Publications by authors named "Zheleznova N"

Acute limb ischemia (ALI) is a sudden lack of blood flow to a limb, primarily caused by arterial embolism and thrombosis. Various experimental animal models, including non-invasive and invasive methods, have been developed and successfully used to induce limb ischemia-reperfusion injuries (L-IRI). However, there is no consensus on the methodologies used in animal models for L-IRI, particularly regarding the assessment of functional recovery.

View Article and Find Full Text PDF
Article Synopsis
  • This study compares the effects of two mTOR inhibitors, rapamycin and PP242, on hypertension and kidney function in salt-sensitive rats.
  • While rapamycin reduced hypertension and kidney inflammation, only PP242 completely prevented hypertension and improved kidney health, showing significant natriuretic effects.
  • The research identified that PP242's natriuretic effect primarily results from inhibiting the Na-Cl cotransporter and reducing Na channel activity, suggesting it may be a better therapeutic option for managing blood pressure and kidney injury in salt-sensitive individuals.
View Article and Find Full Text PDF

Chronic kidney disease (CKD) has a strong genetic component; however, the underlying pathways are not well understood. Dahl salt-sensitive (SS)/Jr rats spontaneously develop CKD with age and are used to investigate the genetic determinants of CKD. However, there are currently several genetically diverse Dahl SS rats maintained at various institutions and the extent to which some exhibit age-related CKD is unclear.

View Article and Find Full Text PDF

Hydrogen peroxide (HO) production in the renal outer medulla is an important determinant of renal medullary blood flow and blood pressure (BP) salt-sensitivity in Dahl salt-sensitive (SS) rats. The mechanisms and pathways responsible for these actions are poorly understood. Recently, we have discovered that the mTOR complex 2 (mTORC2) plays a critical role in BP salt-sensitivity of SS rats by regulating Na homeostasis.

View Article and Find Full Text PDF

We have reported that a high-salt (4.0% NaCl) dietary intake activates mTORC1 and inhibition of this pathway with rapamycin blunts the chronic phase of salt-induced hypertension and renal injury in Dahl salt-sensitive (SS) rats. In SS rats, high-salt intake is known to increase the renal production of HO by NOX4, the most abundant NOX isoform in the kidney, and the global knockout of NOX4 blunts salt-sensitivity in these rats.

View Article and Find Full Text PDF
Article Synopsis
  • Uninephrectomy (UNX) leads to structural and metabolic changes in the remaining kidney, affecting the levels of NADH and FAD, which are crucial for assessing the mitochondrial redox state.
  • A custom fluorescence cryo-imaging technique assessed these changes in rat models 3 days post-UNX, revealing increased kidney weights and reduced redox ratios indicative of heightened reactive oxygen species (ROS) production.
  • The results suggest that the increase in ROS may be linked to enhanced bioenergetics in the remaining kidney due to increased workload, with mitochondria becoming the primary source of ROS after UNX.
View Article and Find Full Text PDF

Hv1 is a voltage-gated proton channel highly expressed in immune cells where, it acts to maintain NAD(P)H oxidase activity during the respiratory burst. We have recently reported that Hv1 is expressed in cells of the medullary thick ascending limb (mTAL) of the kidney and is critical to augment reactive oxygen species (ROS) production by this segment. While Hv1 is associated with NOX2 mediated ROS production in immune cells, the source of the Hv1 dependent ROS in mTAL remains unknown.

View Article and Find Full Text PDF
Article Synopsis
  • mTOR is a crucial signaling pathway involved in various cellular functions, including cell growth and immune responses, consisting of two complexes, mTORC1 and mTORC2, with different roles.
  • mTORC1 has links to health issues like cancer and diabetes, while the effects of mTORC2 on hypertension are less understood, prompting research into its impact on salt-sensitive rats.
  • The study found that inhibiting mTORC2 with a compound called PP242 can prevent and even reverse salt-induced hypertension and kidney damage, suggesting that targeting mTORC2 might be a new strategy for treating high blood pressure.
View Article and Find Full Text PDF

Nox4 and Nox2 are the most abundant NADPH oxidases (Nox) in the kidney and have been shown to contribute to hypertension, renal oxidative stress, and injury in Dahl salt-sensitive (SS) hypertensive rats. The present study focused on the role of Nox4 and p67phox/Nox2 in the generation of H2O2 and O2 (·-) in the renal medullary thick ascending limb of Henle (mTAL) of SS rats in response to increasing luminal flow (from 5 to 20 nl/min). Nox4 and p67phox/Nox2 genes were found to be expressed in the mTAL of SS rats.

View Article and Find Full Text PDF

This study reports the consequences of knocking out NADPH (nicotinamide adenine dinucleotide phosphate) oxidase 4 (Nox4) on the development of hypertension and kidney injury in the Dahl salt-sensitive (SS) rat. Zinc finger nuclease injection of single-cell SS embryos was used to create an 8 base-pair frame-shift deletion of Nox4, resulting in a loss of the ≈68 kDa band in Western blot analysis of renal cortical tissue of the knock out of Nox4 in the SS rat (SS(Nox4-/-)) rats. SS(Nox4-/-) rats exhibited a significant reduction of salt-induced hypertension compared with SS rats after 21 days of 4.

View Article and Find Full Text PDF

The goal of the present study was to quantify and correlate the contribution of the cytosolic p67(phox) subunit of NADPH oxidase 2 to mitochondrial oxidative stress in the kidneys of the Dahl salt-sensitive (SS) hypertensive rat. Whole kidney redox states were uniquely assessed using a custom-designed optical fluorescence three-dimensional cryoimager to acquire multichannel signals of the intrinsic fluorophores NADH and FAD. SS rats were compared with SS rats in which the cytosolic subunit p67(phox) was rendered functionally inactive by zinc finger nuclease mutation of the gene (SS(p67phox)-null rats).

View Article and Find Full Text PDF

The physiological evidence linking the production of superoxide, hydrogen peroxide, and nitric oxide in the renal medullary thick ascending limb of Henle (mTAL) to regulation of medullary blood flow, sodium homeostasis, and long-term control of blood pressure is summarized in this review. Data obtained largely from rats indicate that experimentally induced elevations of either superoxide or hydrogen peroxide in the renal medulla result in reduction of medullary blood flow, enhanced Na(+) reabsorption, and hypertension. A shift in the redox balance between nitric oxide and reactive oxygen species (ROS) is found to occur naturally in the Dahl salt-sensitive (SS) rat model, where selective reduction of ROS production in the renal medulla reduces salt-induced hypertension.

View Article and Find Full Text PDF

Nine commercial kits of "captured" and "indirect" format ELISA assay for the detection of specific IgM and IgG in sera of patients with measles were compared to each other. 72 sera specimens from typical medium-severity cases from a measles outbreak (2010) were collected on the 5-6th day after the rash onset. IgM was detected with "capture" tests (Vecto-Measles IgM, Vector Best, Measles IgM capture EIA, Microimmune Ltd) close to 100% of cases, irrespectively to the age and the initial vaccination status of the patients.

View Article and Find Full Text PDF

The current study, covering the period 2004-2009, is a part of long-term monitoring for hepatitis A virus (HAV) strains circulating in St Petersburg, Russia. The HAV RNA was isolated directly from the sera of hepatitis A patients and RT-PCR was carried out using primer pairs for VP1/2A and VP1 genomic regions. PCR products were sequenced and 324 nucleotides from VP1/2A and 332 from the VP1 region were used for phylogenetic analysis.

View Article and Find Full Text PDF

The renal medullary thick ascending limb (mTAL) of the Dahl salt-sensitive (SS) rat is the site of enhanced NaCl reabsorption and excess superoxide production. In the present studies we isolated mitochondria from mTAL of SS and salt-resistant control strain SS.13(BN) rats on 0.

View Article and Find Full Text PDF

c-Src is a non-receptor tyrosine kinase whose activity is induced by phosphorylation at Y418 and translocation from the cytoplasm to the cell membrane. Increased activity of c-Src has been associated with cell proliferation, matrix adhesion, motility, and apoptosis in tumors. Immunohistochemistry suggested that activated (pY(418))-Src activity is increased in cyst-lining autosomal dominant polycystic kidney disease (ADPKD) epithelial cells in human and mouse ADPKD.

View Article and Find Full Text PDF

Aim: To determine immune structure of different population groups in Saint-Petersburg to hepatitis A virus in 2009 in order to study trends of epidemic process dynamics and planning of prophylactic measures.

Materials And Methods: Nine hundred and three citizens of Saint-Petersburg aged 3 months to 60 years were tested for anti-HAV by ELISA in 2009. Results were compared with data of previous study conducted in Saint-Petersburg in 1999.

View Article and Find Full Text PDF

Members of the epidermal growth factor (EGF) family bind to ErbB (EGFR) family receptors which play an important role in the regulation of various fundamental cell processes including cell proliferation and differentiation. The normal rodent kidney has been shown to express at least three members of the ErbB receptor family and is a major site of EGF ligand synthesis. Polycystic kidney disease (PKD) is a group of diseases caused by mutations in single genes and is characterized by enlarged kidneys due to the formation of multiple cysts in both kidneys.

View Article and Find Full Text PDF

Background: The accumulation of misfolded proteins within the endoplasmic reticulum (ER) triggers a cellular process known as the Unfolded Protein Response (UPR). One of the earliest responses is the attenuation of protein translation. Little is known about the role that Ca2+ mobilization plays in the early UPR.

View Article and Find Full Text PDF

Amiloride-sensitive sodium entry, via the epithelial sodium channel (ENaC), is the rate-limiting step for Na(+) absorption. Epidermal growth factor (EGF) is involved in the regulation of Na(+) transport and ENaC activity. However it is still controversial exactly how EGF regulates ENaC and Na(+) absorption.

View Article and Find Full Text PDF

Integrin-associated focal adhesion complex formation and turnover plays an essential role in directing interactions between epithelial cells and the extracellular matrix during organogenesis, leading to appropriate cell spreading, cell-matrix adhesion, and migration. Autosomal recessive polycystic kidney disease (ARPKD) is associated with loss of function of PKHD1-encoded protein fibrocystin-1 and is characterized by cystic dilation of renal collecting tubules (CT) in utero and loss of renal function in patients if they survive the perinatal period. Normal polycystin-1 (PC-1)/focal adhesion complex function is required for control of CT diameter during renal development, and abnormalities in these complexes have been demonstrated in human PC-1 mutant cystic cells.

View Article and Find Full Text PDF

alphabetadelta-Containing GABA(A) receptors are (1) localized to extra- and perisynaptic membranes, (2) exhibit a high sensitivity to GABA, (3) show little desensitization, and (4) are believed to be one of the primary mediators of tonic inhibition in the central nervous system. This type of signaling appears to play a key role in controlling cell excitability. This review article briefly summarizes recent knowledge on tonic GABA-mediated inhibition.

View Article and Find Full Text PDF

The regulation of epithelial branching morphogenesis by bone morphogenetic protein-7 depends, in part, on functionally defined cyclic adenosine monophosphate (cAMP)-dependent protein kinases. We previously identified protein kinase-X (PRKX), a cAMP-dependent kinase, as a regulator of epithelial morphogenesis during kidney development and found that it binds to and phosphorylates Polycystin-1. Overexpression of PRKX stimulates renal epithelial cell migration, tubulogenesis, ureteric bud branching, and glomerular induction in embryonic mouse kidney explants in organ cultures.

View Article and Find Full Text PDF

Investigation of hepatitis A (HA) outbreak developed in 2005 among workers of food stores networkwas performed using conventional epidemiologic diagnostics as well as methods of molecular epidemiology. In 14 of 15 ill persons, using polymerase chain reaction, HAV RNA was detected by PCR in serum obtained on 2 - 25 day of illness (mean - 9.3 days).

View Article and Find Full Text PDF

Background And Purpose: This study investigated the alpha(1)beta(2)delta isoform of the GABA(A) receptor that is presumably expressed in the forebrain. The functional and pharmacological properties of this receptor combination are largely unknown.

Experimental Approach: We expressed alpha(1)beta(2)delta GABA(A) receptors in Xenopus laevis oocytes.

View Article and Find Full Text PDF