Indoxyl Sulfate Induces Renal Fibroblast Activation through a Targetable Heat Shock Protein 90-Dependent Pathway

Indoxyl sulfate (IS) accumulation occurs early during chronic kidney disease (CKD) progression and contributes to renal dysfunction by inducing fibrosis, inflammation, oxidative stress, and tissue remodeling. Renal toxicity of high IS concentrations (250\u2009\u3bcM) has been widely explored, particularly in resident tubular and glomerular cells, while the effect of a moderate IS increase on kidneys is still mostly unknown. To define the effects of IS accumulation on renal fibroblasts, we first analyzed kidneys of C57BL/6 mice receiving IS (0.1%) in drinking water for 12 weeks. As a next step, we treated renal fibroblasts (NRK-49F) with IS (20\u2009\u3bcM) with or without the HSP90 inhibitor 17-AAG (1\u2009\u3bcM). In mouse kidneys, IS increased the collagen deposition and HSP90 and \u3b1-SMA expression (immunohistochemistry) in interstitial fibroblasts and caused tubular necrosis (histological H&E and picrosirius red staining). In NRK-49F cells, IS induced MCP1, TGF-\u3b2, collagen I, \u3b1-SMA, and HSP90 gene/protein expression and Smad2/3 pathway activation. IS had no effects on fibroblast proliferation and ROS production. 17-AAG counteracted IS-induced MCP1, TGF-\u3b2, collagen I, and \u3b1-SMA expression and Smad2/3 phosphorylation. Our study demonstrates that the IS increase promotes renal fibroblast activation by a HSP90-dependent pathway and indicates HSP90 inhibition as a potential strategy to restrain IS-induced kidney inflammation and fibrosis in CKD

Advanced Oxidation Protein Products-Modified Albumin Induces Differentiation of RAW264.7 Macrophages into Dendritic-Like Cells Which Is Modulated by Cell Surface Thiols.

Local accumulation of Advanced Oxidation Protein Products (AOPP) induces pro-inflammatory and pro-fibrotic processes in kidneys and is an independent predictor of renal fibrosis and of rapid decline of eGFR in patients with chronic kidney disease (CKD). In addition to kidney damage, circulating AOPP may be regarded as mediators of systemic oxidative stress and, in this capacity, they might play a role in the progression of atherosclerotic damage of arterial walls. Atherosclerosis is a chronic inflammatory disease that involves activation of innate and adaptive immunity. Dendritic cells (DCs) are key cells in this process, due to their role in antigen presentation, inflammation resolution and T cell activation. AOPP consist in oxidative modifications of proteins (such as albumin and fibrinogen) that mainly occur through myeloperoxidase (MPO)-derived hypochlorite (HOCl). HOCl modified proteins have been found in atherosclerotic lesions. The oxidizing environment and the shifts in cellular redox equilibrium trigger inflammation, activate immune cells and induce immune responses. Thus, surface thiol groups contribute to the regulation of immune functions. The aims of this work are: (1) to evaluate whether AOPP-proteins induce activation and differentiation of mature macrophages into dendritic cells in vitro; and (2) to define the role of cell surface thiol groups and of free radicals in this process. AOPP-proteins were prepared by in vitro incubation of human serum albumin (HSA) with HOCl. Mouse macrophage-like RAW264.7 were treated with various concentrations of AOPP-HSA with or without the antioxidant N-acetyl cysteine (NAC). Following 48 h of HSA-AOPP treatment, RAW264.7 morphological changes were evaluated by microscopic observation, while markers of dendritic lineage and activation (CD40, CD86, and MHC class II) and allogeneic T cell proliferation were evaluated by flow cytometry. Cell surface thiols were measured by AlexaFluor-maleimide binding, and ROS production was assessed as DCF fluorescence by flow cytometry. HSA-AOPP induced the differentiation of RAW264.7 cells into a dendritic-like phenotype, as shown by morphological changes, by increased CD40, CD86 and MHC class II surface expression and by induction of T cell proliferation. The cell surface thiols dose dependently decreased following HSA-AOPP treatment, while ROS production increased. NAC pre-treatment enhanced the amount of cell surface thiols and prevented their reduction due to treatment with AOPP. Both ROS production and RAW264.7 differentiation into DC-like cells induced by HSA-AOPP were reduced by NAC. Our results highlight that oxidized plasma proteins modulate specific immune responses of macrophages through a process involving changes in the thiol redox equilibrium. We suggest that this mechanism may play a role in determining the rapid progression of the atherosclerotic process observed in CKD patients

Intravenous methylprednisolone pulses in hospitalised patients with severe COVID-19 pneumonia, A double-blind, randomised, placebo-controlled trial

Rationale: Pulse glucocorticoid therapy is used in hyperinflammation related to coronavirus 2019 (COVID-19). We evaluated the efficacy and safety of pulse intravenous methylprednisolone in addition to standard treatment in COVID-19 pneumonia. Methods: In this multicenter, randomised, double-blind, placebo-controlled trial, 304 hospitalised patients with Covid-19 pneumonia were randomised to receive 1 g of methylprednisolone intravenously for 3 consecutive days or placebo in addition to standard dexamethasone. The primary outcome was the duration of the patient hospitalisation, calculated as the time interval between randomisation and hospital discharge without the need of supplementary oxygen. The key secondary outcomes were survival free from invasive ventilation with orotracheal intubation and overall survival. Results: Overall, 112 of 151 (75.4%) patients in the pulse methylprednisolone arm and 111 of 150 (75.2%) in the placebo arm were discharged from hospital without oxygen within 30 days from randomisation. Median time to discharge was similar in both groups [15 days (95% confidence interval (CI), 13.0 to 17.0) and 16 days (95%CI, 13.8 to 18.2); hazard ratio (HR), 0.92; 95% CI 0.71-1.20; p=0.528]. No significant differences between pulse methylprednisolone and placebo arms were observed in terms of admission to Intensive Care Unit with orotracheal intubation or death (20.0% versus 16.1%; HR, 1.26; 95%CI, 0.74-2.16; p=0.176), or overall mortality (10.0% versus 12.2%; HR, 0.83; 95%CI, 0.42-1.64; p=0.584). Serious adverse events occurred with similar frequency in the two groups. Conclusions: Methylprenisolone pulse therapy added to dexamethasone was not of benefit in patients with COVID-19 pneumonia. Message of the study: Pulse glucocorticoid therapy is used for severe and/or life threatening immuno-inflammatory diseases. The addition of pulse glucocorticoid therapy to the standard low dose of dexamethasone scheme was not of benefit in patients with COVID-19 pneumonia

p38 MAPK and JNK Antagonistically Control Senescence and Cytoplasmic p16INK4A Expression in Doxorubicin-Treated Endothelial Progenitor Cells

Patients treated with low-dose anthracyclines often show late onset cardiotoxicity. Recent studies suggest that this form of cardiotoxicity is the result of a progenitor cell disease. In this study we demonstrate that Cord Blood Endothelial Progenitor Cells (EPCs) exposed to low, sub-apoptotic doses of doxorubicin show a senescence phenotype characterized by increased SA-b-gal activity, decreased TRF2 and chromosomal abnormalities, enlarged cell shape, and disarrangement of F-actin stress fibers accompanied by impaired migratory ability. P16 INK4A localizes in the cytoplasm of doxorubicin-induced senescent EPCs and not in the nucleus as is the case in EPCs rendered senescent by different stimuli. This localization together with the presence of an arrest in G2, and not at the G1 phase boundary, which is what usually occurs in response to the cell cycle regulatory activity of p16INK4A, suggests that doxorubicin-induced p16 INK4A does not regulate the cell cycle, even though its increase is closely associated with senescence. The effects of doxorubicin are the result of the activation of MAPKs p38 and JNK which act antagonistically. JNK attenuates the senescence, p16 INK4A expression and cytoskeleton remodeling that are induced by activated p38. We also found that conditioned medium from doxorubicin-induced senescent cardiomyocytes does not attract untreated EPCs, unlike conditioned medium from apoptotic cardiomyocytes which has a strong chemoattractant capacity. In conclusion, this study provides a better understanding of the senescence of doxorubicin-treated EPCs, which may be helpful in preventing and treating late onset cardiotoxicity

PCSK9 and Other Metabolic Targets to Counteract Ischemia/Reperfusion Injury in Acute Myocardial Infarction and Visceral Vascular Surgery

Ischemia/reperfusion (I/R) injury complicates both unpredictable events (myocardial infarction and stroke) as well as surgically-induced ones when transient clampage of major vessels is needed. Although the main cause of damage is attributed to mitochondrial dysfunction and oxidative stress, the use of antioxidant compounds for protection gave poor results when challenged in clinics. More recently, there is an assumption that, in humans, profound metabolic changes may prevail in driving I/R injury. In the present work, we narrowed the field of search to I/R injury in the heart/brain/kidney axis in acute myocardial infarction, major vascular surgery, and to the current practice of protection in both settings; then, to help the definition of novel strategies to be translated clinically, the most promising metabolic targets with their modulatory compounds-when available-and new preclinical strategies against I/R injury are described. The consideration arisen from the broad range of studies we have reviewed will help to define novel therapeutic approaches to ensure mitochondrial protection, when I/R events are predictable, and to cope with I/R injury, when it occurs unexpectedly

INIBIZIONE DA PARTE DEL CELECOXIB DI ALTERAZIONI INFIAMMATORIE NELL\u2019AORTA DI TOPI ESPOSTI A FUMO DI SIGARETTA.

Le malattie cardiovascolari rappresentano la principale causa di morte nel mondo causando 17,5 milioni di decessi pari al 46% delle morti totali. L\u2019abitudine al fumo di sigaretta cos\uec come ipertensione arteriosa, ipercolesterolemia, diabete, obesit\ue0 e inattivit\ue0 fisica, sono i principali fattori che influenzano il rischio di andare sviluppare cardiovascolari. Abbiamo studiato il ruolo di un FAN (celecoxib), inibitore selettivo di COX-2, nella modulazione dei subset monocitari e nel rimodellamento della radice aortica, quale sito di elezione per l\u2019insorgenza di aterosclerosi indotta da fumo di sigaretta. Per lo studio sono stati utilizzati 40 topi maschi, i quali sono stati esposti a fumo di sigaretta principale (MCS), 12 ore dopo la nascita, per un totale di 10 settimane. I topi sono stati suddivisi nei seguenti gruppi: (a) mantenuti in aria filtrata (controlli); (b) esposti a MCS; (c) trattati con celecoxib (1600 mg/kg dieta) dopo lo svezzamento; (d) esposti a MCS e trattati con celecoxib. I risultati ottenuti hanno mostrato un incremento significativo dei monociti circolanti attivati (Ly6Clow) negli animali esposti a MCS rispetto ai controlli, efficacemente contrastato dal trattamento con celecoxib. L\u2019analisi istologica delle valvole aortiche non ha evidenziato significativi rimodellamenti negli animali esposti a MCS, anche se l\u2019immunoistochimica ha rilevato un lieve incremento dell\u2019infiltrato macrofagico negli animali esposti a fumo, che risultava contrastato dal trattamento con celecoxib. La capacit\ue0 di inibire la frazione monocitaria Ly6Clow, presente nei siti di infiammazione endoteliali e l\u2019infiltrato macrofagico a livello delle valvole aortiche rende cos\uec il celecoxib un buon candidato come agente chemiopreventivo per l\u2019aterosclerosi in quanto \ue8 capace di inibire i processi infiammatori come l\u2019attivazione monocitaria, il reclutamento di monociti/macrofagi nell\u2019endotelio e lo stress ossidativo, che sono alla base dello sviluppo dell\u2019ateroma

Adipose tissue immune response: novel triggers and consequences for chronic inflammatory conditions.

open12siThe awareness that chronic kidney disease (CKD) is a condition of dramatically increased cardiovascular risk has prompted an intense research activity, aimed at identifying factors that are specifically involved in the development of cardiovascular complications of CKD and that can be delayed or reduced by novel pharmacological approaches. This may be the case with indoxyl sulfate (IS). IS is an endogenous molecule derived from indole, a product of protein metabolism by intestinal bacteria, which acts via the aryl hydrocarbon receptor (AhR). IS accumulates early in CKD and exerts proinflammatory and other detrimental effects on the cardiovascular system, in particular promoting atherosclerosis and atherosclerosis-related arterial remodeling. Furthermore, IS also contributes to renal damage, thereby fueling a vicious circle. Dialysis is poorly effective in removing IS, but its levels can be lowered by preventing the bacterial generation of indole or by absorbing this latter within the intestine. More intriguing, although still theoretical, is the possibility of inhibiting the action of IS at the cell level, by antagonizing the binding to AhR or IS intracellular signaling. Therefore, IS targeting might become an option for reducing the cardiovascular burden of CKD.openGiorgio Ghigliotti, Chiara Barisione, Silvano Garibaldi, Patrizia Fabbi, Claudio Brunelli, Paolo Spallarossa, Paola Altieri, Gianmarco Rosa, Giovanni Spinella, Domenico Palombo, Razvan Arsenescu, Violeta ArsenescuGhigliotti, Giorgio; Barisione, Chiara; Garibaldi, Silvano; Fabbi, Patrizia; Brunelli, Claudio; Spallarossa, Paolo; Altieri, Paola; Rosa, Gianmarco; Spinella, GIOVANNI SALVATORE GIUSEPPE; Palombo, Domenico; Arsenescu, Razvan; Arsenescu, Violet

Testosterone Antagonizes Doxorubicin-Induced Senescence of Cardiomyocytes

BACKGROUND: Chronic cardiotoxicity is less common in male than in female patients receiving doxorubicin and other anthracyclines at puberty and adolescence. We hypothesized that this sex difference might be secondary to distinct activities of sex hormones on cardiomyocyte senescence, which is thought to be central to the development of long-term anthracycline cardiomyopathy. METHODS AND RESULTS: H9c2 cells and neonatal mouse cardiomyocytes were exposed to doxorubicin with or without prior incubation with testosterone or 17\u3b2-estradiol, the main androgen and estrogen, respectively. Testosterone, but not 17\u3b2-estradiol, counteracted doxorubicin-elicited senescence. Downregulation of telomere binding factor 2, which has been pinpointed previously as being pivotal to doxorubicin-induced senescence, was also prevented by testosterone, as were p53 phosphorylation and accumulation. Pretreatment with the androgen receptor antagonist flutamide, the phosphatidylinositol 3 kinase inhibitor LY294002, and the nitric oxide synthase inhibitor L-NG-nitroarginine methyl ester abrogated the reduction in senescence and the normalization of telomere binding factor 2 levels attained by testosterone. Consistently, testosterone enhanced the phosphorylation of AKT and nitric oxide synthase 3. In H9c2 cells, doxorubicin-stimulated senescence was still observed up to 21 days after treatment and increased further when cells were rechallenged with doxorubicin 14 days after the first exposure to mimic the schedule of anthracycline-containing chemotherapy. Remarkably, these effects were also inhibited by testosterone. CONCLUSIONS: Testosterone protects cardiomyocytes against senescence caused by doxorubicin at least in part by modulating telomere binding factor 2 via a pathway involving the androgen receptor, phosphatidylinositol 3 kinase, AKT, and nitric oxide synthase 3. This is a potential mechanism by which pubescent and adolescent boys are less prone to chronic anthracycline cardiotoxicity than girls