Sodium butyrate suppresses NOD1-mediated inflammatory molecules expressed in bovine hepatocytes during iE-DAP and LPS treatment

A high concentrate diet inhibits forkhead box protein A2 expression, and induces oxidative stress, mitochondrial dysfunction and mitochondrial unfolded protein response in the liver of dairy cows

High-concentrate diet induce subacute ruminal acidosis (SARA) and cause liver damage in ruminants. It has been reported that forkhead box protein A2 (FOXA2) can enhance mitochondrial membrane potential but its function in mitochondrial dysfunction induced by high concentrate diets is still unknown. Therefore, the aim of this study was to elucidate the effect of high-concentrate (HC) diet on hepatic FOXA2 expression, mitochondrial unfolded protein response (UPRmt), mitochondrial dysfunction and oxidative stress. A total of 12 healthy mid-lactation Holstein cows were selected and randomized into 2 groups: the low concentrate (LC) diet group (concentrate:forage = 4:6) and HC diet group (concentrate:forage = 6:4). The trial lasted 21 d. The rumen fluid, blood and liver tissue were collected at the end of the experiment. The results showed that the rumen fluid pH level was reduced in the HC group and the pH was lower than 5.6 for more than 4 h/d, indicating that feeding HC diets successfully induced SARA in dairy cows. Both FOXA2 mRNA and protein abundance were significantly reduced in the liver of the HC group compared with the LC group. The activity of antioxidant enzymes (CAT, G6PDH, T-SOD, Cu/Zn SOD, Mn SOD) and mtDNA copy number in the liver tissue of the HC group decreased, while the level of H2O2 significantly increased, this increase was accompanied by a decrease in oxidative phosphorylation (OXPHOS). The balance of mitochondrial division and fusion was disrupted in the HC group, as evidenced by the decreased mRNA level of OPA1, MFN1, and MFN2 and increased mRNA level of Drp1, Fis1, and MFF. At the same time, HC diet downregulated the expression level of SIRT1, SIRT3, PGC-1α, TFAM, and Nrf 1 to inhibit mitochondrial biogenesis. The HC group induced UPRmt in liver tissue by upregulating the mRNA and protein levels of CLPP, LONP1, CHOP, Hsp10, and Hsp60. In addition, HC diet could increase the protein abundance of Bax, CytoC, Caspase 3 and Cleaved-Caspase 3, while decrease the protein abundance of Bcl-2 and the Bcl-2/Bax ratio. Overall, our study suggests that the decreased expression of FOXA2 may be related to UPRmt, mitochondrial dysfunction, oxidative stress, and apoptosis in the liver of dairy cows fed a high concentrate diet.

Butyrate Protects against γ-d-Glutamyl-meso-diaminopimelic Acid-Induced Inflammatory Response and Tight Junction Disruption through Histone Deacetylase 3 Inhibition in Bovine Mammary Epithelial Cells

The present study was conducted to evaluate the regulatory actions and underlying mechanisms of butyrate on the inflammatory response and tight junction (TJ) disruption in bovine mammary epithelial cells (BMECs). Results showed that butyrate declined histone deacetylase 3 (HDAC3) expression, blocked NF-κB activation, and thus suppressed inflammatory cytokine production in γ-d-glutamyl-meso-diaminopimelic acid (iE-DAP)-triggered BMECs. Butyrate also depressed the protein abundance of myosin light chain kinase (MLCK), elevated the expression of TJ proteins, and restored the cellular distribution of TJ proteins and the barrier function of epithelial cells. HDAC3 overexpression abolished the protective effects of butyrate. In conclusion, butyrate alleviated the iE-DAP-induced inflammatory response and TJ injury by blocking NF-κB activation and decreasing inflammatory cytokine production and MLCK expression in a HDAC3-dependent manner. Our finding provides a mechanistic basis for further exploring the regulatory effects of butyrate on the mammary inflammatory response.

AMPK-endoplasmic reticulum stress axis contributes to lipopolysaccharide-caused mitochondrial dysfunction by regulating mitochondria-associated membrane function in bovine hepatocytes

Mitochondrial homeostasis is closely associated with cellular homeostasis process, whereas mitochondrial dysfunction contributes to apoptosis and mitophagy. Hence, analyzing the mechanism of lipopolysaccharide (LPS)-caused mitochondrial damage is necessary to understand how cellular homeostasis is maintained in bovine hepatocytes. Mitochondria-associated membranes (MAM), a connection between endoplasmic reticulum (ER) and mitochondria, is important to control mitochondrial function. To investigate the underlying mechanisms of the LPS-caused mitochondrial dysfunction, hepatocytes isolated from dairy cows at ∼160 d in milk (DIM) were pretreated with the specific inhibitors of adenosine 5'-monophosphate-activated protein kinase (AMPK), ER stress, RNA-activated protein kinase-like ER kinase (PERK), inositol-requiring enzyme 1α (IRE1α), c-Jun N-terminal kinase, and autophagy followed by a 12 μg/mL LPS treatment. The results showed that inhibiting ER stress with 4-phenylbutyric acid decreased the levels of autophagy and mitochondrial damage with AMPK inactivation in LPS-treated hepatocytes. The AMPK inhibitor compound C pretreatment alleviated LPS-induced ER stress, autophagy and mitochondrial dysfunction by regulating the expression of MAM-related genes, such as mitofusin 2 (MFN2), PERK, and IRE1α. Moreover, inhibiting PERK and IRE1α mitigated autophagy and mitochondrial dynamic disruption by regulating the MAM function. Additionally, blocking c-Jun N-terminal kinase, the downstream sensor of IRE1α, could reduce the levels of autophagy and apoptosis and restore the balance of mitochondrial fusion and fission by modulating the B cell leukemia 2 (BCL-2)/BCL-2 interacting protein 1 (BECLIN1) complex in the LPS-treated bovine hepatocytes. Furthermore, autophagy blockage with chloroquine could intervene in LPS-caused apoptosis to restore mitochondrial function. Collectively, these findings suggest that the AMPK-ER stress axis is involved in the LPS-caused mitochondrial dysfunction by mediating the MAM activity in bovine hepatocytes.

Nutraceutical Effect of Resveratrol on the Mammary Gland: Focusing on the NF-κb /Nrf2 Signaling Pathways

The aim of this study is to evaluate the defensive role of resveratrol, which is antagonistic to the oxidative stress and inflammation that is prompted by LPS in mammary tissue of female mice. Thirty adult mice were distributed into three groups (n = 10) control (CON), lipopolysaccharides at 2.5 mg/kg (LPS), and lipopolysaccharides at 2.5 mg/kg with 2 mg/kg of resveratrol (RES + LPS). The treatments were applied for 15 consecutive days. Spectrophotometry was used to quantify ROS in the blood, and proinflammatory cytokines concentrations were determined through radioimmunoassay. NF-κB, Jnk, IL-1β, Erk, IL-6, Nrf2 and TNF-α were quantified by RT-qPCR, and Western blots were used to quantifyP65 and pP65 protein intensities. MDA production was considerably increased, and the activity of T-AOC declined in the LPS treatment in comparison with the CON group but was significantly reversed in the RES + LPS group. Proinflammatory cytokines production and the genes responsible for inflammation and oxidative stress also showed higher mRNA and pP65 protein intensity in the LPS group, while Nrf2 showed a remarkable decline in mRNA expression in the LPS versus the CON group. All these mRNA intensities were reversed in the RES + LPS group. There were no remarkable changes in P65 protein intensity observed between the CON, LPS, and RES + LPS groups. In conclusion, resveratrol acts as a protective agent to modulate cellular inflammation and oxidative stress caused by LPS in mammary tissue of female mice.

iE-DAP Induced Inflammatory Response and Tight Junction Disruption in Bovine Mammary Epithelial Cells via NOD1-Dependent NF-κB and MLCK Signaling Pathway

γ-D-glutamyl-meso-diaminopimelic acid (iE-DAP), a bacterial cell wall component, can trigger an inflammatory response. A mammary inflammatory response causes tight junction (TJ) dysfunction. This study aimed to explore the effects and involved mechanisms of iE-DAP-induced inflammatory response on the TJ integrity in bovine mammary epithelial cells (BMECs). The results showed that iE-DAP-induced inflammatory response and TJ disruption was associated with increased expression levels of inflammatory cytokines and decreased gene expression of ZO-1 and Occludin, as well as a reduction in transepithelial electrical resistance and elevation in paracellular dextran passage. While MLCK inhibitor ML-7 reversed the TJ disruption induced by iE-DAP. NF-κB inhibitor BAY 11-7085 hindered the activation of NF-κB and MLCK signaling pathways, the inflammatory response and TJ disruption induced by iE-DAP. NOD1-specific shRNA also inhibited the activation of the NOD1/NF-κB signaling pathway and reversed the inflammatory response and TJ injury in iE-DAP-treated BMECs. Above results suggest that iE-DAP activated the NF-κB and MLCK signaling pathway in NOD1-dependent manner, which promoted the transcription of inflammatory cytokines and altered the expression and distribution of tight junction proteins, finally caused inflammatory response and TJ disruption. This study might provide theoretical basis and scientific support for the prevention and treatment of mastitis.

Forkhead box protein A2 alleviates toll-like receptor 4-mediated inflammation, endoplasmic reticulum stress, autophagy, and apoptosis induced by lipopolysaccharide in bovine hepatocytes

Lipopolysaccharide (LPS) is an important stimulus of inflammation via binding to toll-like receptor 4 (TLR4), but the role of TLR4 in LPS-induced cellular homeostasis disruption indicated by the increased level of endoplasmic reticulum (ER) stress, autophagy, and apoptosis is unknown in the liver of dairy cows. Previous studies show that forkhead box protein A2 (FOXA2) is an important transcriptional factor to maintain cellular metabolic homeostasis, but the mechanisms by which FOXA2 mediates cellular homeostasis disruption in response to LPS remains unclear. To achieve the aims, hepatocytes separated from dairy cows at ∼160 d in milk were pretreated with a specific TLR4 inhibitor TAK-242 for 12 h, followed by LPS treatment for another 12 h to investigate the role of TLR4 in LPS-induced disruption of cellular homeostasis. The results indicated that LPS-induced nuclear factor-κB (NF-κB)-mediated inflammatory cascades, ER stress, autophagy, and apoptosis via activating TLR4 and downregulating FOXA2 expression in bovine hepatocytes. The application of TLR4 inhibitor alleviated LPS-induced inflammation through inactivating NF-κB proinflammatory pathway, restored cell homeostasis by decreasing the level of ER stress, autophagy, and apoptosis, and upregulated FOXA2 expression. Furthermore, we also elevated FOXA2 expression with an overexpression plasmid to clarify its molecular role in response to LPS challenge. FOXA2 overexpression reduced LPS-caused inflammation by inhibiting NF-κB signaling pathway. Also, FOXA2 could alleviate ER stress to block unfolded protein response and suppress autophagic flux. In addition, FOXA2 enhanced mitochondrial membrane potential via reducing pro-apoptotic protein BAX, CASPASE3, and Cleaved CASPASE3 expression and elevating anti-apoptotic protein BCL-2 expression to mitigate LPS-induced apoptosis. Taken together, these findings suggested that FOXA2 is a mediator to alleviate TLR4-controlled inflammation, ER stress, autophagy, and apoptosis in LPS-treated bovine hepatocytes, it could serve as a potential target to intervene cell homeostasis disruption caused by LPS in the liver of dairy cows.

The RIPK family: expression profile and prognostic value in lung adenocarcinoma

Receptor interacting protein kinases (RIPKs) are a family of serine/threonine kinases which are supposed to regulate tumor generation and progression. Rare study illustrates the roles and functions of RIPKs family in lung adenocarcinoma (LUAD) comprehensively. Our results indicated that the expression of RIPK2 higher in LUAD patients while RIPK5 (encoded by gene DSTYK) expression was lower. Only RIPK2 had a strong correlation with pathological stage in LUAD patients. Kaplan-Meier plotter revealed that LUAD patients with low RIPK2 or RIPK3 level showed better overall survival (OS), but worse when LUAD patients with high RIPK5. Further, lower expression of RIPK2 and higher expression of RIPK1, RIPK4 and RIPK5 prompted a longer disease free survival (DFS). Genetic alterations based on cBioPortal revealing 16% alteration rates of RIPK2, as well as RIPK5. We also found that the functions of RIPKs family were linked to cellular senescence, protein serine/threonine kinase activity, apoptosis process et al. TIMER database indicated that the RIPKs family members had distinct relationships with the infiltration of six types of immune cells (macrophages, neutrophils, CD8+ T-cells, B-cells, CD4+ T-cells and dendritic cells). Moreover, RIPK2 could be observed as an independent prognostic factor with Cox proportional hazard model analysis. DiseaseMeth databases revealed that the global methylation levels of RIPK2 increased in LUAD patients. Thus, the findings above will enhance the understanding of RIPKs family in LUAD pathology and progression, providing novel insights into RIPKs-core therapy for LUAD patients.

Berberine Ameliorates Dextran Sulfate Sodium-Induced Ulcerative Colitis and Inhibits the Secretion of Gut Lysozyme via Promoting Autophagy

Ulcerative colitis (UC) is one of the primary types of inflammatory bowel disease, the occurrence of which has been increasing worldwide. Research in recent years has found that the level of lysozyme in the feces and blood of UC patients is abnormally elevated, and the bacterial product after the action of lysozyme can be used as an agonist to recognize different cell pattern receptors, thus regulating the process of intestinal inflammation. Berberine (BBR), as a clinical anti-diarrhea and anti-inflammatory drug, has been used in China for hundreds of years. In this study, results showed that BBR can significantly inhibit the expression and secretion of lysozyme in mice. Therefore, we try to investigate the mechanism behind it and elucidate the new anti-inflammatory mechanism of BBR. In vitro, lipopolysaccharide (LPS) was used to establish an inflammatory cell model, and transcriptomic was used to analyze the differentially expressed genes (DEGs) between the LPS group and the LPS + BBR treatment group. In vivo, dextran sulfate sodium salt (DSS) was used to establish a UC mice model, and histologic section and immunofluorescence trails were used to estimate the effect of BBR on UC mice and the expression of lysozyme in Paneth cells. Research results showed that BBR can inhibit the expression and secretion of lysozyme by promoting autophagy via the AMPK/MTOR/ULK1 pathway, and BBR promotes the maturation and expression of lysosomes. Accordingly, we conclude that inhibiting the expression and secretion of intestinal lysozyme is a new anti-inflammatory mechanism of BBR.

Exon-Intron Circular RNA circRNF217 Promotes Innate Immunity and Antibacterial Activity in Teleost Fish by Reducing miR-130-3p Function

Circular RNA (circRNA) is produced by splicing head to tail and is widely distributed in multicellular organisms, and circRNA reportedly can participate in various cell biological processes. In this study, we discovered a novel exon-intron circRNA derived from probable E3 ubiquitin-protein ligase RNF217 (RNF217) gene, namely, circRNF217, which was related to the antibacterial responses in teleost fish. Results indicated that circRNF217 played essential roles in host antibacterial immunity and inhibited the Vibrio anguillarum invasion into cells. Our study also found a microRNA miR-130-3p, which could inhibit antibacterial immune response and promote V. anguillarum invasion into cells by targeting NOD1. Moreover, we also found that the antibacterial effect inhibited by miR-130-3p could be reversed with circRNF217. In mechanism, our data revealed that circRNF217 was a competing endogenous RNA of NOD1 by sponging miR-130-3p, leading to activation of the NF-κB pathway and then enhancing the innate antibacterial responses. In addition, we also found that circRNF217 can promote the antiviral response caused by Siniperca chuatsi rhabdovirus through targeting NOD1. Our study provides new insights for understanding the impact of circRNA on host-pathogen interactions and formulating fish disease prevention to resist the severely harmful V. anguillarum infection.

A new paradigm for a new simple chemical: butyrate & immune regulation

Short-chain fatty acids (SCFAs) play an important role in the host system. Among SCFAs, butyrate has received particular attention for its large effect on host immunity, particularly in supplying energy to enterocytes and producing immune cells. Butyrate enters the cells through the Solute Carrier Family 5 Member 8 (SLC5A8) transporters, then works as a histone deacetylase inhibitor (HDAC) that inhibits the activation of Nuclear factor-κB (NF-κB), which down-regulates the expression of IL-1β, IL-6, TNF-α. Meanwhile, butyrate acts as a ligand to activate G protein-coupled receptors GPR41, GPR43, and GPR109, promoting the expression of anti-inflammatory factors. Besides, it inhibits the proinflammatory factors. Further, it can also suppress the expression of chemokines and reduce inflammation to maintain host homeostasis. This paper reviews the research progress highlighting the potential function of butyrate as a factor impacting intestinal health, obesity and brain disorders.

Sodium Butyrate More Effectively Mitigates the Negative Effects of High-Concentrate Diet in Dairy Cows than Sodium β-Hydroxybutyrate via Reducing Free Bacterial Cell Wall Components in Rumen Fluid and Plasma

The present study was aimed at investigating the effects of sodium butyrate and sodium β-hydroxybutyrate on lactation and health of dairy cows fed a high-concentrate (HC) diet. Eighty mid-lactation dairy cows with an average milk yield of 33.75 ± 5.22 kg/d were randomly allocated to four groups (n = 20 per group) and were fed either a low-concentrate (LC) diet, a HC diet, the HC diet with 1% sodium butyrate (HCSB), or the HC diet with 1% sodium β-hydroxybutyrate (HCHB). The feeding trial lasted for 7 weeks, with a 2-week adaptation period and a 5-week measurement period, and the trial started from 96 ± 13 d in milk. Sodium butyrate supplementation delayed the decline in milk production and improved milk synthesis efficiency and milk fat content. Additionally, it decreased the proinflammatory cytokines and acute phase proteins (APPs) in plasma, the leucocytes in blood, the somatic cell count (SCC) in milk, and the gene expression of pattern recognition receptors (PRRs) and proinflammatory cytokines in the mammary gland, due to decreasing the contents of bacterial cell wall components (lipopolysaccharide, LPS; peptidoglycan, PGN; and lipoteichoic acid, LTA) in the rumen and plasma, compared with the HC diet. Sodium β-hydroxybutyrate supplementation also improved milk yield, milk synthesis efficiency and milk fat content and partially reduced the adverse effects caused by the HC diet, but it had no effect on decreasing bacterial cell wall components in the rumen and plasma, compared with the HC diet. Collectively, both sodium butyrate and sodium β-hydroxybutyrate mitigated the negative effects of HC diet on lactation and health of dairy cows, with sodium butyrate being more effective than sodium β-hydroxybutyrate.

Glutamine pretreatment protects bovine mammary epithelial cells from inflammation and oxidative stress induced by γ-d-glutamyl-meso-diaminopimelic acid (iE-DAP)

Glutamine (GLN) has many types of biological activity in rats, including anti-inflammatory, antioxidative stress, and anti-apoptosis effects. However, little is known about the effects of GLN on bovine mammary epithelial cells (BMEC). γ-d-Glutamyl-meso-diaminopimelic acid (iE-DAP) is a cell wall peptidoglycan component of gram-negative bacteria that can be recognized by the intracellular receptor nucleotide-binding oligomerization domain-containing protein 1 (NOD1) and can cause bovine mastitis. The goal of the present study was to investigate whether GLN protects BMEC from iE-DAP-induced inflammation, oxidative stress, and apoptosis. We cultured BMEC in a GLN-free medium for 24 h and then separated them into 4 groups: cells treated with 1× PBS for 26 or 32 h (control); cells stimulated by 10 μg/mL iE-DAP for 2 or 8 h (2- or 8-h iE-DAP); cells pretreated with 8 or 4 mM GLN for 24 h followed by 2 or 8 h of 1× PBS treatment (8 or 4 mM GLN); and cells pretreated with 8 or 4 mM GLN for 24 h followed by 2 or 8 h of iE-DAP treatment (DG). In the 2-h iE-DAP group, when levels of inflammation peaked, iE-DAP treatment increased both the mRNA and protein expression of NOD1, inhibitor of nuclear factor-κB (NFKBIA, IκB), and nuclear factor-κB subunit p65 (RELA, NF-κB p65), as well as the mRNA expression of IL6 and IL8 and levels of IL-6 and tumor necrosis factor-α in cell culture supernatants. In contrast, 8 mM GLN pretreatment inhibited the mRNA and protein expression of inflammatory-related factors by suppressing the NOD1/NF-κB pathway. In the 8-h iE-DAP group, iE-DAP treatment decreased the mRNA and protein expression of extracellular regulated kinase (Erk, ERK) and nuclear factor erythroid 2-associated factor2 (NFE2L2, Nrf2), as well as the mRNA expression of superoxide dismutase 1 (SOD1), catalase (CAT), coenzyme II oxidoreductase 1 (NQO1), and heme oxygenase 1 (HMOX1, HO1). In addition, iE-DAP treatment increased the expression of malondialdehyde in BMEC when oxidative stress levels peaked. Interestingly, 4 mM GLN pretreatment induced the mRNA and protein expression of antioxidative stress-related factors and inhibited the expression of reactive oxygen species in BMEC by promoting the ERK/Nrf2 pathway. Moreover, GLN reduced apoptosis caused by inflammation and oxidative stress in BMEC. This is the first report showing that GLN protects against iE-DAP-induced inflammation and oxidative stress via the NOD1/NF-κB and ERK/Nrf2 pathways in BMEC.

Sodium valproate attenuates the iE-DAP induced inflammatory response by inhibiting the NOD1-NF-κB pathway and histone modifications in bovine mammary epithelial cells

The anti-inflammatory effects of sodium valproate (VPA) in vivo and in vitro have been demonstrated in recent studies. The aim of this study was to evaluate whether VPA can suppress inflammation in bovine mammary epithelial cells (BMECs) stimulated by γ-D-glutamyl-meso-diaminopimelic acid (iE-DAP). First, the concentration and treatment points of iE-DAP and VPA were optimized. Then, BMECs were cultured in complete media and separated into four groups: untreated control cells (CON group), cells stimulated by 10 μg/mL iE-DAP for 6 h (DAP group), cells stimulated by 0.5 mmol/L VPA for 6 h (VPA group), and cells pretreated with VPA (0.5 mmol/L) for 6 h followed by 10 μg/mL of iE-DAP for 6 h (VD group). The results showed that the level of  interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) in the culture medium increased in the iE-DAP-treated cells and that pretreatment with VPA reversed this increase. iE-DAP increased both mRNA and protein expression levels of nucleotide-binding oligomerization domain-containing protein 1 (NOD1) and receptor-interacting protein kinas (RIPK2) and activated inhibitor of NF-κB (IκB) and nuclear factor-kappa B p65 (NF-κB p65) through phosphorylation. Upon activation of the NF-κB pathway, the expression of the pro-inflammatory cytokines IL-6, interleukin-8 (IL-8) and interleukin-1β (IL-1β), the acute phase protein serum amyloid A 3 (SAA3) and the lingual antimicrobial peptide (LAP) but not  haptoglobi (HP) or bovine neutrophil beta defensing 5 (BNBD5) were increased in the DAP group. The VPA pretreatment induced the acetylation of signal transducers and activators of transcription(STAT1) and histone 3 (H3) by inhibiting histone deacetylase (HDAC) and then suppressed the NF-κB pathway. Moreover, VPA induced autophagy and reduced apoptosis in BMECs in the VD group. These results suggested that VPA treatment can attenuate the inflammatory response induced by iE-DAP.

Microbiome and motor neuron diseases

The microbiome is the ecological community of commensal, symbiotic, and pathogenic microorganisms that share our body space (Medical and Health Genomics, 2016, page 15-28). The human gut is the location where the maximum number of microorganisms can be found. Among the different microorganisms they can be broadly classified into two groups: the beneficial and harmful. In the human gut there is always a balance between the beneficial and the opportunistic microorganism which maintains human health. However, if the balance is not maintained and homeostasis is disturbed, with an increase in opportunistic microorganisms, it may result in various diseases like inflammatory bowel disease, irritable bowel disease, ulcerative colitis, Crohn's disease, colorectal cancer, metabolic disorders and neurodegenerative diseases including motor neuron diseases. In the present chapter we discuss the role of gut bacteria in motor neuron diseases like multiple sclerosis, Parkinson's disease and amyotrophic lateral sclerosis.

Multiple Sclerosis: Melatonin, Orexin, and Ceramide Interact with Platelet Activation Coagulation Factors and Gut-Microbiome-Derived Butyrate in the Circadian Dysregulation of Mitochondria in Glia and Immune Cells

Recent data highlight the important roles of the gut microbiome, gut permeability, and alterations in mitochondria functioning in the pathophysiology of multiple sclerosis (MS). This article reviews such data, indicating two important aspects of alterations in the gut in the modulation of mitochondria: (1) Gut permeability increases toll-like receptor (TLR) activators, viz circulating lipopolysaccharide (LPS), and exosomal high-mobility group box (HMGB)1. LPS and HMGB1 increase inducible nitric oxide synthase and superoxide, leading to peroxynitrite-driven acidic sphingomyelinase and ceramide. Ceramide is a major driver of MS pathophysiology via its impacts on glia mitochondria functioning; (2) Gut dysbiosis lowers production of the short-chain fatty acid, butyrate. Butyrate is a significant positive regulator of mitochondrial function, as well as suppressing the levels and effects of ceramide. Ceramide acts to suppress the circadian optimizers of mitochondria functioning, viz daytime orexin and night-time melatonin. Orexin, melatonin, and butyrate increase mitochondria oxidative phosphorylation partly via the disinhibition of the pyruvate dehydrogenase complex, leading to an increase in acetyl-coenzyme A (CoA). Acetyl-CoA is a necessary co-substrate for activation of the mitochondria melatonergic pathway, allowing melatonin to optimize mitochondrial function. Data would indicate that gut-driven alterations in ceramide and mitochondrial function, particularly in glia and immune cells, underpin MS pathophysiology. Aryl hydrocarbon receptor (AhR) activators, such as stress-induced kynurenine and air pollutants, may interact with the mitochondrial melatonergic pathway via AhR-induced cytochrome P450 (CYP)1b1, which backward converts melatonin to N-acetylserotonin (NAS). The loss of mitochnodria melatonin coupled with increased NAS has implications for altered mitochondrial function in many cell types that are relevant to MS pathophysiology. NAS is increased in secondary progressive MS, indicating a role for changes in the mitochondria melatonergic pathway in the progression of MS symptomatology. This provides a framework for the integration of diverse bodies of data on MS pathophysiology, with a number of readily applicable treatment interventions, including the utilization of sodium butyrate.