The key mediator of diabetic kidney disease:Potassium channel dysfunction

Diabetic kidney disease is a leading cause of end-stage renal disease,making it a global public health concern.The molecular mechanisms underlying diabetic kidney disease have not been elucidated due to its complex pathogenesis.Thus,exploring these mechanisms from new perspectives is the current focus of research concerning diabetic kidney disease.lon channels are important proteins that maintain the physiological functions of cells and organs.Among ion channels,potassium channels stand out,because they are the most common and important channels on eukaryotic cell surfaces and function as the basis for cell excitability.Certain potassium channel abnormalities have been found to be closely related to diabetic kid-ney disease progression and genetic susceptibility,such as K_(ATP),K_(ca),K_(ir),and K_(v).In this review,we summarized the roles of different types of potassium channels in the occurrence and devel-opment of diabetic kidney disease to discuss whether the development of DKD is due to potas-sium channel dysfunction and present new ideas for the treatment of DKD.

Hypertension, type Ⅳ cardiorenal syndrome and chronic kidney disease: Pathophysiological and therapeutical approach

Hypertension represent one of the most important comorbid factors in chronic kidney disease(CKD) patients and its prevalence increases from 65% to 95% according to glomerular filtration rate decline. CKD patients need to maintain their blood pressure levels into 130/80 mm Hg according to most recent guidelines. Despite of many therapeutic agents, achievement of ideal blood pressure levels remains so far from the ideal ones. Hypertensive disease represent most important risk factor to develop a type Ⅳ cardiorenal syndrome, while prevalence of end stage renal disease is still raising and it represents worldwide epidemiological challenge. Correct management of hypertensive disease can obtain better control on CKD progression.

A Novel Apprehension of the Primary Lung Meridian, Sinew Channel, Divergent Channel, Luo-Connecting Channel Acting as a Single Unit System to Serve Respiration Function Based on Modern Neurophysiology and Kinesiology

The TCM philosophy of a meridian and associated channels pertains to the specific function of one or more organs. We define the Lung Primary Meridian (LUM) together with the Lung Sinew (LUSC), Divergent (LUDC), Luo-connecting (LULCC) Channels as a system of routes plus some parts of the body (such as muscles) to fulfil respiration, as a main function under different situations. There is very limited information about the Lung associated channels in classical literature of TCM. With a clear focus on the function of respiration, we have carried out a detailed analysis of the biomedical consequence of stimulating the LUM, analysed the roles played by LUSC, LUDC, and LULCC. The updated LUM and LUDC include acupoints of other meridians, serving the same purpose of performing satisfactory respiration starting from checking the quality of the inflow through the nose. The LUSC includes the respiratory muscles (plus the associated connective tissues) extending to various parts of the body. The muscles of the limb (as part of the LUSC) embrace the nerves that provide routes for somatosensory reflexes and play the role of locomotion, providing voluntary respiration via the pectoralis muscles. The muscles of LUSC are bounded by stiff connective tissue layers, forming compartments, and are part of the pulley system for various body locomotions. Within a compartment, the interstitial fluid, blood, lymph flows must be potent to protect the associated nerves related to LUM;the healthy state of the LUSC also provides freedom of various types of locomotion. The LULCC exists because the vagus nerve has a part of it passing through the spinal cords all the way down to the sacrum domain, with exiting nerve innervating two-third of the large intestine. The crucial steps of our deductions are supported by experimental evidence based on modern neurophysiology and kinesiology. We discover that all the four channels stated above work as a unit system to allow respiration to be possible under various postures/conditions. The complexity of structures and processes is eased off by providing 29 figures and 13 tables for the relevant muscles and nerves. In addition to respiration, the Lung system in TCM context includes interaction of this system with the sweat gland and neuroendocrine system;such aspects will be left to another study.

Protective role of mitochondrial K-ATP channel and mitochondrial membrane transport pore in rat kidney ischemic postconditioning

Background Previous studies suggested that mechanical intervention during early reperfusion, or ischemia postconditioning （Ipo）, could protect kidneys against renal ischemia reperfusion injury （RIRI）. However, the mechanisms responsible for this protection remain unclear. This study therefore investigated the protection afforded by Ipo in rat kidneys in vivo, and the roles of mitochondrial KATP channels （mitOKATP） and mitochondrial permeability transition pores （MPTPs）, by inhibiting mitOKATP with 5-hydroxydecanoate （5-HD）, and by directly detecting open MPTPs using calcein-AM and CoCl2.Methods Thirty-five male Sprague-Dawley rats were randomly assigned to sham-operation （S）, ischemia-reperfusion （I/R）,Ipo, ischemia reperfusion with 5-HD （I/R＋5-HD）, or Ipo with 5-HD （Ipo ＋5-HD） groups. Rats in each group were sacrificed after 6 hours of reperfusion by heart exsanguination or cervical dislocation under anesthesia. RIRI was assessed by determination of creatinine and blood urea nitrogen （BUN）, and by examination of histologic sections. The roles of mitoKATP and MPTP were investigated by analyzing fluorescence intensities of mitochondria, mitochondrial membrane potential,intracellular reactive oxygen species （ROS） and intracellular calcium, using appropriate fluorescent markers. The relationship between apoptosis and RIRI was assessed by determining the apoptotic index （Al） of kidney tubular epithelial cells.Results The RIRI model was shown to be successful. Significantly higher levels of creatinine and BUN, and abnormal pathology of histologic sections, were observed in group I/R, compared with group S. 5-HD eliminated the renoprotective effects of Ipo. Mitochondrial and mitochondrial membrane potential fluorescence intensities increased, and intracellular calcium, ROS fluorescence intensities and AI decreased in group Ipo, compared with group I/R. However, mitochondrial and mitochondrial membrane potential fluorescence intensities decreased, and intracellular calcium and ROS fluorescence intensities and AI increased in group Ipo＋5-HD, compared with group Ipo.Conclusions mitoKATP and MPTPs participated in Ipo-induced renoprotective mechanisms in rat kidneys subjected to RIRI, possibly through decreased renal tubular epithelial cell apoptosis.

Renoprotective Effect of the Combination of Renin-angiotensin System Inhibitor and Calcium Channel Blocker in Patients with Hypertension and Chronic Kidney Disease

Background：Renin-angiotensin system inhibitor and calcium channel blocker （CCB） are widely used in controlling blood pressure （BP） in patients with chronic kidney disease （CKD）.We carried out a meta-analysis to compare the renoprotective effect of the combination of angiotensin-converting enzyme inhibitor （ACEI） or angiotensin receptor blocker （ARB） and CCB （i.e.,ACEI/ARB ＋ CCB） with ACEI/ ARB monotherapy in patients with hypertension and CKD.Methods：Publications were identified from PubMed,Embase,Medline,and Cochrane databases.Only randomized controlled trials （RCTs） of BP lowering treatment for patients with hypertension and CKD were considered.The outcomes of end-stage renal disease （ESRD）,cardiovascular events,BP,urinary protein measures,estimated glomerular filtration rate （GFR）,and adverse events were extracted.Results：Based on seven RCTs with 628 patients,ACEI/ARB ＋ CCB did not show additional benefit for the incidence of ESRD （risk ratio [RR] =0.84;95% confidence interval [CI]：0.52-1.33） and cardiovascular events （RR =0.58;95% CI：0.21-1.63） significantly,compared with ACEI/ARB monotherapy.There were no significant differences in change from baseline to the end points in diastolic BP （weighted mean difference [WMD] =-1.28 mmHg;95% CI：-3.18 to-0.62）,proteinuria （standard mean difference =-0.55;95% CI：-1.41 to-0.30）,GFR （WMD =-0.32 ml/min;95% CI：-1.53 to-0.89）,and occurrence of adverse events （RR =1.05;95% CI：0.72-1.53）.However,ACEI/ARB ＋ CCB showed a greater reduction in systolic BP （WMD =-4.46 mmHg;95% CI：-6.95 to-1.97）,compared with ACEI/ARB monotherapy.Conclusion：ACEI/ARB ＋ CCB had no additional renoprotective benefit beyond than what could be achieved with ACEI/ARB monotherapy.

触脑脊液神经元的研究进展

触脑脊液神经元（cerebrospinal fluid-contacting neurons,CSF-cNs）是一种分布于脑室、中央管、脑室周器及脑实质等处与脑脊液接触的特殊神经元。根据分布位置不同可将CSF-cNs分为室管膜上、室管膜下和远位CSF-cNs三类,不同部位的CSF-cNs分泌不同的神经递质。以往研究CSF-cNs多采用脑室注射辣根过氧化物酶标记的霍乱毒素B亚单位（cholera toxin subunit B labeled with horseradish peroxidase,CB-HRP）进行逆行追踪.

Endothelin receptor antagonist combined with a calcium channel blocker attenuates renal injury in spontaneous hypertensive rats with diabetes

OBJECTIVE: To investigate the effects of the mixed endothelin receptor antagonist, bosentan, combined with the long-acting calcium channel blocker, amlodipine, compared to the angiotensin-converting enzyme inhibitor, cilazapril, on the progressive renal injury in spontaneous hypertensive rats (SHR) with diabetes. METHODS: Diabetic hypertensive rats (SHR-DM) were induced by streptozotozin injected in male SHR (7-week-old),and divided into an untreated and three treated groups: 1) cilazapril treated group; 2) bosentan+amlodipine treated group; and 3) amlodipine treated group. Wistar Kyoto rats (WKY) and SHR rats served as normotensive and hypertensive control, respectively. The mean arterial blood pressure, renal function, endothelin and angiotensin II levels as well as the protein expression of renal extracellular matrix components and transforming growth factor (TGF)-beta1 were determined at the end of the 4th week. RESULTS: Mean arterial blood pressure significantly increased in SHR and SHR-DM rats compared to WKY rats. All the therapies reduced the blood pressure to normal levels. However, the enhanced urinary protein excretion, the decreased creatinine clearance as well as the increased plasma and intrarenal endothelin and angiotens in II levels were found in the untreated SHR-DM and prevented by treatment with bosentan+amlodipine and cilazapril. Similarly, these two kinds of therapies in SHR-DM abolished the overexpression of renal TGF-beta1 by Western blot analysis and reduced the accumulation of collagen type IV, laminin and fibronectin proteins by an immunochemical approach. Amlodipine monotherapy had no detectable effects on the above parameters. CONCLUSION: Bosentan combined with amlodipine can offer similar renoprotective effects on that of cilazapril and may be a potent therapy to attenuate renal injury by reducing renal protein levels of TGF-beta1 in diabetes with a hypertensive state.

Intermediate conductance, Ca^2＋-activated K^＋ channels： a novel target for chronic renal diseases

Renal failure is a medical condition in which the kidneys are not working properly. There are two types of kidney failure： 1） acute kidney failure, which is sudden and often reversible with adequate treatment; and 2） chronic renal failure, which develops slowly and often is not reversible. The last stage of chronic renal failure is fatal without dialysis or kidney transplant. The treatment for chronic renal failure is focusing on slowing the progression of kidney damage. Several reports have described a promising approach to slow the loss of renal function through inhibition of the basolateral membrane, Ca^2＋-activated K^＋ （KCa3.1） channel with a selective and nontoxic blocker TRAM-34. This review summarizes pathophysiological studies that describe the role of KCa3.1 in kidney diseases.