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.

THE DECAY ESTIMATES FOR MAGNETOHYDRODYNAMIC EQUATIONS WITH COULOMB FORCE

In this article we consider the compressible viscous magnetohydrodynamic equations with Coulomb force.By spectral analysis and energy methods,we obtain the optimal time decay estimate of the solution.We show that the global classical solution converges to its equilibrium state at the same decay rate as the solution of the linearized equations.

Brainstem opioid peptidergic neurons regulate cough reflexes in mice

Cough is a vital defensive reflex for expelling harmful substances from the airway.The sensory afferents for the cough reflex have been intensively studied.However,the brain mechanisms underlying the cough reflex remain poorly understood.Here,we developed a paradigm to quantitatively measure cough-like reflexes in mice.Using this paradigm,we found that prodynorphin-expressing(Pdyn+)neurons in the nucleus of the solitary tract(NTS)are critical for capsaicin-induced cough-like reflexes.These neurons receive cough-related neural signals from Trpv1+vagal sensory neurons.The activation of Pdyn+NTS neurons triggered respiratory responses resembling cough-like reflexes.Among the divergent projections of Pdyn+NTS neurons,a glutamatergic pathway projecting to the caudal ventral respiratory group(cVRG),the canonical cough center,was necessary and sufficient for capsaicin-induced cough-like reflexes.These results reveal that Pdyn+NTS neurons,as a key neuronal population at the entry point of the vagus nerve to the brainstem,initiate cough-like reflexes in mice.

Developmental changes in lipid and fatty acid metabolism and the inhibition by in ovo feeding oleic acid in Muscovy duck embryogenesis

Hepatic lipid and fatty acid(FA)metabolism are critical for regulating energetic homeostasis during embryogenesis.At present,it remains unclear how an exogenous FA intervention affects embryonic development in an avian embryo model.In Exp.1,30 fertilized eggs were sampled on embryonic days(E)16,19,22,25,28,31 and the day of hatch(DOH)to determine the critical period of lipid metabolism.In Exp.2,a total of 120 fertilized eggs were divided into two groups(60 eggs/group)for in ovo feeding(IOF)procedures on E25.Eggs were injected into the yolk sac with PBS as the control group and with oleic acid(OA)as the IOF-OA treatment group.Samples were collected on E28 and E31.In Exp.1,hepatic triacylglycerol(TG)and cholesterol(CHO)contents increased while serum TG content decreased from E16 to DOH(P<0.05).Both serum and liver displayed an increase in unsaturated FA and a decrease in saturated FA(P<0.05).There was a quadratic increase in the target gene and protein expression related to hepatic FA de novo synthesis and oxidation(P<0.05),whose inflection period was between E22 and E28.In Exp.2,compared with the control embryos,IOF-OA embryos had an increased yolk sac TG content on E28 and E31,and a decreased serum TG and CHO content on E28(P<0.05).The IOF-OA embryos had less OA in the yolk sac and liver on E28,and less unsaturated FA in the serum and liver on E31 than did the control embryos(P<0.05).Hepatic gene mRNA expression related to FA uptake,synthesis,and oxidation on E28 was lower in IOF-OA than in control embryos(P<0.05),not on E31(P>0.05).Maximal metabolic changes in lipid and FA metabolism occurred on E22-E28 in Muscovy duck embryogenesis,along with the altered target gene and protein expression related to lipogenesis and lipolysis.IOF-OA intervention on E25 could inhibit the target gene expression related to FA uptake,synthesis,and oxidation,which may influence the normal FA metabolism on E28 during embryogenesis.