HSP70 increases extracellular matrix production by human vascular smooth muscle through TGF-β1 up-regulation

Heat Shock Proteins (HSPs) and Cardiovascular Complications of Obesity: Searching for Potential Biomarkers

Heat shock proteins (HSPs), a family of proteins that support cellular proteostasis and perform a protective function under various stress conditions, such as high temperature, intoxication, inflammation, or tissue hypoxia, constitute a promising group of possible biochemical markers for obesity and cardiovascular diseases. HSP27 is involved in essential cellular processes occurring in conditions of obesity and its cardiometabolic complications; it has protective properties, and its secretion may indicate a cellular response to stress. HSP40 plays a controversial role in the pathogenesis of obesity. HSP60 is involved in various pathological processes of the cardiovascular, immune, excretory, and nervous systems and is associated with obesity and concomitant diseases. The hypersecretion of HSP60 is associated with poor prognosis; hence, this protein may become a target for further research on obesity and its cardiovascular complications. According to most studies, intracellular HSP70 is an obesity-promoting factor, whereas extracellular HSP70 exhibited inconsistent dynamics across different patient groups and diagnoses. HSPs are involved in the pathogenesis of cardiovascular pathology. However, in the context of cardiovascular and metabolic pathology, these proteins require further investigation.

Sarcopenia in patients with rheumatic musculoskeletal diseases

AIM

To investigate the impact of high-dose glucocorticoid therapy on sarcopenia in hospitalized patients with rheumatic musculoskeletal diseases (RMDs).

METHODS

We included patients with RMDs who were hospitalized between 2020 and 2022 for remission induction treatment and collected information on skeletal mass index (SMI) before high-dose glucocorticoid therapy and 1 month later. We divided the patients into 2 groups according to the progression of sarcopenia, defined as a >10% decrease in SMI, and compared their clinical characteristics.

RESULTS

Forty-nine patients were included in this analysis. The mean age was 53.3 years, 73.5% were female, and the mean SMI was 5.3 kg/m2 . Before treatment, 83.7% had already met the definition of sarcopenia, and 57.1% experienced further sarcopenia progression after 1 month of high-dose glucocorticoid treatment. Patients with sarcopenia progression were predominantly male (P = 0.025), had a higher body weight (P = 0.048), and showed a higher SMI than those without sarcopenia at baseline (P = 0.008). Multivariable analysis revealed that body weight increase from 0 to week 1 of high-dose glucocorticoid treatment was associated with sarcopenia progression (odds ratio: 0.22, 95% CI: 0.04-0.61, P = 0.007) with a cut-off of -1.8 kg. During a mean observation period of 30.2 days, the incidence of infection was significantly higher in patients with progressive sarcopenia (P = 0.042).

CONCLUSIONS

One-month hospitalization with high-dose glucocorticoid therapy is associated with sarcopenia progression in patients with RMDs. An early decrease in body weight can be used to predict muscle volume loss.

Intestinal fibrosis in aganglionic segment of Hirschsprung's disease revealed by single-cell RNA sequencing

BACKGROUND

Hirschsprung's disease (HSCR) is a relatively common congenital disability. Accumulating extracellular matrix (ECM) prompts intestinal fibrosis remodelling in the aganglionic segments of HSCR. The contributions of various cellular subsets in the fibrogenesis of HSCR segments are poorly understood.

METHODS

Single-cell transcriptomics from 8 aganglionic segments and 5 normal segments of 7 HSCR subjects and 26 healthy segments of seven healthy donors were analysed. Fibrotic phenotype and alterations were explored using differential expression analysis and single-cell trajectory analysis. Fibrosis-related transcription factors were inferred through single-cell regulatory network inference. Bulk transcriptomic data, proteomic data, immunohistochemistry (IHC) and real-time polymerase chain reaction were used to validate the alterations in the HSCR intestine.

RESULTS

Various collagen, fibronectin and laminin protein-coding genes expression were up-regulated in the stromal and glial cells of the HSCR intestine. The number of fibroblasts and myofibroblasts in the aganglionic segments increased, and more myofibroblasts were activated at an earlier stage in HSCR segments, which infers that there is an intestinal fibrosis phenotype in HSCR segments. The fibrotic regulators POSTN, ANXA1 and HSP70 were highly expressed in the ECM-related cellular subsets in the transitional segments and aganglionic segments. The transcription factor regulatory network revealed that fibrosis-related and megacolon-related NR2F1 in the fibroblasts and glial subsets was up-regulated in the aganglionic segment.

CONCLUSIONS

This work identifies intestinal fibrosis and related regulators in aganglionic segments of HSCR; hence, anti-fibrotic therapy may be considered to prevent HSCR-associated enterocolitis (HAEC), relieve intestinal stricture and improve cell therapy.

Functional Nutrients to Ameliorate Neurogenic Muscle Atrophy

Neurogenic muscle atrophy is a debilitating condition that occurs from nerve trauma in association with diseases or during aging, leading to reduced interaction between motoneurons and skeletal fibers. Current therapeutic approaches aiming at preserving muscle mass in a scenario of decreased nervous input include physical activity and employment of drugs that slow down the progression of the condition yet provide no concrete resolution. Nutritional support appears as a precious tool, adding to the success of personalized medicine, and could thus play a relevant part in mitigating neurogenic muscle atrophy. We herein summarize the molecular pathways triggered by denervation of the skeletal muscle that could be affected by functional nutrients. In this narrative review, we examine and discuss studies pertaining to the use of functional ingredients to counteract neurogenic muscle atrophy, focusing on their preventive or curative means of action within the skeletal muscle. We reviewed experimental models of denervation in rodents and in amyotrophic lateral sclerosis, as well as that caused by aging, considering the knowledge generated with use of animal experimental models and, also, from human studies.

Increased eHSP70-to-iHSP70 ratio in prediabetic and diabetic postmenopausal women: a biomarker of cardiometabolic risk

Decreased estrogen levels in menopause are associated with anthropometric, metabolic, and inflammatory impairments, predisposing women to cardiometabolic risk factors such as diabetes. Menopause and type two diabetes (DM2) are marked by altered heat shock response (HSR), shown by decreased expression of the 70-kDa heat shock protein in the intracellular milieu (iHSP70). While iHSP70 plays an anti-inflammatory role, extracellular HSP70 (eHSP70) may mediate pro-inflammatory pathways and has been associated with insulin resistance in DM2. Considering the roles of these proteins according to localization, the eHSP70-to-iHSP70 ratio (H-index) has been proposed as a biomarker for HSR. We, therefore, evaluated whether this biomarker is associated with glycemic and inflammatory status in postmenopausal women. In this transversal study, 36 postmenopausal women were grouped according to fasting glycemia status as either the control group (normoglycemic, ≤ 99 mg/dL) or DM2 (prediabetic and diabetic, glycemia ≥ 100 mg/dL). DM2 group showed higher triglyceride/glucose (TyG) index and plasma atherogenic index (PAI), both of which are indicators of cardiometabolic risk. In addition, we found that the eHSP70-to-iHSP70 ratio (plasma/peripheral blood mononuclear cells-PBMC ratio) was higher in the DM2 group, compared with the control group. Furthermore, blood leukocyte and glycemia levels were positively correlated with the eHSP70-to-iHSP70 ratio in women that presented H-index values above 1.0 (a.u.). Taken together, our results highlight the eHSP70-to-iHSP70 ratio as a biomarker of altered HSR in DM2 postmenopausal women.

Chaperone duality: the role of extracellular and intracellular HSP70 as a biomarker of endothelial dysfunction in the development of atherosclerosis

The 70-kDa heat shock proteins (HSP70) may provide relevant information about the endothelial dysfunction in cardiovascular diseases. Located in the intracellular milieu (iHSP70), they are essential chaperones that inhibit nuclear factor kappa B activation, stimulate nitric oxide production and superoxide dismutase activity, and inhibit apoptosis. However, under stressful conditions, HSP70 can be released into the extracellular medium (eHSP70) and act as an inflammatory mediator. Although studies have reported the vasoprotective role of iHSP70, the evidence regarding eHSP70 is contradictory. eHSP70 can activate NFκB and activator protein-1, thus stimulating the release of inflammatory cytokines and production of reactive oxygen species. Due to the antagonistic nature of HSP70 according to its location, the eHSP70/iHSP70 ratio (Heck index) has been proposed as a better marker of inflammatory status; however, more studies are required to confirm this hypothesis. Therefore, this review summarises studies that, together, describe the role of HSP70 in endothelial dysfunction.

Targeting Fibronectin to Overcome Remyelination Failure in Multiple Sclerosis: The Need for Brain- and Lesion-Targeted Drug Delivery

Multiple sclerosis (MS) is a neuroinflammatory and neurodegenerative disease with unknown etiology that can be characterized by the presence of demyelinated lesions. Prevailing treatment protocols in MS rely on the modulation of the inflammatory process but do not impact disease progression. Remyelination is an essential factor for both axonal survival and functional neurological recovery but is often insufficient. The extracellular matrix protein fibronectin contributes to the inhibitory environment created in MS lesions and likely plays a causative role in remyelination failure. The presence of the blood-brain barrier (BBB) hinders the delivery of remyelination therapeutics to lesions. Therefore, therapeutic interventions to normalize the pathogenic MS lesion environment need to be able to cross the BBB. In this review, we outline the multifaceted roles of fibronectin in MS pathogenesis and discuss promising therapeutic targets and agents to overcome fibronectin-mediated inhibition of remyelination. In addition, to pave the way for clinical use, we reflect on opportunities to deliver MS therapeutics to lesions through the utilization of nanomedicine and discuss strategies to deliver fibronectin-directed therapeutics across the BBB. The use of well-designed nanocarriers with appropriate surface functionalization to cross the BBB and target the lesion sites is recommended.

New insights into the role and therapeutic potential of HSP70 in diabetes

Emerging evidence indicates that HSP70 represents a key mechanism in the pathophysiology of β-cell dysfunction, insulin resistance, and various diabetic complications, including micro- and macro-vascular alterations, as well as impaired hemostasis. Hyperglycemia, a hallmark of both types of diabetes, increases the circulating levels of HSP70 (eHSP70), but there is still divergence about whether diabetes up- or down-regulates the intracellular fraction of this protein (iHSP70). Here, we consider that iHSP70 levels reduce in diabetic arterial structures and that the vascular system is in direct contact with all other systems in the body suggesting that a systemic response might also be happening for iHSP70, which is characterized by decreased levels of HSP70 in the vasculature. Furthermore, although many pathways have been proposed to explain HSP70's functions in diabetes, and organs/tissues/cells-specific variations occur, the membrane-bound receptor of the innate immune system, Toll-like receptor 4, and its downstream signal transduction pathways appear to be a constant, not only when we explore the actions of eHSP70, but also when we assess the contributions of iHSP70. In this review, we focus on discussing the multiple roles of HSP70 across organs/tissues/cells affected by hyperglycemia to further explore the possibility of targeting this protein with pharmacological and non-pharmacological approaches in the context of diabetes.

HSP70 as a biomarker of the thin threshold between benefit and injury due to physical exercise when exposed to air pollution

Physical exercise has acute and chronic effects on inflammatory balance, metabolic regulation, and redox status. Exercise-induced adaptations are mediated by enhanced 70-kDa heat shock protein (HSP70) levels and an improved heat shock response (HSR). Therefore, exercise could be useful against disease conditions [obesity, diabetes mellitus (DM), and exposure to atmospheric pollutants] marked by an impaired HSR. However, exercise performed by obese or diabetic subjects under pollution conditions might also be dangerous at certain intensities. Intensity correlates with an increase in HSP70 levels during physical exercise until a critical point at which the effort becomes harmful and impairs the HSR. Establishing a unique biomarker able to indicate the exercise intensity on metabolism and cellular fatigue is essential to ensure adequate and safe exercise recommendations for individuals with obesity or DM who require exercise to improve their metabolic status and live in polluted regions. In this review, we examined the available evidence supporting our hypothesis that HSP70 could serve as a biomarker for determining the optimal exercise intensity for subjects with obesity or diabetes when exposed to air pollution and establishing the fine threshold between anti-inflammatory and pro-inflammatory exercise effects.

miR-151a-3p-rich small extracellular vesicles derived from gastric cancer accelerate liver metastasis via initiating a hepatic stemness-enhancing niche

Liver metastasis (LM) severely affects gastric cancer (GC) patients' prognosis. Small extracellular vesicles (sEVs) play key roles in intercellular communication. Specific sEV-miRNAs from several types of cancer were found to induce a premetastatic niche in target organs before tumor cell arrive. However, whether the primary GC affects hepatic microenvironment or the role of sEV-miRNAs in GC-LM is yet unclear. We report that GC-derived sEVs are primarily absorbed by Kupffer cells (KCs). sEV-miR-151a-3p is highly expressed in GC-LM patients' plasma and presents poor prognosis. Treating mice with sEVs-enriched in miR-151a-3p promotes GC-LM, whereas has no influence on the proliferation of GC cells in situ. Mechanistically, sEV-miR-151a-3p inhibits SP3 in KCs. Simultaneously, sEV-miR-151a-3p targets YTHDF3 to decrease the transcriptional inhibitory activity of SP3 by reducing SUMO1 translation in a N6-methyladenosine-dependent manner. These factors contribute to TGF-β1 transactivation in KCs, subsequently activating the SMAD2/3 pathway and enhancing the stem cell-like properties of incoming GC cells. Furthermore, sEV-miR-151a-3p induces miR-151a-3p transcription in KCs to form a positive feedback loop. In summary, our results reveal a previously unidentified regulatory axis initiated by sEV-miR-151a-3p that establishes a hepatic stemness-permissive niche to support GC-LM. sEV-miR-151a-3p could be a promising diagnostic biomarker and preventive treatment candidate for GC-LM.

The role of heat shock proteins in the regulation of fibrotic diseases

Heat shock proteins (HSPs) are key players to restore cell homeostasis and act as chaperones by assisting the folding and assembly of newly synthesized proteins and preventing protein aggregation. Recently, evidence has been accumulating that HSPs have been proven to have other functions except for the classical molecular chaperoning in that they play an important role in a wider range of fibrotic diseases via modulating cytokine induction and inflammation response, including lung fibrosis, liver fibrosis, and idiopathic pulmonary fibrosis. The recruitment of inflammatory cells, a large number of secretion of pro-fibrotic cytokines such as transforming growth factor-β1 (TGF-β1) and increased apoptosis, oxidative stress, and proteasomal system degradation are all events occurring during fibrogenesis, which might be associated with HSPs. However, their role on fibrotic process is not yet fully understood. In this review, we discuss new discoveries regarding the involvement of HSPs in the regulation of organ and tissue fibrosis, and note recent findings suggesting that HSPs may be a promising therapeutic target for improving the current frustrating outcome of fibrotic disorders.

Decreased secretion and profibrotic activity of tubular exosomes in diabetic kidney disease

Tubular changes contribute to the development of renal pathologies in diabetic kidney disease (DKD), including interstitial fibrosis. It is unclear how tubular cells relay signals to interstitial fibroblasts. Recently, exosomes have been recognized as crucial mediators of intercellular communication. We hypothesized that exosomes secreted from tubular cells may stimulate fibroblasts for interstitial fibrosis in DKD. In this study, we isolated and purified exosomes from the renal cortex of DKD mice and high glucose-treated mouse proximal tubular cells. Compared with nondiabetic mice, exosome secretion in kidney tissues decreased in DKD mice. Likewise, high glucose incubation reduced exosome secretion in mouse kidney proximal tubular BUMPT cells. To study the effect of tubular cell exosomes on fibroblasts, exosomes from BUMPT cells were added to renal fibroblast NRK-49F cell cultures. Notably, exosomes from high glucose conditioned BUMPT cells induced higher proliferation, significant morphological change, and substantial production of fibronectin, α-smooth muscle actin, and collagen type Ι in NRK-49F fibroblasts. Proteomics analysis was further performed to profile the proteins within tubular cell exosomes. Interestingly, 22 proteins were found to be differentially expressed between tubular exosomes derived from high glucose conditioned cells and those from normal glucose conditioned cells. Cytoscape analysis suggested the existence of two protein-protein interaction networks in these exosomal differentially expressed proteins. While one of the protein-protein interaction networks comprised enolase 1 (Eno1), heat shock protein family A member 8 (Hspa8), thioredoxin 1 (Txn1), peptidylprolyl isomerase A (Ppia), phosphoglycerate kinase 1 (Pgk1), DNA topoisomerase II-β (Top2b), and β-actin (Actb), the other had the family proteins of human leucocyte antigen F (Ywhag), a component of the ND10 nuclear body (Ywhae), interferon regulatory factor-8 (Ywhaq), and human leucocyte antigen A (Ywhaz). Gene expression analysis via Nephroseq showed a correlation of Eno1 expression with DKD clinical manifestation. In conclusion, DKD is associated with a decrease in exosome secretion in renal tubular cells. Exosomes from high glucose conditioned tubular cells may regulate the proliferation and activation of fibroblasts, contributing to the paracrine signaling mechanism responsible for the pathological onset of renal interstitial fibrosis in DKD.

The Role of Toll-like Receptors in Atherothrombotic Cardiovascular Disease

Toll-like receptors (TLRs) are dominant components of the innate immune system. Activated by both pathogen-associated molecular patterns and damage-associated molecular patterns, TLRs underpin the pathology of numerous inflammation related diseases that include not only immune diseases, but also cardiovascular disease (CVD), diabetes, obesity, and cancers. Growing evidence has demonstrated that TLRs are involved in multiple cardiovascular pathophysiologies, such as atherosclerosis and hypertension. Specifically, a trial called the Canakinumab Anti-inflammatory Thrombosis Outcomes Study showed the use of an antibody that neutralizes interleukin-1β, reduces the recurrence of cardiovascular events, demonstrating inflammation as a therapeutic target and also the research value of targeting the TLR system in CVD. In this review, we provide an update of the interplay between TLR signaling, inflammatory mediators, and atherothrombosis, with an aim to identify new therapeutic targets for atherothrombotic CVD.

Bioinformatics analysis of gene expression profile data to screen key genes involved in intracranial aneurysms

Intracranial aneurysm (IA) is a cerebrovascular disease with a high mortality rate. The pathogenesis of IA remains unclear and the treatment limited. The purpose of the present study was to identify the key genes expressed in IAs and provide the basis for further research and treatment. The raw dataset GSE75436 was downloaded from Gene Expression Omnibus, including 15 IA samples and 15 matched superficial temporal artery (STA) samples. Then, differentially expressed genes (DEGs) were identified using the limma package in R software. Hierarchical clustering analysis was performed on the DEGs using the gplot2 package in R. Database for Annotation, Visualization, and Integrated Discovery (DAVID) online tools were used to perform gene ontology (GO) functional enrichment analysis. DAVID and gene set enrichment analysis were separately used to perform the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses. The intersections of the two results were selected as common KEGG pathways. Protein-protein interaction (PPI) analysis among the DEGs involved in the common KEGG pathways was performed using Search Tool for the Retrieval of Interacting Genes online tools, and visualized with Cytoscape software. A total of 782 DEGs were identified, comprising 392 upregulated and 390 downregulated DEGs. Hierarchical clustering demonstrated that the DEGs could precisely distinguish the IAs from the STAs. The GO enrichment analysis demonstrated that the upregulated DEGs were mainly involved in the inflammatory response and the management of extracellular matrix, and the downregulated DEGs were mainly involved in the process of vascular smooth muscle contraction. The KEGG pathway enrichment analysis demonstrated that the common pathways were ‘leishmaniasis’, ‘Toll-like receptor signaling pathway’ and ‘vascular smooth muscle contraction’. In the PPI network, tumor necrosis factor (TNF), interleukin 8 and Toll-like receptor 4 had the highest degrees; they were associated with the inflammatory response. The Toll-like receptor signaling pathway and TNF gene may serve as targets for future research and treatment.

Heat shock protein 70 is a positive regulator of airway inflammation and goblet cell hyperplasia in a mouse model of allergic airway inflammation

Heat shock proteins (Hsps) are highly conserved molecular chaperones that are ubiquitously expressed in all species to aid the solubilization of misfolded proteins, protein degradation, and transport. Elevated levels of Hsp70 have been found in the sputum, serum, and bronchoalveolar lavage (BAL) fluid of asthma patients and are known to correlate with disease severity. However, the function of Hsp70 in allergic airway inflammation has remained largely unknown. This study aimed to determine the role of Hsp70 in airway inflammation and remodeling using a mouse model of allergic airway inflammation. WT and Hsp70 double-knockout (Hsp70.1/.3^-/-) mice were sensitized and challenged intratracheally with Schistosoma mansoni soluble egg antigens (SEAs) to induce robust Th2 responses and airway inflammation in the lungs. The lack of Hsp70 resulted in a significant reduction in airway inflammation, goblet cell hyperplasia, and Th2 cytokine production, including IL-4, IL-5, and IL-13. An analysis of the BAL fluid suggested that Hsp70 is critically required for eosinophilic infiltration, collagen accumulation, and Th2 cytokine production in allergic airways. Furthermore, our bone marrow (BM) transfer studies show that SEA-induced airway inflammation, goblet cell hyperplasia, and Th2 cytokine production were attenuated in WT mice that were reconstituted with Hsp70-deficient BM, but these effects were not attenuated in Hsp70-deficient mice that were reconstituted with WT BM. Together, these studies identify a pathogenic role for Hsp70 in hematopoietic cells during allergic airway inflammation; this illustrates the potential utility of targeting Hsp70 to alleviate allergen-induced Th2 cytokines, goblet cell hyperplasia, and airway inflammation.

Influence of ferulic acid consumption in ameliorating the cadmium-induced liver and renal oxidative damage in rats

The aim of this study relates to the modulatory role of ferulic acid (FA) against cadmium (Cd)-induced oxidative stress in the liver and kidney of male Wistar albino rats. Cd is an extremely toxic industrial and environmental pollutant and is well known for its varied toxic clinical manifestations. FA is a derivative of curcumin and a ubiquitous phenolic compound having a wide range of therapeutic activities. In the current study, Cd (10 mg/kg) was administered subcutaneously for 15 and 30 days to induce hepato-renal toxicity. Cd concentration was found to be significantly high in Cd-intoxicated rats (liver > kidney) while the supplementation of FA (50 mg/kg) significantly reduces the Cd concentration in liver and kidney tissues. Reduced body and organ weights and food and water consumption and increased rectal temperature were noticed in Cd-treated rats while these parameters were significantly ameliorated in FA-supplemented rats. Liver and kidney damage induced by Cd was significantly revealed by the reduction in serum total protein contents (TPC) and increased activities of serum nitric oxide (NO) levels and hepato-nephrotoxicity marker enzymes, namely aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), lactic dehydrogenase (LDH), AST:ALT ratio, uric acid, urea, urea nitrogen, and creatinine, along with the increased levels of hepatic and renal oxidative stress markers, namely lipid peroxidation (MDA levels), lipid hydroperoxides (LOOH), protein carbonyl content (PCC), total oxidant status (TOS), and oxidative stress index (OSI) in liver and kidney tissues. In addition, the toxicity of Cd was also evidenced by a significant decrease in the levels of total thiols (TTH), total antioxidant concentration (TAC), enzymatic antioxidants (superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx)), and non-enzymatic antioxidants (reduced glutathione (GSH) and total free sulfhydryl groups (TSH)). Administration of FA significantly restored the serum total protein levels and activities of serum NO levels and hepatic and renal marker enzymes to normal levels in comparison with Cd-intoxicated rats. Furthermore, FA significantly reduced the oxidative stress markers and recuperated the levels of antioxidant defense in the liver and kidney as evidenced by native PAGE and spectrophotometric assays, correlation and regression analysis and multivariate analysis of variance (MANOVA), and inferring the antioxidant role of FA. Histopathological damage due to Cd intoxication in the liver and kidney is demonstrated as vasodilatation and congestion in central veins and sinusoids as well as around the glomerulus, infiltration of mixed inflammatory cells and peripheral hemorrhage, hemorrhagic and enlarged sinusoids, disorganization of the hepatic parenchyma, focal necrosis, swelling of hepatocytes, calcified tissue inside blood vessels, hepatocyte degeneration and vacuolization of liver cells, hyaline casts, degenerated glomerulus with wide space and detached basement membrane, distal tubule with wide lumen, deformed proximal tubules with detached brush border, and degeneration and hyalinization of glomerular tuft. But, FA significantly reduced the toxicity of Cd and protected the normal histological architecture of the liver and kidney tissues. Cd-intoxicated rats were associated with a significant upregulation of TNF-α, COX-2, and HSP70 proteins, whereas treatment with FA caused downregulation of the above inflammatory markers indicating the anti-inflammatory role of FA. Principal component analysis (PCA) and Euclidean similarity measure studies clearly indicate that the liver is more prone to Cd toxicity than the kidney and FA supplementation significantly prevents oxidative stress, augmenting antioxidative status, and regaining histological parameters of the liver and kidney to normal, indicating hepato-nephroprotective, antiradical, antioxidant, and anti-inflammatory effects of this phenolic compound.

Biomarkers Associated with Atrial Fibrosis and Remodeling

Atrial fibrillation is the most common rhythm disturbance encountered in clinical practice. Although often considered as solely arrhythmic in nature, current evidence has established that atrial myopathy constitutes both the substrate and the outcome of atrial fibrillation, thus initiating a vicious, self-perpetuating cycle. This myopathy is triggered by stress-induced (including pressure/volume overload, inflammation, oxidative stress) responses of atrial tissue, which in the long term become maladaptive, and combine elements of both structural, especially fibrosis, and electrical remodeling, with contemporary approaches yielding potentially useful biomarkers of these processes. Biomarker value becomes greater given the fact that they can both predict atrial fibrillation occurrence and treatment outcome. This mini-review will focus on the biomarkers of atrial remodeling (both electrical and structural) and fibrosis that have been validated in human studies, including biochemical, histological and imaging approaches.

Effect of statins on toll-like receptors: a new insight to pleiotropic effects

The toll-like receptors (TLRs) are a class of transmembrane-spanning receptors that are sentinels of both innate and adaptive immunity. Statins (3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors) are the most commonly prescribed therapeutic agents for treating hypercholesterolemia globally. However, statin therapy appears to have pleiotropic effects including attenuation of chronic low-grade inflammation and modulation of TLR activity. Statins through abolition of TLR4 expression and regulation of the TLR4/Myd88/NF-κB signaling pathway may slow the progression of atherosclerosis and other inflammatory diseases. In this review, we have focused on the impact and mechanism of action of statins on cardiovascular and non-cardiovascular diseases.

Fibronectin aggregates promote features of a classically and alternatively activated phenotype in macrophages

BACKGROUND

Means to promote endogenous remyelination in multiple sclerosis (MS) benefit from insights into the role of inhibitory molecules that preclude remyelination. Fibronectin assembles into aggregates in MS, which impair oligodendrocyte differentiation and remyelination. Microglia and macrophages are required for complete remyelination and normally switch from a pro-inflammatory classical phenotype upon demyelination to a supportive alternative phenotype during remyelination. Here, we investigated the role of fibronectin aggregates in modulating microglia and macrophage behavior and phenotypes.

METHODS

Bone marrow-derived macrophages and microglia from newborn rats were exposed to (a) plasma fibronectin coatings; (b) coatings of deoxycholate-insoluble fibronectin aggregates; (c) interferon-γ (IFNγ) treatment, as an inducer of the pro-inflammatory classically activated phenotype; (d) interleukin-4 (IL-4) treatment, to promote the pro-regenerative anti-inflammatory alternatively activated phenotype; or (e) left unstimulated on uncoated plastic. To examine the in vitro effects of the different stimulations on cell behavior and phenotype, proliferation, phagocytosis, morphology, and pro- and anti-inflammatory features were assessed.

RESULTS

In line with a classically activated phenotype, exposure of microglia and macrophages to both plasma fibronectin and fibronectin aggregates induced an amoeboid morphology and stimulated phagocytosis by macrophages. Furthermore, as observed upon IFNγ treatment, coatings of aggregated, but not plasma fibronectin, promoted nitric oxide release by microglia and macrophages. Remarkably, fibronectin aggregates induced nitric oxide release in an integrin-independent manner. In addition, fibronectin aggregates, but not plasma fibronectin, increased the expression of arginase-1, similarly as observed upon treatment with IL-4. Proteomic analysis revealed that aggregates of fibronectin act as a scaffold for other proteins, including Hsp70 and thrombospondin-1, which may clarify the induction of both pro-inflammatory and anti-inflammatory features in macrophages cultured on fibronectin aggregate, but not plasma fibronectin coatings.

CONCLUSIONS

Macrophages and microglia grown on aggregated fibronectin coatings adopt a distinct phenotype compared to plasma fibronectin coatings, showing pro-inflammatory and anti-inflammatory features. Therefore, the pathological fibronectin aggregates in MS lesions may impair remyelination by promoting and/or retaining several classically activated phenotypic features in microglia and macrophages.

[Biomarkers and atrial fibrillation : Prediction of recurrences and thromboembolic events after rhythm control management]

Atrial fibrillation (AF) is the most common arrhythmia in clinical praxis and is associated with an increased risk for cardio- and cerebrovascular complications leading to an increased mortality. Catheter ablation represents one of the most important and efficient therapy strategies in AF patients. Nevertheless, the high incidence of arrhythmia recurrences after catheter ablation leads to repeated procedures and higher treatment costs. Recently, several scores had been developed to predict rhythm outcomes after catheter ablation. Biomarker research is also of enormous interest. There are many clinical and blood biomarkers pathophysiologically associated with AF occurrence, progression and recurrences. These biomarkers-including different markers in blood (e. g. von Willebrand factor, D‑dimer, natriuretic peptides) or urine (proteins, epidermal grown factor receptor) but also cardiac imaging (echocardiography, computed tomography, magnetic resonance imaging)-could help to improve clinical scores and be useful for individualized AF management and optimized patients' selection for different AF treatment strategies. In this review, the role of diverse biomarkers and their predictive value related to AF-associated complications are discussed.

Implication of molecular vascular smooth muscle cell heterogeneity among arterial beds in arterial calcification

Vascular calcification is a strong and independent predictive factor for cardiovascular complications and mortality. Our previous work identified important discrepancies in plaque composition and calcification types between carotid and femoral arteries. The objective of this study is to further characterize and understand the heterogeneity in vascular calcification among vascular beds, and to identify molecular mechanisms underlying this process. We established ECLAGEN biocollection that encompasses human atherosclerotic lesions and healthy arteries from different locations (abdominal, thoracic aorta, carotid, femoral, and infrapopliteal arteries) for histological, cell isolation, and transcriptomic analysis. Our results show that lesion composition differs between these locations. Femoral arteries are the most calcified arteries overall. They develop denser calcifications (sheet-like, nodule), and are highly susceptible to osteoid metaplasia. These discrepancies may derive from intrinsic differences between SMCs originating from these locations, as microarray analysis showed specific transcriptomic profiles between primary SMCs isolated from each arterial bed. These molecular differences translated into functional disparities. SMC from femoral arteries showed the highest propensity to mineralize due to an increase in basal TGFβ signaling. Our results suggest that biological heterogeneity of resident vascular cells between arterial beds, reflected by our transcriptomic analysis, is critical in understanding plaque biology and calcification, and may have strong implications in vascular therapeutic approaches.

TGF-β1 in Vascular Wall Pathology: Unraveling Chronic Venous Insufficiency Pathophysiology

Chronic venous insufficiency and varicose veins occur commonly in affluent countries and are a socioeconomic burden. However, there remains a relative lack of knowledge about venous pathophysiology. Various theories have been suggested, yet the molecular sequence of events is poorly understood. Transforming growth factor-beta one (TGF-β1) is a highly complex polypeptide with multifunctional properties that has an active role during embryonic development, in adult organ physiology and in the pathophysiology of major diseases, including cancer and various autoimmune, fibrotic and cardiovascular diseases. Therefore, an emphasis on understanding its signaling pathways (and possible disruptions) will be an essential requirement for a better comprehension and management of specific diseases. This review aims at shedding more light on venous pathophysiology by describing the TGF-β1 structure, function, activation and signaling, and providing an overview of how this growth factor and disturbances in its signaling pathway may contribute to specific pathological processes concerning the vessel wall which, in turn, may have a role in chronic venous insufficiency.

Integrin linked kinase regulates the transcription of AQP2 by NFATC3

Two processes are associated with progressive loss of renal function: 1) decreased aquaporin-2 (AQP2) expression and urinary concentrating capacity (Nephrogenic Diabetes Insipidus, NDI); and 2) changes in extracellular matrix (ECM) composition, e.g. increased collagen I (Col I) deposition, characteristic of tubule-interstitial fibrosis. AQP2 expression is regulated by both the ECM-to-intracellular scaffold protein integrin-linked kinase (ILK) by NFATc/AP1 and other transcription factors. In the present work, we used in vivo and in vitro approaches to examine ILK participation in NFATc3/AP-1-mediated increases in AQP2 gene expression. Both NFATc3 knock-out mice and ILK conditional-knockdown mice (cKD-ILK) display symptoms of NDI (polyuria and reduced AQP2 expression). NFATc3 is upregulated in the renal medulla tubular cells of cKD-ILK mice but with reduced nuclear localization. Inner medullary collecting duct mIMCD3 cells were subjected to ILK depletion and transfected with reporter plasmids. Pharmacological activators or inhibitors determined the effect of ILK activity on NFATc/AP-1-dependent increases in transcription of AQP2. Finally, mIMCD3 cultured on Col I showed reduced activity of the ILK/GSK3β/NFATc/AQP2 axis, suggesting this pathway is a potential target for therapeutic treatment of NDI.

Toll-like receptor-4 signaling pathway in aorta aging and diseases: "its double nature"

Recent advances in the field of innate immunity have revealed a complex role of innate immune signaling pathways in both tissue homeostasis and disease. Among them, the Toll-like receptor 4 (TLR-4) pathways has been linked to various pathophysiological conditions, such as cardiovascular diseases (CVDs). This has been interrogated by developing multiple laboratory tools that have shown in animal models and clinical conditions, the involvement of the TLR-4 signaling pathway in the pathophysiology of different CVDs, such as atherosclerosis, ischemic heart disease, heart failure, ischemia-reperfusion injury and aorta aneurysm. Among these, aorta aneurysm, a very complex pathological condition with uncertain etiology and fatal complications (i.e. dissection and rupture), has been associated with the occurrence of high risk cardiovascular conditions, including thrombosis and embolism. In this review, we discuss the possible role of TLR-4 signaling pathway in the development of aorta aneurysm, considering the emerging evidence from ongoing investigations. Our message is that emphasizing the role of TLR-4 signaling pathway in aorta aneurysm may serve as a starting point for future studies, leading to a better understanding of the pathophysiological basis and perhaps the effective treatment of this difficult human disease.

Role of HSP60 (HSPD1) in diabetes-induced renal tubular dysfunction: regulation of intracellular protein aggregation, ATP production, and oxidative stress

Because underlying mechanisms of diabetic nephropathy/tubulopathy remained poorly understood, we aimed to define a key protein involving in hyperglycemia-induced renal tubular dysfunction. All altered renal proteins identified from previous large-scale proteome studies were subjected to global protein network analysis, which revealed heat shock protein 60 (HSP60, also known as HSPD1) as the central node of protein-protein interactions. Functional validation was performed using small interfering RNA (siRNA) to knock down HSP60 (siHSP60). At 48 h after exposure to high glucose (HG) (25 mM), Madin-Darby canine kidney (MDCK) renal tubular cells transfected with controlled siRNA (siControl) had significantly increased level of HSP60 compared to normal glucose (NG) (5.5 mM), whereas siHSP60-transfected cells showed a dramatically decreased HSP60 level. siHSP60 modestly increased intracellular protein aggregates in both NG and HG conditions. Luciferin-luciferase assay showed that HG modestly increased intracellular ATP, and siHSP60 further enhanced such an increase. OxyBlot assay showed significantly increased level of oxidized proteins in HG-treated siControl-transfected cells, whereas siHSP60 caused marked increase of oxidized proteins under the NG condition. However, the siHSP60-induced accumulation of oxidized proteins was abolished by HG. In summary, our data demonstrated that HSP60 plays roles in regulation of intracellular protein aggregation, ATP production, and oxidative stress in renal tubular cells. Its involvement in HG-induced tubular cell dysfunction was most likely via regulation of intracellular ATP production.-Aluksanasuwan, S., Sueksakit, K., Fong-ngern, K., Thongboonkerd, V. Role of HSP60 (HSPD1) in diabetes-induced renal tubular dysfunction: regulation of intracellular protein aggregation, ATP production, and oxidative stress.

Diet-induced elevation of circulating HSP70 may trigger cell adhesion and promote the development of atherosclerosis in rats

Although accumulating evidence indicates that heat shock protein 70 (HSP70) could be secreted into plasma and its levels have been found to have an ambiguous association with atherosclerosis, our knowledge for the exact role of circulating HSP70 in the development of atherosclerosis is still limited. In the present study, we report an adhesion-promoting effect of exogenous HSP70 and evaluate the potential involvement of elevated circulating HSP70 in the development of atherosclerosis. Time-dependent elevation of plasma HSP70 was found in diet-induced atherosclerotic rats, whose effect was investigated through further in vitro experiments. In rat aortic endothelial cell (RAEC) cultures, exogenous HSP70 incubation neither produced cell injuries by itself nor had protective effects on cell injuries caused by Ox-LDL or homocysteine. However, exogenous HSP70 administration could lead to a higher adhesion rate between rat peripheral blood monocytes (PBMCs) and RAECs. This adhesion-promoting effect appeared only when PBMCs, rather than RAECs, were pretreated with HSP70 incubation. PBMCs in an HSP70 environment released more IL-6 to supernatant, which subsequently up-regulated the expression of ICAM-1 in RAECs. These results indicate that the diet-induced elevation of circulating HSP70 could trigger cell adhesion with the help of IL-6 as a mediator, which provides a novel possible mechanism for understanding the role of circulating HSP70 in the pathogenesis of atherosclerosis.

Endogenous sulfur dioxide alleviates collagen remodeling via inhibiting TGF-β/Smad pathway in vascular smooth muscle cells

The study was designed to investigate the role of endogenous sulfur dioxide (SO₂) in collagen remodeling and its mechanisms in vascular smooth muscle cells (VSMCs). Overexpression of endogenous SO₂ synthase aspartate aminotransferase (AAT) 1 or 2 increased SO₂ levels and inhibited collagen I and III expressions induced by transforming growth factor (TGF)-β1 in VSMCs. In contrast, AAT1 or AAT2 knockdown induced a severe collagen deposition in TGF-β1-treated VSMCs. Furthermore, AAT1 or AAT2 overexpression suppressed procollagen I and III mRNA, upregulated matrix metalloproteinase (MMP)-13 expression, downregulated tissue inhibitors of MMP-1 level, and vice versa. Mechanistically, AAT1 or AAT2 overexpression inhibited phosphorylation of type I TGF-β receptor (TβRI) and Smad2/3 in TGF-β1-stimulated VSMCs. Whereas SB431542, an inhibitor of TGF-β1/Smad signaling pathway, attenuated excessive collagen deposition induced by AAT knockdown. Most importantly, ectopically expressing AAT or exogenous addition of 100 μM SO₂ blocked AAT deficiency-aggravated collagen accumulation in TGF-β1-stimulatd VSMCs, while no inhibition was observed at 100 μM ethyl pyruvate. These findings indicated that endogenous SO₂ alleviated collagen remodeling by controlling TGF-β1/TβRI/Smad2/3-mediated modulation of collagen synthesis and degradation.

The detection and role of heat shock protein 70 in various nondisease conditions and disease conditions: a literature review

As an intracellular polypeptide, heat shock protein 70 (HSP70) can be exposed on the plasma membrane and/or released into the circulation. However, the role of HSP70 in various nondisease and disease conditions remains unknown. Quantitative methods for the detection of HSP70 have been used in clinical studies, revealing that an increase in circulating HSP70 is associated with various types of exercise, elderly patients presenting with inflammation, mobile phones, inflammation, sepsis, chronic obstructive pulmonary disease, asthma, carotid intima-media thickness, glutamine-treated ill patients, mortality, diabetes mellitus, active chronic glomerulonephritis, and cancers. Circulating HSP70 decreases with age in humans and in obstructive sleep apnea, arteriosclerosis, atrial fibrillation (AF) following coronary artery bypass surgery, nonalcoholic fatty liver disease, moderate-to-severe alcoholic fatty liver disease, hepatic steatosis, and Helicobacter pylori infection. In conclusion, quantitative methods can be used to detect HSP70, particularly in determining circulating HSP70 levels, using more convenient and rapid screening methods. Studies have shown that changes in HSP70 are associated with various nondisease and disease conditions; thus, HSP70 might be a novel potential biomarker reflecting various nondisease conditions and also the severity of disease conditions. However, the reliability and accuracy, as well as the underlying mechanism, of this relationship remain poorly understood, and large-sample clinical research must be performed to verify the role.

Geranylgeranylacetone attenuates hepatic fibrosis by increasing the expression of heat shock protein 70

Increasing evidence has demonstrated that the heat shock protein 70 (HSP70) gene may be closely associated with tissue fibrosis; however, the association between HSP70 and liver fibrosis remains to be fully elucidated. The present study hypothesized that geranylgeranylacetone (GGA) exerts beneficial effects on liver fibrosis though upregulation of the expression of HSP70. Liver fibrosis was induced in rats using carbon tetrachloride (CCl₄). The rats were subsequently divided into three groups: Control group, CCl₄ model group and CCl₄ model + GGA group. Liver fibrosis in the rats was evaluated using hematoxylin and eosin staining, Masson's trichrome staining and Sirius red staining. The levels of serum alanine aminotransferase, aspartate aminotransferase and total bilirubin were determined using an automated biochemistry analyzer. The levels of total hepatic hydroxyproline were also determined. The expression levels of α-smooth muscle actin (α-SMA) and transforming growth factor-β1 (TGF-β1) were determined using immunofluorescence staining and western blotting, and the protein expression levels of HSP70 were determined using western blotting. The CCl₄-induced rats exhibited liver fibrosis, increased hydroxyproline content, impaired liver function, upregulated expression levels of the α-SMA and TGF-β1 pro-fibrogenic proteins, and increased expression of HSP70, compared with the control group. These changes were attenuated by treatment with GGA. These results demonstrated that GGA exerted beneficial effects in CCl₄-induced liver fibrosis via upregulating the expression of HSP70.

Diethylnitrosamine-induced cirrhosis in Wistar rats: an experimental feasibility study

The experimental models of the development of cirrhosis in rats require a long time. Many studies in animals have demonstrated similarities in histological pattern with human cirrhosis. Just like the relation between cirrhosis and increased lipid peroxidation (LPO), which contributes to the worsening of the disease. However, few studies have focused on the reduction of time to establish cirrhosis and evaluated the expression of heat-shock protein 70 (HSP70) in cirrhotic livers of rodents. The present study proposes the adaptation of an experimental cirrhosis model using diethylnitrosamine (DEN). Twenty-six male Wistar rats, weighing ±270 g, divided into two groups: (i) CO-control and (ii) DEN-diethylnitrosamine. The DEN group received 50 mg/kg of DEN twice a week intraperitoneally for 7 weeks. The model developed cirrhosis in 7 weeks. The liver function tests showed that the animals with DEN-induced cirrhosis had increased levels when compared to control. The histological examination showed changes in the liver architecture, with severe ductal proliferation, signs of chronic damage, cholestasis, lymphocytic infiltrate, steatosis, and extensive parenchymal loss. We also found nodular formations with homogeneous pattern, increased LPO, increased expression of iNOS, TGF beta, α-SMA, and NQO1. However, the HSP70 expression was reduced in cirrhotic animals. This study showed signs of cirrhosis in liver based on biochemical, histological, and molecular analysis. The reduced expression of HSP70 appears to be associated with increased oxidative stress, contributing to the worsening of the disease.

Galectin-3 in patients with atrial fibrillation undergoing radiofrequency catheter ablation

Background

Galectin-3 (Gal-3) is an emerging biomarker in heart failure that is involved in fibrosis and inflammation. However, its potential value as a prognostic marker in atrial fibrillation (AF) is unknown. The aim of this study was to assess the impact of AF catheter ablation on Gal-3 and evaluate its prognostic impact for predicting rhythm outcome after catheter ablation.

Methods

Gal-3 was measured at baseline and after 6 months using specific ELISA. AF recurrences were defined as any atrial arrhythmia lasting longer than 30 sec within 6 months after ablation.

Results

In 105 AF patients (65% males, age 62±9 years, 52% paroxysmal AF) undergoing catheter ablation, Gal-3 was measured at baseline and after 6 months and compared with an AF-free control cohort (n=14, 50 % males, age 58±11 years). Gal-3 was higher in AF patients compared with AF-free controls (7.8±2.9 vs. 5.8±1.8, ng/mL, p=0.013). However, on multivariable analysis, BMI (p=0.007) but not AF (p=0.068) was associated with Gal-3. In the AF cohort, on univariable analysis higher Gal-3 levels were associated with female gender (p=0.028), higher BMI (p=0.005) and both CHADS2 (p=0.008) and CHA2DS2-VASC (p=0.016) scores, however, on multivariable analysis only BMI remained significantly associated with baseline Gal-3 (p=0.016). Gal-3 was similar 6 months after AF catheter ablation and was not associated with sinus rhythm maintenance.

Conclusions

Although galectin-3 levels are higher in AF patients, this is driven by cardiometabolic co-morbidities and not heart rhythm. Gal-3 is not useful for predicting rhythm outcome of catheter ablation.

Toll-like receptor 4 contributes to vascular remodelling and endothelial dysfunction in angiotensin II-induced hypertension

BACKGROUND AND PURPOSE

Toll-like receptor 4 (TLR4) signalling contributes to inflammatory cardiovascular diseases, but its role in hypertension and the associated vascular damage is not known. We investigated whether TLR4 activation contributed to angiotensin II (AngII)-induced hypertension and the associated vascular structural, mechanical and functional alterations.

EXPERIMENTAL APPROACH

AngII was infused (1.44 mg · kg(-1) · day(-1), s.c.) for 2 weeks in C57BL6 mice, treated with a neutralizing anti-TLR4 antibody or IgG (1 μg · day(-1); systolic BP (SBP) and aortic cytokine levels were measured. Structural, mechanical and contractile properties of aortic and mesenteric arterial segments were measured with myography and histology. RT-PCR and Western blotting were used to analyse these tissues and cultured vascular smooth muscle cells (VSMC) from hypertensive rats (SHR).

KEY RESULTS

Aortic TLR4 mRNA levels were raised by AngII infusion. Anti-TLR4 antibody treatment of AngII-treated mice normalised: (i) increased SBP and TNF-α, IL-6 and CCL2 levels; (ii) vascular structural and mechanical changes; (iii) altered aortic phenylephrine- and ACh-induced responses; (iv) increased NOX-1 mRNA levels, superoxide anion production and NAD(P)H oxidase activity and effects of catalase, apocynin, ML-171 and Mito-TEMPO on vascular responses; and (v) reduced NO release and effects of L-NAME on phenylephrine-induced contraction. In VSMC, the MyD88 inhibitor ST-2825 reduced AngII-induced NAD(P)H oxidase activity. The TLR4 inhibitor CLI-095 reduced AngII-induced increased phospho-JNK1/2 and p65 NF-κB subunit nuclear protein expression.

CONCLUSIONS AND IMPLICATIONS

TLR4 up-regulation by AngII contributed to the inflammation, endothelial dysfunction, vascular remodelling and stiffness associated with hypertension by mechanisms involving oxidative stress. MyD88-dependent activation and JNK/NF-κB signalling pathways participated in these alterations.

Suppression of TGF-β1/Smad signaling pathway by sesamin contributes to the attenuation of myocardial fibrosis in spontaneously hypertensive rats

This study investigated the effect of sesamin on myocardial fibrosis in spontaneously hypertensive rats (SHRs) and the possible mechanisms involved. Twenty-eight male SHRs were randomly allocated to SHR group, Ses160 group (sesamin 160 mg/kg), Ses80 group (sesamin 80 mg/kg) and Cap30 group (captopril 30 mg/kg). Seven male WKY rats were used as control. Sesamin and captopril were administered intragastrically for 12 weeks. Captopril significantly reduced systolic blood pressure and angiotensin II (Ang II) levels in SHRs, accompanied by a marked attenuation of left ventricular hypertrophy (LVH) and collagen deposition (P <0.05 or P <0.01). Though sesamin had no significant influence on Ang II levels, and the hypotensive effect was also significantly inferior to that of captopril (P <0.05 or P <0.01), however, the improvement of LVH and collagen deposition was similar to that in captopril group. Sesamin markedly reduced transforming growth factor-β1 (TGF-β1) content in cardiac tissues, with Smad3 phosphorylation decreased and Smad7 protein expression increased notably (P <0.05 or P <0.01). Protein expression of type I collagen and type III collagen, target genes of Smad3, was down-regulated markedly by sesamin (P <0.05 or P <0.01). In addition, sesamin significantly increased total antioxidant capacity and superoxide dismutase protein in cardiac tissues (P <0.05 or P <0.01), while the expression of NADPH oxidase subunit p47phox and malondialdehyde content were reduced markedly (P <0.05 or P <0.01). In vitro studies also demonstrated that sesamin was able to suppress Ang II induced phosphorylation of Smad3 and secretion of TGF-β1 and type I and type III collagen in cultured rat cardiac fibroblasts. These data suggest that sesamin is capable of attenuating hypertensive myocardial fibrosis through, at least partly, suppression of TGF-β1/Smad signaling pathway.

Changes in tumor necrosis factor-α, heat shock protein 70, malondialdehyde, and superoxide dismutase in patients with different severities of alcoholic fatty liver disease: a prospective observational study

The relationships among inflammation, oxidative balance, and the severity of alcoholic fatty liver disease (AFLD) remain unknown. The aim of this study is to explore the relationships among tumor necrosis factor alpha (TNF-α), heat shock protein 70 (HSP70), malondialdehyde (MDA), superoxide dismutase (SOD), and the severity of AFLD.From January 2012 to December 2013, 162 participants were enrolled in this study and divided into 4 groups: 44 cases of mild AFLD (group A), 55 cases of moderate-to-severe AFLD (group B), 44 cases of alcohol consumption without AFLD (group C), and 20 cases of no alcohol consumption without AFLD (group D). A cross-sectional study was conducted by detecting the serum levels of TNF-α, HSP70, MDA, and SOD by enzyme-linked immunosorbent assay.The median serum levels of TNF-α and HSP70 among the 4 groups were statistically significant (P = 0.000 and 0.001, respectively). The median serum levels of TNF-α in groups A and B were significantly lower than in group C (P = 0.002 and 0.000, respectively), and the median serum level of TNF-α in group B was significantly lower than in group D (P = 0.023). In addition, the median serum level of HSP70 in group B was significantly lower than in groups A and C (P = 0.002 and 0.000, respectively), and the median serum level of HSP70 in group C was significantly higher than in group D (P = 0.044). However, the median serum level of MDA in group B was significantly lower than only group C (P = 0.008).Chronic alcohol ingestion without AFLD may result in a significant increase in the circulation of certain inflammatory markers; the severity of AFLD is associated with circulating inflammatory markers, and moderate-to-severe AFLD may result in a more significant reduction of these markers. However, moderate-to-severe AFLD may also result in a significant downregulation of oxidative stress products.

Relationship between HSP70-2 A+1267G Polymorphism and Cardiovascular Events of Chinese Peritoneal Dialysis Patients

BACKGROUND

Heat shock proteins (HSPs) are expressed by cells in response to various environmental stresses. A single-nucleotide polymorphism A+1267G of the HSPA1B gene affects the expression of HSP70-2, with the A allele being protective against inflammatory conditions. We investigated the relation between the HSP A+1267G polymorphism and the clinical outcomes of Chinese peritoneal dialysis (PD) patients.

METHODS

We studied 347 new PD cases (181 males, age 56.6 ± 13.7 years). Genotyping was done by standard methods. Patients were followed for 40.5 ± 20.7 months for survival analysis.

RESULTS

For the entire cohort, there was no difference in the 5-year survival between genotype groups. However, there was a significant interaction between HSP polymorphism and diabetic status on the cardiovascular event-free survival. In patients without pre-existing diabetes, 5-year cardiovascular event-free survival of the GG/AG genotype group was significantly better than that of the AA genotype group (57.2 vs. 32.1%, p = 0.011).

CONCLUSION

The G allele of the HSP70-2 A+1267G polymorphism confers survival advantages in non-diabetic PD patients. The role of HSP in the pathogenesis of cardiovascular disease in renal failure patients needs further investigation.

Are the leukocyte telomere length attrition and telomerase activity alteration potential predictor biomarkers for sporadic TAA in aged individuals?

A large variability in occurrence, complications, and age/gender manifestations characterizes individual susceptibility of sporadic thoracic aortic aneurysms (TAA), even in subjects with the same risk factor profiles. The reasons are poorly understood. On the other hand, TAA pathophysiology mechanisms remain unclear than those involved in abdominal aorta aneurysms. However, recent evidence is suggesting a crucial role of biological ageing in inter-individual risk variation of cardiovascular diseases, including sporadic TAA. Biological age rather than chronological age is a better predictor of vascular risk. Relevant assumptions support this concept. In confirming this evidence and our preliminary data, the mean of blood leukocyte telomere length, through use of terminal restriction fragment assay and in blood samples from sporadic TAA patients and controls, was examined. Telomerase activity was also analyzed in two groups. In addition, we verified the weight of genetic inflammatory variants and the major TAA risk factors in telomere/telomerase impairment. Aorta histopathological abnormalities and systemic inflammatory mediators were ultimately correlated with telomere/telomerase impairment. Data obtained demonstrated shorter telomeres and a reduced telomerase activity in TAA patients significantly associated with a genetic inflammatory risk profile, age, gender, smoking, hypertension, a histopathological phenotype, and higher levels of systemic inflammatory mediators than controls. In conclusion, telomere and telomerase activity's detection might be used as predictor biomarkers of sporadic TAA. Their impairment also suggests a strong role of vascular ageing in sporadic TAA, evocated by both environmental and genetic inflammatory factors.

Can the TLR-4-mediated signaling pathway be "a key inflammatory promoter for sporadic TAA"?

Thoracic aorta shows with advancing age various changes and a progressive deterioration in structure and function. As a result, vascular remodeling (VR) and medial degeneration (MD) occur as pathological entities responsible principally for the sporadic TAA onset. Little is known about their genetic, molecular, and cellular mechanisms. Recent evidence is proposing the strong role of a chronic immune/inflammatory process in their evocation and progression. Thus, we evaluated the potential role of Toll like receptor- (TLR-) 4-mediated signaling pathway and its polymorphisms in sporadic TAA. Genetic, immunohistochemical, and biochemical analyses were assessed. Interestingly, the rs4986790 TLR4 polymorphism confers a higher susceptibility for sporadic TAA (OR = 14.4, P = 0.0008) and it represents, together with rs1799752 ACE, rs3918242 MMP-9, and rs2285053 MMP-2 SNPs, an independent sporadic TAA risk factor. In consistency with these data, a significant association was observed between their combined risk genotype and sporadic TAA. Cases bearing this risk genotype showed higher systemic inflammatory mediator levels, significant inflammatory/immune infiltrate, a typical MD phenotype, lower telomere length, and positive correlations with histopatological abnormalities, hypertension, smoking, and ageing. Thus, TLR4 pathway should seem to have a key role in sporadic TAA. It might represent a potential useful tool for preventing and monitoring sporadic TAA and developing personalized treatments.

Relevant role of PKG in the progression of fibrosis induced by TNF-like weak inducer of apoptosis

TNF-like weak inducer of apoptosis (TWEAK) is an inflammatory cytokine that activates the FGF-inducible 14 receptor. Both TWEAK and the FGF-inducible 14 receptor are constitutively expressed in the kidney. TWEAK has been shown to modulate several biological responses, such as inflammation, proliferation, differentiation, and apoptosis, that contribute to kidney injury. However, the role of TWEAK in fibrosis and TWEAK-activated intracellular signaling pathways remain poorly understood. We tested the hypothesis that TWEAK can be a potent inducer of renal fibrosis by increasing transforming growth factor (TGF)-β1 expression (a well-known switch in the fibrosis process) through PKG-I downregulation. We showed that in human mesangial cells, TWEAK increased TGF-β1 expression and activity, leading to higher levels of the extracellular matrix protein fibronectin and decreased PKG-I expression and activity via the Ras pathway. PKG-I activation with 8-bromo-cGMP, Ras inactivation with dominant negative Ras, or Ras pathway inhibition with the ERK1/2 inhibitor PD-98059 resulted in the prevention of TWEAK-induced TGF-β1 upregulation. In vivo, exogenous administration of TWEAK to wild-type mice downregulated kidney PKG-I and increased kidney TGF-β1 expression. These effects were blunted in H-Ras knockout mice. Together, these data demonstrate, for the first time, the key role of PKG-I in TGF-β1 induction by TWEAK in kidney cells.

Decorin mimic regulates platelet-derived growth factor and interferon-γ stimulation of vascular smooth muscle cells

Following balloon injury, smooth muscle cells (SMCs) serve as targets for many of the pro-inflammatory and pro-fibrotic factors, including platelet-derived growth factor (PDGF) and interferon-γ (IFN-γ) released from activated inflammatory cells and platelets. Previously, our lab designed a mimic of the proteoglycan decorin, termed DS-SILY20, that suppressed vascular SMC proliferation, migration, and protein synthesis in vitro, and injured vessels treated with DS-SILY20 demonstrated reduced hyperplasia in vivo. Here we characterize the effects of DS-SILY20 on modulating PDGF and IFN-γ stimulation in both proliferative and quiescent human SMCs to further evaluate the potential impact of DS-SILY20-SMC interaction on restenosis. Nanomolar dissociation constants were observed between DS-SILY20 and both PDGF and IFN-γ. PDGF significantly increased migration, proliferation, and protein and cytokine expression, as well as increased ERK-1/2 and p38 MAPK phosphorylation in both quiescent and proliferative cultures. However, DS-SILY20 inhibited these increases, presumably through sequestration of the PDGF. Consistent with the complex responses seen with IFN-γ in SMC physiology in the literature, the response of SMC cultures to IFN-γ was variable and complex. However, where increased activity was seen with IFN-γ, DS-SILY20 attenuated this activity. Overall, the results suggest that DS-SILY20 would be an ideal alternative to traditional therapeutics used and may be an effective therapy for the prevention of intimal hyperplasia after balloon angioplasty.

Integrin-linked kinase regulates tubular aquaporin-2 content and intracellular location: a link between the extracellular matrix and water reabsorption

One of the clinical alterations observed in chronic renal disease (CRD) is the impaired urine concentration, known as diabetes insipidus (DI). Tubulointerstitial fibrosis of the kidney is also a pathological finding observed in CRD and involves composition of extracellular matrix (ECM). However, an association between these two events has not been elucidated. In this study, we showed that the extracellular-to-intracellular scaffold protein integrin-linked kinase (ILK) regulates expression of tubular water channel aquaporin-2 (AQP2) and its apical membrane presence in the renal tubule. Basally, polyuria and decreased urine osmolality were present in ILK conditional-knockdown (cKD-ILK) adult mice compared with nondepleted ILK littermates. No changes were observed in arginine-vasopressin (AVP) blood levels, renal receptor (V2R), or AQP3 expression. However, tubular AQP2 was decreased in expression and apical membrane presence in cKD-ILK mice, where the canonical V2R/cAMP axis activation is still functional, but independent of the absence of ILK. Thus, cKD-ILK constitutes a nephrogenic diabetes insipidus (NDI) model. AQP2 and ILK colocalize in cultured inner medullary collecting duct (mIMCD3) cells. Specific ILK siRNAs and collagen I (Col) decrease ILK and AQP2 levels and AQP2 presence on the membrane of tubular mIMCD3 cells, which impairs the capacity of the cells to transport water under hypotonic stress. The present work points to ILK as a therapeutic target in NDI.

Activation of platelet-activating factor receptor exacerbates renal inflammation and promotes fibrosis

Platelet-activating factor (PAF) is a lipid mediator with important pro-inflammatory effects, being synthesized by several cell types including kidney cells. Although there is evidence of its involvement in acute renal dysfunction, its role in progressive kidney injury is not completely known. In the present study, we investigated the role of PAF receptor (PAFR) in an experimental model of chronic renal disease. Wild-type (WT) and PAFR knockout (KO) mice underwent unilateral ureter obstruction (UUO), and at kill time, urine and kidney tissue was collected. PAFR KO animals compared with WT mice present: (a) less renal dysfunction, evaluated by urine protein/creatinine ratio; (b) less fibrosis evaluated by collagen deposition, type I collagen, Lysyl Oxidase-1 (LOX-1) and transforming growth factor β (TGF-β) gene expression, and higher expression of bone morphogenetic protein 7 (BMP-7) (3.3-fold lower TGF-β/BMP-7 ratio); (c) downregulation of extracellular matrix (ECM) and adhesion molecule-related machinery genes; and (d) lower levels of pro-inflammatory cytokines. These indicate that PAFR engagement by PAF or PAF-like molecules generated during UUO potentiates renal dysfunction and fibrosis and might promote epithelial-to-mesenchymal transition (EMT). Also, early blockade of PAFR after UUO leads to a protective effect, with less fibrosis deposition. In conclusion, PAFR signaling contributes to a pro-inflammatory environment in the model of obstructive nephropathy, favoring the fibrotic process, which lately will generate renal dysfunction and progressive organ failure.

Interleukin-33 potentiates bleomycin-induced lung injury

The mechanisms of interstitial lung disease (ILD) remain incompletely understood, although recent observations have suggested an important contribution by IL-33. Substantial elevations in IL-33 expression were found in the lungs of patients with idiopathic pulmonary fibrosis and scleroderma lung disease, as well as in the bleomycin injury mouse model. Most of the observed IL-33 expression was intracellular and intranuclear, suggesting involvement of the full-length (fl) protein, but not of the proteolytically processed mature IL-33 cytokine. The effects of flIL-33 on mouse lungs were assessed independently and in combination with bleomycin injury, using recombinant adenovirus-mediated gene delivery. Bleomycin-induced changes were not affected by gene deficiency of the IL-33 receptor T1/ST2. Combined flIL-33 expression and bleomycin injury exerted a synergistic effect on pulmonary lymphocyte and collagen accumulation, which could be explained by synergistic regulation of the cytokines transforming growth factor-β, IL-6, monocyte chemotactic protein-1, macrophage inflammatory protein\x{2013}1α, and tumor necrosis factor-α. By contrast, no increase in the levels of the Th2 cytokines IL-4, IL-5, or IL-13 was evident. Moreover, flIL-33 was found to increase the expression of several heat shock proteins (HSPs) significantly, and in particular HSP70, which is known to be associated with ILD. Thus, flIL-33 is a synergistic proinflammatory and profibrotic regulator that acts by stimulating the expression of several non-Th2 cytokines, and activates the expression of HSP70.

Rhythm outcomes after catheter ablation of atrial fibrillation. Clinical implication of biomarkers

Atrial fibrillation (AF) occurs as the result of numerous complex physiological processes in the atria leading to AF promotion and maintenance. Improved diagnostic techniques have identified various biomarkers which may play an important role in the prediction of AF related outcomes (cardio- and cerebrovascular events, as well as mortality and rhythm outcomes). Biomarkers refer to 'biological markers' and biomarkers in blood, urine as well as imaging marker (eg, dimensions (left atrial diameter and volume), anatomical features (left appendage and pulmonary vein anatomy), and physiological pattern (LAA flow velocity)) may play important role(s) as clinically important indices in relation to outcomes after different therapeutic strategies. However, the main domain in the biomarker field has focused on blood-based biomarkers, which are widely used to predict therapeutic success regarding underlying pathophysiological mechanism, such as inflammation, fibrosis, endothelial damage. This review provides an update of the role of clinically relevant biomarkers in AF, with particular focus on AF rhythm outcomes.