of AMPK by AdipoR1/2 agonist and inhibitor of EDPs-EBP interaction recover NAFLD through enhancing mitochondrial function in mice

Nonalcoholic fatty liver disease(NAFLD),especially nonalcoholic steatohepatitis(NASH),is a common hepatic manifestation of metabolic syndrome.However,there are no effective therapy to treat this devastating disease.Accumulating evidence suggests that the generation of elastin-derived peptides(EDPs)and the inhibition of adiponectin receptors(Adipo R)1/2 plays essential roles in hepatic lipid metabolism and liver fibrosis.We recently reported that the AdipoR1/2 dual agonist JT003 significantly degraded the extracellular matrix(ECM)and ameliorated liver fibrosis.However,the degradation of the ECM lead to the generation of EDPs,which could further alter liver homeostasis negatively.Thus,in this study,we successfully combined AdipoR1/2 agonist JT003 with V14,which acted as an inhibitor of EDPs-EBP interaction to overcome the defect of ECM degradation.We found that combination of JT003 and V14 possessed excellent synergistic benefits on ameliorating NASH and liver fibrosis than either alone since they compensate the shortage of each other.These effects are induced by the enhancement of the mitochondrial antioxidant capacity,mitophagy,and mitochondrial biogenesis via AMPK pathway.Furthermore,specific suppression of AMPK could block the effects of the combination of JT003 and V14 on reduced oxidative stress,increased mitophagy and mitochondrial biogenesis.These positive results suggested that this administration of combination of AdipoR1/2 dual agonist and inhibitor of EDPs-EBP interaction can be recommended alternatively for an effective and promising therapeutic strategy for the treatment of NAFLD and NASH related fibrosis.

Punicalagin prevents obesity-related cardiac dysfunction through promoting DNA demethylation in mice

The aim of this study was to investigate whether punicalagin(PU)could prevent obesity-related cardiac dysfunction by promoting DNA demethy lation,and to explore its possible mechanism.C57BL/6J mice were fed with standard diet,high-fat diet(HFD),HFD supplemented with resveratrol,low-dose PU(LPU)and high-dose PU(HPU)for 8 weeks.Compared with HFD group,body weight was significantly lower in PU treatment groups,number of cardionwocytes and the protein level of myosin heavy chain 7B were significantly higher in PU treatment groups.Levels of 5-hydroxymethylcytosine and 5-formylcytosine were significantly lower in HFD group than in other groups.Compared with the HFD group,the protein level of ten-eleven translocation enzyme(TET)2 was significantly higher in PU treatment groups,p-AMP-activated protein kinase(AMPK)was significantly higher in LPU group.Levels of total antioxidant capacity and the protein levels of complexesⅡ/Ⅲ/Ⅴ,oxoglutarate dehydrogenase,succinate dehydrogenase B and fumarate hdrolase were significantly lower in HFD group than PU treatment group.The ratio of(succinic acid+fumaric acid)/a-ketoglutarate was significantly higher in HFD group than other groups.In conclusion,PU up-regulated TETs enzyme activities and TET2 protein stability through alleviating mitochondrial dysfunction and activating AMPK,so as to promote DNA demethylation,thus preventing obesity-related cardiac dysfunction.

Hypoglycemic activity of puerarin through modulation of oxidative stress and mitochondrial function via AMPK

Hyperglycemia is the dominant phenotype of diabetes and the main contributor of diabetic complications. Puerarin is widely used in cardiovascular diseases and diabetic vascular complications. However, little is known about its direct effects on diabetes. The aim of our study is to investigate its antidiabetic effect in vivo and in vitro, and explore the underlying mechanism. We used type I diabetic mice induced by streptozotocin to observe the effects of puerarin on glucose metabolism. In addition, oxidative stress and hepatic mitochondrial respiratory activity were evaluated in type I diabetic mice. In vitro, glucose consumption in Hep G2 cells was assayed along with the q PCR detection of glucogenesis genes expression. Moreover, ATP production was examined and phosphorylation of AMPK was determined using Western blot. Finally, the molecular docking was performed to predict the potential interaction of puerarin with AMPK utilizing program Lib Dock of Discovery Studio 2018 software. The results showed that puerarin improved Hep G2 glucose consumption and upregulated the glucogenesis related genes expression. Also, puerarin lowered fasting and fed blood glucose with improvement of glucose tolerance in type I diabetic mice. Further mechanism investigation showed that puerarin suppressed oxidative stress and improved hepatic mitochondrial respiratory function with enhancing ATP production and activating phosphorylation of AMPK. Docking study showed that puerarin interacted with AMPK activate site and enhancing phosphorylation. Taken together, these findings indicated that puerarin exhibited the hypoglycemic effect through attenuating oxidative stress and improving mitochondrial function via AMPK regulation, which may serve as a potential therapeutic option for diabetes treatment.

Metformin alleviates cholestasis-associated nephropathy through regulating oxidative stress and mitochondrial function

Background and aim:Cholestasis-associated renal injury or cholemic nephropathy(CN)is a serious clinical problem.Previous studies mentioned that oxidative stress and mitochondrial impairment play a role in CN.There is no specific pharmacological intervention for CN.Metformin is an anti-diabetic drug administered for decades.On the other hand,novel pharmacological properties have emerged for this drug.The effect of metformin on oxidative stress parameters has been well-recognized in different experimental models.It has also been found that metformin positively affected mitochondrial function.The current study aimed to evaluate the effects of metformin in an animal model of CN.Methods:Rats underwent bile duct ligation(BDL)and were treated with metformin(250 and 500 mg/kg)for 14 consecutive days.Two weeks after the BDL operations,urine,serum,and kidney samples were collected and analyzed.Results:Markers of oxidative stress,including reactive oxygen species(ROS)formation,lipid peroxida-tion,protein carbonylation,depleted antioxidant capacity,and decreased glutathione(GSH)levels were detected in BDL animals.Moreover,mitochondrial indices,including adenosine triphosphate(ATP)level,dehydrogenase activity,mitochondrial membrane potential,and mitochondrial permeability,were impaired in the kidney of cholestatic rats.Renal histopathological alterations in cholestatic animals included tubular degeneration and interstitial inflammation,cast formation,and fibrosis.It was found that metformin significantly alleviated oxidative stress and improved mitochondrial indices in the kidney of cholestatic rats.Tissue histopathological alterations were also mitigated in metformin-treated groups.Conclusions:Metformin could be a candidate for managing CN.The nephroprotective role of metformin is primarily associated with its effects on oxidative stress parameters and mitochondrial function.

Glutamine in suppression of lipopolysaccharide-induced piglet intestinal inflammation:The crosstalk between AMPK activation and mitochondrial function

The study was conducted to investigate the regulatory mechanism of glutamine(Gln)on intestinal inflammation in an Escherichia coli lipopolysaccharide(E.coli LPS)-induced in vivo and in vitro models.Piglets(n=8)weaned at 21 d of age were fed a basal diet(control and LPS groups)or 1%Gln diet(Gln t LPS group)ad libitum for 4 weeks.On d 22,24,26 and 28,piglets in the LPS and Gln t LPS groups were intraperitoneally injected with E.coli LPS.Intestinal porcine epithelial cells(IPEC-J2)(n=6)induced by LPS were used to assess related mechanisms and compound C was used to inhibit adenosine 50-monophosphate-activated protein kinase(AMPK)activity.Our current results showed that compared with the LPS treatment,the Gln t LPS treatment had better growth performance and greater villus height(P<0.05),and the Gln t LPS treatment reduced the rate of diarrhea by 6.4%(P<0.05);the Gln t LPS treatment decreased serum tumor necrosis factor(TNF-ɑ),interleukin-6(IL-6),Kt,cortisol and insulin levels,whereas increased(P<0.05)serum immunoglobulin M and epidermal growth factor levels;the Gln t LPS treatment increased(P<0.05)the expression of aquaporins and AMPK pathwayassociated targets in the jejunum and ileum of piglets,whereas decreased the expression of ion transporters(P<0.05).The in vitro results showed that 4 mmol/L Gln administration could inhibit(P<0.05)cell apoptosis and interleukin-1b(IL-1b),IL-6 and TNF-ɑsecretion in LPS-induced IPEC-J2 cells,promote(P<0.05)mitochondrial respiratory metabolism and increase(P<0.05)the number of mitochondria and mitochondrial membrane potential.The activity of AMPK was elevated by 70%to 300%in Gln-treated IPEC-J2 cells under LPS challenge or normal conditions.Our results indicate that pre-administration of Gln to piglets suppresses intestinal inflammation by modulating the crosstalk between AMPK activation and mitochondrial function.

Knockdown of insulin-like growth factor 2 gene disrupts mitochondrial functions in the liver

Even though insulin-like growth factor 2(IGF2)has been reported to be overexpressed in nonalcoholic fatty liver disease(NAFLD),its role in the progression of NAFLD and the potential mechanism remain largely unclear.Using in vitro models,we found that IGF2 was the key overexpressed gene in steatosis,suggesting a possible association between IGF2 and NAFLD.Interestingly,loss-of-function experiments revealed that inhibition of IGF2 protein impaired mitochondrial biogenesis and respiration.It additionally disrupted the expression changes of mitochondrial fusion and fission-related proteins necessary in maintaining mitochondrial homeostasis.Consistently,IGF2 knockdown reduced the mitochondrial membrane potential and increased the production of reactive oxygen species.Mechanistically,IGF2 regulates mitochondrial functions by modulating the expression of SIRT1 and its downstream gene PGCla.This research opens a new frontier on the role of IGF2 in energy metabolism,which potentially participates in the development of NAFLD.As such,IGF2 is a potential therapeutic target against NAFLD.

Maternal zinc alleviates tert-butyl hydroperoxide-induced mitochondrial oxidative stress on embryonic development involving the activation of Nrf2/PGC-1αpathway

Background Mitochondrial dysfunction induced by excessive mitochondrial reactive oxygen species(ROS)damages embryonic development and leads to growth arrest.Objective The purpose of this study is to elucidate whether maternal zinc(Zn)exert protective effect on oxidative stress targeting mitochondrial function using an avian model.Result In ovo injected tert-butyl hydroperoxide(BHP)increases(P<0.05)hepatic mitochondrial ROS,malondialdehyde(MDA)and 8-hydroxy-2-deoxyguanosine(8-OHdG),and decreases(P<0.05)mitochondrial membrane potential(MMP),mitochondrial DNA(mtDNA)copy number and adenosine triphosphate(ATP)content,contributing to mitochondrial dysfunction.In vivo and in vitro studies revealed that Zn addition enhances(P<0.05)ATP synthesis and metallothionein 4(MT4)content and expression as well as alleviates(P<0.05)the BHP-induced mitochondrial ROS generation,oxidative damage and dysfunction,exerting a protective effect on mitochondrial function by enhancing antioxidant capacity and upregulating the mRNA and protein expressions of Nrf2 and PGC-1α.Conclusions The present study provides a new way to protect offspring against oxidative damage by maternal Zn supplementation through the process of targeting mitochondria involving the activation of Nrf2/PGC-1αsignaling.

Shenmai Injection attenuated doxorubicin-induced cardiac dysfunction via maintaining mitochondrial homeostasis

OBJECTIVE Shenmai Injection(SMI)is widely used in the treatment of cardiovascular diseases,such as heart failure and myocardial ischemia.In clinic,SMI showed protective effects on doxorubicin(Dox)-induced cardiac toxicity.In current study,we investigate the mitochondrial protective mechanisms of SMI on Dox-induced myocardial injury.METHODS C57BL/6 mice were divided into four groups:①control group;②Dox injury group;③SMI+Dox group and dexrazoxane(DRZ)+Dox group.Dex was a positive control.Myocardial injury was evaluated by echocardiography,HE and TUNEL staining,myocardial markers measurement.H9C2 cardiomyocytes pretreatment with SMI for 24 h were exposed to Dox.Cell viability and apoptosis were measured by CCK8,Hoechst33342 staining,and Annexin V/PI staining.MitoSOX,mitochondrial membrane potential,and mitochondrial respiratory function were measured to evaluate mito⁃chondrial function.RESULTS SMI decreased mortality rate of Dox-injected mice,serum CK and CK-MB levels in vivo.SMI significantly prevented Dox-induced cardiac dysfunction and apoptosis and increased expression level of PI3K,p-Akt,and p-GSK-3β.Moreover,SMI significantly inhibited Dox-induced apoptosis,mitochondrial ROS production,and reduction of mitochondrial membrane potential in H9C2 cells.Mechanismly,the cardio-protective effect of SMI was suppressed by PI3K inhibitor LY294002.CONCLUSION SMI prevents Dox-induced cardiotoxicity and mitochondrial damage through activation of PI3K/Akt signaling pathway.

Recent Advances of Traditional Chinese Medicine in the Regulation of Myocardial Mitochondrial Function

Cardiovascular disease is a crucial disease threatening human health, and its mortality rate ranks first among Chinese residents. Myocardial mitochondrial dysfunction is the main cause of various heart diseases such as myocardial infarction, myocarditis, hypertrophic cardiomyopathy, and heart failure. In recent years, many studies have confirmed that traditional Chinese medicine(TCM) can be used to improve myocardial mitochondrial function and treat heart disease. The purpose of this review was to analyze the regulatory mechanism of myocardial mitochondrial function by summarizing the effect of TCM on cardiovascular disease.

6-Gingerol, asarinin, and deoxyschizandrin improve bronchial epithelium functions in an interleukin-13einduced BEAS-2B cell model

Objective:To explore the effects of 6-gingerol,asarinin,and deoxyschizandrindthe main components of Zingiber officinale(Willd.)Rosc.(Gan Jiang),Asarum heterotropoides f.var.mandshuricum(Maxim.)(Xi Xin),and Schisandra chinensis(Turcz.)Baill.(Wu Wei Zi),respectivelydon an interleukin(IL)-13einduced BEAS-2B cell model in vitro.Methods:The BEAS-2B cell model was established using 25 ng/mL IL-13 combined with 1%fetal bovine serum(FBS)in vitro.Mitoquinone mesylate(Mito-Q)treatment was used as a positive control group,and different concentrations of 6-gingerol,asarinin,and deoxyschizandrin were used to treat the models.The level of reactive oxygen species(ROS)production was detected by flow cytometry.The expression levels of LC3B,Beclin1,adenosine 50-monophosphate(AMP)eactivated protein kinase(AMPK),phosphory-lated-AMPeactivated protein kinase(P-AMPK),dynamin-related protein 1(DRP1),and mitochondrial fusion protein 2(MFN2)were detected by Western blot.Mitochondrial membrane potential(MMP)assay kit with JC-1 was utilized to detect the level of MMP.Results:The BEAS-2B cells exposed to 25 ng/mL IL-13 with 1%FBS showed an increased ROS level and a decreased MMP.6-Gingerol,asarinin,and deoxyschizandrin were able to downregulate ROS level and upregulate the MMP in the BEAS-2B model.Asarinin and deoxyschizandrin reduced the expression of autophagy protein LC3B,while deoxyschizandrin significantly increased the expression of DRP1 in the BEAS-2B model.Conclusion:6-Gingerol,asarinin,and deoxyschizandrin can reduce ROS generation and increase MMP,but have different regulatory effects on the expression of autophagy protein and mitochondrial mitotic protein.The three components have both synergistic and complementary effects in classic medicine compatibility.This study may provide an innovative strategy to reduce the lung inflammation related to IL-13.

Translocation of telomerase reverse transcriptase coincided with ATP release in postnatal cochlear supporting cells

The spontaneous bursts of electrical activity in the developing auditory system are derived from the periodic release of adenosine triphosphate(ATP)by supporting cells in the Kölliker’s organ.However,the mechanisms responsible for initiating spontaneous ATP release have not been determined.Our previous study revealed that telomerase reverse transcriptase(TERT)is expressed in the basilar membrane during the first postnatal week.Its role in cochlear development remains unclear.In this study,we investigated the expression and role of TERT in postnatal cochlea supporting cells.Our results revealed that in postnatal cochlear Kölliker’s organ supporting cells,TERT shifts from the nucleus into the cytoplasm over time.We found that the TERT translocation tendency in postnatal cochlear supporting cells in vitro coincided with that observed in vivo.Further analysis showed that TERT in the cytoplasm was mainly located in mitochondria in the absence of oxidative stress or apoptosis,suggesting that TERT in mitochondria plays roles other than antioxidant or anti-apoptotic functions.We observed increased ATP synthesis,release and activation of purine signaling systems in supporting cells during the first 10 postnatal days.The phenomenon that TERT translocation coincided with changes in ATP synthesis,release and activation of the purine signaling system in postnatal cochlear supporting cells suggested that TERT may be involved in regulating ATP release and activation of the purine signaling system.Our study provides a new research direction for exploring the spontaneous electrical activity of the cochlea during the early postnatal period.

Artemisia argyi extract subfraction exerts an antifungal effect against dermatophytes by disrupting mitochondrial morphology and function

Artemisia argyi(A.argyi),a plant with a longstanding history as a raw material for traditional medicine and functional diets in Asia,has been used traditionally to bathe and soak feet for its disinfectant and itch-relieving properties.Despite its widespread use,scientific evidence validating the antifungal efficacy of A.argyi water extract(AAWE)against dermatophytes,particularly Trichophyton rubrum,Trichophyton mentagrophytes,and Microsporum gypseum,remains limited.This study aimed to substantiate the scientific basis of the folkloric use of A.argyi by evaluating the antifungal effects and the underlying molecular mechanisms of its active subfraction against dermatophytes.The results indicated that AAWE exhibited excellent antifungal effects against the three aforementioned dermatophyte species.The subfraction AAWE6,isolated using D101 macroporous resin,emerged as the most potent subfraction.The minimum inhibitory concentrations(MICs)of AAWE6 against T.rubrum,M.gypseum,and T.mentagrophytes were 312.5,312.5,and 625μg·mL−1,respectively.Transmission electron microscopy(TEM)results and assays of enzymes linked to cell wall integrity and cell membrane function indicated that AAWE6 could penetrate the external protective barrier of T.rubrum,creating breaches(“small holes”),and disrupt the internal mitochondrial structure(“granary”).Furthermore,transcriptome data,quantitative real-time PCR(RT-qPCR),and biochemical assays corroborated the severe disruption of mitochondrial function,evidenced by inhibited tricarboxylic acid(TCA)cycle and energy metabolism.Additionally,chemical characterization and molecular docking analyses identified flavonoids,primarily eupatilin(131.16±4.52 mg·g^(−1))and jaceosidin(4.17±0.18 mg·g^(−1)),as the active components of AAWE6.In conclusion,the subfraction AAWE6 from A.argyi exerts antifungal effects against dermatophytes by disrupting mitochondrial morphology and function.This research validates the traditional use of A.argyi and provides scientific support for its antidermatophytic applications,as recognized in the Chinese patent(No.ZL202111161301.9).

Enhancement of porcine in vitro embryonic development through luteolin‑mediated activation of the Nrf2/Keap1 signaling pathway

Background Oxidative stress,caused by an imbalance in the production and elimination of intracellular reactive oxygen species(ROS),has been recognized for its detrimental effects on mammalian embryonic development.Luteolin(Lut)has been documented for its protective effects against oxidative stress in various studies.However,its specific role in embryonic development remains unexplored.This study aims to investigate the influence of Lut on porcine embryonic development and to elucidate the underlying mechanism.Results After undergoing parthenogenetic activation(PA)or in vitro fertilization,embryos supplemented with 0.5μmol/L Lut displayed a significant enhancement in cleavage and blastocyst formation rates,with an increase in total cell numbers and a decrease in the apoptosis rate compared to the control.Measurements on D2 and D6 revealed that embryos with Lut supplementation had lower ROS levels and higher glutathione levels compared to the control.Moreover,Lut supplementation significantly augmented mitochondrial content and membrane potential.Intriguingly,activation of the Nrf2/Keap1 signaling pathway was observed in embryos supplemented with Lut,leading to the upregulation of antioxidant-related gene transcription levels.To further validate the relationship between the Nrf2/Keap1 signaling pathway and effects of Lut in porcine embryonic development,we cultured PA embryos in a medium supplemented with brusatol,with or without the inclusion of Lut.The positive effects of Lut on developmental competence were negated by brusatol treatment.Conclusions Our findings indicate that Lut-mediated activation of the Nrf2/Keap1 signaling pathway contributes to the enhanced production of porcine embryos with high developmental competence,and offers insight into the mechanisms regulating early embryonic development.

Membrane Lipid Replacement: Clinical Studies Using a Natural Medicine Approach to Restoring Membrane Function and Improving Health

Functional oral supplements containing cell membrane glycerolphospholipids and antioxidants have been used to safely replace damaged membrane lipids that accumulate during aging and in various clinical conditions. This approach differs from other dietary and intravenous interventions in the composition of phospholipids and the presence of fructooligosaccharides that protect the phospholipids against oxidation and bile and enzymatic damage. Various chronic clinical conditions are characterized by membrane phospholipid oxidative damage, resulting in loss of cellular function. Recent clinical trials have shown the benefits of Membrane Lipid Replacement in replenishing damaged membrane lipids and restoring mitochondrial function, resulting in reductions in fatigue in aged subjects and patients with a variety of clinical diagnoses. Recent in vitro experiments with nonphysiological concentrations of phospholipids did not result in enhancement of mitochondrial electron transport enzyme activities. This can be explained by the use of the wrong phospholipid fatty acids, over-dilution of membrane constituents and mitochondrial swelling. A similar phenomenon was seen when human sperm were incubated in vitro with high concentrations of glycerolphospholipids and their motility was assessed. Only lower, more physiological concentrations of glycerolphospholipids stimulated sperm motility. Additional studies are needed to determine the functional effects of Membrane Lipid Replacement on other cellular membranes, such as the plasma membrane and other intracellular membranes of various cells and tissues.