Suppression of Sproutys Has a Therapeutic Effect for a Mouse Model of Ischemia by Enhancing Angiogenesis

Sprouty proteins (Sproutys) inhibit receptor tyrosine kinase signaling and control various aspects of branching morphogenesis. In this study, we examined the physiological function of Sproutys in angiogenesis, using gene targeting and short-hairpin RNA (shRNA) knockdown strategies. Sprouty2 and Sprouty4 double knockout (KO) (DKO) mice were embryonic-lethal around E12.5 due to cardiovascular defects. The number of peripheral blood vessels, but not that of lymphatic vessels, was increased in Sprouty4 KO mice compared with wild-type (WT) mice. Sprouty4 KO mice were more resistant to hind limb ischemia and soft tissue ischemia than WT mice were, because Sprouty4 deficiency causes accelerated neovascularization. Moreover, suppression of Sprouty2 and Sprouty4 expression in vivo by shRNA targeting accelerated angiogenesis and has a therapeutic effect in a mouse model of hind limb ischemia. These data suggest that Sproutys are physiologically important negative regulators of angiogenesis in vivo and novel therapeutic targets for treating peripheral ischemic diseases

Sprouty4 Is an Endogenous Negative Modulator of TrkA Signaling and Neuronal Differentiation Induced by NGF

The Sprouty (Spry) family of proteins represents endogenous regulators of downstream signaling pathways induced by receptor tyrosine kinases (RTKs). Using real time PCR, we detect a significant increase in the expression of Spry4 mRNA in response to NGF, indicating that Spry4 could modulate intracellular signaling pathways and biological processes induced by NGF and its receptor TrkA. In this work, we demonstrate that overexpression of wild-type Spry4 causes a significant reduction in MAPK and Rac1 activation and neurite outgrowth induced by NGF. At molecular level, our findings indicate that ectopic expression of a mutated form of Spry4 (Y53A), in which a conserved tyrosine residue was replaced, fail to block both TrkA-mediated Erk/MAPK activation and neurite outgrowth induced by NGF, suggesting that an intact tyrosine 53 site is required for the inhibitory effect of Spry4 on NGF signaling. Downregulation of Spry4 using small interference RNA knockdown experiments potentiates PC12 cell differentiation and MAPK activation in response to NGF. Together, these findings establish a new physiological mechanism through which Spry4 regulates neurite outgrowth reducing not only the MAPK pathway but also restricting Rac1 activation in response to NGF

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

MDR-1 gene C/T polymorphism in COPD: Data from Aegean part of Turkey

Results: The frequencies of MDR-1 genotypes were found 17.0% for CC, 51.1% for CT and 31.9% for TT in the COPD group and 39.1% for CC, 53.1% for CT and 7.8% for TT in the control group. The distribution of MDR-1 gene C alleles were found 32.3% in COPD group and 67.7% in control group; T alleles were found 55.1% in COPD group and 44.9% in control group. There was statistically significant difference between the groups for genotype and allele frequency of MDR-1 gene (P = 0.001).Conclusion: TT genotype of MDR-1 gene was significantly more frequent in COPD patients. MDR-1 gene C/T polymorphism may play a role in COPD development.Objective: Genetic factors, in addition to oxidative stress factors, have been implicated in the development of chronic obstructive pulmonary disease (COPD). Multi-drug resistant-1 (MDR-1) is a gene located on chromosome 7 and the products of this gene protect lung tissue from oxidative stress. We searched the frequency of MDR-1 gene C/T polymorphism in patients with COPD and aimed to explain the association between MDR-1 gene and COPD development.Methods: 47 patients with COPD and 64 healthy control participants were placed in this study. DNAs were extracted from blood samples and MDR-1 amplification of DNA was performed using polymerase chain reaction and enzyme digestion techniques. © 2014, E-Century Publishing Corporation. All rights reserved

MDR-1 gene C/T polymorphism in COPD: data from Aegean part of Turkey

Objective: Genetic factors, in addition to oxidative stress factors, have been implicated in the development of chronic obstructive pulmonary disease (COPD). Multi-drug resistant-1 (MDR-1) is a gene located on chromosome 7 and the products of this gene protect lung tissue from oxidative stress. We searched the frequency of MDR-1 gene C/T polymorphism in patients with COPD and aimed to explain the association between MDR-1 gene and COPD development. Methods: 47 patients with COPD and 64 healthy control participants were placed in this study. DNAs were extracted from blood samples and MDR-1 amplification of DNA was performed using polymerase chain reaction and enzyme digestion techniques. Results: The frequencies of MDR-1 genotypes were found 17.0% for CC, 51.1% for CT and 31.9% for TT in the COPD group and 39.1% for CC, 53.1% for CT and 7.8% for TT in the control group. The distribution of MDR-1 gene C alleles were found 32.3% in COPD group and 67.7% in control group; T alleles were found 55.1% in COPD group and 44.9% in control group. There was statistically significant difference between the groups for genotype and allele frequency of MDR-1 gene (P = 0.001). Conclusion: TT genotype of MDR-1 gene was significantly more frequent in COPD patients. MDR-1 gene C/T polymorphism may play a role in COPD development