ORMDL3 regulates NLRP3 inflammasome activation by maintaining ER-mitochondria contacts in human macrophages and dictates ulcerative colitis patient outcome.

Genome-wide association studies in inflammatory bowel disease have identified risk loci in the orosomucoid-like protein 3/ORMDL sphingolipid biosynthesis regulator 3 (ORMDL3) gene to confer susceptibility to ulcerative colitis (UC), but the underlying functional relevance remains unexplored. Here, we found that a subpopulation of the UC patients who had higher disease activity shows enhanced expression of ORMDL3 compared to the patients with lower disease activity and the non-UC controls. We also found that the patients showing high ORMDL3 mRNA expression have elevated interleukin-1ß cytokine levels indicating positive correlation. Further, knockdown of ORMDL3 in the human monocyte-derived macrophages resulted in significantly reduced interleukin-1ß release. Mechanistically, we report for the first time that ORMDL3 contributes to a mounting inflammatory response via modulating mitochondrial morphology and activation of the NLRP3 inflammasome. Specifically, we observed an increased fragmentation of mitochondria and enhanced contacts with the endoplasmic reticulum (ER) during ORMDL3 over-expression, enabling efficient NLRP3 inflammasome activation. We show that ORMDL3 that was previously known to be localized in the ER also becomes localized to mitochondria-associated membranes and mitochondria during inflammatory conditions. Additionally, ORMDL3 interacts with mitochondrial dynamic regulating protein Fis-1 present in the mitochondria-associated membrane. Accordingly, knockdown of ORMDL3 in a dextran sodium sulfate -induced colitis mouse model showed reduced colitis severity. Taken together, we have uncovered a functional role for ORMDL3 in mounting inflammation during UC pathogenesis by modulating ER-mitochondrial contact and dynamics.

Pattern recognition receptor signaling in human dendritic cells is enhanced by ICOS ligand and modulated by the Crohn's disease ICOSLG risk allele.

Inflammatory bowel disease (IBD) is characterized by dysregulated intestinal immune homeostasis and cytokine secretion. Multiple loci are associated with IBD, but a functional explanation is missing for most. Here we found that pattern-recognition receptor (PRR)-induced cytokine secretion was diminished in human monocyte-derived dendritic cells (MDDC) from rs7282490 ICOSLG GG risk carriers. Homotypic interactions between the costimulatory molecule ICOS and the ICOS ligand on MDDCs amplified nucleotide-binding oligomerization domain 2 (NOD2)-initiated cytokine secretion. This amplification required arginine residues in the ICOSL cytoplasmic tail that recruited the adaptor protein RACK1 and the kinases PKC and JNK leading to PKC, MAPK, and NF-κB activation. MDDC from rs7282490 GG risk-carriers had reduced ICOSL expression and PRR-initiated signaling and this loss-of-function ICOSLG risk allele associated with an ileal Crohn's disease phenotype, similar to polymorphisms in NOD2. Taken together, ICOSL amplifies PRR-initiated outcomes, which might contribute to immune homeostasis.

Dynamic scaling and stochastic fractal in nucleation and growth processes.

A class of nucleation and growth models of a stable phase is investigated for various different growth velocities. It is shown that for growth velocities v ≈ s ( t ) / t and v ≈ x / τ ( x ), where s ( t ) and τ are the mean domain size of the metastable phase (M-phase) and the mean nucleation time, respectively, the M-phase decays following a power law. Furthermore, snapshots at different time t that are taken to collect data for the distribution function c ( x , t ) of the domain size x of the M-phase are found to obey dynamic scaling. Using the idea of data-collapse, we show that each snapshot is a self-similar fractal. However, for v = const ., such as in the classical Kolmogorov-Johnson-Mehl-Avrami model, and for v ≈ 1 / t, the decays of the M-phase are exponential and they are not accompanied by dynamic scaling. We find a perfect agreement between numerical simulation and analytical results.

The gut-liver-kidney axis: Novel regulator of fatty liver associated chronic kidney disease.

Increased interest in understanding the liver-kidney axis in health and disease during the last decade unveiled multiple recent evidence that suggested a strong association of fatty liver diseases with chronic kidney disease (CKD). Low-grade systemic inflammation is thought to be the major contributing factor to the pathogenesis of CKD associated with fatty liver. However, other contributing factors largely remained unclear, for example, gut microbiota and intestinal barrier integrity. Homeostasis of the gut microbiome is very crucial for the health of an individual. Imbalance in the gut microbiota leads to various diseases like fatty liver disease and CKD. On the contrary, disease conditions can also distinctly change gut microbiota. In this review, we propose the pathogenic role of the gut-liver-kidney axis in the development and progression of CKD associated with chronic fatty liver diseases, either non-alcoholic fatty liver disease or non-alcoholic steatohepatitis in experimental models and humans. Further, we discuss the therapeutic potential and highlight the future research directions for therapeutic targeting of the gut-liver-kidney axis.

Huntingtin-interacting protein 1 (HIP1) regulates arthritis severity and synovial fibroblast invasiveness by altering PDGFR and Rac1 signalling.

OBJECTIVES: While new treatments for rheumatoid arthritis (RA) have markedly improved disease control by targeting immune/inflammatory pathways, current treatments rarely induce remission, underscoring the need for therapies that target other aspects of the disease. Little is known about the regulation of disease severity and joint damage, which are major predictors of disease outcome, and might be better or complementary targets for therapy. In this study, we aimed to discover and characterise a new arthritis severity gene. METHODS: An unbiased and phenotype-driven strategy including studies of unique congenic rat strains was used to identify new arthritis severity and joint damage genes. Fibroblast-like synoviocytes (FLS) from rats and patients with RA expressing or not Huntingtin-interacting protein 1 (HIP1) were studied for invasiveness, morphology and cell signalling. HIP1 knockout mice were used in in vivo confirmatory studies. Paired t-test was used. RESULTS: DNA sequencing and subcongenic strains studied in pristane-induced arthritis identified a new amino acid changing functional variant in HIP1. HIP1 was required for the increased invasiveness of FLS from arthritic rats and from patients with RA. Knocking down HIP1 expression reduced receptor tyrosine kinase-mediated responses in RA FLS, including RAC1 activation, affecting actin cytoskeleton and cell morphology and interfering with the formation of lamellipodia, consistent with reduced invasiveness. HIP1 knockout mice were protected in KRN serum-induced arthritis and developed milder disease. CONCLUSION: HIP1 is a new arthritis severity gene and a potential novel prognostic biomarker and target for therapy in RA.

MTMR3 risk allele enhances innate receptor-induced signaling and cytokines by decreasing autophagy and increasing caspase-1 activation.

Inflammatory bowel disease (IBD) is characterized by dysregulated host:microbial interactions and cytokine production. Host pattern recognition receptors (PRRs) are critical in regulating these interactions. Multiple genetic loci are associated with IBD, but altered functions for most, including in the rs713875 MTMR3/HORMAD2/LIF/OSM region, are unknown. We identified a previously undefined role for myotubularin-related protein 3 (MTMR3) in amplifying PRR-induced cytokine secretion in human macrophages and defined MTMR3-initiated mechanisms contributing to this amplification. MTMR3 decreased PRR-induced phosphatidylinositol 3-phosphate (PtdIns3P) and autophagy levels, thereby increasing PRR-induced caspase-1 activation, autocrine IL-1ß secretion, NFκB signaling, and, ultimately, overall cytokine secretion. This MTMR3-mediated regulation required the N-terminal pleckstrin homology-GRAM domain and Cys413 within the phosphatase domain of MTMR3. In MTMR3-deficient macrophages, reducing the enhanced autophagy or restoring NFκB signaling rescued PRR-induced cytokines. Macrophages from rs713875 CC IBD risk carriers demonstrated increased MTMR3 expression and, in turn, decreased PRR-induced PtdIns3P and autophagy and increased PRR-induced caspase-1 activation, signaling, and cytokine secretion. Thus, the rs713875 IBD risk polymorphism increases MTMR3 expression, which modulates PRR-induced outcomes, ultimately leading to enhanced PRR-induced cytokines.

T cell-extrinsic CD18 attenuates antigen-dependent CD4+ T cell activation in vivo.

The ß2 integrins (CD11/CD18) are heterodimeric leukocyte adhesion molecules expressed on hematopoietic cells. The role of T cell-intrinsic CD18 in trafficking of naive T cells to secondary lymphoid organs and in Ag-dependent T cell activation in vitro and in vivo has been well defined. However, the T cell-extrinsic role for CD18, including on APC, in contributing to T cell activation in vivo is less well understood. We examined the role for T cell-extrinsic CD18 in the activation of wild-type CD4(+) T cells in vivo through the adoptive transfer of DO11.10 Ag-specific CD4(+) T cells into CD18(-/-) mice. We found that T cell-extrinsic CD18 was required for attenuating OVA-induced T cell proliferation in peripheral lymph nodes (PLN). The increased proliferation of wild-type DO11.10 CD4(+) T cells in CD18(-/-) PLN was associated with a higher percentage of APC, and these APC demonstrated an increased activation profile and increased Ag uptake, in particular in F4/80(+) APC. Depletion of F4/80(+) cells both reduced and equalized Ag-dependent T cell proliferation in CD18(-/-) relative to littermate control PLN, demonstrating that these cells play a critical role in the enhanced T cell proliferation in CD18(-/-) mice. Consistently, CD11b blockade, which is expressed on F4/80(+) macrophages, enhanced the proliferation of DO11.10 CD4(+) T cells in CD18(+/-) PLN. Thus, in contrast to the T cell-intrinsic essential role for CD18 in T cell activation, T cell-extrinsic expression of CD18 attenuates Ag-dependent CD4(+) T cell activation in PLN in vivo.

Peptide utilizing carbon starvation gene yjiY is required for flagella mediated infection caused by Salmonella.

Peptide metabolism forms an important part of the metabolic network of Salmonella and to acquire these peptides the pathogen possesses a number of peptide transporters. While various peptide transporters known in Salmonella are well studied, very little is known about the carbon starvation (cst) genes, cstA and yjiY, which are also predicted to be involved in peptide metabolism. We investigated the role of these genes in the metabolism and pathogenesis of Salmonella and demonstrated for the first time that cst genes actually participate in transport of specific peptides in Salmonella. Further, we established that the carbon starvation gene yjiY affects the expression of flagella leading to poor adhesion of the bacterium to host cells. In contrast with the previously reported role of the gene cstA in virulence of Salmonella in C. elegans, we showed that yjiY is required for successful colonization of Salmonella in the mouse gut. Thus, cst genes not only contribute to the metabolism of Salmonella but also influence its virulence.

NOD2 regulates CXCR3-dependent CD8+ T cell accumulation in intestinal tissues with acute injury.

Polymorphisms in NOD2 confer risk for Crohn's disease, characterized by intestinal inflammation. How NOD2 regulates both inflammatory and regulatory intestinal T cells, which are critical to intestinal immune homeostasis, is not well understood. Anti-CD3 mAb administration is used as therapy in human autoimmune diseases, as well as a model of transient intestinal injury. The stages of T cell activation, intestinal injury, and subsequent T tolerance are dependent on migration of T cells into the small intestinal (SI) lamina propria. Upon anti-CD3 mAb treatment of mice, we found that NOD2 was required for optimal small intestinal IL-10 production, in particular from CD8(+) T cells. This requirement was associated with a critical role for NOD2 in SI CD8(+) T cell accumulation and induction of the CXCR3 ligands CXCL9 and CXCL10, which regulate T cell migration. NOD2 was required in both the hematopoietic and nonhematopoietic compartments for optimal expression of CXCR3 ligands in intestinal tissues. NOD2 synergized with IFN-γ to induce CXCL9 and CXCL10 secretion in dendritic cells, macrophages, and intestinal stromal cells in vitro. Consistent with the in vitro studies, during anti-CD3 mAb treatment in vivo, CXCR3 blockade, CD8(+) T cell depletion, or IFN-γ neutralization each inhibited SI CD8(+) T cell recruitment, and reduced chemokine expression and IL-10 expression. Thus, NOD2 synergizes with IFN-γ to promote CXCL9 and CXCL10 expression, thereby amplifying CXCR3-dependent SI CD8(+) T cell migration during T cell activation, which, in turn, contributes to induction of both inflammatory and regulatory T cell outcomes in the intestinal environment.

Activation of pattern recognition receptors up-regulates metallothioneins, thereby increasing intracellular accumulation of zinc, autophagy, and bacterial clearance by macrophages.

BACKGROUND & AIMS: Continuous stimulation of pattern recognition receptors (PRRs), including nucleotide-binding oligomerization domain-2 (NOD2) (variants in NOD2 have been associated with Crohn's disease), alters the phenotype of myeloid-derived cells, reducing production of inflammatory cytokines and increasing microbe clearance. We investigated the mechanisms by which microbial clearance increases in macrophages under these conditions. METHODS: Monocytes were purified from human peripheral blood mononuclear cells and differentiated to monocyte-derived macrophages (MDMs). We also isolated human intestinal macrophages. Bacterial clearance by MDMs was assessed in gentamicin protection assays. Effects of intracellular zinc and autophagy were measured by flow cytometry, immunoblot, reverse-transcription polymerase chain reaction, and microscopy experiments. Small interfering RNAs were used to knock down specific proteins in MDMs. NOD2-/- and C57BL/6J mice, maintained in a specific pathogen-free facility, were given antibiotics, muramyl dipeptide (to stimulate NOD2), or dextran sodium sulfate; intestinal lamina propria cells were collected and analyzed. RESULTS: Chronic stimulation of human MDMs through NOD2 up-regulated the expression of multiple genes encoding metallothioneins, which bind and regulate levels of intracellular zinc. Intestinal myeloid-derived cells are stimulated continually through PRRs; metallothionein expression was up-regulated in human and mouse intestinal myeloid-derived cells. Continuous stimulation of NOD2 increased the levels of intracellular zinc, thereby increasing autophagy and bacterial clearance. The metal-regulatory transcription factor-1 (MTF-1) was required for regulation of metallothionein genes in human MDMs. Knockdown of MTF-1 did not affect baseline clearance of bacteria by MDMs. However, the increase in intracellular zinc, autophagy, and bacterial clearance observed with continuous NOD2 stimulation was impaired in MDMs upon MTF-1 knockdown. The addition of zinc or induction of autophagy restored bacterial clearance to MDMs after metallothionein knockdown. NOD2 synergized with the PRRs Toll-like receptors 5 and 9 increase the effects of metallothioneins in MDMs. In mice, the intestinal microbiota contributed to the regulation in expression of metallothioneins, levels of zinc, autophagy, and bacterial clearance by intestinal macrophages. CONCLUSIONS: In studies of human MDMs and in mice, continuous stimulation of PRRs induces expression of metallothioneins. This leads to increased levels of intracellular zinc and enhanced clearance of bacteria via autophagy in macrophages.

Cooperative STAT3-NFkB signaling modulates mitochondrial dysfunction and metabolic profiling in hepatocellular carcinoma.

BACKGROUND: Hepatocellular carcinoma (HCC) continues to pose a significant health challenge and is often diagnosed at advanced stages. Metabolic reprogramming is a hallmark of many cancer types, including HCC and it involves alterations in various metabolic or nutrient-sensing pathways within liver cells to facilitate the rapid growth and progression of tumours. However, the role of STAT3-NFκB in metabolic reprogramming is still not clear. APPROACH AND RESULTS: Diethylnitrosamine (DEN) administered animals showed decreased body weight and elevated level of serum enzymes. Also, Transmission electron microscopy (TEM) analysis revealed ultrastructural alterations. Increased phosphorylated signal transducer and activator of transcription-3 (p-STAT3), phosphorylated nuclear factor kappa B (p-NFκß), dynamin related protein 1 (Drp-1) and alpha-fetoprotein (AFP) expression enhance the carcinogenicity as revealed in immunohistochemistry (IHC). The enzyme-linked immunosorbent assay (ELISA) concentration of IL-6 was found to be elevated in time dependent manner both in blood serum and liver tissue. Moreover, immunoblot analysis showed increased level of p-STAT3, p-NFκß and IL-6 stimulated the upregulation of mitophagy proteins such as Drp-1, Phosphatase and tensin homolog (PTEN)-induced putative kinase 1 (PINK-1). Meanwhile, downregulation of Poly [ADP-ribose] polymerase 1 (PARP-1) and cleaved caspase 3 suppresses apoptosis and enhanced expression of AFP supports tumorigenesis. The mRNA level of STAT3 and Drp-1 was also found to be significantly increased. Furthermore, we performed high-field 800 MHz Nuclear Magnetic Resonance (NMR) based tissue and serum metabolomics analysis to identify metabolic signatures associated with the progression of liver cancer. The metabolomics findings revealed aberrant metabolic alterations in liver tissue and serum of 75th and 105th days of intervention groups in comparison to control, 15th and 45th days of intervention groups. Tissue metabolomics analysis revealed the accumulation of succinate in the liver tissue samples, whereas, serum metabolomics analysis revealed significantly decreased circulatory levels of ketone bodies (such as 3-hydroxybutyrate, acetate, acetone, etc.) and membrane metabolites suggesting activated ketolysis in advanced stages of liver cancer. CONCLUSION: STAT3-NFκß signaling axis has a significant role in mitochondrial dysfunction and metabolic alterations in the development of HCC.

Role of mitochondria in regulating immune response during bacterial infection.

Mitochondria are dynamic organelles of eukaryotes involved in energy production and fatty acid oxidation. Besides maintaining ATP production, calcium signaling, cellular apoptosis, and fatty acid synthesis, mitochondria are also known as the central hub of the immune system as it regulates the innate immune pathway during infection. Mitochondria mediated immune functions mainly involve regulation of reactive oxygen species production, inflammasome activation, cytokine secretion, and apoptosis of infected cells. Recent findings indicate that cellular mitochondria undergo constant biogenesis, fission, fusion and degradation, and these dynamics regulate cellular immuno-metabolism. Several intracellular pathogens target and modulate these normal functions of mitochondria to facilitate their own survival and growth. De-regulation of mitochondrial functions and dynamics favors bacterial infection and pathogens are able to protect themselves from mitochondria mediated immune responses. Here, we will discuss how mitochondria mediated anti-bacterial immune pathways help the host to evade pathogenic insult. In addition, examples of bacterial pathogens modulating mitochondrial metabolism and dynamics will also be elaborated. Study of these interactions between the mitochondria and bacterial pathogens during infection will lead to a better understanding of the mitochondrial metabolism pathways and dynamics important for the establishment of bacterial diseases. In conclusion, detailed studies on how mitochondria regulate the immune response during bacterial infection can open up new avenues to develop mitochondria centric anti-bacterial therapeutics.

Role of mitochondrial dysfunction in the pathogenesis of rheumatoid arthritis: Looking closely at fibroblast- like synoviocytes.

Rheumatoid arthritis (RA) is a chronic, autoimmune, and inflammatory disease that primarily targets the joints, leading to cartilage and bone destruction.Fibroblast-like synoviocytes (FLS) are specialized cells of the synovial lining in the joint that plays a fundamental role in the development of RA. Particularly, FLS of RA patients (RA-FLS) in the joint exhibit specific characteristics like higher invading and immunogenic properties, hyperproliferation, and reduced apoptotic capacity, suggesting a dysfunctional mitochondrial pool in these cells. Mitochondria are emerging as a potential organelle that can decide cellular immunometabolism, invasion properties, and cell death. Accordingly, multiplestudies established that mitochondria are crucial in establishing RA. However, the underlying mechanism of impaired mitochondrial function in RA remains poorly understood. This review will provide an overview of the mitochondrial role in the progression of RA, specifically in the context of FLS biology. We will also outline how mitochondria-centric therapeutics can be achieved that would yield novel avenues of research in pathological mediation and prevention.

CLUH functions as a negative regulator of inflammation in human macrophages and determines ulcerative colitis pathogenesis.

Altered mitochondrial function without a well-defined cause has been documented in patients with ulcerative colitis (UC). In our efforts to understand UC pathogenesis, we observed reduced expression of clustered mitochondrial homolog (CLUH) only in the active UC tissues compared with the unaffected areas from the same patient and healthy controls. Stimulation with bacterial Toll-like receptor (TLR) ligands similarly reduced CLUH expression in human primary macrophages. Further, CLUH negatively regulated secretion of proinflammatory cytokines IL-6 and TNF-α and rendered a proinflammatory niche in TLR ligand-stimulated macrophages. CLUH was further found to bind to mitochondrial fission protein dynamin related protein 1 (DRP1) and regulated DRP1 transcription in human macrophages. In the TLR ligand-stimulated macrophages, absence of CLUH led to enhanced DRP1 availability for mitochondrial fission, and a smaller dysfunctional mitochondrial pool was observed. Mechanistically, this fissioned mitochondrial pool in turn enhanced mitochondrial ROS production and reduced mitophagy and lysosomal function in CLUH-knockout macrophages. Remarkably, our studies in the mouse model of colitis with CLUH knockdown displayed exacerbated disease pathology. Taken together, this is the first report to our knowledge explaining the role of CLUH in UC pathogenesis, by means of regulating inflammation via maintaining mitochondrial-lysosomal functions in the human macrophages and intestinal mucosa.

Modulation of the arginase pathway in the context of microbial pathogenesis: a metabolic enzyme moonlighting as an immune modulator.

Arginine is a crucial amino acid that serves to modulate the cellular immune response during infection. Arginine is also a common substrate for both inducible nitric oxide synthase (iNOS) and arginase. The generation of nitric oxide from arginine is responsible for efficient immune response and cytotoxicity of host cells to kill the invading pathogens. On the other hand, the conversion of arginine to ornithine and urea via the arginase pathway can support the growth of bacterial and parasitic pathogens. The competition between iNOS and arginase for arginine can thus contribute to the outcome of several parasitic and bacterial infections. There are two isoforms of vertebrate arginase, both of which catalyze the conversion of arginine to ornithine and urea, but they differ with regard to tissue distribution and subcellular localization. In the case of infection with Mycobacterium, Leishmania, Trypanosoma, Helicobacter, Schistosoma, and Salmonella spp., arginase isoforms have been shown to modulate the pathology of infection by various means. Despite the existence of a considerable body of evidence about mammalian arginine metabolism and its role in immunology, the critical choice to divert the host arginine pool by pathogenic organisms as a survival strategy is still a mystery in infection biology.

Typhoid fever & vaccine development: a partially answered question.

Typhoid fever is a systemic disease caused by the human specific Gram-negative pathogen Salmonella enterica serovar Typhi (S. Typhi). The extra-intestinal infections caused by Salmonella are very fatal. The incidence of typhoid fever remains very high in impoverished areas and the emergence of multidrug resistance has made the situation worse. To combat and to reduce the morbidity and mortality caused by typhoid fever, many preventive measures and strategies have been employed, the most important being vaccination. In recent years, many Salmonella vaccines have been developed including live attenuated as well as DNA vaccines and their clinical trials have shown encouraging results. But with the increasing antibiotic resistance, the development of potent vaccine candidate for typhoid fever is a need of the hour. This review discusses the latest trends in the typhoid vaccine development and the clinical trials which are underway.

FOXO3a acetylation regulates PINK1, mitophagy, inflammasome activation in murine palmitate-conditioned and diabetic macrophages.

Nucleotide-binding oligomerization domain, leucine-rich repeat, and pyrin domain containing 3 inflammasome and mitophagy play an important role in cytokine release and diabetes progression; however, the role of saturated fatty acid that is induced under such conditions remains little explored. Therefore, the present study evaluates mechanisms regulating mitophagy and inflammasome activation in primary murine diabetic and palmitate-conditioned wild-type (WT) peritoneal macrophages. Peritoneal macrophage, from the diabetic mice and WT mice, challenged with LPS/ATP and palmitate/LPS/ATP, respectively, showed dysfunctional mitochondria as assessed by their membrane potential, mitochondrial reactive oxygen species (mtROS) production, and mitochondrial DNA (mtDNA) release. A defective mitophagy was observed in the diabetic and palmitate-conditioned macrophages stimulated with LPS/ATP as assessed by translocation of PTEN-induced kinase 1 (PINK1)/Parkin or p62 in the mitochondrial fraction. Consequently, increased apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC) oligomerization, caspase-1 activation, and IL1ß secretion were observed in LPS/ATP stimulated diabetic and palmitate-conditioned macrophages. LPS/ATP induced Forkhead box O3a (FOXO3a) binding to PINK1 promoter and increased PINK1 mRNA expression in WT macrophages. However, PINK1 mRNA and protein expression were significantly decreased in diabetic and palmitate-conditioned macrophages in response to LPS/ATP. Palmitate-induced acetyl CoA promoted FOXO3a acetylation, which prevented LPS/ATP-induced FOXO3a binding to the PINK1 promoter. C646 (P300 inhibitor) and SRT1720 (SIRT1 activator) prevented FOXO3a acetylation and restored FOXO3a binding to the PINK1 promoter, PINK1 mRNA expression, and mitophagy in palmitate-conditioned macrophages treated with LPS/ATP. Also, a significant decrease in the LPS/ATP-induced mtROS production, mtDNA release, ASC oligomerization, caspase-1 activation, and IL-1ß release was observed in the palmitate-conditioned macrophages. Similarly, modulation of FOXO3a acetylation also prevented LPS/ATP-induced mtDNA release and inflammasome activation in diabetic macrophages. Therefore, FOXO3a acetylation regulates PINK1-dependent mitophagy and inflammasome activation in the palmitate-conditioned and diabetic macrophages.

Estradiol overcomes adiponectin-resistance in diabetic mice by regulating skeletal muscle adiponectin receptor 1 expression.

Adiponectin and insulin resistance creates a vicious cycle that exacerbates type 2 diabetes. Earlier, we observed that female leptin receptor-deficient BLKS mice (BKS-db/db) were more sensitive to an adiponectin mimetic GTDF than males, which led us to explore if E2 plays a crucial role in modulation of adiponectin-sensitivity. Male but not female BKS-db/db mice were resistant to metabolic effects of globular adiponectin treatment. Male BKS-db/db displayed reduced skeletal muscle AdipoR1 protein expression, which was consequent to elevated polypyrimidine tract binding protein 1 (PTB) and miR-221. E2 treatment in male BKS-db/db, and ovariectomized BALB/c mice rescued AdipoR1 protein expression via downregulation of PTB and miR-221, and also directly increased AdipoR1 mRNA by its classical nuclear receptors. Estrogen receptor regulation via dietary or pharmacological interventions may improve adiponectin resistance and consequently ameliorate insulin resistance in type 2 diabetes.

A machine learning-based approach to determine infection status in recipients of BBV152 (Covaxin) whole-virion inactivated SARS-CoV-2 vaccine for serological surveys.

Data science has been an invaluable part of the COVID-19 pandemic response with multiple applications, ranging from tracking viral evolution to understanding the vaccine effectiveness. Asymptomatic breakthrough infections have been a major problem in assessing vaccine effectiveness in populations globally. Serological discrimination of vaccine response from infection has so far been limited to Spike protein vaccines since whole virion vaccines generate antibodies against all the viral proteins. Here, we show how a statistical and machine learning (ML) based approach can be used to discriminate between SARS-CoV-2 infection and immune response to an inactivated whole virion vaccine (BBV152, Covaxin). For this, we assessed serial data on antibodies against Spike and Nucleocapsid antigens, along with age, sex, number of doses taken, and days since last dose, for 1823 Covaxin recipients. An ensemble ML model, incorporating a consensus clustering approach alongside the support vector machine model, was built on 1063 samples where reliable qualifying data existed, and then applied to the entire dataset. Of 1448 self-reported negative subjects, our ensemble ML model classified 724 to be infected. For method validation, we determined the relative ability of a random subset of samples to neutralize Delta versus wild-type strain using a surrogate neutralization assay. We worked on the premise that antibodies generated by a whole virion vaccine would neutralize wild type more efficiently than delta strain. In 100 of 156 samples, where ML prediction differed from self-reported uninfected status, neutralization against Delta strain was more effective, indicating infection. We found 71.8% subjects predicted to be infected during the surge, which is concordant with the percentage of sequences classified as Delta (75.6%-80.2%) over the same period. Our approach will help in real-world vaccine effectiveness assessments where whole virion vaccines are commonly used.

TolA mediates the differential detergent resistance pattern between the Salmonella enterica subsp. enterica serovars Typhi and Typhimurium.

The tol-pal genes are essential for maintaining the outer membrane integrity and detergent resistance in various Gram-negative bacteria, including Salmonella. The role of TolA has been well established for the bile resistance of Salmonella enterica subsp. enterica serovar Typhimurium. We compared the bile resistance pattern between the S. enterica serovars Typhi and Typhimurium and observed that Typhi is more resistant to bile-mediated damage. A closer look revealed a significant difference in the TolA sequence between the two serovars which contributes to the differential detergent resistance. The tolA knockout of both the serovars behaves completely differently in terms of membrane organization and morphology. The role of the Pal proteins and difference in LPS organization between the two serovars were verified and were found to have no direct connection with the altered bile resistance. In normal Luria broth (LB), S. Typhi ΔtolA is filamentous while S. Typhimurium ΔtolA grows as single cells, similar to the wild-type. In low osmolarity LB, however, S. Typhimurium ΔtolA started chaining and S. Typhi ΔtolA showed no growth. Further investigation revealed that the chaining phenomenon observed was the result of failure of the outer membrane to separate in the dividing cells. Taken together, the results substantiate the evolution of a shorter TolA in S. Typhi to counteract high bile concentrations, at the cost of lower osmotic tolerance.