AQP7

Aquaporins comprise a family of 13 members of water channels (AQP0-12) that facilitate a rapid transport of water across cell membranes. In some cases, these pores are also permeated by small solutes, particularly glycerol, urea or nitric oxide, among other solutes. Several aquaporins have been identified in the pancreas, an exocrine and endocrine organ that plays an essential role in the onset of insulin resistance and type 2 diabetes. The exocrine pancreas, which accounts for 90% of the total pancreas, secretes daily large volumes of a near-isotonic fluid containing digestive enzymes into the duodenum...

Ischemia-reperfusion injury (IRI) is a major cause of cardiac damage following various pathological processes, such as free radical damage and cell apoptosis. This study aims to investigate whether microRNA-292-5p (miR-292-5p) protects against myocardial ischemia-reperfusion injury (IRI) via the peroxisome proliferator-activated receptor (PPAR)-α/-γ signaling pathway in myocardial IRI mice models. Mouse models of myocardial IRI were established. Adult male C57BL/6 mice were divided into different groups. The hemodynamic indexes, levels of related inflammatory factors and serum myocardial enzymes, and malondialdehyde (MDA) content and the activity of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) were detected...

Background: Previous research has revealed a strong inflammatory response within adipose (AT) tissue during the transition into lactation. Whether this effect is a result of oxidative stress induced by lipolysis and fatty acid oxidation associated with differences in prepartum body condition score remains to be determined. The objectives of this study were to investigate systemic biomarkers of energy balance and inflammation and the expression of lipid metabolism- and inflammation-related genes in AT during the transition period in dairy cows...

The aquaglyceroporin AQP7 is a pore-forming transmembrane protein that facilitates the transport of glycerol across cell membranes. Glycerol is utilized both in carbohydrate and lipid metabolism. It is primarily stored in white adipose tissue as part of the triglyceride molecules. During states with increased lipolysis, such as fasting and diabetes, glycerol is released from adipose tissue and metabolized in other tissues. AQP7 is expressed in adipose tissue where it facilitates the efflux of glycerol, and AQP7 deficiency has been linked to increased glycerol kinase activity and triglyceride accumulation in adipose tissue, leading to obesity and secondary development of insulin resistance...

The sparse number of high-resolution human membrane protein structures severely restricts our comprehension of molecular physiology and ability to exploit rational drug design. In the search for a standardized, cheap and easily handled human membrane protein production platform, we thoroughly investigated the capacity of S. cerevisiae to deliver high yields of prime quality human AQPs, focusing on poorly characterized members including some previously shown to be difficult to isolate. Exploiting GFP labeled forms we comprehensively optimized production and purification procedures resulting in satisfactory yields of all nine AQP targets...

Aquaglyceroporins-aquaporin membrane channels (AQP) that conduct glycerol and other small neutral solutes in addition to water-play major roles in obesity. In adipocytes, aquaglyceroporins mediate glycerol uptake and release across the plasma membrane, which are two key steps for triacylglycerols (TAGs) synthesis (lipogenesis) and hydrolysis (lipolysis). The aim of this study was to assess both glycerol permeability and metabolism in undifferentiated 3T3-L1 cells (UDCs) as well as in untreated (CTL-DCs) versus lipopolysaccharide (LPS-DCs)-treated differentiated 3T3-L1 adipocytes...

Aquaporins (AQPs) play a vital role for the transport of water and solutes across cell membranes. Classification of these ubiquitous proteins into three categories (orthodox AQPs, aquaglyceroporins and superaquaporins) is based on their sequence similarity and substrate selectivity. In the male reproductive tract of mammals, most AQPs (except AQP6 and AQP12) are found in different organs (including testis, efferent ducts and epididymis). AQP1 and AQP9 are the most abundant AQPs in the efferent ducts and epididymis and play a crucial role for the secretion/reabsorption dynamics of luminal fluid during sperm transport and maturation...

Aquaporins (AQPs) are transmembrane proteins found in all cells and are responsible for the transport of water and small solutes. While these proteins have been found in the spermatozoa of humans, rodents, pigs and cattle, where not only do they play a role for the regulation of sperm volume but are also related with the sperm resilience to withstand freeze-thawing procedures, their presence in stallion sperm is yet to be reported. Therefore, the objectives of this work were as follows: (i) to determine whether AQP3, AQP7 and AQP11 are present in stallion sperm and (ii) to investigate whether the relative amounts of these three AQPs play any role in the cryopreservation success...

Cryopreservation is the most suitable method to preserve boar spermatozoa over long-term storage. However, freeze-thawing protocols inflict extensive damage to sperm cells, reducing their viability and compromising their fertilizing ability. In addition, high individual variability is known to exist between boar ejaculates, which may be classified as of good (GFE) or poor (PFE) freezability. While conventional spermiogram parameters fail to predict sperm cryotolerance in fresh spermatozoa, high levels of certain proteins, also known as freezability markers, have been found to be related to the sperm resilience to withstand freeze-thawing procedures...

Orthodox aquaporins are transmembrane channel proteins that facilitate rapid diffusion of water, while aquaglyceroporins facilitate the diffusion of small uncharged molecules such as glycerol and arsenic trioxide. Aquaglyceroporins play important roles in human physiology, in particular for glycerol metabolism and arsenic detoxification. We have developed a unique system applying the strain of the yeast Pichia pastoris, where the endogenous aquaporins/aquaglyceroporins have been removed and human aquaglyceroporins AQP3, AQP7, and AQP9 are recombinantly expressed enabling comparative permeability measurements between the expressed proteins...

PURPOSE: To determine survival in afatinib-treated patients after treatment with first-generation EGFR tyrosine kinase inhibitors (TKIs) and to study resistance mechanisms in afatinib-resistant tumors. METHODS: Characteristics and survival of patients treated with afatinib after resistance to erlotinib or gefitinib in two large Dutch centers were collected. Whole exome sequencing (WES) and pathway analysis was performed on available pre- and post-afatinib tumor biopsies and normal tissue...

Skin function deteriorates with aging, and the dermal water content decreases. In this study, we have analyzed the mechanism of aging-related skin dryness focusing on aquaporins (AQPs), which are the water channels. Mice aged 3 and 20 months were designated as young and aged mice, respectively, to be used in the experiments. No differences were observed in transepidermal water loss between the young mice and aged mice. However, the dermal water content in aged mice was significantly lower than that in young mice, thus showing skin dryness...

BACKGROUND: Understanding molecular basis involved in overweight is an important first step in developing therapeutic pathways against excess in body weight gain. OBJECTIVE: The purpose of our pilot study was to evaluate the gene expression profiles in the peripheral blood of obese patients without other metabolic complications. DESIGN: A sample of 17 obese patients without metabolic syndrome and 15 non obese control subjects was evaluated in a prospective way...

BACKGROUND/OBJECTIVES: Glycerol is a key metabolite for lipid accumulation in insulin-sensitive tissues as well as for pancreatic insulin secretion. We examined the role of aquaporin-7 (AQP7), the main glycerol channel in β-cells, and AQP12, an aquaporin related to pancreatic damage, in the improvement of pancreatic function and steatosis after sleeve gastrectomy in diet-induced obese rats. SUBJECTS/METHODS: Male Wistar obese rats (n=125) were subjected to surgical (sham operation and sleeve gastrectomy) or dietary (pair-fed to the amount of food eaten by sleeve-gastrectomized animals) interventions...

Although the mechanisms linking obesity to insulin resistance (IR) and type 2 diabetes (T2D) are not entirely understood, it is likely that alterations of adipose tissue function are involved. The aim of this study was to identify new genes controlling insulin sensitivity in adipocytes from obese women with either insulin resistant (OIR) or sensitive (OIS) adipocytes. Insulin sensitivity was first determined by measuring lipogenesis in isolated adipocytes from abdominal subcutaneous white adipose tissue (WAT) in a large observational study...

Differentiation of adipocytes is a highly regulated process modulated by multiple transcriptional co-activators and co-repressors. JMJD1C belongs to the family of jumonji C (jmjC) domain-containing histone demethylases and was originally described as a ligand-dependent co-activator of thyroid hormone and androgen receptors. Here, we explored the potential role of Jmjd1c in white adipocyte differentiation. To investigate the relevance of Jmjd1c in adipogenesis, murine 3T3-L1 preadipocyte cells with transient knock-down of Jmjd1c (3T3_Jmjd1c) were generated...

OBJECTIVE: Elevated fat mass and redistribution of body fat are commonly observed in postmenopausal women. Aquaporin 7 (AQP7), a unique glycerol permeable integral membrane protein, has been associated with the onset of obesity. We hypothesized that estrogen supplementation could counteract this fat accumulation and redistribution through tissue-specific modulation of AQP7. METHODS: We measured fat depot weight, adipocyte size, and the expression of AQP7 and glycerol kinase (GK) in visceral and subcutaneous fat tissues of ovariectomized mice supplemented with or without 17β-estradiol...

Obesity is one of the most important metabolic disorders of this century and is associated with a cluster of the most dangerous cardiovascular disease risk factors, such as insulin resistance and diabetes , dyslipidemia and hypertension , collectively named Metabolic Syndrome. The role of aquaporins in glycerol metabolism facilitating glycerol release from the adipose tissue and distribution to various tissues and organs, unveils these membrane channels as important players in lipid balance and energy homeostasis and points to their involvement in a variety of pathophysiological mechanisms including insulin resistance, obesity and diabetes...

Several aquaporin (AQP )-type water channels are expressed in kidney: AQP1 in the proximal tubule, thin descending limb of Henle, and vasa recta; AQP2 -6 in the collecting duct; AQP7 in the proximal tubule; AQP8 in the proximal tubule and collecting duct; and AQP11 in the endoplasmic reticulum of proximal tubule cells. AQP2 is the vasopressin-regulated water channel that is important in hereditary and acquired diseases affecting urine-concentrating ability. The roles of AQPs in renal physiology and transepithelial water transport have been determined using AQP knockout mouse models...

Recent studies have shown that some aquaporins (AQPs ), including AQP1, AQP4, AQP7 and AQP9, are expressed in endothelial cells, vascular smooth muscle cells and heart of cardiovascular system. These AQPs are involved in the cardiovascular function and in pathological process of related diseases, such as cerebral ischemia , congestion heart failure , hypertension and angiogenesis. Therefore, it is important to understand the accurate association between AQPs and cardiovascular system, which may provide novel approaches to prevent and treat related diseases...