CCN2 Binds to Tubular Epithelial Cells in the Kidney.

Cellular communication network-2 (CCN2), also called connective tissue growth factor (CTGF), is considered a fibrotic biomarker and has been suggested as a potential therapeutic target for kidney pathologies. CCN2 is a matricellular protein with four distinct structural modules that can exert a dual function as a matricellular protein and as a growth factor. Previous experiments using surface plasmon resonance and cultured renal cells have demonstrated that the C-terminal module of CCN2 (CCN2(IV)) interacts with the epidermal growth factor receptor (EGFR). Moreover, CCN2(IV) activates proinflammatory and profibrotic responses in the mouse kidney. The aim of this paper was to locate the in vivo cellular CCN2/EGFR binding sites in the kidney. To this aim, the C-terminal module CCN2(IV) was labeled with a fluorophore (Cy5), and two different administration routes were employed. Both intraperitoneal and direct intra-renal injection of Cy5-CCN2(IV) in mice demonstrated that CCN2(IV) preferentially binds to the tubular epithelial cells, while no signal was detected in glomeruli. Moreover, co-localization of Cy5-CCN2(IV) binding and activated EGFR was found in tubules. In cultured tubular epithelial cells, live-cell confocal microscopy experiments showed that EGFR gene silencing blocked Cy5-CCN2(IV) binding to tubuloepithelial cells. These data clearly show the existence of CCN2/EGFR binding sites in the kidney, mainly in tubular epithelial cells. In conclusion, these studies show that circulating CCN2(IV) can directly bind and activate tubular cells, supporting the role of CCN2 as a growth factor involved in kidney damage progression.

Molecular Mechanisms of Kidney Injury and Repair.

Chronic kidney disease (CKD) will become the fifth global cause of death by 2040, thus emphasizing the need to better understand the molecular mechanisms of damage and regeneration in the kidney. CKD predisposes to acute kidney injury (AKI) which, in turn, promotes CKD progression. This implies that CKD or the AKI-to-CKD transition are associated with dysfunctional kidney repair mechanisms. Current therapeutic options slow CKD progression but fail to treat or accelerate recovery from AKI and are unable to promote kidney regeneration. Unraveling the cellular and molecular mechanisms involved in kidney injury and repair, including the failure of this process, may provide novel biomarkers and therapeutic tools. We now review the contribution of different molecular and cellular events to the AKI-to-CKD transition, focusing on the role of macrophages in kidney injury, the different forms of regulated cell death and necroinflammation, cellular senescence and the senescence-associated secretory phenotype (SAPS), polyploidization, and podocyte injury and activation of parietal epithelial cells. Next, we discuss key contributors to repair of kidney injury and opportunities for their therapeutic manipulation, with a focus on resident renal progenitor cells, stem cells and their reparative secretome, certain macrophage subphenotypes within the M2 phenotype and senescent cell clearance.

Leuprolide Acetate Inhibits Spinal Cord Inflammatory Response in Experimental Autoimmune Encephalomyelitis by Suppressing NF-κB Activation.

OBJECTIVE: Recent findings have shown that gonadotropin-releasing hormone (GnRH) administration in an animal model of multiple sclerosis (experimental autoimmune encephalomyelitis, EAE) improves clinical signs of locomotion. The present study was designed to determine whether the administration of the synthetic analog of GnRH, leuprolide acetate (LA) - besides its effects on clinical signs of locomotion - also has an effect on the activation/expression levels of molecular markers of EAE, namely transcription nuclear factor (NF)-κB and the proinflammatory cytokines IL-1ß, IL-17A, IL-23 and TNF-α. METHODS: EAE spinal cords were collected from control and LA-administered rats. Lumbar sections were processed at four different time points during the course of the disease to analyze NF-κB activation by chemiluminescent Western blot, and during the EAE recovery phase to evaluate proinflammatory cytokine levels by quantitative real-time PCR. RESULTS: It was found that LA administration to EAE rats promoted a significant reduction of NF-κB activation during the course of the disease and also decreased the mRNA expression levels of the proinflammatory cytokines IL-1ß, IL-17A and TNF-α in the EAE recovery phase; both effects are consistent with the decrease in the severity of clinical signs of locomotion induced by the treatment. CONCLUSION: LA causes a reduction in the severity of locomotor activity, as well as in the activation of NF-κB and the number of proinflammatory markers in rats with EAE. These results suggest the use of this agonist as a potential therapeutic approach for multiple sclerosis.

Las enfermedades pulmonares intersticiales difusas en el ámbito laboral / Diffuse interstitial lung diseasesin the workplace

La enfermedad pulmonar intersticial difusa (EPID) se refiere a un grupo heterogéneo de condiciones pulmonares caracterizadas clínicamente por disnea y empeoramiento de la función pulmonar y radiológicamente por una infiltración intersticial evidente que afecta predominantemente las bases pulmonares. No existe una clasificación estándar o internacional sobre la misma, pero muchos autores tienden a clasificarla en uno de los dos siguientes grupos: los de causa conocida, secundarios a enfermedades de causa desconocida y los idiopáticos (que son 7 identidades clínicas claramente descritas). Como se ha visto, una de las causas dilucidadas de esta condición se asocia directamente con materiales irritantes como agentes y sustancias químicas tales como: el asbesto, silicón, y carbón utilizadas comúnmente en distintos ámbitos laborales, por lo que aquellas personas que se vieran continuamente expuestas a estos tienen un riesgo aumentado de desarrollar dicha patología. Las EPID son alteraciones que, a pesar de medidas, precauciones y regulaciones impuestas en distintas organizaciones de la promoción de la salud continúan siendo una de las principales enfermedades adquiridas en ámbitos laborales y además es de suma importancia clínica dado que estos pacientes pueden tener un rápido deterioro de función pulmonar. Este factor, sumado al hecho que su fisiopatología, incidencia e historia natural no han logrado ser suficientemente esclarecidos, constituyen la base que soporta la revisión que se ha propuesto realizar. Finalmente, es importante destacar que puede existir un largo tiempo entre la exposición a los agentes causales de la enfermedad y el inicio de las manifestaciones clínicas, por lo que se han documentado pacientes con estos diagnósticos aún años o hasta décadas después de que ocurrió la exposición, por lo que una adecuada regulación (por ejemplo, vacaciones profilácticas) y prevención a la misma podría evitar las consecuencias...

Diffuse interstitial lung disease (ILD) refers to a heterogeneous group of lung conditions characterized clinically by dyspnea, worsening of lung function and radiologically by an evident interstitial infiltration predominantly affecting the lung bases. There is no standard classification on it, but many authors tend to separate it into one of two groups: those with known cause, secondary to diseases of unknown cause and those idiopathic (with 7 clinical identities described). It is known that the condition is also directly associated with irritating materials, agents and chemicals such as asbestos, silicon, and carbon commonly used in industrial fields, so that people continouslly working with these have an increased risk of developing this disease. Despite measures, precautions and regulations imposed by various organizations of health promotion, ILD remains one of the major diseases acquired in work environments and it is of great clinical importance since these patients may have a rapid impaired lung function. This factor, besides the fact that its pathophysiology , incidence and natural history have failed to be sufficiently understood , constitute the base supporting the following review. Finally, we must know that there may be a long time between exposure to the causative agents of disease and the onset of clinical manifestations so that patients could present the diagnoses years or even decades after exposure. Hence derives the importance of proper regulations (eg, prophylactic holidays) and prevention to avoid the possible consequences...

P450-mediated O-demethylated metabolite is responsible for rat hepatobiliary toxicity of pyridyltriazine-containing PI3K inhibitors.

The dysregulation of phosphatidylinositol 3-kinase (PI3K)-dependent pathways is implicated in several human cancers making it an attractive target for small molecule PI3K inhibitors. A series of potent pyridyltriazine-containing inhibitors of class Ia PI3Ks were synthesized and a subset of compounds was evaluated in exploratory repeat-dose rat toxicology studies. Daily oral dosing of compound 1: in Sprague Dawley rats for four consecutive days was associated with hepatobiliary toxicity that included biliary epithelial hyperplasia and hypertrophy, periductular edema, biliary stasis, and acute peribiliary inflammatory infiltrates. These histological changes were associated with clinical pathology changes that included increased serum liver enzymes, total bile acids, and bilirubin. The predominant clearance pathway of 1: was shown in vitro and in a bile-duct cannulated rat (14)C-ADME study to be P450-mediated oxidative metabolism. An O-demethylated pyridine metabolite, M3: , was identified as a candidate proximal metabolite that caused the hepatotoxicity. Co-administration of the pan-P450 inhibitor 1-aminobenzotriazole with 1: to rats significantly reduced the formation of M3: and prevented liver toxicity, whereas direct administration of M3: reproduced the toxicity. Structural changes were introduced to 1: to make the methoxypyridine ring less susceptible to P450 oxidation (compound 2: ), and addition of a methyl group to the benzylic carbon (compound 3: ) improved the pharmacokinetic profile. These changes culminated in the successful design of a clinical candidate 3: (AMG 511) that was devoid of liver toxicity in a 14-day rat toxicity study. Herein, we describe how a metabolism-based structure-activity relationship analysis allowed for the successful identification of a PI3K inhibitor devoid of off-target toxicity.

Leuprolide acetate, a GnRH agonist, improves experimental autoimmune encephalomyelitis: a possible therapy for multiple sclerosis.

Gonadotrophin-releasing hormone (GnRH), a well known hypothalamic neuropeptide, has been reported to possess neurotrophic properties. Leuprolide acetate, a synthetic analogue of GnRH is considered to be a very safe and tolerable drug and it has been used for diverse clinical applications, including the treatment of prostate cancer, endometriosis, uterine fibroids, central precocious puberty and in vitro fertilization techniques. The present study was designed to determine whether Leuprolide acetate administration, exerts neurotrophic effects on clinical signs, body weight gain, neurofilaments (NFs) and myelin basic protein (MBP) expression, axonal morphometry and cell infiltration in spinal cord of experimental autoimmune encephalomyelitis (EAE) rats. In this work, we have found that Leuprolide acetate treatment decreases the severity of clinical signs of locomotion, induces a significantly greater body weight gain, increases the MBP and NFs expression, axonal area and cell infiltration in EAE animals. These results suggest the use of this agonist as a potential therapeutic approach for multiple sclerosis.