Expression Of Proinflammatory Chemokines Research Articles

The cellular response of lipopolysaccharide-induced inflammation in keratoconus human corneal fibroblasts to RB-PDT: Insights into cytokines, chemokines and related signaling pathways.

Rose Bengal Photodynamic Therapy (RB-PDT) offers dual therapeutic benefits by enhancing corneal stiffness and providing antibacterial activity, presenting significant potential for patients with keratoconus complicated by keratitis. Our purpose was to assess the effect of rose bengal photodynamic therapy (RB-PDT) on the expression of pro-inflammatory cytokines and chemokines, as well as on extracellular matrix (ECM)-related molecules, in lipopolysaccharide (LPS)-induced inflammation of keratoconus human corneal fibroblasts (KC-HCFs). Additionally, the involvement of the mitogen-activated protein kinase (MAPK) and nuclear factor kappa B (NF-κB) signaling pathways which are downstream of the Toll-like receptor 4 (TLR4) pathway were examined. KC-HCFs were stimulated with varying concentrations of LPS (0-10 μg/ml), which was followed by RB-PDT. The expression levels of interleukin-1β (IL-1β), IL-6, IL-8, interferon alpha 2 (IFNA2), IFNB1, intercellular adhesion molecule 1 (ICAM-1), chemokine (C-C motif) ligand 4 (CCL-4), collagen I, collagen V, lysyl oxidase (LOX), transforming growth factor β 1(TGF-β1) were measured using qPCR, ELISA, or western blot. The activation of the NF-κB and MAPK pathways was assessed using qPCR and western blot. In LPS-induced inflammation of KC-HCFs, the expression of IL-6 was further amplified by the treatment with RB-PDT (p = 0.001). However, the activation of the MAPK and NF-κB pathways did not increase following RB-PDT. Additionally, RB-PDT reduced the transcription of collagen I and collagen V (p≤0.03), while the transcription of LOX and TGF-β1 secretion remained unchanged in KC-HCFs exposed to LPS. In LPS-induced inflammation of KC-HCFs treated with RB-PDT, despite the increased expression of pro-inflammatory cytokines, the activation of the TLR4 signaling pathways is lacking. RB-PDT may have no adverse effects on corneal scar formation of keratoconus corneas in the short term.

Prenatal Lipopolysaccharide Stimulation Modulates Gastrointestinal Immunity and Oxidative Status in Weaned Pigs.

Gastrointestinal immunity and antioxidant defenses may be bolstered in young animals through prenatal immune system stimulation (PIS), but this is largely uninvestigated in swine. This study tested the hypothesis that PIS could regulate offspring's gastrointestinal immune response and oxidative stress profile. To this end, a PIS model was utilized in sows, delivering low-dose LPS during the final third of gestation to target the developing immune system. On day 78±1.8 of gestation, 14 Camborough sows (parity = 2.6±1.4) received either saline (CON) or LPS from E. coli O111:B4 (2.5 μg/kg of body weight). A subset of 34 weaned barrows (n=17 CON, PIS), weaned at 21±1.3 days, were anesthetized for subcutaneous temperature loggers and jugular catheter placement. Following recovery, all pigs received an intravenous injection of LPS (10 μg/kg body weight) from E. coli O111:B4. Our findings demonstrate that PIS enhances the gut immune response by upregulating key inflammatory cytokines, indicative of a proinflammatory profile. Consistently across the jejunum and ileum, SCF was modulated with heightened expression in PIS than CON (P≤ 0.05). In the ileum alone, PIS exhibited heightened expression of proinflammatory cytokines and chemokines, including TNFα, IL-6, IL-1β, and CCL3L1, compared to CON (P≤ 0.05). Exposure to PIS resulted in reduced systemic total antioxidant capacity (TAC) at hours 2-4 post-challenge (P= 0.004). Piglets exposed to PIS had decreased jejunal tissue malondialdehyde (MDA) concentrations (P= 0.049). Together, these data indicate that exposure to PIS alters the inflammatory profile of the GI immune response and oxidative status in weaned pigs.

OP37 Delineating molecular and microbial signatures across disease severity in Inflammatory Bowel Disease in adult treatment naive patients through single-cell transcriptomic and microbiome profiling.

Abstract Background Inflammatory Bowel Disease (IBD), including Crohn's disease (CD) and Ulcerative Colitis (UC), is a chronic inflammatory condition with complex etiology involving genetic, immune, microbiome, and environmental factors. This study aims to elucidate the cellular and microbial landscape of adult treatment-naive IBD patients with varying disease severity to identify potential disease mechanisms and therapeutic targets, presenting one of the largest single-clinic, IBD single-cell datasets to date. Methods Tissue biopsies were collected from inflamed and non-inflamed regions of the colon in UC patients and colon + ileum in CD patients. Using 10x Genomics single-cell RNA sequencing (scRNA-seq), we analyzed 1.4 million cells from 68 treatment-naive IBD patients (38 CD, 30 UC) and 70 symptomatic healthy controls. Shotgun metagenomic sequencing was performed on 36 IBD patients with matched scRNA-seq data to explore host-microbe interactions, and a further 49 patients with paired clinical data. At presentation, standard clinical metadata, Patient Reported Outcomes, post-biopsy treatment, and 6/12-month treatment response were collected for stratification across disease severity and response. Results Our analysis revealed distinct cellular populations and gene expression profiles between IBD patients and healthy controls along the disease severity axis. Specific immune cell subsets were significantly expanded in IBD patients, with inflammatory monocytes particularly prominent in those with higher disease severity, exhibiting upregulated expression of pro-inflammatory cytokines and chemokines. Additionally, a shift from IgA to IgG antibody-producing cells was observed along the disease severity axis, indicating a dysregulated immune response associated with disease progression. Fecal microbial community typing based on pathway abundance revealed two clusters defined by low or high abundance of Bacteroidetes phylum taxa. Integration with clinical metadata and transcriptional profiles showed that Bacteroidetes-high UC patients displayed lower levels of inflammation and up-regulation of interferon signaling in B cells and myeloid cells. Conclusion This comprehensive profiling of adult treatment-naive IBD patients provides valuable insights into the cellular and microbial factors contributing to IBD prior to treatment perturbation. Our findings offer a deeper understanding of the underlying disease pathology of IBD patients at the time of presentation along the axis of disease severity, expanding the dynamic range of IBD patient profiling and informing future therapeutic strategies that may more quickly put patients on the right treatment and better address the causes of IBD in addition to the inflammatory response alone.

Microbial-derived bile acid reverses inflammation in IBD via GPBAR1 agonism and RORγt inverse agonism

The interplay between the dysbiotic microbiota and bile acids is a critical determinant for development of a dysregulated immune system in inflammatory bowel disease (IBD). Here we have investigated the fecal bile acid metabolome, gut microbiota composition, and immune responses in IBD patients and murine models of colitis and found that IBD associates with an elevated excretion of primary bile acids while secondary, allo- and oxo- bile acids were reduced. These changes correlated with the disease severity, mucosal expression of pro-inflammatory cytokines and chemokines, and reduced inflow of anti-inflammatory macrophages and Treg in the gut. Analysis of bile acids metabolome in the feces allowed the identification of five bile acids: 3-oxo-DCA, 3-oxo-LCA, allo-LCA, iso-allo-LCA and 3-oxo-UDCA, whose excretion was selectively decreased in IBD patients and diseased mice. By transactivation assay and docking calculations all five bile acids were shown to act as GPBAR1 agonists and RORγt inverse agonists, skewing Th17/Treg ratio and macrophage polarization toward an M2 phenotype. In a murine model of colitis, administration of 3-oxo-DCA suffices to reverse colitis development and intestinal dysbiosis in a GPBAR1-dependent manner. In vivo administration of 3-oxo-DCA to colitic mice also reverses disease severity and RORγt activation induced by a RORγt agonist and IL-23, a Th17 inducing cytokine. These results demonstrated that intestinal excretion of 3-oxoDCA, a dual GPBAR1 agonist and RORγt inverse agonist, is reduced in IBD and in models of colitis and its restitution protects against colitis development, highlighting a potential role for this agent in IBD management.

Engineered GM-CSF polarizes protumorigenic tumor-associated macrophages to an antitumorigenic phenotype and potently synergizes with IL-12 immunotherapy

BackgroundThe use of immune checkpoint inhibitors (CPIs) has become a dominant regimen in modern cancer therapy, however immune resistance induced by tumor-associated macrophages (TAMs) with immune suppressive and evasion properties...

SBP1 contributes to mesangial proliferation and inflammation through mitochondrial respiration in glomerulus during IgA nephropathy

Mesangial expansion and proliferation have been implicated in the pathogenesis of IgA nephropathy (IgAN). Mesangial cells in glomerulus are important contributors to commencement of IgAN. From minimal mesangial expansion to diffuse proliferation, the mesangial alteration is linked to clinical and pathological features of IgAN. Although selenium-binding protein 1 (SBP1) is associated with tissue injury, the roles of SBP1 in mesangial proliferation and inflammation in glomerulus during IgAN remains unclear. In the present study, we found that SBP1 gene levels were elevated in kidney tissues of patients with IgAN. Also, SBP1 protein levels were elevated in proliferative mesangial cells of glomerulus in kidney tissues from patients with IgAN. Urinary SBP1 protein levels were elevated in patients with IgAN. Elevated urinary SBP1 levels were positively correlated with segmental glomerulosclerosis of the Oxford classification related to mesangial proliferation in patients with IgAN. Over-expression of SBP1 induced cellular proliferation via mitochondrial respiration in human renal mesangial cells. Consistently, SBP1 knockdown and mitochondrial respiration inhibition suppressed cellular proliferation and induced mitochondrial oxidative stress in human renal mesangial cells. Furthermore, SBP1 induced pro-inflammatory phenotype by gene expression and production of pro-inflammatory cytokines and chemokines including IL-6, CXCL10, and CCL5 via NF-κB activation in human renal mesangial cells. These results suggest that SBP1 contributes to mesangial proliferation and inflammation via mitochondrial respiration during IgAN.

Aging, brain-derived neurotrophic factor, and allergen-induced pulmonary responses in mice.

Asthma in the elderly is being recognized as more severe, resistant to standard therapies, and having greater morbidity. Therefore, it comes important to understand the impact of aging-associated airway structure and function changes towards pathogenesis of asthma in the elderly. Here, airway smooth muscle plays important roles in airway hyperreactivity and structural remodeling. The role of smooth muscle in asthma can be modulated by growth factors (including neurotrophins such as brain-derived neurotrophic factor (BDNF)) and pro-inflammatory senescence factors. In this study, we investigated aging effects on airway hyperreactivity, structural remodeling, inflammation, and senescence in a mouse model of allergic asthma. C57BL/6J wildtype mice or smooth muscle-specific BDNF knockout mice at 4, 18 and 24 months of age were intranasally exposed to mixed allergens (ovalbumin, aspergillus, Alternaria, and house dust mite) over 4 weeks. Assessing lung function by FlexiVent, we found that compared with 4 month old mice, 18 and 24 month old C57BL/6J mice showed decreased airway resistance and increased airway compliance after PBS or MA treatment. Deletion of smooth muscle BDNF blunted airway hyperreactivity in aged mice. Lung histology analysis revealed that aging increased bronchial airway thickness and decreased lung inflammation. Multiplex assays showed that aging largely reduced allergen-induced lung expression of proinflammatory chemokines and cytokines. By immunohistochemistry staining, we found that aging increased bronchial airway expression of senescence markers, including p21, phospho-p53 and phospho-gH2A.X. Our data suggest that aging associated increase of airway senescence in the context of allergen exposure may contribute to asthma pathology in the elderly.

Abstract P159: Conditional deletion of ADAM17 (A disintegrin and metalloprotease 17) in microglia attenuates hypertension and associated inflammation.

Microglia, the resident immune cell in the brain, contributes to neuroinflammation and neurogenic hypertension by secreting various cytokines and chemokines. ADAM17 shedding of these signaling molecules) in microglia modulates synaptic function but the consequences of this process have not been studied in neurogenic hypertension. Accordingly, we hypothesize that deletion of ADAM17 in microglia opposes microglia activation and cytokine secretion thus preventing the development of neuroinflammation in salt-sensitive hypertension. To test our hypothesis, a new mouse model (ADAM17::CX3CR1-CreERT2; A17-Mic-/-) amenable for selective deletion of ADAM17 in microglia was developed. Following the initiation of deoxycorticosterone acetate plus salt (DOCA-salt) hypertension, tamoxifen was injected intracerebroventricularly to delete ADAM17 in microglia and blood pressure (BP) monitored over 3 weeks. In A17-Mic-/- mice, lacking ADAM17 in microglia, the BP increase induced by DOCA-salt treatment was blunted compared to control mice (127.4±5 vs. 143.4±4 mmHg, P<0.05). However, it was not abated in iRhom2-/- mice (149.5±3 mmHg), lacking the rhomboid protein involved in ADAM17 maturation in microglia, suggesting possible compensation by iRhom1. Interestingly, A17-Mic-/- mice showed a reduced level of proinflammatory cytokines and chemokines in the plasma, including TNF-α (A17-Mic-/-: 5.21±0.97, iRhom2-/-: 3.867±1 vs. control: 20.72±4 pg/mL), IL-6 (A17-Mic-/-: 36.53±11.33, iRhom2-/-: 91.41±14 vs. control: 79.65±15.72 pg/mL) and G-CSF (A17-Mic-/-: 508.4±98.7, iRhom2-/-: 3523±897 vs. 838.2±238.2 pg/mL) and MCP-1 (A17-Mic-/-: 38.41±9, iRhom2-/-: 51.87±7 vs. control: 75.52±12 pg/mL), respectively (P<0.05). Together, our data suggests that conditional deletion of ADAM17 opposes the activation of microglia and reduces pro-inflammatory cytokine and chemokine expression in hypertension. Overall, our data highlights the pivotal role of microglial ADAM17 in regulating salt-sensitive hypertension and the associated inflammation.

Analysis of intracellular communication reveals consistent gene changes associated with early-stage acne skin

A comprehensive understanding of the intricate cellular and molecular changes governing the complex interactions between cells within acne lesions is currently lacking. Herein, we analyzed early papules from six subjects with active acne vulgaris, utilizing single-cell and high-resolution spatial RNA sequencing. We observed significant changes in signaling pathways across seven different cell types when comparing lesional skin samples (LSS) to healthy skin samples (HSS). Using CellChat, we constructed an atlas of signaling pathways for the HSS, identifying key signal distributions and cell-specific genes within individual clusters. Further, our comparative analysis revealed changes in 49 signaling pathways across all cell clusters in the LSS— 4 exhibited decreased activity, whereas 45 were upregulated, suggesting that acne significantly alters cellular dynamics. We identified ten molecules, including GRN, IL-13RA1 and SDC1 that were consistently altered in all donors. Subsequently, we focused on the function of GRN and IL-13RA1 in TREM2 macrophages and keratinocytes as these cells participate in inflammation and hyperkeratinization in the early stages of acne development. We evaluated their function in TREM2 macrophages and the HaCaT cell line. We found that GRN increased the expression of proinflammatory cytokines and chemokines, including IL-18, CCL5, and CXCL2 in TREM2 macrophages. Additionally, the activation of IL-13RA1 by IL-13 in HaCaT cells promoted the dysregulation of genes associated with hyperkeratinization, including KRT17, KRT16, and FLG. These findings suggest that modulating the GRN-SORT1 and IL-13-IL-13RA1 signaling pathways could be a promising approach for developing new acne treatments.

Abstract Mo137: Modulation of the Inflammatory and Fibrotic Effects of Angiotensin on Cardiomyocytes through YAP-mediated Transcription.

Introduction: Signaling through the transcriptional co-activator Yes-associated protein (YAP) has been shown to protect the myocardium against ischemic or mechanical stress. Research Question: In light of the critical role of inflammation on adverse cardiac responses we examined the possibility that YAP regulates inflammatory responses to Angiotensin II (AngII)-mediated stress. Approach: Cardiomyocyte specific YAP-KO mice were generated, implanted with AngII minipumps, infused with AngII (1.5 mg/kg/min) or vehicle for periods of 3 hrs to 3 days and hearts collected for analysis. Results: YAP deletion markedly enhanced AngII-induced mRNA expression of pro-inflammatory cytokines and chemokines (e.g. CCL2, CXCL2, IL-6) at 3 or 24 hrs in the cardiomyocyte, but not non-myocyte cell fraction. Expression of mRNA for the hypertrophic genes ANP and MHC-β, in contrast, was decreased in YAP KO mice. After 3 days of AngII infusion there was enhanced mRNA for pro-fibrotic genes (Col1a1, Col3a1 and Periostin) and increased staining for COL1A1 and F4/80, indicative of increased fibrosis and inflammatory cell recruitment in the absence of YAP signaling. Single cell RNA sequencing revealed specific subsets of genes that were upregulated in the cardiomyocyte subcluster from YAP KO mice. These included pro-inflammatory cytokines, cJun family genes, TLR4 and, surprisingly, CaMKIId. Elevated activation of CaMKIIδ in response to AngII in YAP KO hearts was confirmed by increased phosphorylation of phospholamban. Cardiomyocytes expressing siYAP also showed enhanced expression of TLR4 and CaMKIIδ. Conclusion: Upregulated expression of cJun, TLR4 and CaMKII occurs in the absence of YAP and this conspires to create a greatly enhanced inflammatory milieu which fuels adverse responses to external insults. YAP activation serves to suppress these responses and thus temper development of maladaptive inflammation.

Targeting Myeloid Differentiation Primary Response Protein 88 (MyD88) and Galectin-3 to Develop Broad-Spectrum Host-Mediated Therapeutics against SARS-CoV-2.

Nearly six million people worldwide have died from the coronavirus disease (COVID-19) outbreak caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Although COVID-19 vaccines are largely successful in reducing the severity of the disease and deaths, the decline in vaccine-induced immunity over time and the continuing emergence of new viral variants or mutations underscore the need for an alternative strategy for developing broad-spectrum host-mediated therapeutics against SARS-CoV-2. A key feature of severe COVID-19 is dysregulated innate immune signaling, culminating in a high expression of numerous pro-inflammatory cytokines and chemokines and a lack of antiviral interferons (IFNs), particularly type I (alpha and beta) and type III (lambda). As a natural host defense, the myeloid differentiation primary response protein, MyD88, plays pivotal roles in innate and acquired immune responses via the signal transduction pathways of Toll-like receptors (TLRs), a type of pathogen recognition receptors (PRRs). However, recent studies have highlighted that infection with viruses upregulates MyD88 expression and impairs the host antiviral response by negatively regulating type I IFN. Galectin-3 (Gal3), another key player in viral infections, has been shown to modulate the host immune response by regulating viral entry and activating TLRs, the NLRP3 inflammasome, and NF-κB, resulting in the release of pro-inflammatory cytokines and contributing to the overall inflammatory response, the so-called "cytokine storm". These studies suggest that the specific inhibition of MyD88 and Gal3 could be a promising therapy for COVID-19. This review presents future directions for MyD88- and Gal3-targeted antiviral drug discovery, highlighting the potential to restore host immunity in SARS-CoV-2 infections.

Antiretroviral drug dolutegravir induces inflammation at the mouse brain barriers.

Integrase strand transfer inhibitors (INSTIs) based antiretroviral therapy (ART) is currently used as first-line regimen to treat HIV infection. Despite its high efficacy and barrier to resistance, ART-associated neuropsychiatric adverse effects remain a major concern. Recent studies have identified a potential interaction between the INSTI, dolutegravir (DTG), and folate transport pathways at the placental barrier. We hypothesized that such interactions could also occur at the two major blood-brain interfaces: blood-cerebrospinal fluid barrier (BCSFB) and blood-brain barrier (BBB). To address this question, we evaluated the effect of two INSTIs, DTG and bictegravir (BTG), on folate transporters and receptor expression at the mouse BCSFB and the BBB invitro, exvivo and invivo. We demonstrated that DTG but not BTG significantly downregulated the mRNA and/or protein expression of folate transporters (RFC/SLC19A1, PCFT/SLC46A1) in human and mouse BBB models invitro, and mouse brain capillaries exvivo. Our invivo study further revealed a significant downregulation in Slc19a1 and Slc46a1 mRNA expression at the BCSFB and the BBB following a 14-day DTG oral treatment in C57BL/6 mice. However, despite the observed downregulatory effect of DTG in folate transporters/receptor at both brain barriers, a 14-day oral treatment of DTG-based ART did not significantly alter the brain folate level in animals. Interestingly, DTG treatment robustly elevated the mRNA and/or protein expression of pro-inflammatory cytokines and chemokines (Cxcl1, Cxcl2, Cxcl3, Il6, Il23, Il12) in primary cultures of mouse brain microvascular endothelial cells (BBB). DTG oral treatment also significantly upregulated proinflammatory cytokines and chemokine (Il6, Il1β, Tnfα, Ccl2) at the BCSFB in mice. We additionally observed a downregulated mRNA expression of drug efflux transporters (Abcc1, Abcc4, and Abcb1a) and tight junction protein (Cldn3) at the CP isolated from mice treated with DTG. Despite the structural similarities, BTG only elicited minor effects on the markers of interest at both the BBB and BCSFB. In summary, our current data demonstrates that DTG but not BTG strongly induced inflammatory responses in a rodent BBB and BCSFB model. Together, these data provide valuable insights into the mechanism of DTG-induced brain toxicity, which may contribute to the pathogenesis of DTG-associated neuropsychiatric adverse effect.

Endothelial Protection by Sodium-Glucose Cotransporter 2 Inhibitors: A Literature Review of In Vitro and In Vivo Studies.

Endothelial dysfunction often precedes the development of cardiovascular diseases, including heart failure. The cardioprotective benefits of sodium-glucose cotransporter 2 inhibitors (SGLT2is) could be explained by their favorable impact on the endothelium. In this review, we summarize the current knowledge on the direct in vitro effects of SGLT2is on endothelial cells, as well as the systematic observations in preclinical models. Four putative mechanisms are explored: oxidative stress, nitric oxide (NO)-mediated pathways, inflammation, and endothelial cell survival and proliferation. Both in vitro and in vivo studies suggest that SGLT2is share a class effect on attenuating reactive oxygen species (ROS) and on enhancing the NO bioavailability by increasing endothelial nitric oxide synthase activity and by reducing NO scavenging by ROS. Moreover, SGLT2is significantly suppress inflammation by preventing endothelial expression of adhesion receptors and pro-inflammatory chemokines in vivo, indicating another class effect for endothelial protection. However, in vitro studies have not consistently shown regulation of adhesion molecule expression by SGLT2is. While SGLT2is improve endothelial cell survival under cell death-inducing stimuli, their impact on angiogenesis remains uncertain. Further experimental studies are required to accurately determine the interplay among these mechanisms in various cardiovascular complications, including heart failure and acute myocardial infarction.

Aconitate decarboxylase 1 (Acod1) suppresses inflammatory stimuli-induced immune responses in Japanese flounder (Paralichthys olivaceus)

Aconitate decarboxylase 1 (ACOD1, formerly termed as immunoresponsive gene 1) is an enzyme responsible for generation of anti-inflammatory metabolite itaconate through decarboxylation of cis-aconitate and plays a key role in inflammation regulation and anti-microbial host defense in mammals. However, the immune functions of Acod1 in fish remain largely undetermined. Here, we characterize a Acod1 homolog that is highly induced by LPS, poly(I:C) and extracellular ATP (eATP) challenges in the Japanese flounder Paralichthys olivaceus head kidney macrophages (HKMs). We find that Acod1 syntenic genes in P. olivaceus are similar with those in mammalian species and the deduced Japanese flounder ACOD1 protein shares similar protein domains and 3-D structures with its counterparts in mammals. We next show that itaconate derivatives dimethyl itaconate (DMI) and citraconate (Cit) can markedly down-regulate inflammatory stimuli, including LPS-, poly(I:C)- and eATP-induced inflammatory mediator nitric oxide (NO) production and gene expression of proinflammatory cytokines (IL-1β and TNF-α), chemokines (CXCL-8, CXCL-9 and CXCL-13), HMGB1 and inflammasome components (NLRP3, NLRC3, caspase1, ASC and GSDME), but up-regulate anti-inflammatory gene (IL-10 and SOCS1/3) expression in P. olivaceus HKMs. In addition, DMI and Cit treatment significantly inhibits Edwardsiella piscicida growth in P. olivaceus HKMs. Furthermore, knockdown of the endogenous Acod1 expression by siRNA silencing not only significantly increases LPS-, poly(I:C)- and eATP-induced proinflammatory gene expression but also decreases anti-inflammatory gene expression in the HKMs. In contrast, the LPS-, poly(I:C)- and eATP-indued proinflammatory gene expression and NO production are greatly attenuated in ACOD1 overexpressed Japanese flounder FG-9307 cells. Collectively, our studies demonstrate that the inducible fish Acod1 gene is a novel immune regulator in dampening inflammatory stimuli-induced immune responses and ACOD1-produced itaconate may play an essential role in anti-bacterial immunity in fish macrophages.

JCPyV infection of primary choroid plexus epithelial cells reduces expression of critical junctional proteins and increases expression of barrier disrupting inflammatory cytokines.

The human polyomavirus, JCPyV, causes a rapidly progressing demyelinating disease in the CNS of patients whose immune systems are compromised. JCPyV infection has been demonstrated in the choroid plexus both in vivo and in vitro and this highly vascularized organ may be important in viral invasion of brain parenchyma. Our data show that infection of primary choroid plexus epithelial cells results in increased expression of pro-inflammatory chemokines and downregulation of critical junctional proteins that maintain the blood-CSF barrier. These data have direct implications for mechanisms used by JCPyV to invade the CNS and cause neurological disease.

Apoptosis signal-regulating kinase 1 promotes inflammation in senescence and aging

Cellular senescence is a stress-induced, permanent cell cycle arrest involved in tumor suppression and aging. Senescent cells secrete bioactive molecules such as pro-inflammatory cytokines and chemokines. This senescence-associated secretory phenotype (SASP) has been implicated in immune-mediated elimination of senescent cells and age-associated chronic inflammation. However, the mechanisms regulating the SASP are incompletely understood. Here, we show that the stress-responsive kinase apoptosis signal-regulating kinase 1 (ASK1) promotes inflammation in senescence and aging. ASK1 is activated during senescence and increases the expression of pro-inflammatory cytokines and chemokines by activating p38, a kinase critical for the SASP. ASK1-deficient mice show impaired elimination of oncogene-induced senescent cells and an increased rate of tumorigenesis. Furthermore, ASK1 deficiency prevents age-associated p38 activation and inflammation and attenuates glomerulosclerosis. Our results suggest that ASK1 is a driver of the SASP and age-associated chronic inflammation and represents a potential therapeutic target for age-related diseases.

Analysis of Intracellular Communication Reveals Consistent Gene Changes Associated with Early-Stage Acne Skin.

A comprehensive understanding of the intricate cellular and molecular changes governing the complex interactions between cells within acne lesions is currently lacking. Herein, we analyzed early papules from six subjects with active acne vulgaris, utilizing single-cell and high-resolution spatial RNA sequencing. We observed significant changes in signaling pathways across seven different cell types when comparing lesional skin samples (LSS) to healthy skin samples (HSS). Using CellChat, we constructed an atlas of signaling pathways for the HSS, identifying key signal distributions and cell-specific genes within individual clusters. Further, our comparative analysis revealed changes in 49 signaling pathways across all cell clusters in the LSS- 4 exhibited decreased activity, whereas 45 were upregulated, suggesting that acne significantly alters cellular dynamics. We identified ten molecules, including GRN, IL-13RA1 and SDC1 that were consistently altered in all donors. Subsequently, we focused on the function of GRN and IL-13RA1 in TREM2 macrophages and keratinocytes as these cells participate in inflammation and hyperkeratinization in the early stages of acne development. We evaluated their function in TREM2 macrophages and the HaCaT cell line. We found that GRN increased the expression of proinflammatory cytokines and chemokines, including IL-18, CCL5, and CXCL2 in TREM2 macrophages. Additionally, the activation of IL-13RA1 by IL-13 in HaCaT cells promoted the dysregulation of genes associated with hyperkeratinization, including KRT17, KRT16, and FLG. These findings suggest that modulating the GRN-SORT1 and IL-13-IL-13RA1 signaling pathways could be a promising approach for developing new acne treatments.

Identification of a functional missense variant in the matrix metallopeptidase 10 (MMP10) gene in two families with premature myocardial infarction

A positive family history is a major independent risk factor for atherosclerosis, and genetic variation is an important aspect of cardiovascular disease research. We identified a heterozygous missense variant p.L245P in the MMP10 gene in two families with premature myocardial infarction using whole-exome sequencing. The aim of this study was to investigate the consequences of this variant using in-silico and functional in-vitro assays. Molecular dynamics simulations were used to analyze protein interactions, calculate free binding energy, and measure the volume of the substrate-binding cleft of MMP10-TIMP1 models. The p.L245P variant showed an altered protein surface, different intra- and intermolecular interactions of MMP10-TIMP1, a lower total free binding energy between MMP10-TIMP1, and a volume-minimized substrate-binding cleft of MMP10 compared to the wild-type. For the functional assays, human THP-1 cells were transfected with plasmids containing MMP10 cDNA carrying the p.L245P and wild-type variant and differentiated into macrophages. Macrophage adhesion and migration assays were then conducted, and pro-inflammatory chemokine levels were evaluated. The p.L245P variant led to macrophages that were more adherent, less migratory, and secreted higher levels of the pro-inflammatory chemokines CXCL1 and CXCL8 than wild-type macrophages. Thus, the p.L245P variant in MMP10 may influence the pathogenesis of atherosclerosis in families with premature myocardial infarction by altering protein - protein interactions, macrophage adhesion and migration, and expression of pro-inflammatory chemokines, which may increase plaque rupture. These results could contribute to the development of selective MMP10 inhibitors and reduce the risk of atherosclerosis in families with a history of premature myocardial infarction.

Anti-Inflammatory Therapeutic Mechanisms of Isothiocyanates: Insights from Sulforaphane.

Isothiocyanates (ITCs) belong to a group of natural products that possess a highly reactive electrophilic -N=C=S functional group. They are stored in plants as precursor molecules, glucosinolates, which are processed by the tyrosinase enzyme upon plant tissue damage to release ITCs, along with other products. Isolated from broccoli, sulforaphane is by far the most studied antioxidant ITC, acting primarily through the induction of a transcription factor, the nuclear factor erythroid 2-related factor 2 (Nrf2), which upregulates downstream antioxidant genes/proteins. Paradoxically, sulforaphane, as a pro-oxidant compound, can also increase the levels of reactive oxygen species, a mechanism which is attributed to its anticancer effect. Beyond highlighting the common pro-oxidant and antioxidant effects of sulforaphane, the present paper was designed to assess the diverse anti-inflammatory mechanisms reported to date using a variety of in vitro and in vivo experimental models. Sulforaphane downregulates the expression of pro-inflammatory cytokines, chemokines, adhesion molecules, cycloxyhenase-2, and inducible nitric oxide synthase. The signalling pathways of nuclear factor κB, activator protein 1, sirtuins 1, silent information regulator sirtuin 1 and 3, and microRNAs are among those affected by sulforaphane. These anti-inflammatory actions are sometimes due to direct action via interaction with the sulfhydryl structural moiety of cysteine residues in enzymes/proteins. The following are among the topics discussed in this paper: paradoxical signalling pathways such as the immunosuppressant or immunostimulant mechanisms; crosstalk between the oxidative and inflammatory pathways; and effects dependent on health and disease states.

Lack of Pkd1 enhances intestinal integrity and motility prior to accelerated kidney cyst growth

Autosomal dominant polycystic kidney disease (ADPKD) is the most common inherited kidney disorder, primarily caused by PKD1 germline mutations. Polycystin-1, PKD1’s encoded protein, is essential to maintain kidney epithelial cell integrity, but its role in the gut has yet to be determined. Considering macrophage infiltration precedes accelerated cyst growth in Pkd1 knockout ( Pkd1KO) mice, and the gut is the body’s largest reservoir of inflammatory cells, we hypothesized that loss of Pkd1 would weaken the intestinal epithelial cell barrier and mount an inflammatory response, potentially preceding kidney damage. Plasma, urine, kidney, and intestines were collected from 11-12 week old male and female conditional Pkd1KO (CAGG-creER; tamoxifen-induced at 5-6 weeks) and flox (control) mice. Plasma was used to measure intestinal permeability as well as monocyte chemoattractant protein-1 (MCP-1) and lipocalin-2 (LCN-2) concentration. Urine was utilized to assess kidney injury, while tissues were used for RT-PCR and histology. Pkd1KO mice had significantly elevated kidney-to-body weight ratio, cyst ratio, and expression of tubular injury markers kidney injury molecule 1 (Kim1) and Lcn2 compared to flox mice. Despite this cellular injury, kidney inflammatory gene expression and urine osmolality did not differ between genotypes. No overt morphological changes were observed in the ileum or colon, nor were there differences in expression of proinflammatory chemokines or cytokines in either tissue. Plasma abundance of MCP-1 and LCN-2 was similar between genotypes. Epithelial permeability in the small and large intestines was significantly decreased in Pkd1KO versus flox mice. Moreover, Pkd1KO mice had a significantly reduced whole gut transit time compared to flox mice. This corresponded with increases in colonic expression of epithelial integrity marker occludin and water channels aquaporin 4 and aquaporin 8 in Pkd1KO mice. Together, these data insinuate that loss of Pkd1 in the intestines leads to a tighter intestinal barrier accompanied by increased water channel expression and gut motility. These findings appear unrelated to inflammatory involvement in early PKD. These studies were supported by NIH T32 DK007545 to RS, R01 DK132028 to TS, and R03 DK119717 to TS. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.