Kidney Development in the Absence of Gdnf and Spry1 Requires Fgf10

GDNF signaling through the Ret receptor tyrosine kinase (RTK) is required for ureteric bud (UB) branching morphogenesis during kidney development in mice and humans. Furthermore, many other mutant genes that cause renal agenesis exert their effects via the GDNF/RET pathway. Therefore, RET signaling is believed to play a central role in renal organogenesis. Here, we re-examine the extent to which the functions of Gdnf and Ret are unique, by seeking conditions in which a kidney can develop in their absence. We find that in the absence of the negative regulator Spry1, Gdnf, and Ret are no longer required for extensive kidney development. Gdnf−/−;Spry1−/− or Ret−/−;Spry1−/− double mutants develop large kidneys with normal ureters, highly branched collecting ducts, extensive nephrogenesis, and normal histoarchitecture. However, despite extensive branching, the UB displays alterations in branch spacing, angle, and frequency. UB branching in the absence of Gdnf and Spry1 requires Fgf10 (which normally plays a minor role), as removal of even one copy of Fgf10 in Gdnf−/−;Spry1−/− mutants causes a complete failure of ureter and kidney development. In contrast to Gdnf or Ret mutations, renal agenesis caused by concomitant lack of the transcription factors ETV4 and ETV5 is not rescued by removing Spry1, consistent with their role downstream of both RET and FGFRs. This shows that, for many aspects of renal development, the balance between positive signaling by RTKs and negative regulation of this signaling by SPRY1 is more critical than the specific role of GDNF. Other signals, including FGF10, can perform many of the functions of GDNF, when SPRY1 is absent. But GDNF/RET signaling has an apparently unique function in determining normal branching pattern. In contrast to GDNF or FGF10, Etv4 and Etv5 represent a critical node in the RTK signaling network that cannot by bypassed by reducing the negative regulation of upstream signals

Sprouty Proteins Inhibit Receptor-mediated Activation of Phosphatidylinositol-specific Phospholipase C

PLCγ03B3 binds Spry1 and Spry2. Overexpression of Spry decreased PLCγ03B3 activity and IP3 and DAG production, whereas Spry-deficient cells yielded more IP3. Spry overexpression inhibited T-cell receptor signaling and Spry1 null T-cells hyperproliferated with TCR ligation. Through action of PLCγ03B3, Spry may influence signaling through multiple receptors

Seroprevalence of 13 common pathogens in a rapidly growing U.S. minority population: Mexican Americans from San Antonio, TX

<p>Abstract</p> <p>Background</p> <p>Infection risks vary among individuals and between populations. Here we present information on the seroprevalence of 13 common infectious agents in a San Antonio-based sample of Mexican Americans. Mexican Americans represent the largest and most rapidly growing minority population in the U.S., and they are also considered a health disparities population.</p> <p>Methods</p> <p>We analyzed 1227 individuals for antibody titer to <it>Chlamydophila pneumoniae, Helicobacter pylori, Toxoplasma gondii</it>, cytomegalovirus, Epstein-Barr virus, herpes simplex virus-1, herpes simplex virus-2 (HSV-2), human herpesvirus-6 (HHV-6), varicella zoster virus (VZV), adenovirus-36, hepatitis A virus, and influenza A and B. Seroprevalence was examined as a function of sex, age, household income, and education.</p> <p>Results</p> <p>Seroprevalence estimates ranged from 9% for <it>T. gondii</it> to 92% for VZV, and were similar in both sexes except for HSV-2, which was more prevalent in women. Many pathogens exhibited a significant seroprevalence change over the examined age range (15-94 years), with 7 pathogens increasing and HHV-6 decreasing with age. Socioeconomic status significantly correlated with serostatus for some pathogens.</p> <p>Conclusions</p> <p>Our findings demonstrate substantial seroprevalence rates of these common infections in this sample of Mexican Americans from San Antonio, Texas that suffers from high rates of chronic diseases including obesity and type-2 diabetes.</p

Hypertensive Rats

Apelin, a novel multifunctional peptide implicated in the regulation of the cardiovascular system, including blood pressure and cardiac function control, has been postulated to be involved in the pathophysiology of hypertension and hypertensive heart disease. The aim of this study was to investigate, for the first time, whether the effects of apelin's chronic application might be involved in deoxycorticosterone acetate-salt-induced hypertensive rats (DOCA-salt rats). In this study, 8-10-week-old male Wistar rats were divided into four groups: control, control + apelin, DOCA-salt rats, DOCA-salt rats + apelin. Deoxycorticosterone Acetate (25 mg/kg of body weight) was injected subcutaneously, twice a week for 4 weeks. These rats received NaCl 1% instead of tap water for drinking during the experimental period. Later, rats were randomly treated with pyroglutamylated apelin-13 (200 mu g.kg(-1). day(-1) intraperitonealy) for 17 days. The concentrations of apelin, endothelin-1, angiotensin-converting enzyme, angiotensinogen, and angiotensin II were analyzed in the plasma. The mRNA level of apelin and apelin receptor were determined in the heart and aorta tissue by real-time polymerase chain reaction, respectively. It was found that apelin reduces blood pressure in DOCA-salt rats. Apelin can be used as a therapeutic agent in the treatment of hypertension in the future

The effects of apelin treatment on a rat model of type 2 diabetes

Purpose: Apelin is an adipokine that plays a role in the regulation of many biological functions in mammals including the neuroendocrine, cardiovascular, immune systems, glucose homeostasis and obesity. It can act via autocrine, paracrine, endocrine, and exocrine signaling. We aimed to identify the role of apelin pathophysiology of diabetes.Material/methods: 37 male Wistar Albino rats aged 8-10 weeks were divided in four experimental groups as: control group (C) control + apelin group (C + A), diabetic group (D) diabetic + apelin group (D + A). Apelin and apelin receptor mRNA gene expressions in heart and aorta tissue were determined by real-time polymerase chain reaction. The plasma levels of insulin and plasma apelin were determined by ELISA.Results: Plasma levels of insulin, glucose, blood pressure levels were significantly lower in D + A group. There was no statistically significant difference for level of apelin between diabetic groups. On the other hand, differences for apelin and APJ mRNA expression in heart and vascular tissue were found significant between groups.Conclusions: Apelin can be used as a therapeutic agent in the treatment of type II diabetes in the future. (C) 2014 Medical University of Bialystok. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved

The effects of apelin treatment on a rat model of type 2 diabetes.

PURPOSE: Apelin is an adipokine that plays a role in the regulation of many biological functions in mammals including the neuroendocrine, cardiovascular, immune systems, glucose homeostasis and obesity. It can act via autocrine, paracrine, endocrine, and exocrine signaling. We aimed to identify the role of apelin pathophysiology of diabetes. MATERIAL/METHODS: 37 male Wistar Albino rats aged 8-10 weeks were divided in four experimental groups as: control group (C) control+apelin group (C+A), diabetic group (D) diabetic+apelin group (D+A). Apelin and apelin receptor mRNA gene expressions in heart and aorta tissue were determined by real-time polymerase chain reaction. The plasma levels of insulin and plasma apelin were determined by ELISA. RESULTS: Plasma levels of insulin, glucose, blood pressure levels were significantly lower in D+A group. There was no statistically significant difference for level of apelin between diabetic groups. On the other hand, differences for apelin and APJ mRNA expression in heart and vascular tissue were found significant between groups. CONCLUSIONS: Apelin can be used as a therapeutic agent in the treatment of type II diabetes in the future