Recombinant Erythropoietin Provides Protection against Renal Fibrosis in Adenine-Induced Chronic Kidney Disease.

Chronic kidney disease (CKD) causes anemia by renal damage. In CKD, the kidney is submitted to hypoxia, persistent inflammation, leading to fibrosis and permanent loss of renal function. Human recombinant erythropoietin (rEPO) has been widely used to treat CKD-associated anemia and is known to possess organ-protective properties that are independent from its well-established hematopoietic effects. Nonhematopoietic effects of EPO are mediated by an alternative receptor that is proposed to consist of a heterocomplex between the erythropoietin receptor (EPOR) and the beta common receptor (ßcR). The present study explored the effects of rEPO to prevent renal fibrosis in adenine-induced chronic kidney disease (Ad-CKD) and their association with the expression of the heterodimer EPOR/ßcR. Male Wistar rats were randomized to control group (CTL), adenine-fed rats (Ad-CKD), and Ad-CKD with treatment of rEPO (1050 IU/kg, once weekly for 4 weeks). Ad-CKD rats exhibited anemia, uremia, decreased renal function, increased infiltration of inflammatory cells, tubular atrophy, and fibrosis. rEPO treatment not only corrected anemia but reduced uremia and partially improved renal function as well. In addition, we observed that rEPO diminishes tubular injury, prevents fibrosis deposition, and induces the EPOR/ßcR heteroreceptor. The findings may explain the extrahematopoietic effects of rEPO in CKD and provide new strategies for the treatment of renal fibrosis in CKD.

Natural polymorphisms and unusual mutations in HIV-1 protease with potential antiretroviral resistance: a bioinformatic analysis.

BACKGROUND: The correlations of genotypic and phenotypic tests with treatment, clinical history and the significance of mutations in viruses of HIV-infected patients are used to establish resistance mutations to protease inhibitors (PIs). Emerging mutations in human immunodeficiency virus type 1 (HIV-1) protease confer resistance to PIs by inducing structural changes at the ligand interaction site. The aim of this study was to establish an in silico structural relationship between natural HIV-1 polymorphisms and unusual HIV-1 mutations that confer resistance to PIs. RESULTS: Protease sequences isolated from 151 Mexican HIV-1 patients that were naïve to, or subjected to antiretroviral therapy, were examined. We identified 41 unrelated resistance mutations with a prevalence greater than 1%. Among these mutations, nine exhibited positive selection, three were natural polymorphisms (L63S/V/H) in a codon associated with drug resistance, and six were unusual mutations (L5F, D29V, L63R/G, P79L and T91V). The D29V mutation, with a prevalence of 1.32% in the studied population, was only found in patients treated with antiretroviral drugs. Using in silico modelling, we observed that D29V formed unstable protease complexes when were docked with lopinavir, saquinavir, darunavir, tipranavir, indinavir and atazanavir. CONCLUSIONS: The structural correlation of natural polymorphisms and unusual mutations with drug resistance is useful for the identification of HIV-1 variants with potential resistance to PIs. The D29V mutation likely confers a selection advantage in viruses; however, in silico, presence of this mutation results in unstable enzyme/PI complexes, that possibly induce resistance to PIs.

Effects of Etanercept on TNF-α Inhibition in Rats with Adenine-Induced Chronic Kidney Disease.

Introduction: Chronic kidney disease (CKD) constitutes a chronic inflammatory state associated with an increase in inflammatory mediators and profibrotic molecules such as tumor necrosis factor-α (TNF-α). Etanercept (ETA) is a TNF inhibitor widely used in treatment of autoimmune inflammatory diseases. However, the effects of TNF-α inhibition in the establishment of CKD have not been fully elucidated. We evaluate the effects of TNF inhibition by ETA in adenine- (Ad-) induced CKD in rats. Methods: Rats were divided into three groups: control, renal injury model, and model plus ETA (2 mg/kg, 3 times per week (w); sc). Renal injury was induced by Ad administration (100 mg/kg, daily for 2 or 4 w; orogastric). Serum TNF-α levels and biochemical parameters for renal function were evaluated. Histopathological changes in the kidney were assessed using H&E and Masson's trichrome staining and also immunostaining for tubular cells. Results: Ad administration produced a renal functional decline, tubular atrophy, interstitial inflammation, and fibrosis for 2 w, followed by renal anemia, several renal dysfunctions, tubular atrophy, and fibrosis at 4 w. A significant increase in serum TNF-α levels was observed from 2 w of Ad administration and remained elevated up to 4 w. Treatment with ETA partially reduced kidney damage but was very effective to blocking serum TNF-α. Conclusion: Although inhibition of TNF by ETA was very effective in reducing serum TNF-α, this strategy was partially effective in preventing Ad-induced CKD.

Combinatorial gene therapy renders increased survival in cirrhotic rats.

BACKGROUND: Liver fibrosis ranks as the second cause of death in México's productive-age population. This pathology is characterized by accumulation of fibrillar proteins in hepatic parenchyma causing synthetic and metabolic disfunction. Remotion of excessive fibrous proteins might result in benefit for subjects increasing survival index. The goal of this work was to find whether the already known therapeutical effect of human urokinase Plasminogen Activator and human Matrix Metalloprotease 8 extends survival index in cirrhotic animals. METHODS: Wistar rats (80 g) underwent chronic intoxication with CCl4: mineral oil for 8 weeks. Cirrhotic animals were injected with a combined dose of Ad-delta-huPA plus Ad-MMP8 (3 x 10(11) and 1.5 x 10(11) vp/Kg, respectively) or with Ad-beta-Gal (4.5 x 10(11)) and were killed after 2, 4, 6, 8 and 10 days. Then, liver and serum were collected. An additional set of cirrhotic animals injected with combined gene therapy was also monitored for their probability of survival. RESULTS: Only the cirrhotic animals treated with therapeutical genes (Ad-delta-huPA+Ad-MMP-8) showed improvement in liver fibrosis. These results correlated with hydroxyproline determinations. A significant decrement in alpha-SMA and TGF-beta1 gene expression was also observed. Cirrhotic rats treated with Ad-delta-huPA plus Ad-MMP8 had a higher probability of survival at 60 days with respect to Ad-beta-Gal-injected animals. CONCLUSION: A single administration of Ad-delta-huPA plus Ad-MMP-8 is efficient to induce fibrosis regression and increase survival in experimental liver fibrosis.

Black bean extract ameliorates liver fibrosis in rats with CCl4-induced injury.

UNLABELLED: We assessed the anti-fibrotic effects of methanolic black bean extract antioxidants in a carbon tetrachloride (CCl4) liver injury model in rats. Experimentally intoxicated animals received CCl4 for eight weeks, the reference and test groups received daily intragastric quercetin or daily intragastric black bean extract. Liver fibrosis was assessed and quantified using morphometric analysis. Expression of fibrosis related genes was measured by real time RT-PCR. Qualitative and quantitative histological analysis showed that administration of 70 mg/kg b.w. of black bean extract reduced hepatic fibrosis index by 18% compared to positive controls (P 0.006), as a result of a decrease in type I (44.3% less, P 0.03) and type IV (68.9% less, P 0.049) collagen gene expression compared to CCl4-injured and Quercetin treated rats. In conclusion, we provide evidence that this methanol black bean extract ameliorates liver fibrosis and types I and IV collagen gene expression, in the animal model used. PRACTICAL APPLICATIONS: The compounds contained in this black bean extract exhibited strong antifibrotic effects in the CCl4 chronic liver injury model used; considering that this compounds are contained in a leguminous that has been used in human diet for a long time, their toxic potential should be very low, and this characteristic should favor their potential use in some other chronic or degenerative states that include an increase in inflammation and oxidative burst in their pathogenesis. Another possible application of this kind of extract could be its use as an antimicrobial or even antiparasitic therapeutic agent, although it is purely speculative.

Isosorbide dinitrate spray as therapeutic strategy for treatment of chronic venous ulcers.

Venous ulcers are the most common form of leg ulcers, which induce lesion because of the loss of substances deposited on the damaged skin. Isosorbide dinitrate is a vasodilator with effects on both arteries and veins and induces opening of vascular layers. The objective is to study the effects of isosorbide dinitrate-spray in patients with chronic venous ulcers. Forty-five patients of both sexes with chronic venous ulcers were randomized to receive isosorbide dinitrate or placebo sprays daily for 3 months. The ulcers were measured and clinical characteristics were taken every 15 days during the treatment. Patients treated with isosorbide dinitrate showed an improvement of the ulcerated area (71.29%) compared with patients treated with placebo (54.35%). The histopathological study indicated an increment in the number of hypertrophic and hyperplasic capillaries. Macroscopically, the isosorbide dinitrate-treatment showed the best results, but it was only during the first 6 weeks of treatment. Patients with chronic venous ulcer receiving isosorbide dinitrate spray showed improvement.

[Histological evaluation of hepatic fibrosis in patients with post surgical bile duct injury]. / Evaluación histológica de la fibrosis hepática en pacientes con lesión posquirúrgica de vías biliares.

BACKGROUND: Bile duct injuries after cholecystectomy can produce fibrous and collagen deposit tissue. Our objective was to evaluate the liver fibrosis measured in histological tissue in patients with bile duct injury after cholecystectomy. METHODS: Three normal liver biopsies and 21 from patients with bile duct injuries were studied. Group I: with three normal liver biopsies. Group II: with external abdominal fistula alone in six patients. Group III with complete bile duct obstruction in 15 patients. The surgical biliary enteric reconstructions were performed 8 weeks after bile duct injury in all cases. The fibrosis and collagen deposits were studied by Masson's trichrome and Sirius red stains and they were measured by a digital program. RESULTS: Group I showed 2 % of fibrosis tissue and 1% of collagen deposit and was considered as normal. Group II showed unexpected 1 fold more liver fibrosis and 9 fold more collagen deposit in extracellular matrix macromolecule (p < 0.05, Anova) against group I. Patients in group III, had fibrous tissue increase 43 folds more and 14 collagen folds more (p < 0.0001, Bonferroni's post hoc) versus group I. CONCLUSIONS: The patients in groups II and III showed liver fibrosis, being this more important in group III.

Reduction of NrF2 as coadjuvant during the development of persistent periapical lesions

Background: Persistent periapical lesions (PPL) are the result of pulpar necrosis induced by bacterial infection resulting in bone degradation and culminating with the loss of dental piece. Pathological changes in the peripapice are associated with the presence of free radicals. The transcription factor Nrf2 is the main regulator of the endogenous antioxidant response against oxidative stress and has been implicated in the regulation of osteoclastogenesis.The aim is to determine the oxidative condition in samples from patients with Persistent Periapical Injuries as a detonating factor of tissue damage. Material and methods: An observational, descriptive, cross-sectional study was carried out in samples with PPL (cases) and samples by removal of third molars (controls) obtained in the clinic of the specialty in endodontics, University of Guadalajara. Samples were submitted to histological staining with Hematoxylin-Eosin, lipoperoxide analysis, Superoxide Dismutase (SOD), Glutathione-Peroxidase (GPx) and Catalase (CAT) activities were determined by immunoenzymatic assays and NrF2 by Western Blot analysis. Results: Samples from PPL patients histologically showed an increased presence of lymphocytes, plasma cells, and eosinophils, as well as a decrease in extracellular matrix proteins and fibroblast cells. There was a rise in lipid peroxidation, GPx and SOD activities, but an important decline (36%) in Catalase activity was observed (p<0.005); finally, NrF2-protein was diminished at 10.41%. All comparisons were between cases vs controls. Conclusions: The alterations in antioxidants endogenous NrF2-controlled are related to osseous destruction in patients with PPL. (AU)

Anti-Inflammatory Effect of Atorvastatin on the Kidney Graft of Living Donor Transplants.

BACKGROUND Recent studies have demonstrated that statins have anti-inflammatory and immunomodulatory properties, which could be considered beneficial in kidney transplantations. This study assesses the anti-inflammatory effect of atorvastatin on the kidney grafts of living donor transplants. MATERIAL AND METHODS In a randomized clinical trial, kidney donors were divided into 2 groups. The study group constituted 24 donors who received 40 mg atorvastatin, and 24 donors who received a placebo control, 4 weeks prior to transplantation. Serum C-reactive protein (CRP) levels were measured before and after atorvastatin administration. CRP and renal function of kidney recipients were measured at baseline and 1, 6, and 24 hours after transplantation. RESULTS After 4 weeks of treatment, the CRP level was 5.62±3.82 mg/dL in the control group and 3.27±0.62 mg/dL in the study group (P=0.007). Upon reperfusion, CRP levels in recipients at 1 hour were, 5.8±3.9 and 3.8±1.0 mg/dL, respectively (P=0.04). Twenty-four hours after the kidney transplantations, serum creatinine levels were 2.5±1.5 mg/dL in the study group and 3.7±2.4 mg/dL in the control group (P=0.04). CONCLUSIONS Our study suggests that the use of atorvastatin prior to allograft procurement of kidney transplant, reduces the acute kidney inflammatory burden profile, and promotes an improved kidney function recovery following transplantation.

[Hepatic fibrosis: role of matrix metalloproteases and TGFbeta]. / Fibrosis hepática. El papel de las metaloproteinasas y de TGF-beta.

Liver fibrosis and cirrhosis involve multiple cellular and molecular events that lead to deposition of an excess of extracellular matrix proteins and increase the distortion of normal liver architecture. Etiologies include chronic viral hepatitis, alcohol abuse and drug toxicity. Degradation of these matrix proteins occurs predominantly as a result of a family of enzymes called metalloproteases (MMPs) that specifically degrade collagenous and non-collagenous substrates. Matrix degradation in the liver is due to the action of at least four of these enzymes: MMP-1, MMP-2, MMP-3 and MMP-9. In the fibrinolytic system, MMPs can be activated through proteolytic cleavage by the action of urokinase plasminogen activator; a second mechanism includes the same metalloproteases. This activity is regulated at many levels in the fibrinolytic system. The main regulator is the PAI-1. This molecule blocks the conversion of plasminogen into plasmin, and the MMP cannot be activated. At a second level, the inhibition is possible by binding to inhibitors called TIMP that can inhibit the proteolitic activity even when the MMPs had been previously activated by plasmin. During abnormal conditions, overexpression of these inhibitors is directed by the transforming growth factor-beta that in a fibrotic disease acts as an extremely important adverse factor.

[Hepatocyte growth factor (HGF) and its therapeutic applications]. / Factor de crecimiento de hepatocitos (HGF) y sus aplicaciones terapéuticas.

Hepatocyte growth factor (HGF) also known as "scatter factor" (SF), was identified for the first time as a potent mitogen of primary cultured hepatocytes; it has multiple biological responses in a variety of cells including mitogenic, motogenic, morphogenic and antiapoptotic activities. It is secreted as an inactive single chain protein and isproteolitically cleaved to form an active two chain HGF. The hepatocyte growth factor activator (HGFA) is the principal activator of HGF. HGF exerts its biological effects through transmembrane tyrosine kinase receptor (c-Met). HGF is a growth factor displaying a remarkable ability to promote tissue repair and organ regeneration after injury. Therefore attention should be set on the clinical potential of HGF as a treatment for various diseases.

The synthetic cathelicidin HHC-10 inhibits Mycobacterium bovis BCG in vitro and in C57BL/6 mice.

Tuberculosis causes close to 1.5 million deaths in the world, with new cases exceeding 9 million in recent years. Coinfection with HIV further worsens the global situation. New molecules that overcome the limitations of currently used drugs are needed. We aimed to determine whether HHC-10 is active against the Mycobacterium tuberculosis complex bacteria Mycobacterium bovis bacille calmette guerin (BCG) in vitro and in vivo. For this, HHC-10 was tested in vitro using different peptide concentrations, and in vivo, in C57BL/6 mice infected intratracheally, at two doses (1.25 and 2.5 mg kg(-1), once a week, 4 weeks). Interferon (IFN)-γ, TNF-α, interleukin (IL)-4, and IL-10 mRNA transcript levels were compared between treated and nontreated mice. In vitro, HHC-10 decreased 69% and 88% the number of colony-forming units (CFU) per millileter recovered after 24-hr treatment at 50 and 100 µg/ml, respectively. In vivo, BCG CFUs in mouse lungs were reduced 77.8% and 95.8% at 1.25 and 2.5 mg kg(-1), respectively. IFN-γ expression was lower in the HHC-10-treated group than that of nontreated animals. Considering genomic conservation between BCG and M. tuberculosis, the in vitro and in vivo activities of HHC-10 observed in this study suggest that the use of this peptide may be useful as therapeutic agent against tuberculosis.

Hibiscus sabdariffa L. aqueous extract attenuates hepatic steatosis through down-regulation of PPAR-γ and SREBP-1c in diet-induced obese mice.

The growing incidence of obesity is a worldwide public health problem leading to a risk factor for non-alcoholic fatty liver disease, which extends from steatosis to steatohepatitis and cirrhosis. We investigated whether the aqueous extract of Hibiscus sabdariffa L. (Hs) reduces body weight gain and protects the liver by improving lipid metabolism in high fat diet-induced obese C57BL/6NHsd mice. We found that oral administration of the Hs extract reduced fat tissue accumulation, diminished body weight gain and normalized the glycemic index as well as reduced dyslipidemia compared to the obese mice group that did not receive Hs treatment. In addition, Hs treatment attenuated liver steatosis, down-regulated SREBP-1c and PPAR-γ, blocked the increase of IL-1, TNF-α mRNA and lipoperoxidation and increased catalase mRNA. Our results suggest that the anti-obesity, anti-lipidemic and hepatoprotective effects of the Hs extract are related to the regulation of PPAR-γ and SREBP-1c in the liver.

[Transforming growth factor-beta as a therapeutic target]. / El factor de crecimiento transformante beta como blanco terapéutico.

Transforming growth factor-beta (TGF-beta) family members include TGF-beta, activins, and bone morphogenetic proteins (BMP). These proteins are structurally related cytokines secreted in diverse Metazoans. TGF-beta family members regulate cellular functions such as proliferation, apoptosis, differentiation, and migration, and play an important role in organism development. Deregulated TGF-beta family signaling participates in various human pathologies including autoimmune diseases, vascular disorders, fibrotic disease, and cancer. Ligand-induced activation of TGF-beta family receptors with intrinsic serine/threonine kinase activity, triggers phosphorylation of the intracellular effectors of TGF-beta signaling, the Smads proteins. Once these proteins are activated they translocate into the nucleus, where they induce transcription of target genes and regulate cellular processes and functions. Novel therapeutic strategies are currently being developed to correct alterations in pathologies that involve TGF-beta as the main mediator. The English version of this paper is available at: http://www.insp.mx/salud/index.html.

Fibrosis Hepática: El papel de las metaloproteinasas y de TGF-β / Hepatic fibrosis: Role of matrix Metallopoteases and TGF-β

La fibrosis hepática involucra múltiples eventos celulares y moleculares que inducen un excesivo depósito de proteínas de matriz extracelular que distorsionan la arquitectura del parénquima hepático, cuya etapa final es conocida como cirrosis. El daño proviene de una variedad de causas como abuso de drogas y enfermedades virales, autoinmunes, metabólicas y colestásicas. La degradación de estas proteínas de matriz ocurre predominantemente como una consecuencia de la acción de metalopro teinasas (MMPs) que degradan sustratos colágenos y no colágenos. La degradación de la matriz en el hígado se lleva a cabo principalmente por la acción de cuatro de estas enzimas: MMP-1, MMP-2, MMP-3 y MMP-9. En el sistema fibrinolítico, las MMPs pueden ser activadas a través de un corte proteolítico por acción del activador de plasminógeno tipo urocinasa y un segundo mecanismo de activación es realizado por las mismas MMPs. La regulación para restringir la actividad puede ser a diferentes niveles; en el sistema fibrinolítico el principal regulador es el PAI- 1, molécula que bloquea la conversión de plasminógeno a plasmina y la MMP no puede ser activada. Un segundo nivel de inhibición es posible a través del TIMP, que inhibe la actividad proteolítica aun cuando las MMPs hayan sido activadas vía plasmina. Durante condiciones patológicas la sobreexpresión de estos inhibidores es dirigida por el factor de crecimiento transformante β, el cual en un padecimiento fibrótico actúa como el más importante factor adverso.

Liver fibrosis and cirrhosis involve multiple cellular and molecular events that lead to deposition of an excess of extracellular matrix proteins and increase the distortion of normal liver architecture. Etiologies include chronic viral hepatitis, alcohol abuse and drug toxicity. Degradation of these matrix proteins occurs predominantly as a result of a family of enzymes called metalloproteinases (MMPs) that specifically degrade collagenous and non collagenous substrates. Matrix degradation in the liver is due to the action of at least four of these enzymes: MMP-1, MMP-2, MMP 3 and MMP 9. In the fibrinolytic system, MMPs can be activated through proteolytic cleavage by the action of urokinase plasminogen activator; a second mechanism includes the same metalloproteinases. This activity is regulated at many levels in the fibrinolytic system. The main regulator is the PAI- 1. This molecule blocks the conversion of plasminogen into plasmin, and the MMP cannot be activated. At a second level, the inhibition is possible by binding to inhibitors called TIMP that can inhibit the proteolytic activity even when the MMPs had been previously activated by plasmin. During abnormal conditions, overexpression of these inhibitors is directed by the transforming growth factor-β that in a fibrotic disease acts as an extremely important adverse factor.

El factor de crecimiento transformante beta como blanco terapéutico / Transforming growth factor-beta as a therapeutic target

El factor de crecimiento transformante beta (TGF-beta) es una familia de proteínas que incluye al TGF-beta, activinas y a la proteína morfogénica de hueso (BMP, por sus siglas en inglés), citocinas que son secretadas y se relacionan estructuralmente en diferentes especies de metazoarios. Los miembros de la familia del TGF-beta regulan diferentes funciones celulares como proliferación, apoptosis, diferenciación, migración, y tienen un papel clave en el desarrollo del organismo. El TGF-beta está implicado en varias patologías humanas, incluyendo desórdenes autoinmunes y vasculares, así como enfermedades fibróticas y cáncer. La activación del receptor del TGF-beta propicia su fosforilación en residuos de serina/treonina y dispara la fosforilación de proteínas efectoras intracelulares (smad), que una vez activas se translocan al núcleo para inducir la transcripción de genes blanco, y así regular procesos y funciones celulares. Se están desarrollando novedosas estrategias terapéuticas encaminadas a corregir las alteraciones presentes en patologías que involucran al TGF-beta como actor principal.