Effects of chronic 4-n-nonylphenol treatment on aortic vasoconstriction and vasorelaxation in rats

Ameliorative Effects of Camel Milk and Its Exosomes on Diabetic Nephropathy in Rats

Contradictory results were obtained regarding the effects of extracellular vesicles such as exosomes (EXOs) on diabetes and diabetic nephropathy (DN). Some studies showed that EXOs, including milk EXOs, were involved in the pathogenesis of DN, whereas other studies revealed ameliorative effects. Compared to other animals, camel milk had unique components that lower blood glucose levels. However, little is known regarding the effect of camel milk and its EXOs on DN. Thus, the present study was conducted to evaluate this effect on a rat model of DN induced by streptozotocin. Treatment with camel milk and/or its EXOs ameliorated DN as evidenced by (1) reduced levels of kidney function parameters (urea, creatinine, retinol-binding protein (RBP), and urinary proteins), (2) restored redox balance (decreased lipid peroxide malondialdehyde (MDA) and increased the activity of antioxidants enzymes superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx)), (3) downregulated expression of DN-related genes (transforming growth factor-beta 1 (TGFβ1), intercellular adhesion molecules 1 (ICAM1), and transformation specific 1 (ETS1), integrin subunit beta 2 (ITGβ2), tissue inhibitors of matrix metalloproteinase 2 (TIMP2), and kidney injury molecule-1 (KIM1)), and (4) decreased renal damage histological score. These results concluded that the treatment with camel milk and/or its EXOs could ameliorate DN with a better effect for the combined therapy.

Validation of canine uterine and testicular arteries for the functional characterisation of receptor-mediated contraction as a replacement for laboratory animal tissues in teaching

Teaching practicals for receptor physiology/pharmacology in medical and veterinary schools have involved the use of in vitro experiments using tissues from laboratory animals, which have been killed for isolated vascular strip or ring preparations. However, the use of scavenged tissues has been advocated to reduce animal use. Utilising discarded tissues from routine surgical procedures, such as canine neutering, has not previously been investigated. Canine testicular and uterine tissues (discarded tissues) were obtained from routine neutering procedures performed by the veterinary team at a local animal neutering clinic for stray dogs. Rings of uterine and testicular artery were dissected and mounted on a Mulvany-Halpern wire myograph in order to characterize the adrenergic and serotonergic receptors mediating vasoconstriction. Cumulative contractile concentration-response curves were constructed for the alpha adrenoceptor agonists epinephrine (α₁ and α₂ receptors), phenylephrine (α₁ selective) and UK14304 (α₂ selective). Pre-treatment with the α₁-selective antagonist, prazosin, was also investigated. The response to serotonin (5-HT) receptor agonists were also investigated, including 5-HT (acting at both 5-HT₁ and 5-HT₂ receptors), 5-carboxamidotryptamine (5-CT; 5-HT₁ selective) and α-methyl 5-HT (5-HT₂ selective). A contractile response was observed in both canine uterine and testicular arteries to epinephrine and phenylephrine, and prazosin caused a dose-dependent parallel rightward shift in the phenylephrine dose-response curve (pA₂ values of 7.97 and 8.39, respectively). UK14304 caused a contractile response in canine testicular arteries but very little appreciable contractile response in uterine arteries. The maximum responses produced by the uterine arteries to 5-HT was significantly lower than those of the testicular arteries. In the testicular artery, the 5-HT₂ receptor selective agonist, α-methyl 5-HT, produced a similar contractile response to 5-HT but the administration of 5-CT failed to produce a response in either the testicular or uterine artery segments. These results validate the use of discarded tissue from routine canine neutering procedures as a useful source of vascular tissue for pharmacological teaching, for characterizing alpha and 5-HT receptor contractile responses.

Protective effect of p53 knockout on 4-nonylphenol-induced nephrotoxicity in medaka (Oryzias latipes)

In the past few decades, environmental pollutants have become common because of misused nonionic surfactants and detergents. Nonylphenol ethoxylates (NPs) are one of the most important contaminants of water. Therefore, the present study aimed to investigate the protective blocking effect of apoptosis (deficient P53 gene) on 4-nonylphenol (4-NP)-induced nephrotoxicity of medaka (Oryzias latipes). We divided 36 fish into six groups: two different control groups of wild type (Wt; Hd-rR) control and p53 (-/-) control, and four different treated with 4-nonylphenol (50 μg/L and 100 μg/L) for 15 days. Histology, immunochemistry, and TUNEL assays confirmed that 4-NP causes nephrotoxicity. Our results showed that 4-NP administration significantly disturbed the kidney structure and function and 4-NP-treated fish showed dilated glomerular vessels, had less glomerular cellular content, decreased expression of glomerular proteins, and an increased level of apoptosis compared with a Wt control group (P < 0.05). As p53 is an apoptotic inducer, some protection in p53-deficient medaka was found as nephrotoxic effects of 4-NP were minimized significantly. Our study demonstrated for the first time to our knowledge that 4-NP induces apoptosis, causing nephrotoxicity in medaka. We found that blocking apoptosis blocking was able to protect the kidney from the toxic effects of 4-NP.

Mesenchymal Stem Cell-Derived Exosomes Ameliorated Diabetic Nephropathy by Autophagy Induction through the mTOR Signaling Pathway

BACKGROUND

Diabetic nephropathy (DN) is a serious complication of diabetes mellitus and a common cause of end-stage renal disease. Autophagy has a defensive role against kidney damage caused by hyperglycemia. Mesenchymal stem cell (MSC)-derived exosomes are currently considered as a new promising therapy for chronic renal injury. However, the renal-protective mechanism of exosomes on DN is not completely understood. We examined the potential role of MSC-derived exosomes for enhancement of autophagy activity and their effect on DN. In our study, we used five groups of rats: control; DN; DN treated with exosomes; DN treated with 3-methyladenine (3-MA) and chloroquine (inhibitors of autophagy); and DN treated with 3-methyladenine (3-MA), chloroquine, and exosome groups. We assessed renal function, morphology, and fibrosis. Moreover, ratios of the autophagy markers mechanistic target of rapamycin (mTOR), Beclin-1, light chain-3 (LC3-II), and LC3-II/LC3-I were detected. Additionally, electron microscopy was used for detection of autophagosomes.

RESULTS

Exosomes markedly improved renal function and showed histological restoration of renal tissues, with significant increase of LC3 and Beclin-1, and significant decrease of mTOR and fibrotic marker expression in renal tissue. All previous effects were partially abolished by the autophagy inhibitors chloroquine and 3-MA.

CONCLUSION

We conclude that autophagy induction by exosomes could attenuate DN in a rat model of streptozotocin-induced diabetes mellitus.

Protective Effect of Ginkgo biloba and Magnetized Water on Nephropathy in Induced Type 2 Diabetes in Rat

We aimed in our current study to explore the protective effect of Ginkgo biloba (GB) and magnetized water (MW) against nephrotoxicity associating induced type 2 diabetes mellitus in rat. Here, we induced diabetes by feeding our lab rats on a high fat-containing diet (4 weeks) and after that injecting them with streptozotocin (STZ). We randomly divided forty rats into four different groups: nontreated control (Ctrl), nontreated diabetic (Diabetic), Diabetic+GB (4-week treatment), and Diabetic+MW (4-week treatment). After the experiment was finished, serum and kidney tissue samples were gathered. Blood levels of glucose, triglycerides, cholesterol, creatinine, and urea were markedly elevated in the diabetic group than in the control group. In all animals treated with GB and MW, the levels of urea, creatinine, and glucose were significantly reduced (all P < 0.01). GB and MW attenuated glomerular and tubular injury as well as the histological score. Furthermore, they normalized the contents of glutathione reductase and SOD2. In summary, our data showed that GB and MW treatment protected type 2 diabetic rat kidneys from nephrotoxic damages by reducing the hyperlipidemia, uremia, oxidative stress, and renal dysfunction.

Protective effect of Nigella sativa on 4-nonylphenol-induced nephrotoxicity in Clarias gariepinus (Burchell, 1822)

The aim of this study was to examine the protective effects of Nigella sativa (N. sativa) on 4-Nonylphenol-induced nephrotoxicity in Clarias gariepinus. 30 fishes were divided into five groups: control, 4-nonylphenol-treated, 1% N. sativa treated, 2.5% N. sativa treated, and 5% N. sativa treated. N. sativa and 4-Nonylphenol were given for 3weeks. 4-NP and 4-NP-N. sativa treated fishes were compared with the control group. Kidney histology, immunochemistry, and electron microscope were assessed after 4-NP exposure. In the African catfish, 4-NP is mainly excreted through the kidney causing nephrotoxicity. Our results showed that 4-NP administration significantly disturbed the kidney structure and function. 4-NP treated fishes showed dilated glomerular vessels, fewer glomerular cells content, decreased expressions of glomerular proteins, and increased level of autophagy compared to control group (P<0.05). As N. sativa has different immunological and pharmacological effects such as anti-apoptotic and anti-oxidant, therefore, the administration of N. sativa with 4-Nonylphenol significantly minimize the nephrotoxic effect of 4-NP and maintain the normal kidney structure and function. Our novel study demonstrated for the first time that N. sativa could protect the kidney against 4-NP induced-nephrotoxicity.

Endocrine disruptors and bone metabolism

Bone microenvironment is a complex dynamic equilibrium between osteoclasts and osteoblasts and is modulated by a wide variety of hormones and osteocyte mediators secreted in response to physiological and pathological conditions. The rate of remodeling involves tight coupling and regulation of both cells population and is regulated by a wide variety of hormones and mediators such as parathyroid hormone, prostaglandins, thyroid hormone, sex steroids, etc. It is also well documented that bone formation is easily influenced by the exposure of osteoblasts and osteoclasts to chemical compounds. Currently, humans and wildlife animals are exposed to various environmental xenoestrogens typically at low doses. These compounds, known as endocrine disruptor chemicals (EDCs), can alter the systemic hormonal regulation of the bone remodeling process and the skeletal formation. This review highlights the effects of the EDCs on mammalian bone turnover and development providing a macro and molecular view of their action.

Chronic exposure to environmental contaminant nonylphenol exacerbates adenine-induced chronic renal insufficiency: role of signaling pathways and therapeutic impact of rosuvastatin

Although chronic exposure to environmental contaminants is hazardous to health, the association between chronic kidney disease (CKD) and nonylphenol (NP), a common environmental compound, remains unclear. This study tested the hypothesis that chronic NP exposure aggravated adenine (AD)-induced CKD that could be mitigated with rosuvastatin treatment. Fifty Wistar rats were randomly (n=10/each group) categorized into normal controls (N(C)), NP only (2.0mg/kg/day), AD only (0.25% AD in fodder), combined NP-AD, and NP-AD with rosuvastatin (20.0mg/kg/day) (NP-AD-R(OSU)). All animals received treatment for 24 weeks prior to being sacrificed. Results showed that ratio of urine protein to creatinine were increased in NP-AD group than in groups N(C), NP, and AD, but reduced in NP-AD-R(OSU) group compared with NP-AD group (all p<0.003). Protein expression of TGF-β and phosphorylated Smad3, indexes of tissue fibrosis, were increased in NP-AD group than in groups N(C), NP and AD, but reduced in NP-AD-R(OSU) group compared with NP-AD group (all p<0.001). BMP-2 and phosphorylated Smad1/5, two indicators of anti-fibrosis, were lower in NP-AD group than in groups N(C), NP and AD, but higher in NP-AD-R(OSU) group compared with NP-AD group (all p<0.001). Protein expressions of JNK and PKC-α in membranous compartment were higher in group NP-AD than in groups N(C), NP and AD, but reduced in NP-AD-R(OSU) group compared with NP-AD group (all p<0.001). More TGF-β+cells but less BMP-2+, CD31+, vWF+and GR+cells were noted in groups AD and NP-AD than in groups N(C), NP and NP-AD-R(OSU) (all p<0.04). In conclusion, NP exposure worsened aggravated AD-induced CKD that could be ameliorated with rosuvastatin treatment.

GPER/GPR30 and Regulation of Vascular Tone and Blood Pressure

Natural estrogens such as 17β-estradiol are endogenous vasodilators and have been implicated in the gender differences of hypertension. These hormones activate estrogen receptors ERα and ERβ, which mediate part of estrogen-dependent vasodilation. In addition, a novel G protein-coupled estrogen-binding receptor termed GPER/GPR30 has been identified that is expressed in the cardiovascular system. Using knock-out animals or drugs selectively targeting GPER/GPR30, a significant role for this receptor as a mediator of acute estrogen-dependent vasodilation involving nitric oxide (NO) and blood pressure-lowering activity has been demonstrated. The accumulating evidence that GPER/GPR30 is responsible for control of vascular tone indicates that this receptor may represent a novel drug target for pharmacologic treatment of hypertension in postmenopausal women and possibly also men.

The G protein-coupled estrogen receptor GPER/GPR30 as a regulator of cardiovascular function

Endogenous estrogens are important regulators of cardiovascular homeostasis in premenopausal women and delay the development of hypertension and coronary artery disease. These hormones act via three different estrogen receptors affecting both gene transcription and rapid signaling pathways in a complex interplay. In addition to the classical estrogen receptors ERα and ERβ, which are known mediators of estrogen-dependent vascular effects, a G protein-coupled estrogen receptor termed GPER that is expressed in the cardiovascular system has recently been identified. Endogenous human 17β-estradiol, selective estrogen receptor modulators (SERMs) including tamoxifen and raloxifene, and selective estrogen receptor downregulators (SERDs) such as ICI 182,780 are all agonists of GPER, which has been implicated in the regulation of vasomotor tone and protection from myocardial ischemia/reperfusion injury. As a result, understanding the individual role of ERα, ERβ, and GPER in cardiovascular function has become increasingly complex. With accumulating evidence that GPER is responsible for a variety of beneficial cardiovascular effects of estrogens, this receptor may represent a novel target to develop effective strategies for the treatment of cardiovascular diseases by tissue-specific, selective activation of estrogen-dependent molecular pathways devoid of side effects seen with conventional hormone therapy.