Palmitoleic acid on top of HFD ameliorates insulin resistance independent of diacylglycerols and alters gut microbiota in C57BL/6J mice

With the prevalence of obesity and obesity-related metabolic syndrome,such as insulin resistance in recent years,it is urgent to explore effective interventions to prevent the progression of obesity-related metabolic syndrome.Palmitoleic acid is a monounsaturated fatty acid that is available from dietary sources,mainly derived from marine products.P almitoleic acid plays a positive role in maintaining glucose homeostasis and reducing inflammation.However,it is still unknow the mechanism of palmitoleic acid in ameliorating insulin resistance.Here,we investigated the effects of palmitoleic acid on chow diet(CD)-fed and high-fat diet(HFD)-fed mice,which were fed CD or HFD for 12 weeks before administration.We administrated mice with BSA(control),oleic acid,or palmitoleic acid for 6 weeks on top of CD or HFD feeding.We found that palmitoleic acid only improved glucose homeostasis in HFD-fed obese mice by increasing glucose clearance and reducing HOMA-IR.Further study explored that palmitoleic acid changed the composition of gut microbiota by decreasing Firmicutes population and increasing Bacteroidetes population.In colon,palmitoleic acid increased intestinal tight junction integrity and reduced inflammation.Moreover,palmitoleic acid decreased macrophage infiltration in liver and adipose tissue and increase glucose uptake in adipose tissue.Diacylglycerol(DAG)in tissue(for example,liver)is found to positively correlated with HOMA-IR.HFD enhanced the levels of DAGs in liver but not in adipose tissue in this study.Palmitoleic acid did not reverse the high DAG levels induced by HFD in liver.Therefore,in HFD-fed mice,palmitoleic acid reduced insulin resistance by an independent-manner of DAGs.It might be associated with the beneficial effects of palmitoleic acid on altering the gut microbiota composition,improving of intestinal barrier function,and downregulating the inflammation in colon,liver,and adipose tissue.

LOXL3 Inhibits Autophagy of Chondrocytes by Activating Rheb in Osteoarthritis

Objective This study aimed to investigate the potential mechanisms by which lysyl oxidase like 3(LOXL3)affects the autophagy in chondrocytes in osteoarthritis(OA),specifically through the activation of mammalian target of rapamycin complex 1(mTORC1).Methods To establish an OA model,rats underwent anterior cruciate ligament transection(ACLT).Chondrocytes were isolated from cartilage tissues and cultured.Western blotting was performed to assess the expression of LOXL3,Rheb,phosphorylation of p70S6K(p-p70S6K,a downstream marker of mTORC1),and autophagy markers.The autophagy of chondrocytes was observed using an immunofluorescence assay.Results The expression levels of both LOXL3 and Rheb proteins were upregulated in chondrocytes isolated from the OA model cartilage,in comparison to those from the normal cartilage.The silencing of LOXL3 resulted in a decrease in the protein levels of Rheb and p-p70S6K,as well as an increase in the expression of autophagy-related proteins.Additionally,the effect of LOXL3 could be reversed through the silencing of Rheb.The results of the immunofluorescence assay confirmed the impact of LOXL3 and Rheb on chondrocyte autophagy.Conclusion LOXL3 inhibits chondrocyte autophagy by activating the Rheb and mTORC1 signaling pathways.

Association of Glial Activation and α-Synuclein Pathology in Parkinson's Disease

The accumulation of pathological α-synuclein(α-syn)in the central nervous system and the progressive loss of dopaminergic neurons in the substantia nigra pars compacta are the neuropathological features of Parkinson's disease(PD).Recently,the findings of prion-like transmission of α-syn pathology have expanded our understanding of the region-specific distribution ofα-syn in PD patients.Accumulating evidence suggests that α-syn aggregates are released from neurons and endocytosed by glial cells,which contributes to the clearance of α-syn.However,the activation of glial cells by α-syn species produces pro-inflammatory factors that decrease the uptake of α-syn aggregates by glial cells and promote the transmission of α-syn between neurons,which promotes the spread of α-syn pathology.In this article,we provide an overview of current knowledge on the role of glia and α-syn pathology in PD pathogenesis,highlighting the relationships between glial responses and the spread ofα-syn pathology.

Role of the Voltage-Gated Proton Channel Hv1 in Nervous Systems

Hv1 is the only voltage-gated proton-selective channel in mammalian cells.It contains a conserved voltage-sensor domain,shared by a large class of voltage-gated ion channels,but lacks a pore domain.Its primary role is to extrude protons from the cytoplasm upon pH reduction and membrane depolarization.The best-known function of Hv1 is the regulation of cytosolic pH and the nicotinamide adenine dinucleotide phosphate oxidase-dependent production of reactive oxygen species.Accumulating evidence indicates that Hv1 is expressed in nervous systems,in addition to immune cells and others.Here,we summarize the molecular properties,distribution,and physiological functions of Hv1 in the peripheral and central nervous systems.We describe the recently discovered functions of Hv1 in various neurological diseases,including brain or spinal cord injury,ischemic stroke,demyelinating diseases,and pain.We also summarize the current advances in the discovery and application of Hv1-targeted small molecules in neurological diseases.Finally,we discuss the current limitations of our understanding of Hv1 and suggest future research directions.

MYC promotes global transcription in part by controlling P-TEFb complex formation via DNA-binding independent inhibition of CDK9 SUMOylation

MYC is an oncogenic transcription factor with a novel role in enhancing global transcription when overexpressed. However, how MYC promotes global transcription remains controversial. Here, we used a series of MYC mutants to dissect the molecular basis for MYC-driven global transcription. We found that MYC mutants deficient in DNA binding or known transcriptional activation activities can still promote global transcription and enhance serine 2 phosphorylation(Ser2P) of the RNA polymerase(Pol) II Cterminal domain(CTD), a hallmark of active elongating RNA Pol II. Two distinct regions within MYC can promote global transcription and Ser2P of Pol II CTD. The ability of various MYC mutants to promote global transcription and Ser2P correlates with their ability to suppress CDK9 SUMOylation and enhance positive transcription elongation factor b(P-TEFb) complex formation. We showed that MYC suppresses CDK9 SUMOylation by inhibiting the interaction between CDK9 and SUMO enzymes including UBC9 and PIAS1. Furthermore, MYC's activity in enhancing global transcription positively contributes to its activity in promoting cell proliferation and transformation. Together, our study demonstrates that MYC promotes global transcription, at least in part, by promoting the formation of the active P-TEFb complex via a sequence-specific DNA-binding activity-independent manner.

Soluble CD4 effectively prevents excessive TLR activation of resident macrophages in the onset of sepsis

T lymphopenia,occurring in the early phase of sepsis in response to systemic inflammation,is commonly associated with morbidity and mortality of septic infections.We have previously shown that a sufficient number of T cells is required to constrain Toll-like receptors(TLRs)mediated hyperinflammation.However,the underlying mechanisms remains unsolved.Herein,we unveil that CD4^(+)T cells engage with MHC II of macrophages to downregulate TLR pro-inflammatory signaling.

Chemical Stimulation of Renal Tissue Induces Sympathetic Activation and a Pressor Response via the Paraventricular Nucleus in Rats

Sympathetic activation and the kidney play critical roles in hypertension and chronic heart failure.The role of the kidney in sympathetic activation is still not well known.In this study,we revealed an excitatory renal reflex(ERR)in rats induced by chemical stimulation of the kidney that regulated sympathetic activity and blood pressure.The ERR was induced by renal infusion of capsaicin,and evaluated by the changes in renal sympathetic outflow,blood pressure,and heart rate.Renal infusion of capsaicin dose-dependently increased the contralateral renal sympathetic nerve activity,mean arterial pressure,and heart rate.Capsaicin in the corticomedullary border had greater effects than in the cortex or medulla.Intravenous infusion of capsaicin had no significant effects.The effects of renal infusion of capsaicin were abolished by ipsilateral renal denervation,but were not affected by bilateral sinoaortic denervation.Renal infusion of capsaicin increased the ipsilateral renal afferent activity.The ERR was also induced by renal infusion of bradykinin,adenosine,and angiotensin II,but not by ATP.Renal infusion of capsaicin increased c-Fos expression in the paraventricular nucleus(PVN)of hypothalamus.Lesion of neurons in the PVN with kainic acid abolished the capsaicin-induced ERR.These findings indicate that chemical stimulation of kidney causes an excitatory reflex,leading to sympathetic activation,pressor response,and accelerated heart rate.The PVN is an important central nucleus in the pathway of the ERR.

Keratin 5-Cre-driven deletion of Ncstn in an acne inversa-like mouse model leads to a markedly increased IL-36a and Sprr2 expression

Familial acne inversa (AI) is an autoinflammatory disorder that affects hair follicles and is caused by loss-of-function mutations in y-secretase component genes.We and other researchers showed that nicastrin (NCSTN) is the most frequently mutated gene in familial AI.In this study,we generated a keratin 5-Cre-driven epidermis-specific Ncstn conditional knockout mutant in mice.We determined that this mutant recapitulated the major phenotypes of AI,including hyperkeratosis of hair follicles and inflammation.In Ncstnflox/flox;K5-Cre mice,the IL-36a expression level markedly increased starting from postnatal day 0 (P0),and this increase occurred much earlier than those of TNF-α,IL-23A,IL-1 3,and TLR4.RNA-Seq analysis indicated that Sprr2d,a member of the small proline-rich protein 2 family,in the skin tissues of the Ncstnflox/flox,;K5-Cre mice was also upregulated on P0.Quantitative reverse-transcription polymerase chain reaction showed that other Sprr2 genes had a similar expression pattern.Our findings suggested that IL-36a might be a key inflammatory cytokine in the pathophysiology of AI and implicate malfunction of the skin barrier in the pathogenesis of AI.

Enhanced host immune responses in presence of HCV facilitate HBV clearance in coinfection

Hepatitis B virus(HBV)/Hepatitis C virus(HCV)coinfection is frequently observed because of the common infection routine.Despite the reciprocal inhibition exerted by HBV and HCV genomes,the coinfection of HBV and HCV is associated with more severe forms of liver diseases.However,the complexity of viral interference and underlying pathological mechanism is still unclarified.With the demonstration of absence of direct viral interplay,some in vitro studies suggest the indirect effects of viral-host interaction on viral dominance outcome.Here,we comprehensively investigated the viral replication and host immune responses which might mediate the interference between viruses in HBV/HCV coinfected Huh7-NTCP cells and immunocompetent HCV human receptors transgenic ICR mice.We found that presence of HCV significantly inhibited HBV replication in vitro and in vivo irrespective of the coinfection order,while HBV did not affect HCV replication.Pathological alteration was coincidently reproduced in coinfected mice.In addition to the participation of innate immune response,an involvement of HCV in up-regulating HBV-specific immune responses was described to facilitate HBV clearance.Our systems partially recapitulate HBV/HCV coinfection and unveil the uncharacterized adaptive anti-viral immune responses during coinfection,which renews the knowledge on the nature of indirect viral interaction during HBV/HCV coinfection.

A novel rat model of fatty organ degeneration induced by poloxamer 407

Traditional methods of inducing hyperlipidemia in animal models are either costly(genetic manipulation)or it is difficult to control for the effects of other variables.For example,during high-fat feeding,the amount of high-fat diet intake per animal cannot be precisely controlled.The aim of this study was to develop an experimental model of fatty organ degeneration induced by poloxamer 407(P-407).The study was conducted in 2-month-old,male Sprague-Dawley rats that were administered intraperitoneally with either 10%(w/w)P-407(1 g/kg)or saline(10 mL/kg)for 4 months.Their lipid profile,organ degeneration due to fat deposition,and body mass were assessed.Intraperitoneal administration of P-407 resulted in significant increases in plasma triglycerides(P
0.001),total cholesterol(P<0.001),high-density lipoprotein-cholesterol(P
0.001),and low-density lipoprotein(P<0.001)cholesterol.In contrast to the control group,fatty tissue degeneration was observed in the liver,spleen,and kidneys of P-407-treated rats.Positive correlations between fatty tissue degeneration,and the atherogenic index of plasma(P<0.001)and the ratio of total cholesterol to high-density-lipoprotein(P<0.001)were identified.In addition,treatment with P-407 for 3 to 4 months caused a significant reduction in body mass relative to controls(P<0.001).Thus,this study describes the development of a cost-effective experimental rat model of organ degeneration,characterized by fat accumulation in the liver,spleen,and kidneys,which could be used for the study of steatosis and related diseases arising from sustained untreated dyslipidemia.Furthermore,both the atherogenic index of plasma and the ratio of total cholesterol to high-density lipoprotein-cholesterol can be used to predict the risk of fatty tissue degeneration in this model.The study was approval of the University of Jishou Biomedical Research Ethics Committee,China.

Temporal profiling of plasma cytokines,chemokines and growth factors from mild,severe and fatal COVID-19 patients

Dear Editor,In December 2019,a novel coronavirus that is related to severe acute respiratory syndrome coronavirus(SARS-CoV)and Middle East respiratory syndrome coronavirus(MERS-CoV)in phylogenetic distance was identified.1 This virus,which was later designated as SARS-CoV-2,also causes acute respiratory disease syndrome(ARDS)termed coronavirus disease 2019(COVID-19),which was declared as a pandemic by the World Health Organization in March 2020.

Macrophage-derived exosomes modulate wear particle-induced osteolysis via miR-3470b targeting TAB3/NF-κB signaling

Aseptic prosthesis loosening(APL)is one of the most prevalent complications associated with arthroplasty.The main cause is the periprosthetic osteolysis induced by wear particles.However,the specific mechanisms of crosstalk between immune cells and osteoclasts/osteoblasts during osteolysis are unclear.In this study,we report the role and mechanism of macrophage-derived exosomes in wear particle-induced osteolysis.The results of exosomes up-taken experiments revealed that osteoblast and mature osteoclasts capture macrophage-derived exosomes(M-Exo).Next-generation sequencing and RT-qPCR on M-Exo revealed that exosomal microRNA miR-3470b was downregulated in wear particle-induced osteolysis.The results of analysis on Luciferase reporter assays/fluorescence in situ hybridization(FISH)/immunofluorescence(IF)/immunohistochemistry(IHC)and co-culture experiments demonstrated that wear particles induced osteoclast differentiation by increasing the expression of NFatc1 via M-Exo miR-3470b targeting TAB3/NF-κB signaling.We also illustrate that engineered exosomes enriching miR-3470b facilitated to suppressed the osteolysis;the microenvironment enriching with miR-3470b could suppress wear particle-induced osteolysis via inhibition of TAB3/NF-κB in vivo.In summary,our findings indicate that macrophage-derived exosomes transfer to osteoclasts to induce osteolysis in wear particle-induced APL.Engineering exosomes enriching with miR-3470b might be a novel strategy for the targeting treatment of bone resorption-related diseases.

Identification of fangchinoline as a broad-spectrum enterovirus inhibitor through reporter virus based high-content screening

Hand,foot,and mouth disease(HFMD)is a common pediatric illness mainly caused by enteroviruses,which are important human pathogens.Currently,there are no available antiviral agents for the therapy of enterovirus infection.In this study,an excellent high-content antiviral screening system utilizing the EV-A71-eGFP reporter virus was developed.Using this screening system,we screened a drug library containing 1042 natural compounds to identify potential EV-A71 inhibitors.Fangchinoline(FAN),a bis-benzylisoquinoline alkaloid,exhibits potential inhibitory effects against various enteroviruses that cause HFMD,such as EV-A71,CV-A10,CV-B3 and CV-A16.Further investigations revealed that FAN targets the early stage of the enterovirus life cycle.Through the selection of FAN-resistant EV-A71 viruses,we demonstrated that the VP1 protein could be a potential target of FAN,as two mutations in VP1(E145G and V258I)resulted in viral resistance to FAN.Our research suggests that FAN is an efficient inhibitor of EV-A71 and has the potential to be a broad-spectrum antiviral drug against human enteroviruses.

Human cytomegalovirus infection dysregulates neural progenitor cell fate by disrupting Hes1 rhythm and down-regulating its expression

Human cytomegalovirus(HCMV) infection is a leading cause of birth defects, primarily affecting the central nervous system and causing its maldevelopment. As the essential downstream effector of Notch signaling pathway, Hes1, and its dynamic expression, plays an essential role on maintaining neural progenitor/stem cells(NPCs) cell fate and fetal brain development. In the present study, we reported the first observation of Hes1 oscillatory expression in human NPCs, with an approximately1.5 hour periodicity and a Hes1 protein half-life of about 17(17.6 ± 0.2) minutes. HCMV infection disrupts the Hes1 rhythm and down-regulates its expression. Furthermore, we discovered that depleting Hes1 protein disturbed NPCs cell fate by suppressing NPCs proliferation and neurosphere formation, and driving NPCs abnormal differentiation. These results suggested a novel mechanism linking disruption of Hes1 rhythm and down-regulation of Hes1 expression to neurodevelopmental disorders caused by congenital HCMV infection.

Angiotensin Type 1 Receptors and Superoxide Anion Production in Hypothalamic Paraventricular Nucleus Contribute to Capsaicin-Induced Excitatory Renal Reflex and Sympathetic Activation

Chemical stimulation of the kidney increases sympathetic activity and blood pressure in rats.The hypothalamic paraventricular nucleus(PVN)is important in mediating the excitatory renal reflex(ERR).In this study,we examined the role of molecular signaling in the PVN in mediating the capsaicin-induced ERR and sympathetic activation.Bilateral PVN microinjections were performed in rats under anesthesia.The ERR was elicited by infusion of capsaicin into the cortico-medullary border of the right kidney.The reflex was evaluated as the capsaicin-induced changes in left renal sympathetic nerve activity and mean arterial pressure.Blockade of angiotensin type 1 receptors with losartan or inhibition of angiotensin-converting enzyme with captopril in the PVN abolished the capsaicin-induced ERR.Renal infusion of capsaicin significantly increased NAD(P)H oxidase activity and superoxide anion production in the PVN,which were prevented by ipsilateral renal denervation or microinjection of losartan into the PVN.Furthermore,either scavenging of superoxide anions or inhibition of NAD(P)H oxidase in the PVN abolished the capsaicin-induced ERR.We conclude that the ERR induced by renal infusion of capsaicin is mediated by angiotensin type 1 receptor-related NAD(P)H oxidase activation and superoxide anion production within the PVN.

An effective system for detecting protein-protein interaction based on in vivo cleavage by PPV NIa protease

Detection of protein-protein interaction can provide valuable information for investigating the biological function of proteins.The current methods that applied in protein-protein interaction,such as co-immunoprecipitation and pull down etc.,often cause plenty of working time due to the burdensome cloning and puri-fication procedures.Here we established a system that characterization of protein-protein interaction was accomplished by co-expression and simply purification of target proteins from one expression cassette within E.coli system.We modified pET vector into co-expression vector pInvivo which encoded PPV NIa protease,two cleavage site F and two multiple cloning sites that flanking cleavage sites.The target proteins(for example:protein A and protein B)were inserted at multiple cloning sites and translated into polyprotein in the order of MBP tag-protein A-site F-PPV NIa protease-site F-protein B-His6 tag.PPV NIa protease carried out intracellular cleavage along expression,then led to the separation of polyprotein components,therefore,the interaction between protein A-protein B can be detected through one-step purification and analysis.Negative control for protein B was brought into this system for monitoring interaction specificity.We successfully employed this system to prove two cases of reported protien-protein interaction:RHA2a/ANAC and FTA/FTB.In conclusion,a convenient and efficient system has been successfully developed for detecting protein-protein interaction.

Correction to:Human cytomegalovirus DNA and immediate early protein 1/2 are highly associated with glioma and prognosis

In the original publication the email addresses of corresponding authors have not been displayed.The correct email addresses of corresponding authors are provided in this correction.Fang-Cheng Li(sjwklfc@126.com),Fei Hu(neuron111@163.com),Min-Hua Luo(luomh@wh.iov.cn).

Human cytomegalovirus DNA and immediate early protein 1/2 are highly associated with glioma and prognosis

Dear Editor,Gliomas are the most common brain tumors in adults which encompass all primary central nervous system(CNS)tumors of glial cell origin.The World Health Organization(WHO)classifies gliomas into four grades based on the histologic/prognostic features.Because of the unclear etiol-ogy and pathogenesis,therapeutic efficacy and prognosis is poor.

Ellipsoidal porous patch with anisotropic cell inducing ability for inhibiting skin scar formation

Scar formation has always been a difficult point to overcome in the field of clinical wound care.Here,we present an ellipsoidal porous patch with cell inducing ability for inhibiting scar formation.The patch was prepared by stretching a poly(lactic-co-glycolic acid)(PLGA)inverse opal film at the glass transition temperature to form a neatly arranged three-dimensional ellipsoidal porous structure.Such anisotropic structure showed dramatic capability in directing cell growth and arrangement by reconstructing cell morphology.Besides,the prolifera-tion of cells growing on the stretched patch was significantly suppressed without cell cytotoxicity.In addition,benefitting from the abundant and connected nanopores,the patch could be imparted with a potent ability to promote cell migration by encapsulating fibroblast growth factor 2(FGF2)via the second filling of functional gelatin methacryloyl(GelMA)hydrogel into its scaffold.In a typical scar model,we have demonstrated that the resultant patch performed well in inhibiting scar formation characterized by inhibiting the excessive proliferation of fibroblasts,decreasing the deposition of type I collagen,reducing the scar index and achieved complete tissue reconstruction.These results indicate the anisotropic inverse opal patch has an excellent application prospect in inhibiting scar formation during wound repair.