Interleukin-6 regulation of transforming growth factor (TGF)-beta receptor compartmentalization and turnover enhances TGF-beta1 signaling

Myeloid-Specific JAK2 Contributes to Inflammation and Salt Sensitivity of Blood Pressure

BACKGROUND

Salt sensitivity of blood pressure (SSBP), characterized by acute changes in blood pressure with changes in dietary sodium intake, is an independent risk factor for cardiovascular disease and mortality in people with and without hypertension. We previously found that elevated sodium concentration activates antigen-presenting cells (APCs), resulting in high blood pressure, but the mechanisms are unknown. Here, we hypothesized that APC-specific JAK2 (Janus kinase 2) through STAT3 (signal transducer and activator of transcription 3) and SMAD3 (small mothers against decapentaplegic homolog 3) contributes to SSBP.

METHODS

We performed bulk or single-cell transcriptomic analyses following in vitro monocytes exposed to high salt and in vivo high sodium treatment in humans using a rigorous salt-loading/depletion protocol to phenotype SSBP. We also used a myeloid cell-specific CD11c+ JAK2 knockout mouse model and measured blood pressure with radiotelemetry after N-omega-nitro-L-arginine-methyl ester and a high salt diet treatment. We used flow cytometry for immunophenotyping and measuring cytokine levels. Fluorescence in situ hybridization and immunohistochemistry were performed to spatially visualize the kidney's immune cells and cytokine levels. Echocardiography was performed to assess cardiac function.

RESULTS

We found that high salt treatment upregulates gene expression of the JAK/STAT/SMAD pathway while downregulating inhibitors of this pathway, such as suppression of cytokine signaling and cytokine-inducible SH2, in human monocytes. Expression of the JAK2 pathway genes mirrored changes in blood pressure after salt loading and depletion in salt-sensitive but not salt-resistant humans. Ablation of JAK2, specifically in CD11c+ APCs, attenuated salt-induced hypertension in mice with SSBP. Mechanistically, we found that SMAD3 acted downstream of JAK2 and STAT3, leading to increased production of highly reactive isolevuglandins and proinflammatory cytokine IL (interleukin)-6 in renal APCs, which activate T cells and increase production of IL-17A, IL-6, and TNF-α (tumor necrosis factor-alpha).

CONCLUSIONS

Our findings reveal the APC JAK2 signaling pathway as a potential target for the diagnosis and treatment of SSBP in humans.

Follistatin lowers blood pressure and improves vascular structure and function in essential and secondary hypertension

Hypertension is characterized by resistance artery remodeling driven by oxidative stress and fibrosis. We previously showed that an activin A antagonist, follistatin, inhibited renal oxidative stress and fibrosis in a model of hypertensive chronic kidney disease. Here, we investigate the effects of follistatin on blood pressure and vascular structure and function in models of essential and secondary hypertension. 5/6 nephrectomised mice, a model of secondary hypertension, were treated with either exogenous follistatin or with a follistatin miRNA inhibitor to increase endogenous follistatin for 9 weeks. Blood pressure in mice was measured by tail cuff. Spontaneously hypertensive rats, a model of essential hypertension, were treated with follistatin for 8 weeks. Wistar Kyoto (WKY) rats were used as the normotensive control. Blood pressure in rats was measured by radiotelemetry. Mouse superior mesenteric arteries and rat first branch mesenteric arteries were isolated for structural and functional analyses. In both models, follistatin significantly lowered blood pressure and improved vascular structure, decreasing medial thickness and collagen content. Follistatin also reduced agonist-induced maximum contraction and improved endothelium-dependent relaxation. Increased vessel oxidative stress was attenuated by follistatin in both models. In ex vivo WKY vessels, activin A increased oxidative stress, augmented constriction, and decreased endothelium-dependent relaxation. Inhibition of oxidative stress restored vessel relaxation. This study demonstrates that follistatin lowers blood pressure and improves vascular structure and function in models of essential and secondary hypertension. Effects were likely mediated through its inhibition of activin A and oxidative stress. These data suggest a potential therapeutic role for follistatin as a novel antihypertensive agent. Follistatin, through antagonization of activin A, inhibits oxidative stress and improves vascular structure and function in resistance arteries from models of essential and secondary HTN. FST decreases collagen content and vascular ROS. Functionally, FST improves endothelium-dependent relaxation and decreases maximal vasoconstriction. Improved resistance artery structure and function are correlated with a decrease in BP in both models.

The role of perirenal adipose tissue deposition in chronic kidney disease progression: Mechanisms and therapeutic implications

Chronic kidney disease (CKD) represents a significant and escalating global health challenge, with morbidity and mortality rates rising steadily. Evidence increasingly implicates perirenal adipose tissue (PRAT) deposition as a contributing factor in the pathogenesis of CKD. This review explores how PRAT deposition may exert deleterious effects on renal structure and function. The anatomical proximity of PRAT to the kidneys not only potentially causes mechanical compression but also leads to the dysregulated secretion of adipokines and inflammatory mediators, such as adiponectin, leptin, visfatin, tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and exosomes. Additionally, PRAT deposition may contribute to renal lipotoxicity through elevated levels of free fatty acids (FFA), triglycerides (TAG), diacylglycerol (DAG), and ceramides (Cer). PRAT deposition is also linked to the hyperactivation of the renin-angiotensin-aldosterone system (RAAS), which further exacerbates CKD progression. Recognizing PRAT deposition as an independent risk factor for CKD underscores the potential of targeting PRAT as a novel strategy for the prevention and management of CKD. This review further discusses interventions that could include measuring PRAT thickness to establish a baseline, managing metabolic risk factors that promote its deposition, and inhibiting key PRAT-induced signaling pathways.

Caveolin-1 differentially regulates the transforming growth factor-β and epidermal growth factor signaling pathways in MDCK cells

Caveolin-1 is critical for interacting with the TGF-β receptor (TGFβR) and EGF receptor (EGFR) signaling, often observed in advanced cancers and tissue fibrosis. However, the mechanism underlying caveolin-1-mediated transactivation of TGFβR and EGFR signaling remains unclear. Therefore, we sought to determine whether caveolin-1 is involved in canonical and non-canonical TGFβR and EGFR signaling transactivation in this study. Methyl-β-cyclodextrin (MβCD) was used to disrupt the cholesterol-containing membranes domains, and the caveolin-1 scaffolding domain (CSD) peptide was used to mimic the CSD of caveolin-1. Additionally, we transfected the Madin-Darby canine kidney cells with wild-type or phosphorylation-defective caveolin-1. We discovered that tyrosine 14 of caveolin-1 was critical for the negative regulation of TGFβR and EGFR canonical signaling. On the contrary, caveolin-1 inhibited TGF-β1-induced ERK2 activation independent of tyrosine 14 phosphorylation. Although EGF failed to induce Smad3 phosphorylation in caveolin-1 knockdown cells, it activated Smad3 upon MβCD co-treatment, indicating that caveolin-1 indirectly regulated the non-canonical pathway of EGF. In conclusion, caveolin-1 differentially modulates TGFβR and EGFR signaling. Thus, targeting caveolin-1 is a potential strategy for treating diseases involving TGF-β1 and EGF signaling.

Association between visceral adiposity index and incidence of diabetic kidney disease in adults with diabetes in the United States

Visceral adiposity index (VAI) is a reliable indicator of visceral adiposity. However, no stu-dies have evaluated the association between VAI and DKD in US adults with diabetes. Theref-ore, this study aimed to explore the relationship between them and whether VAI is a good pr-edictor of DKD in US adults with diabetes. Our cross-sectional study included 2508 participan-ts with diabetes who were eligible for the National Health and Nutrition Examination Survey (NHANES) from 2007 to 2018. Univariate and multivariate logistic regression were used to an-alyze the association between VAI level and DKD. Three models were used to control for pot-ential confounding factors, and subgroup analysis was performed for further verification. A tot-al of 2508 diabetic patients were enrolled, of whom 945 (37.68%) were diagnosed with DKD. Overall, the VAI was 3.36 ± 0.18 in the DKD group and 2.76 ± 0.11 in the control group. VAI was positively correlated with DKD (OR = 1.050, 95% CI 1.049, 1.050) after fully adjusting for co-nfounding factors. Compared with participants in the lowest tertile of VAI, participants in the highest tertile of VAI had a significantly increased risk of DKD by 35.9% (OR = 1.359, 95% CI 1.355, 1.362). Through subgroup analysis, we found that VAI was positively correlated with the occurrence of DKD in all age subgroups, male(OR = 1.043, 95% CI 1.010, 1.080), participants wit-hout cardiovascular disease(OR = 1.038, 95% CI 1.011, 1.069), hypertension (OR = 1.054, 95% CI 1.021, 1.090), unmarried participants (OR = 1.153, 95% CI 1.036, 1.294), PIR < 1.30(OR = 1.049, 95% CI 1.010, 1.094), PIR ≧ 3 (OR = 1.085, 95% CI 1.021, 1.160), BMI ≧ 30 kg/m2 (OR = 1.050, 95% CI 1.016, 1.091), former smokers (OR = 1.060, 95% CI 1.011, 1.117), never exercised (OR = 1.033, 95% CI 1.004, 1.067), non-Hispanic white population (OR = 1.055, 95% CI 1.010, 1.106) and non-Hipanic black population (OR = 1.129, 95% CI 1.033, 1.258). Our results suggest that elevated VAI levels are closely associated with the development of DKD in diabetic patients. VAI may be a simpl-e and cost-effective index to predict the occurrence of DKD. This needs to be verified in furt-her prospective investigations.

A common secretomic signature across epithelial cancers metastatic to the pleura supports IL-6 axis therapeutic targeting

Background

Many cancers metastasize to the pleura, resulting in effusions that cause dyspnea and discomfort. Regardless of the tissue of origin, pleural malignancies are aggressive and uniformly fatal, with no treatment shown to prolong life. The pleural mesothelial monolayer is joined by tight junctions forming a contained bioreactor-like space, concentrating cytokines and chemokines secreted by the mesothelium, tumor, and infiltrating immune cells. This space represents a unique environment that profoundly influences tumor and immune cell behavior. Defining the pleural secretome is an important step in the rational development localized intrapleural immunotherapy.

Method

We measured cytokine/chemokine content of 252 malignant pleural effusion (MPE) samples across multiple cancers using a 40-analyte panel and Luminex multiplexing technology.

Results

Eleven analytes were consistently present in concentrations ≥ 10.0 pM: CXCL10/IP10 (geometric mean = 672.3 pM), CCL2/MCP1 (562.9 pM), sIL-6Rα (403.1 pM), IL-6 (137.6 pM), CXCL1/GRO (80.3 pM), TGFβ1 (76.8 pM), CCL22/MDC (54.8 pM), CXCL8/IL-8 (29.2 pM), CCL11/Eotaxin (12.6 pM), IL-10 (11.3 pM), and G-CSF (11.0 pM). All are capable of mediating chemotaxis, promotion of epithelial to mesenchymal transition, or immunosuppression, and many of are reportedly downstream of a pro-inflammatory cytokine cascade mediated by cytokine IL-6 and its soluble receptor.

Conclusion

The data indicate high concentrations of several cytokines and chemokines across epithelial cancers metastatic to the pleura and support the contention that the pleural environment is the major factor responsible for the clinical course of MPE across cancer types. A sIL-6Rα to IL-6 molar ratio of 2.7 ensures that virtually all epithelial, immune and vascular endothelial cells in the pleural environment are affected by IL-6 signaling. The central role likely played by IL-6 in the pathogenesis of MPE argues in favor of a therapeutic approach targeting the IL-6/IL-6R axis.

Angiotensin AT2 receptors reduce inflammation and fibrosis in cardiovascular remodeling

The angiotensin AT2 receptor (AT2R), an important member of the "protective arm" of the renin-angiotensin system (RAS), has been recently defined as a therapeutic target in different pathological conditions. The AT2R activates complex signalling pathways linked to cellular proliferation, differentiation, anti-inflammation, antifibrosis, and induction or inhibition of apoptosis. The anti-inflammatory effect of AT2R activation is commonly associated with reduced fibrosis in different models. Current discoveries demonstrated a direct impact of AT2Rs on the regulation of cytokines, transforming growth factor beta1 (TGF-beta1), matrix metalloproteases (MMPs), and synthesis of the extracellular matrix components. This review article summarizes current knowledge on the AT2R in regard to immunity, inflammation and fibrosis in the heart and blood vessels. In particular, the differential influence of the AT2R on cardiovascular remodeling in preclinical models of myocardial infarction, heart failure and aneurysm formation are discussed. Overall, these studies demonstrate that AT2R stimulation represents a promising therapeutic approach to counteract myocardial and aortic damage in cardiovascular diseases.

Extracorporeal Photopheresis Reduces Fibrotic and Inflammatory Transcriptomic Biological Marker of Chronic Antibody-mediated Kidney Rejection

Background

The benefit of extracorporeal photopheresis on the course of kidney transplant rejection is unknown. The aim of our study was to investigate the variations in transcriptomics on graft biopsies when extracorporeal photopheresis was used to treat chronic humoral rejection after kidney transplantation.

Methods

We retrospectively analyzed the mRNA expression of 770 genes of interest in graft biopsies performed before and after treatment. Eight patients received an average of 23 extracorporeal photopheresis sessions over 4 mo between the 2 biopsies.

Results

Transcriptomic analysis of the graft biopsies identified a significant (adjusted P < 0.05) increase in CAV1 mRNA in all patients and a significant decrease in CD19, IL21, PAX5, and SFTPA2 mRNAs in 7 of 8 patients.

Conclusions

In patients treated with extracorporeal photopheresis for chronic humoral rejection after renal transplantation, omic analysis of repeated biopsies shows a reduction in fibrotic and inflammatory transcriptomic biologicals markers.

Adaptive Autonomic and Neuroplastic Control in Diabetic Neuropathy: A Narrative Review

BACKGROUND

Type 2 diabetes mellitus (T2DM) is a worldwide socioeconomic burden, and is accompanied by a variety of metabolic disorders, as well as nerve dysfunction referred to as diabetic neuropathy (DN). Despite a tremendous body of research, the pathogenesis of DN remains largely elusive. Currently, two schools of thought exist regarding the pathogenesis of diabetic neuropathy: a) mitochondrial-induced toxicity, and b) microvascular damage. Both mechanisms signify DN as an intractable disease and, as a consequence, therapeutic approaches treat symptoms with limited efficacy and risk of side effects.

OBJECTIVE

Here, we propose that the human body exclusively employs mechanisms of adaptation to protect itself during an adverse event. For this purpose, two control systems are defined, namely the autonomic and the neural control systems. The autonomic control system responds via inflammatory and immune responses, while the neural control system regulates neural signaling, via plastic adaptation. Both systems are proposed to regulate a network of temporal and causative connections which unravel the complex nature of diabetic complications.

RESULTS

A significant result of this approach infers that both systems make DN reversible, thus opening the door to novel therapeutic applications.

Interleukin-6 and epidermal growth factor as noninvasive biomarkers of progression in chronic glomerulonephritis

Several cytokines and chemokines are involved in the pathogenesis and progressive injury of renal tissues in patients with primary chronic glomerulonephritis (CGN). The objective of this study was to determine whether the urinary excretion of interleukin-6 (IL-6), transforming growth factor β1 (TGFβ1), monocytes chemoattractant protein (MCP-1), soluble tumor necrosis factor receptor 1 (sTNFR1), and epidermal growth factor (EGF) in patients with newly recognized CGN can serve as prognostic biomarkers in patients with newly recognized CGN and whether they can be effective in predicting a progressive reduction of renal function in prospective observation. The study included 150 Caucasian patients. UIL-6, UTGFβ1, UMCP-1, UsTNFR1, and UEGF were measured using enzyme-linked immunosorbent assay (ELISA) methods (Quantikine R&D System). UIL-6, UTGFβ1, UMCP-1, and UsTNFR1 were significantly higher, yet UEGF excretion was significantly lower in nephrotic patients, in patients with estimated glomerular filtration rate (eGFR) < 60/min/1.73 m2 at presentation, as well as in the progressor (PG) subgroup. In a multivariate regression analysis basal eGFR correlated with UsTNFR1, UIL-6, and UEGF excretion, although in the follow-up, ΔeGFR (delta estimated glomerular filtration rate) significantly correlated only with UEGF excretion. A logistic regression analysis showed that the most significant independent risk factors for the deterioration of renal function with time are initial high (>11.8 pg/mgCr) UIL-6 excretion, initial low (<15.5 ng/mgCr) urinary UEGF excretion, and male gender. In patients with newly diagnosed CGN, UIL-6, and UEGF can serve as prognostic biomarkers for the progression of the disease.NEW & NOTEWORTHY Baseline high urinary interleukin-6 (IL-6) excretion and low urinary epidermal growth factor (EGF) excretion and particularly high IL-6/EGF ratio were stronger predictive factors of the progression of the deterioration of the kidney function than initial estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m2 or proteinuria. In patients with newly diagnosed chronic glomerulonephritis, UIL-6 and UEGF can serve as prognostic biomarkers for the progression of the disease.

Macrophages release IL11-containing filopodial tip vesicles and contribute to renal interstitial inflammation

Macrophage filopodia, which are dynamic nanotube-like protrusions, have mainly been studied in the context of pathogen clearance. The mechanisms by which they facilitate intercellular communication and mediate tissue inflammation remain poorly understood. Here, we show that macrophage filopodia produce a unique membrane structure called "filopodial tip vesicle" (FTV) that originate from the tip of macrophages filopodia. Filopodia tip-derived particles contain numerous internal-vesicles and function as cargo storage depots via nanotubular transport. Functional studies indicate that the shedding of FTV from filopodia tip allows the delivery of many molecular signalling molecules to fibroblasts. We observed that FTV derived from M1 macrophages and high glucose (HG)-stimulated macrophages (HG/M1-ftv) exhibit an enrichment of the chemokine IL11, which is critical for fibroblast transdifferentiation. HG/M1-ftv induce renal interstitial fibrosis in diabetic mice, while FTV inhibition or targeting FTV IL11- alleviates renal interstitial fibrosis, suggesting that the HG/M1-ftvIL11 pathway may be a novel mechanism underlying renal fibrosis in diabetic nephropathy. Collectively, FTV release could represent a novel function by which filopodia contribute to cell biological processes, and FTV is potentially associated with macrophage filopodia-related fibrotic diseases. Video Abstract.

Suppression of TGFβ-Induced Interleukin-6 Secretion by Sinulariolide from Soft Corals through Attenuation of the p38-NF-kB Pathway in Carcinoma Cells

Sinulariolide (SC-1) is a natural product extracted from the cultured-type soft coral Sinularia flexibilis and possesses anti-inflammation, anti-proliferative, and anti-migratory in several types of cancer cells. However, the molecular pathway behind its effects on inflammation remains poorly understood. Since inflammatory cytokines such as TGFβ, TNFα, IL-1, IL-6, and IL-8 activate transcription factors such as Smads, NF-κB, STAT3, Snail, Twist, and Zeb that drive the epithelial-to-mesenchymal transition (EMT), in this study, we focus on the investigation in effects of SC-1 on TGFβ-induced interleukin-6 (IL-6) releases in an in vitro cell culture model. We showed that both intracellular IL-6 expression and secretion were stimulated by TGFβ and associated with strong upregulation of IL-6 mRNA and increased transcription in A549 cells. SC-1 blocked TGFβ-induced secretion of IL-6 while showing no effect on the induction of fibronectin and plasminogen activator inhibitor-1 genes, indicating that SC-1 interferes with only a subset of TGFβ activities. In addition, SC-1 inhibits TGFβ-induced IL-6 by suppressing p38 MAPK signaling and subsequently inhibits NF-κB and its nuclear translocation without affecting the canonical Smad pathway and receptor turnover. Overall, these data suggest that p38 may involve in the inhibition of SC-1 in IL-6 release, thus illustrating an inhibitory effect for SC-1 in the suppression of inflammation, EMT phenotype, and tumorigenesis.

Delayed skeletal muscle repair following inflammatory damage in simulated agent-based models of muscle regeneration

Healthy skeletal muscle undergoes repair in response to mechanically localised strains during activities such as exercise. The ability of cells to transduce the external stimuli into a cascade of cell signalling responses is important to the process of muscle repair and regeneration. In chronic myopathies such as Duchenne muscular dystrophy and inflammatory myopathies, muscle is often subject to chronic necrosis and inflammation that perturbs tissue homeostasis and leads to non-localised, widespread damage across the tissue. Here we present an agent-based model that simulates muscle repair in response to both localised eccentric contractions similar to what would be experienced during exercise, and non-localised widespread inflammatory damage that is present in chronic disease. Computational modelling of muscle repair allows for in silico exploration of phenomena related to muscle disease. In our model, widespread inflammation led to delayed clearance of tissue damage, and delayed repair for recovery of initial fibril counts at all damage levels. Macrophage recruitment was delayed and significantly higher in widespread compared to localised damage. At higher damage percentages of 10%, widespread damage led to impaired muscle regeneration and changes in muscle geometry that represented alterations commonly observed in chronic myopathies, such as fibrosis. This computational work offers insight into the progression and aetiology of inflammatory muscle diseases, and suggests a focus on the muscle regeneration cascade in understanding the progression of muscle damage in inflammatory myopathies.

The association between visceral adiposity index and decreased renal function: A population-based study

Aims

We aimed to investigate the association of visceral adiposity index (VAI) with decreased renal function in US adults.

Design and methods

Cross-sectional data were analyzed for 35,018 adults in the National Health and Nutrition Examination Survey (NHANES) 2005–2018. VAI was determined using waist circumference, body mass index (BMI), triglycerides (TGs) and high-density lipoprotein-cholesterol. Albuminuria was defined as urinary albumin-to-creatinine ratio (ACR) &gt;30 mg/g. A low estimated-glomerular filtration rate (eGFR) was defined as an eGFR lower than 60 ml/min/1.73 m2. Chronic kidney disease (CKD) was defined as either albuminuria or low-eGFR. A multivariable logistic regression analysis was utilized to explore the relationship of VAI with albuminuria, low-eGFR and CKD. Subgroup analysis and interaction tests were also conducted.

Results

A total of 35,018 participants were enrolled with albuminuria, low-eGFR, and CKD prevalence rates of 5.18, 6.42, and 10.62%, respectively, which increased with the higher VAI tertiles. After full adjustment, a positive association of VAI with albuminuria (OR = 1.03, 95% CI: 1.00, 1.06) and CKD (OR = 1.04, 95% CI: 1.02, 1.06) was observed. Participants in the highest VAI tertile had a significantly 30% increased risk for albuminuria (OR = 1.30, 95% CI: 1.07, 1.58) and a 27% increased risk for CKD (OR = 1.27, 95% CI: 1.08, 1.49) compared with those in the lowest VAI tertile. No statistically significant association between VAI and low-eGFR was detected. Subgroup analysis and the interaction term indicated that there was no significant difference among different stratifications.

Conclusion

Visceral adiposity accumulation evaluating by VAI was associated with increased likelihood of the decline in renal function.

Microvascular significance of TGF-β axis activation in COVID-19

As 2023 approaches, the COVID-19 pandemic has killed millions. While vaccines have been a crucial intervention, only a few effective medications exist for prevention and treatment of COVID-19 in breakthrough cases or in unvaccinated or immunocompromised patients. SARS-CoV-2 displays early and unusual features of micro-thrombosis and immune dysregulation that target endothelial beds of the lungs, skin, and other organs. Notably, anticoagulation improves outcomes in some COVID-19 patients. The protein transforming growth factor-beta (TGF-β1) has constitutive roles in maintaining a healthy microvasculature through its roles in regulating inflammation, clotting, and wound healing. However, after infection (including viral infection) TGF-β1 activation may augment coagulation, cause immune dysregulation, and direct a path toward tissue fibrosis. Dysregulation of TGF-β signaling in immune cells and its localization in areas of microvascular injury are now well-described in COVID-19, and such events may contribute to the acute respiratory distress syndrome and skin micro-thrombosis outcomes frequently seen in severe COVID-19. The high concentration of TGF-β in platelets and in other cells within microvascular thrombi, its ability to activate the clotting cascade and dysregulate immune pathways, and its pro-fibrotic properties all contribute to a unique milieu in the COVID-19 microvasculature. This unique environment allows for propagation of microvascular clotting and immune dysregulation. In this review we summarize the physiological functions of TGF-β and detail the evidence for its effects on the microvasculature in COVID-19. In addition, we explore the potential role of existing TGF-β inhibitors for the prevention and treatment of COVID-19 associated microvascular thrombosis and immune dysregulation.

Dysfunction of Caveolae-Mediated Endocytic TβRI Degradation Results in Hypersensitivity of TGF-β/Smad Signaling in Osteogenesis Imperfecta

Osteogenesis imperfecta (OI) is a genetic disorder caused by mutations of type I collagen-related genes, and excessive transforming growth factor-beta (TGF-β) signaling is a common mechanism. TGF-β/Smad signaling has inhibitory effects on osteoblast differentiation and maturation and is mainly transduced and regulated by the internalization of a tetrameric receptor complex comprising types I and II TGF-β receptors (TβRI and TβRII). During internalization, clathrin-mediated endocytosis enhances TGF-β/Smad signaling via Smad2/3 phosphorylation and receptors recycling, while caveolae-mediated endocytosis turns off TGF-β/Smad signaling by promoting receptor ubiquitination and degradation. In this study, using an animal model of OI (Colla2^oim , osteogenesis imperfecta murine [oim]/oim mouse), we found that osteoblastic cells of oim/oim mice were more sensitive to the inhibitory effects of TGF-β on osteoblast differentiation and maturation and had much higher cell membrane protein levels of TGF-β receptors than those of wild-type (wt)/wt mice. Further results showed that clathrin-mediated endocytosis of TβRI was enhanced, whereas caveolae-mediated TβRI endocytic degradation was reduced in oim/oim mice, combined with reduced caveolin-1 (Cav-1) phosphorylation. In addition, type I collagen downregulated TβRI via focal adhesion kinase (FAK) and Src activation-dependent Cav-1 phosphorylation. To further examine this mechanism, 4-week-old oim/oim and wt/wt mice were treated with either TβRI kinase inhibitor (SD-208) or vehicle for 8 weeks. SD-208 treatment significantly reduced the fracture incidence in oim/oim mice. Micro-computed tomography and biomechanical testing showed that femoral bone mass and strength were significantly improved with SD-208 treatment in both genotypes. Additionally, SD-208 significantly promoted osteoblast differentiation and bone formation and inhibited bone resorption. In conclusion, dysfunction of caveolae-mediated endocytic TβRI degradation is a possible mechanism for the enhanced TGF-β/Smad signaling in OI. Targeting this mechanism using a TβRI kinase inhibitor effectively reduced fractures and improved bone mass and strength in OI model and, thus, may offer a new strategy for the treatment of OI. © 2022 American Society for Bone and Mineral Research (ASBMR).

Trypanosoma cruzi Dysregulates piRNAs Computationally Predicted to Target IL-6 Signaling Molecules During Early Infection of Primary Human Cardiac Fibroblasts

Trypanosoma cruzi, the etiological agent of Chagas disease, is an intracellular protozoan parasite, which is now present in most industrialized countries. About 40% of T. cruzi infected individuals will develop severe, incurable cardiovascular, gastrointestinal, or neurological disorders. The molecular mechanisms by which T. cruzi induces cardiopathogenesis remain to be determined. Previous studies showed that increased IL-6 expression in T. cruzi patients was associated with disease severity. IL-6 signaling was suggested to induce pro-inflammatory and pro-fibrotic responses, however, the role of this pathway during early infection remains to be elucidated. We reported that T. cruzi can dysregulate the expression of host PIWI-interacting RNAs (piRNAs) during early infection. Here, we aim to evaluate the dysregulation of IL-6 signaling and the piRNAs computationally predicted to target IL-6 molecules during early T. cruzi infection of primary human cardiac fibroblasts (PHCF). Using in silico analysis, we predict that piR_004506, piR_001356, and piR_017716 target IL6 and SOCS3 genes, respectively. We validated the piRNAs and target gene expression in T. cruzi challenged PHCF. Secreted IL-6, soluble gp-130, and sIL-6R in condition media were measured using a cytokine array and western blot analysis was used to measure pathway activation. We created a network of piRNAs, target genes, and genes within one degree of biological interaction. Our analysis revealed an inverse relationship between piRNA expression and the target transcripts during early infection, denoting the IL-6 pathway targeting piRNAs can be developed as potential therapeutics to mitigate T. cruzi cardiomyopathies.

Blood purification in sepsis and COVID-19: what´s new in cytokine and endotoxin hemoadsorption

Sepsis and COVID-19 are two clinical conditions that can lead to a dysregulated inflammatory state causing multiorgan dysfunction, hypercytokinemia, and a high risk of death. Specific subgroups of critically ill patients with particular characteristics could benefit from rescue treatment with hemoadsorption. There is a lack of adequately designed randomized controlled trials evaluating the potential benefits of cytokine or endotoxin hemoadsorption. Critically ill COVID-19 patients with severe acute respiratory failure poorly responsive to conventional treatment could be candidates to receive cytokine hemoadsorption in the presence of high levels of interleukin 6. This treatment can also be suitable for patients with refractory septic shock and hypercytokinemia. In the context of high endotoxin activity, hemoadsorption with polymyxin B could improve clinical parameters and the prognosis of patients with refractory septic shock. Predictive enrichment, using biomarkers or other individual features, identifies potential responders to cytokine, endotoxin, or sequential hemoadsorption. Besides, recognizing the particular subsets of patients likely to respond to one or both types of hemoadsorption will aid the design of future studies that accurately validate the effectiveness of these therapies.

Manipulation of Interleukin-6 (IL-6) and Transforming Growth Factor Beta-1(TGFβ-1) towards viral induced liver cancer pathogenesis

Hepatocellular carcinoma (HCC) is the most common liver malignancy. Early diagnosis of HCC has always been challenging. This study aims to assess the pathogenicity and the prevalence of IL-6 -174G/C (rs1800795) and TGFβ-1 +29C/T (rs1800470) polymorphisms in HCV-infected HCC patients. Experimental strategies are integrated with computational approaches to analyse the pathogenicity of the TGFβ-1 +29C/T and IL-6-174 G/C polymorphisms in HCV-induced HCC. AliBaba2 was used to predict the effect of IL-6-174 G/C on transcription factor binding site in IL-6 gene. Structural changes in the mutant TGFβ-1 structure were determined through project HOPE. To assess the polymorphic prevalence of IL-6 -174G/C and TGFβ-1 +29C/T genotypes in HCC and control subjects, amplification refractory mutation system PCR (ARMS-PCR) was performed on 213 HCC and 216 control samples. GraphPad Prism version 8.0 was used for the statistical analysis of the results. In-silico analysis revealed the regulatory nature of both IL-6 -174G/C and TGFβ-1 +29C/T polymorphisms. ARMS-PCR results revealed that the individuals carrying TT genotype for TGFβ-1 gene have an increased risk of developing HCC (p<0.0001, OR = 5.403, RR = 2.062) as compared to individuals with CT and CC genotype. Similarly, GC genotype carriers for IL-6 gene exhibit an increased risk of HCC susceptibility (p<0.0001, OR = 2.276, RR = 1.512) as compared to the people carrying the GG genotype. Genotype TT of TGFβ-1 gene and genotype GC of IL-6 gene are found to be associated with HCV-induced HCC. IL-6 polymorphism may alter its transcription that leads to its pathogenicity. TGFβ-1 polymorphism may alter protein structure stability.

Hypoxia-induced pulmonary hypertension upregulates eNOS and TGF-β contributing to sex-linked differences in BMPR2 +/R899X mutant mice

Dysfunctional bone morphogenetic protein receptor 2 (BMPR2) and endothelial nitric oxide synthase (eNOS) have been largely implicated in the pathogenesis of pulmonary arterial hypertension (PAH); a life-threatening cardiopulmonary disease. Although the incident of PAH is about three times higher in females, males with PAH usually have a worse prognosis, which seems to be dependent on estrogen-associated cardiac and vascular protection. Here, we evaluated whether hypoxia-induced pulmonary hypertension (PH) in humanized BMPR2+/R899X loss-of-function mutant mice contributes to sex-associated differences observed in PAH by altering eNOS expression and inducing expansion of hyperactivated TGF-β-producing pulmonary myofibroblasts. To test this hypothesis, male and female wild-type (WT) and BMPR2+/R899X mutant mice were kept under hypoxic or normoxic conditions for 4 weeks, and then right ventricular systolic pressure (RVSP) and right ventricular hypertrophy (RVH) were measured. Chronic hypoxia exposure elevated RVSP, inducing RVH in both groups, with a greater effect in BMPR2+/R899X female mice. Lung histology revealed no differences in vessel thickness/area between sexes, suggesting RVSP differences in this model are unlikely to be in response to sex-dependent vascular narrowing. On the other hand, hypoxia exposure increased vascular collagen deposition, the number of TGF-β-associated α-SMA-positive microvessels, and eNOS expression, whereas it also reduced caveolin-1 expression in the lungs of BMPR2+/R899X females compared to males. Taken together, this brief report reveals elevated myofibroblast-derived TGF-β and eNOS-derived oxidants contribute to pulmonary microvascular muscularization and sex-linked differences in incidence, severity, and outcome of PAH.

Urinary interleukin-6 is a potentially useful diagnostic and prognostic marker of acute kidney injury in dogs

BACKGROUND

Interleukin-6 (IL6) is a pro-inflammatory cytokine implicated in the pathophysiology of urinary tract diseases. The objective of this study was to evaluate the diagnostic and prognostic utilities of urinary IL6 (uIL6) in dogs with acute kidney injury (AKI) and other urinary tract diseases.

METHODS

Eighty client-owned dogs were included and divided into four groups: AKI, chronic kidney disease (CKD), urinary tract infection and healthy controls. Urine samples were analysed for uIL6 and normalised to urinary creatinine (uIL6/uCr).

RESULTS

Dogs in the AKI group had higher uIL6/uCr compared with the control and CKD groups (p < 0.001 and 0.012, respectively). Receiver operator characteristic (ROC) curve analysis of uIL6/uCr as a diagnostic marker for AKI had an area under the curve (AUC) of 0.91 (95% confidence interval [CI], 0.81-1.0) with 82% sensitivity and 90% specificity (cutoff point 4.5 pg/mg) when including the AKI and control groups. ROC analysis including AKI compared with all other groups had an AUC of 0.77 (95% CI, 0.67-0.87) for the diagnosis of AKI with sensitivity and specificity of 71% and 78%, respectively (cutoff point 10.4 pg/mg). The 30-day mortality of the AKI group was 34%, and there was no difference in uIL6/uCr between survivors and non-survivors of AKI.

CONCLUSIONS

uIL6/uCr is a potentially sensitive and specific diagnostic marker for AKI in dogs.

Human Cytomegalovirus and Human Herpesvirus 6 Coinfection of Dermal Fibroblasts Enhances the Pro-Inflammatory Pathway Predisposing to Fibrosis: The Possible Impact on Systemic Sclerosis

Systemic sclerosis (SSc) is a severe autoimmune disease likely triggered by genetic and environmental factors, including viral infections. Human cytomegalovirus (HCMV) and human herpesvirus 6A species (HHV-6A) have been associated with SSc, based on in vivo and in vitro evidence, but the data are still inconclusive. Furthermore, despite both viruses being highly prevalent in humans and able to exacerbate each other’s effects, no data are available on their joint effects. Hence, we aimed to study their simultaneous impact on the expression of cell factors correlated with fibrosis and apoptosis in in vitro coinfected fibroblasts, representing the main target cell type in SSc. The results, obtained by a microarray detecting 84 fibrosis/apoptosis-associated factors, indicated that coinfected cells underwent higher and more sustained expression of fibrosis-associated parameters compared with single-infected cells. Thus, the data, for the first time, suggest that HCMV and HHV-6A may cooperate in inducing alterations potentially leading to cell fibrosis, thus further supporting their joint role in SSc. However, further work is required to definitively answer whether β-herpesviruses are causally linked to the disease and to enable the possible use of targeted antiviral treatments to improve clinical outcomes.

Inflammation, Immune Senescence, and Dysregulated Immune Regulation in the Elderly

An optimal immune response requires the appropriate interaction between the innate and the adaptive arms of the immune system as well as a proper balance of activation and regulation. After decades of life, the aging immune system is continuously exposed to immune stressors and inflammatory assaults that lead to immune senescence. In this review, we will discuss inflammaging in the elderly, specifically concentrating on IL-6 and IL-1b in the context of T lymphocytes, and how inflammation is related to mortality and morbidities, specifically cardiovascular disease and cancer. Although a number of studies suggests that the anti-inflammatory cytokine TGF-b is elevated in the elderly, heightened inflammation persists. Thus, the regulation of the immune response and the ability to return the immune system to homeostasis is also important. Therefore, we will discuss cellular alterations in aging, concentrating on senescent T cells and CD4+ CD25+ FOXP3+ regulatory T cells (Tregs) in aging

Gal-3BP in Viral Infections: An Emerging Role in Severe Acute Respiratory Syndrome Coronavirus 2

Galectin-3 binding protein (Gal-3BP) is a multifunctional glycoprotein involved in cell–cell and cell–matrix interactions known to be upregulated in cancer and various viral infections, including HIV-1, HCV, and SARS-CoV-2, with a key role in regulating the antiviral immune response. Studies have identified a direct correlation between circulating levels of Gal-3BP and the severity of disease and/or disease progression for some viral infections, including SARS-CoV-2, suggesting a role of Gal-3BP in these processes. Due to Gal-3BP’s complex biology, the molecular mechanisms underlying its role in viral diseases have been only partially clarified. Gal-3BP induces the expression of interferons (IFNs) and proinflammatory cytokines, including interleukin-6 (IL-6), mainly interacting with galectin-3, targeting the TNF receptor-associated factors (TRAF-6 and TRAF-3) complex, thus having a putative role in the modulation of TGF-β signaling. In addition, an antiviral activity of Gal-3BP has been ascribed to a direct interaction of the protein with virus components. In this review, we explored the role of Gal-3BP in viral infections and the relationship between Gal-3BP upregulation and disease severity and progression, mainly focusing on SARS-CoV-2. Augmented knowledge of Gal-3BP’s role in virus infections can be useful to evaluate its possible use as a prognostic biomarker and as a putative target to block or attenuate severe disease.

Therapeutic Approaches for Treating Pulmonary Arterial Hypertension by Correcting Imbalanced TGF-β Superfamily Signaling

Pulmonary arterial hypertension (PAH) is a rare disease characterized by high blood pressure in the pulmonary circulation driven by pathological remodeling of distal pulmonary arteries, leading typically to death by right ventricular failure. Available treatments improve physical activity and slow disease progression, but they act primarily as vasodilators and have limited effects on the biological cause of the disease—the uncontrolled proliferation of vascular endothelial and smooth muscle cells. Imbalanced signaling by the transforming growth factor-β (TGF-β) superfamily contributes extensively to dysregulated vascular cell proliferation in PAH, with overactive pro-proliferative SMAD2/3 signaling occurring alongside deficient anti-proliferative SMAD1/5/8 signaling. We review the TGF-β superfamily mechanisms underlying PAH pathogenesis, superfamily interactions with inflammation and mechanobiological forces, and therapeutic strategies under development that aim to restore SMAD signaling balance in the diseased pulmonary arterial vessels. These strategies could potentially reverse pulmonary arterial remodeling in PAH by targeting causative mechanisms and therefore hold significant promise for the PAH patient population.

Precision medicine in sepsis and septic shock: From omics to clinical tools

Sepsis is a heterogeneous disease with variable clinical course and several clinical phenotypes. As it is associated with an increased risk of death, patients with this condition are candidates for receipt of a very well-structured and protocolized treatment. All patients should receive the fundamental pillars of sepsis management, which are infection control, initial resuscitation, and multiorgan support. However, specific subgroups of patients may benefit from a personalized approach with interventions targeted towards specific pathophysiological mechanisms. Herein, we will review the framework for identifying subpopulations of patients with sepsis, septic shock, and multiorgan dysfunction who may benefit from specific therapies. Some of these approaches are still in the early stages of research, while others are already in routine use in clinical practice, but together will help in the effective generation and safe implementation of precision medicine in sepsis.

OUP accepted manuscript

Drug-induced nephrotoxicity is a common problem in clinical medicine and the frequency of drug-related acute and chronic kidney dysfunction worldwide. One of them is anti-tuberculosis (TB) drugs that cause renal function impairment during TB treatment. Medicinal plants contain bioactive compounds that are capable for treating drug or toxin-induced renal disorders. The aim of the present study was to assess the protective effect of the ethanolic extract of Nigella sativa seeds (NS) against anti-TB drugs (ATDs) induced nephrotoxicity in Wistar albino rats. Rats were treated with ATDs for 12weeks (3 alternative days in a week). Supplementation with 125mg NS/kg, p.o. was administered to the experimental rats for 12weeks (3 alternative days in a week considering next day of ATDs treatment). The results demonstrated that NS treatment protected against renal damage induced by ATDs, as evidenced by the reduction in serum urea, creatinine, uric acid, urea nitrogen levels, pro-inflammatory markers (TNF-α and IL-6), whereas improvement in histological tubular and glomerular damage. In addition, NS enhanced the antioxidant enzyme activity (superoxide dismutase and catalase) and decreased the lipid peroxidation and glutathione level in the kidney. In conclusion, NS could reduce chronic nephritis in ATDs treated group through suppressing inflammation and oxidative stress. It suggests that NS can be used as supplementary preventive and protective drug against kidney injury during anti-TB treatment.

OUP accepted manuscript

Background

We investigated the incidence of chronic kidney disease (CKD) progression and its factors relevant to patients with stable rheumatoid arthritis (RA).

Methods

We enrolled consecutive patients with RA who had initiated treatment with a biologic disease-modifying anti-rheumatic drug (bDMARD) at our institution and continued the same drug for >5 years between 2001 and 2016. Patients with CKD at bDMARD initiation were excluded. C-reactive protein (CRP) level, Clinical Disease Activity Index (CDAI) score and estimated glomerular filtration rate were measured every 6 months.

Results

We included 423 patients, with 196 on tumour necrosis factor inhibitors, 190 on tocilizumab and 37 on abatacept. Among these patients, 34 (8.0%) progressed to CKD within 5 years. The mean CRP level and CDAI score over 5 years were significantly lower in patients without CKD progression than in those with CKD progression (P < .001 and P = .008, respectively). Multivariable analysis revealed that age at bDMARD initiation [odds ratio (OR) 1.05, P = .002], non-steroidal anti-inflammatory drug use (OR 3.47, P = .004) and mean CRP >0.14 mg/dL (OR 5.89, P = .015) were independently associated with CKD progression, while tocilizumab use was associated with a decreased risk of CKD progression (OR 0.31, P = .027).

Conclusions

Controlling inflammation contributes to the inhibition of CKD progression in RA patients.

Resolution of inflammation in bone regeneration: From understandings to therapeutic applications

Impaired bone healing occurs in 5-10% of cases following injury, leading to a significant economic and clinical impact. While an inflammatory response upon injury is necessary to facilitate healing, its resolution is critical for bone tissue repair as elevated acute or chronic inflammation is associated with impaired healing in patients and animal models. This process is governed by important crosstalk between immune cells through mediators that contribute to resolution of inflammation in the local healing environment. Approaches modulating the initial inflammatory phase followed by its resolution leads to a pro-regenerative environment for bone regeneration. In this review, we discuss the role of inflammation in bone repair, the negative impact of dysregulated inflammation on bone tissue regeneration, and how timely resolution of inflammation is necessary to achieve normal healing. We will discuss applications of biomaterials to treat large bone defects with a specific focus on resolution of inflammation to modulate the immune environment following bone injury, and their observed functional benefits. We conclude the review by discussing future strategies that could lead to the realization of anti-inflammatory therapeutics for bone tissue repair.

Renal denervation alleviates renal ischemic reperfusion injury-induced acute and chronic kidney injury in rats partly by modulating miRNAs

BACKGROUND

Renal denervation (RDN) has been used to promote kidney injury repair, whereas miRNAs have been found to be involved in the pathophysiology of renal injury. However, the miRNA alterations that occur after RDN and the related protective mechanisms remain to be determined.

METHODS

Renal ischemic reperfusion injury (IRI) rat model was established and RDN was performed. Animals were killed at 24 h and 2 weeks following the operation. Tyrosine hydroxylase (TH) levels, renal function, tubular cell apoptosis and histological sections were examined at 24 h, whereas renal fibrosis and capillary vessels were assessed at 2 weeks. Furthermore, the expression of miRNAs in the injured kidney was determined using micro-array and the target genes were analyzed.

RESULTS

We found that TH was eliminated and that renal function was improved in the denervation group at 24 h. RDN reduced tubular cell apoptosis and mitigated the histological lesion. Furthermore, an increase of capillary vessel density and reduction of renal fibrosis were observed after 2 weeks. Moreover, the numbers of miRNAs were up-regulated after RDN treatment, and the miRNAs targeted pro-angiogenic, anti-fibrotic and inflammatory pathways.

CONCLUSIONS

RDN is a reliable method for alleviating IRI-induced acute and chronic kidney injury, and modulating the miRNA-related pro-angiogenic, anti-fibrotic or inflammatory pathways involved in this process.

Canonical TGFβ Signaling and Its Contribution to Endometrial Cancer Development and Progression-Underestimated Target of Anticancer Strategies

Endometrial cancer is one of the leading gynecological cancers diagnosed among women in their menopausal and postmenopausal age. Despite the progress in molecular biology and medicine, no efficient and powerful diagnostic and prognostic marker is dedicated to endometrial carcinogenesis. The canonical TGFβ pathway is a pleiotropic signaling cascade orchestrating a variety of cellular and molecular processes, whose alterations are responsible for carcinogenesis that originates from different tissue types. This review covers the current knowledge concerning the canonical TGFβ pathway (Smad-dependent) induced by prototypical TGFβ isoforms and the involvement of pathway alterations in the development and progression of endometrial neoplastic lesions. Since Smad-dependent signalization governs opposed cellular processes, such as growth arrest, apoptosis, tumor cells growth and differentiation, as well as angiogenesis and metastasis, TGFβ cascade may act both as a tumor suppressor or tumor promoter. However, the final effect of TGFβ signaling on endometrial cancer cells depends on the cancer disease stage. The multifunctional role of the TGFβ pathway indicates the possible utilization of alterations in the TGFβ cascade as a potential target of novel anticancer strategies.

Combination therapy of tanshinone IIA and puerarin for pulmonary fibrosis via targeting IL6-JAK2-STAT3/STAT1 signaling pathways

Efficient therapy of idiopathic pulmonary fibrosis (IPF) is still a major challenge. The current studies with single-target drug therapy are the pessimistic approaches due to the complex characteristics of IPF. Here, a combination therapy of Tanshinone IIA and Puerarin for IPF was proposed to alleviate IPF due to their antiinflammatory and anti-fibrotic effects. In vivo, the combination therapy could significantly attenuate the area of ground glass opacification that was presented by 85% percentile density score of the micro-CT images when compared to single conditions. In addition, the combination therapy enormously improved the survival rate and alleviated pathological changes in bleomycin (BLM)-induced IPF mice. By using a wide spectrum of infiltration biomarkers in immunofluorescence assay in pathological sections, we demonstrate that fewer IL6 related macrophage infiltration and fibrosis area after this combination therapy, and further proved that IL6-JAK2-STAT3/STAT1 is the key mechanism of the combination therapy. In vitro, combination therapy markedly inhibited the fibroblasts activation and migration which was induced by TGF-β1 or/and IL6 through JAK2-STAT3/STAT1 signaling pathway. This study demonstrated that combination therapeutic effect of TanIIA and Pue on IPF may be related to the reduced inflammatory response targeting IL6, which could be an optimistic and effective approach for IPF.

Fibroblast pathology in inflammatory joint disease

Rheumatoid arthritis is an immune-mediated inflammatory disease in which fibroblasts contribute to both joint damage and inflammation. Fibroblasts are a major cell constituent of the lining of the joint cavity called the synovial membrane. Under resting conditions, fibroblasts have an important role in maintaining joint homeostasis, producing extracellular matrix and joint lubricants. In contrast, during joint inflammation, fibroblasts contribute to disease pathology by producing pathogenic levels of inflammatory mediators that drive the recruitment and retention of inflammatory cells within the joint. Recent advances in single-cell profiling techniques have transformed our ability to examine fibroblast biology, leading to the identification of specific fibroblast subsets, defining a previously underappreciated heterogeneity of disease-associated fibroblast populations. These studies are challenging the previously held dogma that fibroblasts are homogeneous and are providing unique insights into their role in inflammatory joint pathology. In this review, we discuss the recent advances in our understanding of how fibroblast heterogeneity contributes to joint pathology in rheumatoid arthritis. Finally, we address how these insights could lead to the development of novel therapies that directly target selective populations of fibroblasts in the future.

Interleukin-6 participates in human pancreatic stellate cell activation and collagen I production via TGF-β1/Smad pathway

Pancreatic stellate cells (PSCs) play a key role in fibrogenesis during alcoholic chronic pancreatitis (ACP). Transforming growth factor-β1 (TGF-β1) is a major regulator of PSC activation and extracellular matrix production. Interleukin-6 (IL-6) has shown to participate in TGF-β1 production and rat PSC activation. This study aimed to investigate whether IL-6 promotes human PSC activation and collagen 1(Col1) production through the TGF-β1/Smad pathway. Our results showed that the expression of IL-6 and IL-6R in activated PSCs and macrophages (Mφs) were enhanced in the pancreas of ACP compared to healthy controls and that the mRNA expression of IL-6, IL-6R, TGF-β1, α-SMA or Col1a1 were significantly increased in the pancreas of ACP, showing positive correlations between elevated IL-6 levels and either TGF-β1 or α-SMA or Col1a1 levels and between elevated TGF-β1 levels and α-SMA or Col1a1 levels. In in vitro studies, we identified that IL-6R expression or IL-6 and TGF-β1 secretions were significantly increased in, respectively, Mφs and PSCs by ethanol (EtOH) or lipopolysaccharide (LPS) stimulation while EtOH- or LPS-induced α-SMA or Col1a1 mRNA and protein production in PSCs were partially blocked by IL-6 antibody. IL-6-induced TGF-β1 production in PSCs was antagonized by si-IL-6R RNA or by an inhibitor of STAT3. Additionally, IL-6-promoted α-SMA or Col1a1 protein production was blocked by TGF-β1 antibody and IL-6-induced phosphorylation of Smad2/3 and transcription of α-SMA and Col1a1 mRNA were antagonized by si-TGF-β1 RNA. Our findings indicate that IL-6 contributes to PSC activation and Col1 production through up-regulation of TGF-β1/Smad2/3 pathway.

Spatial mapping of SARS-CoV-2 and H1N1 lung injury identifies differential transcriptional signatures

Severe SARS-CoV-2 infection often leads to the development of acute respiratory distress syndrome (ARDS), with profound pulmonary patho-histological changes post-mortem. It is not clear whether ARDS from SARS-CoV-2 is similar to that observed in influenza H1N1, another common viral cause of lung injury. Here, we analyze specific ARDS regions of interest utilizing a spatial transcriptomic platform on autopsy-derived lung tissue from patients with SARS-CoV-2 (n = 3), H1N1 (n = 3), and a dual infected individual (n = 1). Enhanced gene signatures in alveolar epithelium, vascular tissue, and lung macrophages identify not only increased regional coagulopathy but also increased extracellular remodeling, alternative macrophage activation, and squamous metaplasia of type II pneumocytes in SARS-CoV-2. Both the H1N1 and dual-infected transcriptome demonstrated an enhanced antiviral response compared to SARS-CoV-2. Our results uncover regional transcriptional changes related to tissue damage/remodeling, altered cellular phenotype, and vascular injury active in SARS-CoV-2 and present therapeutic targets for COVID-19-related ARDS.

A roadmap to target interleukin-6 in osteoarthritis

Joint inflammation is present in the majority of OA patients and pro-inflammatory mediators, such as IL-6, are actively involved in disease progression. Increased levels of IL-6 in serum or synovial fluid from OA patients correlate with disease incidence and severity, with IL-6 playing a pivotal role in the development of cartilage pathology, e.g. via induction of matrix-degrading enzymes. However, IL-6 also increases expression of anti-catabolic factors, suggesting a protective role. Until now, this dual role of IL-6 is incompletely understood and may be caused by differential effects of IL-6 classic vs trans-signalling. Here, we review current evidence regarding the role of IL-6 classic- and trans-signalling in local joint pathology of cartilage, synovium and bone. Furthermore, we discuss targeting of IL-6 in experimental OA models and provide future perspective for OA treatment by evaluating currently available IL-6 targeting strategies.

Gender difference in the association of chronic kidney disease with visceral adiposity index and lipid accumulation product index in Korean adults: Korean National Health and Nutrition Examination Survey

BACKGROUND

This study was conducted to assess gender difference in the association of chronic kidney disease (CKD) with visceral adiposity index (VAI) and lipid accumulation product index (LAP) in Korean adults.

MATERIALS AND METHODS

The study was performed using data from the 2015 Korean National Health and Nutrition Examination Survey and included 4947 adults aged 20 years or older.

RESULTS

There were several key findings in the present study. First, overall, after adjusting for related variables (including age), CKD (estimated glomerular filtration rate < 60 ml/min/1.73 m²) was positively associated with the quartiles of VAI and LAP. Second, when analyzed separately for gender, the results in men and women were different. After adjusting for the related variables (except age), CKD was positively associated with the quartiles of VAI and LAP in both men and women. After further adjustment for age, CKD was still positively associated with the quartiles of VAI and LAP in men. However, in women, the relationships between CKD and the quartiles of VAI and LAP were no longer significant.

CONCLUSIONS

The VAI and LAP index were positively associated with CKD in Korean men but not in women.

Recapitulating pancreatic tumor microenvironment through synergistic use of patient organoids and organ-on-a-chip vasculature

Tumor progression relies heavily on the interaction between the neoplastic epithelial cells and their surrounding stromal partners. This cell cross-talk affects stromal development, and ultimately the heterogeneity impacts drug efflux and efficacy. To mimic this evolving paradigm, we have micro-engineered a three-dimensional (3D) vascularized pancreatic adenocarcinoma tissue in a tri-culture system composed of patient derived pancreatic organoids, primary human fibroblasts and endothelial cells on a perfusable InVADE platform situated in a 96-well plate. Uniquely, through synergistic engineering we combined the benefits of cellular fidelity of patient tumor derived organoids with the addressability of a plastic organ-on-a-chip platform. Validation of this platform included demonstrating the growth of pancreatic tumor organoids by monitoring the change in metabolic activity of the tissue. Investigation of tumor microenvironmental behavior highlighted the role of fibroblasts in symbiosis with patient organoid cells, resulting in a six-fold increase of collagen deposition and a corresponding increase in tissue stiffness in comparison to fibroblast free controls. The value of a perfusable vascular network was evident in drug screening, as perfusion of gemcitabine into a stiffened matrix did not show the dose-dependent effects on tumor viability as those under static conditions. These findings demonstrate the importance of studying the dynamic synergistic relationship between patient cells with stromal fibroblasts, in a 3D perfused vascular network, to accurately understand and recapitulate the tumor microenvironment.

Anti-Inflammatory, Antioxidant, and Antifibrotic Effects of Kefir Peptides on Salt-Induced Renal Vascular Damage and Dysfunction in Aged Stroke-Prone Spontaneously Hypertensive Rats

The increased prevalence of renal dysfunction and chronic kidney disease (CKD) and the high costs and poor outcomes of treatment are a significant health issue. The consequence of chronic high blood pressure is the increased prevalence of target organ end-stage renal disease, which has been proven to be a strong independent risk factor for adverse cardiovascular disease. A previous study showed that kefir products have anti-inflammatory and anti-hypertensive activities and immunological modulation functions. However, no data regarding the beneficial effects of kefir peptides (KPs) on salt-induced renal damage or related kidney diseases are available. In this study, KPs were orally administered to aged salt-induced stroke-prone spontaneously hypertensive (SHRSP) rats, and the effects of KPs against inflammation and oxidative stress and their ability to protect against renal dysfunction were evaluated. Fifty-five-week-old SHRSP rats under induction with 1% NaCl in drinking water for 4 weeks showed multiple renal injuries with increased renal inflammation, fibrosis, oxidative stress, tubular atrophy, and glomerulosclerosis. In contrast, oral gavage with KPs reduced the urine protein to creatinine (UPC) ratio, the fractional excretion of electrolytes (FeNa and FeCl), extracellular matrix deposition, and the interstitial fibrotic α-smooth muscle actin (α-SMA) levels in salt-induced SHRSP rats. The renal infiltration of inflammatory cells; the release of monocyte chemoattractant protein-1 (MCP-1), vascular cell adhesion molecule-1 (VCAM-1), endothelin-1 (ET-1), and the cytokine nucleotide-binding oligomerization domain (NOD)-like receptor family pyrin domain containing 3 (NLRP3) and transforming growth factor-β (TGF-β); the reactive oxygen species (ROS) levels; and histopathological lesions were also decreased in salt-induced SHRSP rats. Furthermore, KP treatment significantly increased the renal superoxide dismutase (SOD) activity and the glomerular filtration rate (GFR), which exerted potent protection against salt-induced chronic kidney disease in SHRSP rats. The results of this study suggest that KPs ameliorate salt-induced renal damage, tubular atrophy, and glomerular dysfunction through anti-inflammatory, antioxidative stress, and antifibrotic activities, and might be a promising protective agent against high salt-induced renovascular-related diseases.

Tocilizumab improves oxidative stress and endothelial glycocalyx: A mechanism that may explain the effects of biological treatment on COVID-19

We investigated the effects of tocilizumab on endothelial glycocalyx, a determinant of vascular permeability, and myocardial function in rheumatoid arthritis (RA). Eighty RA patients were randomized to tocilizumab (n = 40) or conventional synthetic disease-modifying antirheumatic drugs (csDMARDs) and glucocorticoids (GC) (n = 40) for 3 months. Forty healthy subjects with similar age and sex served as controls. We measured: (a)perfused boundary region (PBR) of the sublingual arterial microvessels (increased PBR indicates reduced glycocalyx thickness), (b)pulse wave velocity (PWV), (c)global LV longitudinal strain (GLS), (d)global work index (GWI) using speckle tracking echocardiography and e)C-reactive protein (CRP), malondialdehyde (MDA) and protein carbonyls (PCs) as oxidative stress markers at baseline and post-treatment. Compared to controls, RA patients had impaired glycocalyx and myocardial deformation markers (P < 0.05). Compared with baseline, tocilizumab reduced PBR(2.14 ± 0.2 versus 1.97 ± 0.2 μm; P < 0.05) while no significant differences were observed post-csDMARDs + GC(P > 0.05). Compared with csDMARDs + GC, tocilizumab achieved a greater increase of GLS, GWI and reduction of MDA, PCs and CRP(P < 0.05). The percent improvement of glycocalyx thickness (PBR) was associated with the percent decrease of PWV, MDA, PCs and the percent improvement of GLS and GWI(P < 0.05). Tocilizumab improves endothelial function leading to a greater increase of effective myocardial work than csDMARDs + GC through a profound reduction of inflammatory burden and oxidative stress. This mechanism may explain the effects of tocilizumab on COVID-19.

Clinical trial registration

url: https://www.clinicaltrials.gov. Unique identifier: NCT03288584.

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Tocilizumab improves endothelial glycocalyx and increases effective myocardial work.

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IL-6 inhibition significantly reduces the inflammatory burden and oxidative stress.

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Tocilizumab may have favorable effects on diseases with excess IL-6 release.

[The balance of proinflammatory cytokines and Treg cells in chronic glomerulonephritis]

Chronic glomerulonephritis (CGN) is a disease with a steadily progressing course, which is based on inflammation with the activation of immune cells. The severity of the inflammatory reaction in the kidney tissue is determined by the balance of locally pro-inflammatory factors and protective mechanisms, which include anti-inflammatory cytokines and T-regulatory lymphocytes (Treg). The study of processes that can modulate the severity of inflammation in the kidney is of particular interest for understanding the basic patterns of CGN progression.

AIM

To determine the clinical significance of the Th17, Th1, and Treg cytokines in urine to assess the activity and progression of chronic glomerulonephritis with nephrotic syndrome (NS).

MATERIALS AND METHODS

The study included 98 patients with CGN 37 women and 61 men. Patients were divided into two groups according to the degree of CGN activity. Group I consisted of 51 patients with NS. In 21 subjects, a decrease in GFR60 ml/min was revealed. Group II included 47 patients with proteinuria from 1 to 3 g/day without NS. GFR60 ml/min/1.73 m2 was observed in 26 patients. A kidney biopsy was performed in 65 patients and the hystological diagnosis was verified: 20 had mesangioproliferative GN, 16 had membranous nephropathy, 18 had focal segmental glomerulosclerosis, and 11 had membranoproliferative GN. The control group consisted of 15 healthy people. The levels of IL-6, IL-10, IL-17, tumor necrosis factor a (TNF-a) in the urine were determined using enzyme-linked immunosorbent assay. The number of FoxP3-positive cells in the inflammatory interstitial infiltrate of the cortical layer was determined in 39 patients (in a biopsy sample in a 1.5 mm2 area).

RESULTS

In group of patients with CGN, there was an increase in the levels of Th17, Th1, and Treg cytokines in urine TNF-a and IL-10 compared with healthy individuals. An increase in the levels of IL-6 in the urine of patients with high clinical activity of CGN (with NS and renal dysfunction) was more pronounced than in patients with NS and normal renal function. There was a decrease in the number of Treg cells in the interstitium of the kidney and a decrease in the production of anti-inflammatory IL-10 in CGN patients with NS, compared with patients without NS. The most pronounced changes in the cytokine profile were observed in patients with FSGS with an increase in pro-inflammatory cytokines and a decrease in Treg in the kidney tissue/anti-inflammatory IL-10 in the urine.

CONCLUSION

An imbalance of cytokines characterized by an increased levels of pro-inflammatory IL-17, IL-6, TNF-a, and a reduced levels of anti-inflammatory IL-10 and T-regulatory cells in the kidney tissue is noted in patients with NS, especially with FSGS. Imbalance of cytokines reflects the high activity of CGN and the risk of the progression of the disease.

Positive Feedback Loop of SNAIL-IL-6 Mediates Myofibroblastic Differentiation Activity in Precancerous Oral Submucous Fibrosis

Oral submucosal fibrosis (OSF) is a premalignant disorder of the oral cavity, and areca nut chewing is known to be a major etiological factor that could induce epithelial to mesenchymal transition (EMT) and activate buccal mucosal fibroblasts (BMFs). However, this detailed mechanism is not fully understood. In this study, we showed that the upregulation of Snail in OSF samples and fibrotic BMFs (fBMFs) may result from constant irritation by arecoline, a major alkaloid of the areca nut. The elevation of Snail triggered myofibroblast transdifferentiation and was crucial to the persistent activation of fBMFs. Meanwhile, Snail increased the expression of numerous fibrosis factors (e.g., α-SMA and collagen I) as well as IL-6. Results from bioinformatics software and a luciferase-based reporter assay revealed that IL-6 was a direct target of Snail. Moreover, IL-6 in BMFs was found to further increase the expression of Snail and mediate Snail-induced myofibroblast activation. These findings suggested that there was a positive loop between Snail and IL-6 to regulate the areca nut-associated myofibroblast transdifferentiation, which implied that the blockage of Snail may serve as a favorable therapeutic strategy for OSF treatment.

Genetics of developmental dysplasia of the hip

In the last decade, the advances in the molecular analyses and sequencing techniques allowed researchers to study developmental dysplasia of the hip (DDH) more thoroughly. Certain chromosomes, genes, loci and polymorphisms are being associated with variable severity of this disorder. The wide range of signs and symptoms is dependent either on isolated or systemic manifestation. Phenotypes of isolated cases range from only a mild ligamental laxity, through subluxation, to a complete dislocation of the femoral head. Systemic manifestation is connected to various forms of skeletal dysplasia and other malformations characterized by significant genetic aberrations. To reveal the background of DDH heredity, multiple studies focused on large sample sizes with an emphasis on the correlation between genotype, phenotype and continuous clinical examination. Etiological risk factors that have been observed and documented in patients include genetic, environmental, and mechanical factors, which significantly contribute to the familial or nonfamilial occurrence and phenotypic variability of this disorder. Still, the multifactorial etiology and pathogenesis of DDH are not yet sufficiently clarified, explained, or understood. Formation of connective tissue, osteogenesis, chondrogenesis, and all other affected pathways and variations in the function of their individual elements contribute to the creation of the pathology in a developing human body. This review article presents an up-to-date list of known DDH associated genes, their products, and functional characteristics.

Extracellular vesicles released by melanocytes after UVA irradiation promote intercellular signaling via miR21

Skin pigmentation is controlled by complex crosstalk between melanocytes and keratinocytes and is primarily induced by exposure to ultraviolet (UV) irradiation. Several aspects of UVA-induced signaling remain to be explored. In skin cells, UVA induces plasma membrane damage, which is repaired by lysosomal exocytosis followed by instant shedding of extracellular vesicles (EVs) from the plasma membrane. The released EVs are taken up by neighboring cells. To elucidate the intercellular crosstalk induced by UVA irradiation, EVs were purified from UVA-exposed melanocytes and added to keratinocytes. Transcriptome analysis of the keratinocytes revealed the activation of TGF-β and IL-6/STAT3 signaling pathways and subsequent upregulation of microRNA (miR)21. EVs induced phosphorylation of ERK and JNK, reduced protein levels of PDCD4 and PTEN, and augment antiapoptotic signaling. Consequently, keratinocyte proliferation and migration were stimulated and UV-induced apoptosis was significantly reduced. Interestingly, melanoma cells and melanoma spheroids also generate increased amounts of EVs with capacity to stimulate proliferation and migration upon UVA. In conclusion, we present a novel intercellular crosstalk mediated by UVA-induced lysosome-derived EVs leading to the activation of proliferation and antiapoptotic signaling via miR21.

Human Skin Keratinocytes on Sustained TGF-β Stimulation Reveal Partial EMT Features and Weaken Growth Arrest Responses

Defects in wound closure can be related to the failure of keratinocytes to re-epithelize. Potential mechanisms driving this impairment comprise unbalanced cytokine signaling, including Transforming Growth Factor-β (TFG-β). Although the etiologies of chronic wound development are known, the relevant molecular events are poorly understood. This lack of insight is a consequence of ethical issues, which limit the available evidence to humans. In this work, we have used an in vitro model validated for the study of epidermal physiology and function, the HaCaT cells to provide a description of the impact of sustained exposure to TGF-β. Long term TGF-β1 treatment led to evident changes, HaCaT cells became spindle-shaped and increased in size. This phenotype change involved conformational re-arrangements for actin filaments and E-Cadherin cell-adhesion structures. Surprisingly, the signs of consolidated epithelial-to-mesenchymal transition were absent. At the molecular level, modified gene expression and altered protein contents were found. Non-canonical TGF-β pathway elements did not show relevant changes. However, R-Smads experienced alterations best characterized by decreased Smad3 levels. Functionally, HaCaT cells exposed to TGF-β1 for long periods showed cell-cycle arrest. Yet, the strength of this restraint weakens the longer the treatment, as revealed when challenged by pro-mitogenic factors. The proposed setting might offer a useful framework for future research on the mechanisms driving wound chronification.

miR-29b attenuates histone deacetylase-4 mediated podocyte dysfunction and renal fibrosis in diabetic nephropathy

Purpose

As epigenetic modifications like chromatin histone modifications have been suggested to play a role in the pathophysiology of Diabetic Nephropathy (DN) and are also found to be regulated by microRNAs. Our main purpose was to explore the role of microRNA in histone modulations associated with DN. There is downregulation of miR-29b due to advanced glycation end products in diabetes. Histone Deacetylase-4 (HDAC4) is amongst the histone modulators which promotes podocytes' impairment and upregulates transforming growth factor-1 (TGF-β1) leading to renal fibrosis. Moreover, macrophage infiltration causes podocytes' apoptosis and IL-6 mediated inflammation. As miR-29b is downregulated in diabetes and HDAC4, TGF-β1 and IL-6 could be the possible therapeutic targets in DN, our study was focussed on unveiling the role of miR-29b in modulation of HDAC4 and hence, in podocyte dysfunction and renal fibrosis in DN.

Methods

In silico analysis and luciferase assay were done to study the interaction between miR-29b and HDAC4. In-vitro DN model was developed in podocytes and miR-29b mimics were transfected. Also, podocytes were co-cultured with macrophage and miR-29b mimics were transfected. At the end, in-vivo DN model was generated in C57BL/6 J male mice and the effect of miR-29b mimics was reconfirmed.

Results

It was found that miR-29b targets the 3' untranslated region of HDAC4. In both in-vitro and in-vivo DN model, downregulation of miR-29b and subsequent increase in HDAC4 expression was observed. The miR-29b mimics suppressed podocytes' inflammation mediated through macrophages and attenuated HDAC4 expression, glomerular damage and renal fibrosis.

Conclusion

This study concludes that miR-29b regulates the expression of HDAC4 which plays a role in controlling renal fibrosis and podocytes' impairment in DN.

Developmental dysplasia of the hip: a systematic literature review of the genes related with its occurrence

Developmental dysplasia of the hip (DDH) is one of the most prevalent congenital malformations. It has a wide spectrum of anatomical abnormalities of the hip joint and is characterized by mild or incomplete formation of the acetabulum leading to laxity of the joint capsule, secondary deformity of the proximal femur and irreducible hip dislocation. It is the leading cause of early hip osteoarthritis in young individuals.

Both genetic and environmental factors have been proposed to play an important role in the pathogenesis of DDH. A high prevalence is present in Asian, Caucasian, Mediterranean and American populations, with females being more frequently affected. We evaluated a variety of genetic studies indexed in the PubMed database.

Several susceptive genes, including WISP3, PAPPA2, HOXB9, HOXD9, GDF5, TGF Beta 1, CX3CR1, UQCC, COL1A1, TbX4 and ASPN have been identified as being associated with the development of DDH. Moreover, genetic association has also been reported between hip dysplasia and other comorbidities. Even though genetic components are a crucial part in the aetiology of DDH, several DDH susceptibility genes need further investigation.

The purpose of this review is to present current literature evidence regarding genes responsible for DDH development.

Cite this article: EFORT Open Rev 2019;4:595-601. DOI: 10.1302/2058-5241.4.190006

The Roles of IL-1 Family Cytokines in the Pathogenesis of Systemic Sclerosis

The IL-1 family consists of 11 cytokines, 7 ligands with agonist activity (IL-1α, IL-1β, IL-18, IL-33, IL-36α, IL-36β, IL-36γ) and four members with antagonistic activities [IL-1 receptor antagonist (IL-1Ra), IL-36Ra, IL-37, IL-38]. Recent articles have described that most members of IL-1 family cytokines are involved in the process of innate and adaptive immunity as well as fibrosis in systemic sclerosis (SSc). IL-1 family gene polymorphisms, abnormal expression of IL-1 and its potential role in the fibrosis process have been explored in SSc. IL-33 and IL-18 have also been discussed in the recent years. IL-33 may contribute to the fibrosis of SSc, while IL-18 remains to be researched to confirm its role in fibrosis process. There is a lack of study on the pathophysiological roles of IL-36, IL-37, and IL-38 in SSc, which might provide us new study area. Here, we aim to give a brief overview of IL-1 family cytokines and discuss their pivotal roles in the pathogenesis of SSc.