Novel insights in phosphodiesterase 4 subtype inhibition to target neuroinflammation and stimulate remyelination

In neurodegenerative and classically demyelinating disorders such as multiple sclerosis(MS),spinal cord injury(SCI),stroke,and Charcot-Marie-Tooth disease,glial functioning is compromised and nervous tissue integrity is lost.Recently,primary neurodegenerative disorders such as Alzheimer’s disease,amyotrophic lateral sclerosis(ALS),and Parkinson’s disease(PD)are increasingly linked to impaired oligodendroglia functioning upon neurodegeneration.Due to the destructive micro-environment created by nervous tissue damage,the progressive cellular loss in these disorders,and the amitotic nature of neurons,spontaneous endogenous repair process are limited in nature.Hence,there is a medical need for efficient therapeutic strategies capable of supporting neuro-reparative processes to occur,likely supported by improved oligodendroglia cell functioning.

The miR-9-5p/CXCL11 pathway is a key target of hydrogen sulfide-mediated inhibition of neuroinflammation in hypoxic ischemic brain injury

We previously showed that hydrogen sulfide(H2S)has a neuroprotective effect in the context of hypoxic ischemic brain injury in neonatal mice.However,the precise mechanism underlying the role of H2S in this situation remains unclear.In this study,we used a neonatal mouse model of hypoxic ischemic brain injury and a lipopolysaccharide-stimulated BV2 cell model and found that treatment with L-cysteine,a H2S precursor,attenuated the cerebral infarction and cerebral atrophy induced by hypoxia and ischemia and increased the expression of miR-9-5p and cystathionineβsynthase(a major H2S synthetase in the brain)in the prefrontal cortex.We also found that an miR-9-5p inhibitor blocked the expression of cystathionineβsynthase in the prefrontal cortex in mice with brain injury caused by hypoxia and ischemia.Furthermore,miR-9-5p overexpression increased cystathionine-β-synthase and H2S expression in the injured prefrontal cortex of mice with hypoxic ischemic brain injury.L-cysteine decreased the expression of CXCL11,an miR-9-5p target gene,in the prefrontal cortex of the mouse model and in lipopolysaccharide-stimulated BV-2 cells and increased the levels of proinflammatory cytokines BNIP3,FSTL1,SOCS2 and SOCS5,while treatment with an miR-9-5p inhibitor reversed these changes.These findings suggest that H2S can reduce neuroinflammation in a neonatal mouse model of hypoxic ischemic brain injury through regulating the miR-9-5p/CXCL11 axis and restoringβ-synthase expression,thereby playing a role in reducing neuroinflammation in hypoxic ischemic brain injury.

Monomeric C-reactive protein:a link between chronic inflammation and neurodegeneration?

Pre-diabetic insulin resistance is associated with sub-clinical inflammation and concomitant increase in systemic C-reactive protein(CRP)levels.Type 2 diabetes mellitus(T2DM)patients register even higher chronic levels of inflammation,with excess circulating CRP originating from both typical hepatic synthesis,and also visceral white adipose tissue.

Advanced brain organoids for neuroinflammation disease modeling

Brain organoids mimic closely the embryonic human brain:Over the last decade,the development of human organoid systems has evolved rapidly.Different tissues have been modeled with organoids,such as the gut,lung,liver,kidney retina and brain.These systems have a high cellular heterogeneity,with many cell types integrated into the same system.Organoids'cellular populations interact between and amongst each other in a cellular and molecular level,which represents an advantage with respects to monolayer 2D cell culture systems.

Sex-dependent alterations in extracellular vesicles linking chronic spinal cord injury to brain neuroinflammation and neurodegeneration

Traumatic spinal cord injury(SCI)is a devastating exogenous injury with long-lasting consequences and a leading cause of death and disability worldwide.Advances in assistive technology,rehabilitative interventions,and the ability to identify and intervene in secondary conditions have significantly increased the long-term survival rate of SCI patients,with some people even living well into their seventh or eighth decade.These survival changes have led neurotrauma researchers to examine how SCI interacts with brain aging.Public health and epidemiological data showed that patients with long-term SCI can have a lower life expectancy and quality of life,along with a higher risk of comorbidities and complications.

Neuroinflammation as a therapeutic target in Huntington's disease

In 1872, George Huntington presented his essay “On Chorea” to the Meigs and Mason Academy of Medicine and, in doing so, detailed a disease that would later bear his name. Huntington's disease(HD) is a genetic, neurodegenerative disease that manifests as the loss of motor control,cognitive impairment,and mood and psychiatric changes in paents.

Kdm6a-CNN1 axis orchestrates epigenetic control of traumainduced spinal cord microvascular endothelial cell senescence to balance neuroinflammation for improved neurological repair

Cellular senescence assumes pivotal roles in various diseases through the secretion of proinflammatory factors.Despite extensive investigations into vascular senescence associated with aging and degenerative diseases,the molecular mechanisms governing microvascular endothelial cell senescence induced by traumatic stress,particularly its involvement in senescence-induced inflammation,remain insufficiently elucidated.In this study,we present a comprehensive demonstration and characterization of microvascular endothelial cell senescence induced by spinal cord injury(SCI).Lysine demethylase 6A(Kdm6a),commonly known as UTX,emerges as a crucial regulator of cell senescence in injured spinal cord microvascular endothelial cells(SCMECs).Upregulation of UTX induces senescence in SCMECs,leading to an amplified release of proinflammatory factors,specifically the senescenceassociated secretory phenotype(SASP)components,thereby modulating the inflammatory microenvironment.Conversely,the deletion of UTX in endothelial cells shields SCMECs against senescence,mitigates the release of proinflammatory SASP factors,and promotes neurological functional recovery after SCI.UTX forms an epigenetic regulatory axis by binding to calponin 1(CNN1),orchestrating trauma-induced SCMECs senescence and SASP secretion,thereby influencing neuroinflammation and neurological functional repair.Furthermore,local delivery of a senolytic drug reduces senescent SCMECs and suppresses proinflammatory SASP secretion,reinstating a local regenerative microenvironment and enhancing functional repair after SCI.In conclusion,targeting the UTX-CNN1 epigenetic axis to prevent trauma-induced SCMECs senescence holds the potential to inhibit SASP secretion,alleviate neuroinflammation,and provide a novel treatment strategy for SCI repair.

Human endogenous retrovirus type-W and multiple sclerosis–related smoldering neuroinflammation

Introduction to human endogenous retrovirus type-W(HERV-W): Genomic inheritance from the past includes retroviral sequences that have been stably incorporated into our genomes and account for up to 8% of human DNA.

Systemic low-grade inflammation associated with specific depressive symptoms:insights from network analyses of five independent NHANES samples

To the editor:Major depressive disorder(MDD)is a heterogeneous disorder with varying symptom presentations and underlying biological mechanisms.1 The mainstream neurobiological hypotheses of depression involve monoamine neurotransmitters,hypothalamic-pituitary-adrenal axis,immune-inflammation and the glutamate system.

Asking one mechanism in glial cells during neuroinflammation

Multiple sclerosis(MS),which is characterized by inflammatory demyelination in the central nervous system(CNS),is the most common neurological disease in the young adult population.Experimental autoimmune encephalomyelitis(EAE),an animal model of MS,is often used in preclinical studies.Accumulating data indicate that in addition to immune cells such as T cells and dendritic cells,CNS resident microglia and astrocytes play important roles in demyelinating neuroinflammation(Healy et al.,2022).In particular,microglia are key immune-competent cells that can respond to environmental changes.Conditional depletion of transforming growth factor-β-activated kinase 1,a mitogen-associated protein kinase kinase kinase,in microglia is reported to reduce CNS inflammation and diminish axonal and myelin damage significantly.This suggests that elucidating the mechanisms of microglia-specific responses during pathologies may help in the development of treatments that reduce EAE/MS disease severity(Goldmann et al.,2013).

Coumarin and eugenol ameliorate LPS-induced inflammation in RAW 264.7 cells via modulating the NLRP3 inflammasome pathway

Objective:To investigate the underlying mechanism of anti-inflammatory action of coumarin and eugenol in lipopolysaccharide(LPS)-stimulated RAW 264.7 cells.Methods:RAW 264.7 cells were treated with 2.5μg/mL of LPS,50μM of coumarin,and 50μM eugenol for 24 h.The viability of the cells was assessed using MTT assay.The production of nitric oxide was determined using Griess reagent and DCFH-DA was used to measure the production of reactive oxygen species.The protein expression of NLRP3,IL-1β,NF-κB,and cyclooxygenase 2 was assessed using Western blot analysis.Results:Coumarin and eugenol showed anti-inflammatory effects against LPS-induced inflammatory response by ameliorating the expression of NLRP3 inflammasome and NF-κB,which further led to a subsequent reduction in IL-1β,nitric oxide,and reactive oxygen species.Conclusions:Coumarin and eugenol exert their anti-inflammatory activities by modulating the NLRP3 inflammasome pathway and NF-κB.These compounds may have promising therapeutic applications for the treatment of various inflammatory diseases.

Immunomodulation of Proton-activated G Protein-coupled Receptors in Inflammation

Proton-activated G protein-coupled receptors(GPCRs),initially discovered by Ludwig in 2003,are widely distributed in various tissues.These receptors have been found to modulate the immune system in several inflammatory diseases,including inflammatory bowel disease,atopic dermatitis,and asthma.Proton-activated GPCRs belong to the G protein-coupled receptor family and can detect alternations in extracellular pH.This detection triggers downstream signaling pathways within the cells,ultimately influencing the function of immune cells.In this review,we specifically focused on investigating the immune response of proton-activated GPCRs under inflammatory conditions.

Benzydamine hydrochloride ameliorates ethanol-induced inflammation in RAW 264.7 macrophages by stabilizing redox homeostasis

Objective:To evaluate the protective effect of benzydamine hydrochloride against ethanol-induced oxidative stress and inflammation in RAW 264.7 macrophages.Methods:RAW 264.7 macrophages were treated with ethanol(100 mM)and benzydamine hydrochloride(7.5μM).The imflammatory status was confirmed by measuring pro-(TNF-αand IL-6)and anti-inflammatory(IL-10)cytokines through ELISA and RT-PCR assays.Reactive oxygen species generation and mitochondrial membrane potential were investigated to study the protective role of benzydamine hydrochloride against ethanol-induced oxidative stress.Apoptosis detection was also investigated using flow cytometry and acridine orange/ethidium bromide staining.Results:Benzydamine hydrochloride significantly decreased the secretion of TNF-αand IL-6,as well as the generation of reactive oxygen species inside the cells,thereby stabilizing the mitochondrial membrane potential and reducing DNA fragmentation.The ethanol-induced cellular necrosis was also reversed by the administration of benzydamine hydrochloride.Conclusions:Benzydamine hydrochloride ameliorates ethanol-induced cell apoptosis and inflammation in RAW macrophages.

Quercetin Alleviates Lipopolysaccharide-Induced Cardiac Inflammation via Inhibiting Autophagy and Programmed Cell Death

Objective The aim of this study is to explore the potential modulatory role of quercetin against Endotoxin or lipopolysaccharide(LPS)induced septic cardiac dysfunction.Methods Specific pathogen-free chicken embryos(n=120)were allocated untreated control,phosphate buffer solution(PBS)vehicle,PBS with ethanol vehicle,LPS(500 ng/egg),LPS with quercetin treatment(10,20,or 40 nmol/egg,respectively),Quercetin groups(10,20,or 40 nmol/egg).Fifteenday-old embryonated eggs were inoculated with abovementioned solutions via the allantoic cavity.At embryonic day 19,the hearts of the embryos were collected for histopathological examination,RNA extraction,real-time polymerase chain reaction,immunohistochemical investigations,and Western blotting.Results They demonstrated that the heart presented inflammatory responses after LPS induction.The LPS-induced higher mRNA expressions of inflammation-related factors(TLR4,TNFα,MYD88,NF-κB1,IFNγ,IL-1β,IL-8,IL-6,IL-10,p38,MMP3,and MMP9)were blocked by quercetin with three dosages.Quercetin significantly decreased immunopositivity to TLR4 and MMP9 in the treatment group when compared with the LPS group.Quercetin significantly decreased protein expressions of TLR4,IFNγ,MMP3,and MMP9 when compared with the LPS group.Quercetin treatment prevented LPS-induced increase in the mRNA expression of Claudin 1 and ZO-1,and significantly decreased protein expression of claudin 1 when compared with the LPS group.Quercetin significantly downregulated autophagyrelated gene expressions(PPARα,SGLT1,APOA4,AMPKα1,AMPKα2,ATG5,ATG7,Beclin-1,and LC3B)and programmed cell death(Fas,Bcl-2,CASP1,CASP12,CASP3,and RIPK1)after LPS induction.Quercetin significantly decreased immunopositivity to APOA4,AMPKα2,and LC3-II/LC3-I in the treatment group when compared with the LPS group.Quercetin significantly decreased protein expressions of AMPKα1,LC3-I,and LC3-II.Quercetin significantly decreased the protein expression to CASP1 and CASP3 by immunohistochemical investigation or Western blotting in treatment group when compared with LPS group.Conclusion Quercetin alleviates cardiac inflammation induced by LPS through modulating autophagy,programmed cell death,and myocardiocytes permeability.

Tilapia Head Glycolipid Alleviates Indomethacin-Induced Gastric Ulcer via Regulating Oxidative Stress and Inflammation Through COX/PGE2 Signaling Pathway in Adult Rats

The aim of this experiment was to investigate the ameliorative effect and molecular mechanism of tilapia head glycolipid(TH-GL)on indomethacin(IDM)-induced gastric ulcer in male Sprague Dawley(SD)rats.The gastric ulcer model was established by oral administration of 30mgkg^(-1) IDM after 7 days of TH-GL or omeprazole(OME)administration in rats.Then the macroscopic gastric injury symptoms,gastric mucosa protective factor cyclooxygenase 1(COX-1),cyclooxygenase 2(COX-2),prostaglandin E_(2)(PGE_(2)),the levels of oxidative stress,and inflammatory cytokine expression levels in the rats were analyzed.The experimental results showed that multiple ulcers appeared on the gastric surface of the rats in the model group.Compared to the model group,TH-GL significantly alleviated gastric ulcers and reduced the gastric damage index in rats.In addition,TH-GL significantly promoted the expression of constitutive enzyme COX-1 while inhibited the expression of inducible enzyme COX-2,and make PGE2 maintain at normal levels.TH-GL also inhibited oxidative stress and inflammatory responses,increased superoxide dismutase(SOD)activity and glutathione(GSH)content,decreased the level of malondialdehyde(MDA)and the content of pro-inflammatory factor.In conclusion,these results suggested that TH-GL could maintain the expression levels of COX-1 and PGE2 while inhibit the expression of COX-2 in the gastric of rat and then prevent IDM-induced gastric ulcer,which may be related to the regulation of oxidative stress and inflammatory response.Therefore,TH-GL might be a new option for the prevention of gastric diseases induced by IDM.

Boeravinone B ameliorates allergic nasal inflammation by modulating the GATA-3/T-bet signaling pathway in a mouse model of allergic rhinitis

Objective:To evaluate the anti-allergic effect of boeravinone B against ovalbumin-induced allergic rhinitis in mice and explore its possible mechanism.Methods:For the induction of allergic rhinitis,mice were intraperitoneally sensitized and intranasally challenged with ovalbumin,as well as orally received various concentrations of boeravinone B.Nasal mucosal inflammation,and the levels of nitric oxide,β-hexosaminidase,IFN-γ,LTC-4,myeloperoxidase,Nrf2,HO-1,GATA-3,ROR-γ,T-bet,antioxidant parameters,and allergen-specific cytokines were assessed.Results:Boeravinone B markedly reduced ovalbumin-induced increase in the number of episodes of nasal sneezing,rubbing,and discharge,as well as the levels of IgE,IgG1,andβ-hexosaminidase(P<0.05).It also significantly reduced differential cell count,myeloperoxidase,oxide-nitrosative stress,and the levels of IL-1β,IL-4,IL-5,IL-6,IL-13,IL-17,tumor necrosis factor-α,GATA-3,and ROR-γwhile enhancing the level of T-bet.Conclusions:Boeravinone B is a potential therapeutic agent for allergic rhinitis by modulating various inflammatory mediators and immune responses.

Bowel function and inflammation: Is motility the other side of the coin?

Digestion and intestinal absorption allow the body to sustain itself and are the emblematic functions of the bowel.On the flip side,functions also arise from its role as an interface with the environment.Indeed,the gut houses microorganisms,collectively known as the gut microbiota,which interact with the host,and is the site of complex immune activities.Its role in human pathology is complex and scientific evidence is progressively elucidating the functions of the gut,especially regarding the pathogenesis of chronic intestinal diseases and inflammatory conditions affecting various organs and systems.This editorial aims to highlight and relate the factors involved in the pathogenesis of intestinal and systemic inflammation.

Metabolite acetyl-L-carnitine participates in Bifidobacterium animalis F1-7 to ameliorate atherosclerotic inflammation by downregulating theTLR4/NF-κB pathway

This study aimed to explore the effect of Bifidobacterium animalis F1-7 on the improvement of atherosclerotic inflammation.Arteriosclerosis model ApoE^(-/-)mice were orally administered with B.animalis F1-7 for 12 weeks.The probiotic intervention reduced the plaque areas in aorta and the accumulation of macrophages,and downregulated the expression of toll-like receptor 4(TLR4)/nuclear factorκB(NF-κB)pathway to reduce the levels of inflammatory factors.The widely-targeted metabolomics analysis showed that acetyl-L-carnitine(ALC)in the intestine of atherosclerotic mice was significantly increased after B.animalis F1-7 intervention.Correlation analysis proved that ALC was associated with atherosclerotic inflammatory response.By using oxidized low density lipoprotein induced macrophage foam cells,we further verified that ALC could reduce lipid accumulation and inflammatory response in foam cells by downregulating the TLR4/NF-κB pathway.Finally,our results revealed that B.animalis F1-7 upregulated the metabolite ALC to downregulate the inflammatory responses,leading to the reduction of plaque accumulation of atherosclerosis.

All-trans retinoic acid alleviates transmissible gastroenteritis virus-induced intestinal inflammation and barrier dysfunction in weaned piglets

Background Transmissible gastroenteritis virus(TGEV)is one of the main pathogens causing severe diarrhea of pig-lets.The pathogenesis of TGEV is closely related to intestinal inflammation.All-trans retinoic acid(ATRA)is the main active metabolite of vitamin A,which has immunomodulatory and anti-inflammatory properties.However,it is unclear whether ATRA can alleviate TGEV-induced intestinal inflammation and barrier dysfunction in piglets.This study aimed to investigate the effects of ATRA on growth performance,diarrhea,intestinal inflammation and intesti-nal barrier integrity of TGEV-challenged piglets.Methods In a 19-d study,32 weaned piglets were randomly divided into 4 treatments:Control group(basal diet),TGEV group(basal diet+TGEV challenge),TGEV+ATRA5 group(basal diet+5 mg/d ATRA+TGEV challenge)and TGEV+ATRA15 group(basal diet+15 mg/d ATRA+TGEV challenge).On d 14,piglets were orally administered TGEV or the sterile medium.Results Feeding piglets with 5 and 15 mg/d ATRA alleviated the growth inhibition and diarrhea induced by TGEV(P<0.05).Feeding piglets with 5 and 15 mg/d ATRA also inhibited the increase of serum diamine oxidase(DAO)activ-ity and the decrease of occludin and claudin-1 protein levels in jejunal mucosa induced by TGEV,and maintained intestinal barrier integrity(P<0.05).Meanwhile,5 mg/d ATRA feeding increased the sucrase activity and the expres-sions of nutrient transporter related genes(GLUT2 and SLC7A1)in jejunal mucosa of TGEV-challenged piglets(P<0.05).Furthermore,5 mg/d ATRA feeding attenuated TGEV-induced intestinal inflammatory response by inhibit-ing the release of interleukin(IL)-1β,IL-8 and tumor necrosis factor-α(TNF-α),and promoting the secretion of IL-10 and secretory immunoglobulin A(sIgA)(P<0.05).Feeding 5 mg/d ATRA also down-regulated the expressions of Toll-like receptors and RIG-I like receptors signaling pathway related genes(TLR3,TLR4,RIG-I,MyD88,TRIF and MAVS)and the phosphorylation level of nuclear factor-κB-p65(NF-κB p65),and up-regulated the inhibitor kappa B alpha(IκBα)protein level in jejunal mucosa of TGEV-challenged piglets(P<0.05).Conclusions ATRA alleviated TGEV-induced intestinal barrier damage by inhibiting inflammatory response,thus improving the growth performance and inhibiting diarrhea of piglets.The mechanism was associated with the inhibi-tion of NF-κB signaling pathway mediated by TLR3,TLR4 and RIG-I.

Protective effects of CY-09 and astaxanthin on NaIO_(3)-induced photoreceptor inflammation via the NLRP3/autophagy pathway

AIM:To study the effect of the NLRP3/autophagy pathway on the photoreceptor inflammatory response and the protective mechanism of CY-09 and astaxanthin(AST).METHODS:ICR mice were intraperitoneally injected NaIO_(3),CY-09,AST successively and divided into 5 groups,including the control,NaIO_(3),NaIO_(3)+CY-09,NaIO_(3)+AST,and NaIO_(3)+CY-09+AST groups.Spectral domain optical coherence tomography and flash electroretinogram were examined and the retina tissues were harvested for immunohistochemistry,enzyme linked immunosorbent assay(ELISA),and Western blotting.Retinal pigment epithelium cell line(ARPE-19 cells)and mouse photoreceptor cells line(661W cells)were also treated with NaIO_(3),CY-09,and AST successively.Cell proliferation was assessed by cell counting kit-8(CCK-8)assay.Apoptosis was analyzed by flow cytometry.Changes in autophagosome morphology were observed by transmission electron microscopy.Quantitative polymerase chain reaction(qPCR)was used to detect NLRP3 and caspase-1.NLRP3,caspase-1,cleaved caspase-1,p62,Beclin-1,and LC3 protein levels were measured by Western blotting.IL-1βand IL-18 were measured by ELISA.RESULTS:Compared with the control group,the activity of NaIO_(3)-treated 661W cells decreased within 24 and 48h,apoptosis increased,NLRP3,caspase-1,IL-1βand IL-18 levels increased,and autophagy-related protein levels increased(P<0.05).Compared with NaIO_(3) group,CY-09 and AST inhibited apoptosis(P<0.05),reduced NLRP3,caspase-1,IL-1βand IL-18 expression(P<0.05),and inhibited autophagy.Compared with the other groups,CY-09 combined with AST significantly decreased NLRP3 expression and inhibited the expression of the autophagy-related proteins p62,Beclin-1,and LC3 in vitro and in vivo(P<0.05).CONCLUSION:CY-09 and AST inhibit NaIO_(3)-induced inflammatory damage through the NLRP3/autophagy pathway in vitro and in vivo.CY-09 and AST may protect retina from inflammatory injury.