We review evidence supporting the conclusion that renal dysfunction underlies the development of all forms of hypertension in humans and experimental animals. Indexes of global renal function are generally normal in the early stages of most genetic forms of hypertension, but renal function is clearly impaired in long-established hypertension. Studies in our laboratory over the past decade summarized below have established that the renal medulla plays an important role in sodium and water homeostasis and in the long-term control of arterial pressure. Development of implanted optical fibers for measurement of cortical and medullary blood flows with laser-Doppler flowmetry and techniques for delivery of vasoactive compounds into the medullary interstitial space enabled us to examine determinants of medullary flow (nitric oxide, atrial natriuretic peptides, kinins, eicosanoids, vasopressin, renal sympathetic nerves, etc). We have shown in spontaneously hypertensive rats that the initial changes of renal function begin as a reduction of medullary blood flow in the absence of changes of cortical flow. Long-term medullary interstitial infusion of captopril, which preferentially increased medullary blood flow, resulted in a lowering of arterial pressure. In normal Sprague-Dawley rats, selective reduction of medullary flow with medullary interstitial or intravenous infusion of small amounts of NG-nitro-L-arginine methyl ester resulted in hypertension. These and other studies we review show that although blood flow to the inner renal medulla comprises less than 1% of the total renal blood flow, changes in flow to this region can have a major effect on sodium and water homeostasis and on the long-term control of arterial blood pressure.

The effects of chronic nitric oxide inhibition in the renal medulla on renal cortical and medullary blood flow, sodium balance, and blood pressure were evaluated in conscious uninephrectomized Sprague-Dawley rats. During a 5-day renal medullary interstitial infusion of the nitric oxide inhibitor NG-nitro-L-arginine methyl ester (L-NAME, 120 micrograms/h) in saline (0.5 ml/min), renal medullary blood flow was selectively decreased by 30% after 2 h and was maintained at that level for the entire infusion. The decrease in medullary blood flow was associated with sodium retention and increased blood pressure. After the cessation of L-NAME infusion, medullary blood flow returned to control, and the sodium balance became negative as blood pressure returned to baseline. These data indicate that renal medullary nitric oxide plays an important role in the regulation of renal blood flow, sodium excretion, and blood pressure.

The present study examined the autoregulation of blood flow in different regions of the renal cortex and medulla in volume-expanded or hydropenic anesthetized rats. Blood flow was measured in the whole kidney by electromagnetic flowmetry, in the superficial cortex with implanted fibers and external probes for laser-Doppler flowmetry, and in the deep cortex and inner and outer medulla with implanted fibers for laser-Doppler flowmetry. At renal perfusion pressure > 100 mmHg, renal blood flow, superficial cortical blood flow, and deep cortical blood flow were all very well autoregulated in both volume-expanded and hydropenic rats. Inner and outer medullary blood flow were also well autoregulated in hydropenia, but blood flow in these regions was very poorly autoregulated in volume-expanded animals. As renal perfusion pressure was decreased below 100 mmHg in volume-expanded and hydropenic animals, renal blood flow, superficial and deep cortical blood flow, and inner and outer medullary blood flow all decreased. The results of these experiments demonstrate that blood flow in both the inner and outer portions of the renal medulla of the kidney is poorly autoregulated in volume-expanded rats but well autoregulated in hydropenic animals. In contrast, blood flow in all regions of the renal cortex is well autoregulated in both volume-expanded and hydropenic animals. These results suggest that changes in resistance in the postglomerular circulation of deep nephrons are responsible for the poor autoregulation of medullary blood flow in volume expansion despite well autoregulated cortical blood flow.

The role of renal papillary blood flow in regulation of fluid and electrolyte excretion was examined. The effects of an acute infusion of diltiazem (5 micrograms.kg-1 x min-1) into the renal medullary interstitium on papillary blood flow and sodium and water excretion were studied. Changes of renal blood flow were measured using an electromagnetic flow probe. Cortical and papillary blood flows were measured using laser-Doppler flowmetry. Renal and cortical blood flows were unchanged during medullary interstitial infusion of diltiazem, but papillary blood flow increased 26% (P < 0.05) and remained elevated for 1 h after diltiazem infusion was discontinued. Glomerular filtration rate (GFR) of the infused kidney increased by 21% from a control of 1.0 +/- 0.1 ml.min-1 x g-1 during infusion of diltiazem (P < 0.05), but it returned to control after diltiazem infusion was stopped. Urine flow and sodium excretion increased by 70% (P < 0.05), and fractional sodium excretion rose from 1.5 +/- 0.2 to 2.4 +/- 0.3% of the filtered load during the hour after diltiazem infusion. Renal blood flow, cortical and papillary blood flow, GFR, urine flow, and sodium excretion in the 0.9% sodium chloride vehicle-infused kidney were not significantly altered during the experiment. Intravenous infusion of the same dose of diltiazem (5 micrograms.kg-1 x min-1) increased GFR by 22%, but had no effect on urine flow and sodium excretion. These results indicate that renal medullary interstitial infusion of diltiazem selectively increased renal papillary blood flow, which was associated with an increase of sodium and water excretion.

Metastasis is a critical determinant for the treatment strategy and prognosis in patients with squamous cell carcinoma of the head and neck (SCCHN). However, the mechanisms underlying SCCHN metastasis are poorly understood. Our study sought to determine the key microRNA and their functional mechanisms involved in SCCHN metastasis. For The Cancer Genome Atlas (TCGA) data analysis, quantitative PCR was used to quantify the level of miR-30e-5p in SCCHN and its clinical significance was further analyzed. A series of in vitro and in vivo experiments were applied to determine the effects of miR-30e-5p and its target AEG-1 on SCCHN metastasis. A mechanism investigation further revealed that AEG-1 was implicated in the angiogenesis and metastasis mediated by miR-30e-5p. Overall, our study confirms that miR-30e-5p is a valuable predictive biomarker and potential therapeutic target in SCCHN metastasis. K E Y W O R D SAEG-1, angiogenesis, metastasis, miR-30e-5p, squamous cell carcinoma of the head and neck

Introduction: Amomum villosum Lour., a herbaceous plant in the ginger family, has been proven to be effective in treating gastrointestinal diseases. It has been listed in the Chinese Pharmacopeia as a legal source of Amomi Fructus. In our previous study, we demonstrated that treatment with extracts of A. villosum prevented the development and progression of intestinal mucositis. In the current study, we aimed to verify and explain the potential beneficial effects of A. villosum on inflammatory bowel disease (IBD).Methods: The effect of water extracts (WEAV) and volatile oil of A. villosum (VOAV) were evaluated on the immunological role of T lymphocytes and intestinal microecology in IBD rats induced with 2,4,6-trinitrobenzenesulfonic acid (TNBS). Body weight, food intake, colon length/weight, and disease activity index (DAI) as well as tissue damage scores were evaluated. The inflammatory response to IBD was assessed by measuring the expression of myeloperoxidase, interleukin (IL)-17 (IL-17), interferon-γ (IFN-γ), IL-10, tumor necrosis factor-α (TNF-α), and transforming growth factor-β (TGF-β). The percentage of regulatory CD4+ T cells in rat spleen was measured by flow cytometry and effects on the microbial community were evaluated by 16S rDNA gene sequencing.Results: All TNBS-induced rats showed typical clinical manifestations of IBD. IBD rats in the WEAV and VOAV treatment groups were effective in relieving body weight and appetite loss. Middle and high dosage of VOAV and WEAV significantly reduced the DAI, and tissue damage scores, whereas colon weight/length ratio was increase. All rats in the WEAV and VOAV groups showed significantly decreased IFN-γ levels and increased levels of IL-10 and TGF-β. Moreover, we observed that the percentage of regulatory CD4+ T cells was significantly enhanced during treatment with WEAV. In addition, administration of WEAV and VOAV effectively inhibited the release of enterogenic endotoxin, increased short-chain fatty acid-producing bacteria belonging to Firmicutes and Bacteroidetes, and decreased the abundance of Proteobacteria.Conclusion: Treatment with WEAV and VOAV significantly attenuated intestinal inflammation in IBD rats, which was possibly associated with its regulation on inflammatory cytokine and CD4+CD25+FOXP3+ T cells. Moreover, WEAV and VOAV may help maintaining the balance of intestinal microecology.

BackgroundNasopharyngeal carcinoma (NPC) is a malignant epithelial carcinoma of the head and neck with strong ability of invasion and metastasis. Our previous study indicated that miR-324-3p, as a tumor-suppressive factor, could regulate radioresistance of NPC cells by targeting WNT2B. The purpose of this study is to investigate the role of miR-324-3p on migration and invasion in NPC cells.MethodsQuantitative real time PCR was applied to measure the expression level of miR-324-3p and WNT2B mRNA in both cells and tissues, and the expression level of WNT2B protein was determined by western blotting. The capacity of migration and invasion were tested by using wound healing and transwell invasion assay.ResultsEctopic expression of miR-324-3p or silencing its target gene WNT2B could dramatically suppress migration and invasion capacity of NPC cells. Meanwhile, the alterations of miR-324-3p in NPC cells could influence the expression level of the biomarkers of epithelial-mesenchymal transition (EMT), including E-cadherin and Vimentin. Moreover, the expression of miR-324-3p was obviously downregulated and WNT2B was significantly upregulated in NPC tissues. The expression levels of miR-324-3p and WNT2B were closely correlated with T stage, clinic stage and cervical lymph node metastasis of NPC (P < 0.05).ConclusionmiR-324-3p could suppress the migration and invasion of NPC by targeting WNT2B and the miR-324-3p/WNT2B pathway possibly provide new potential therapeutic clues for NPC.Electronic supplementary materialThe online version of this article (doi:10.1186/s12935-016-0372-8) contains supplementary material, which is available to authorized users.

The present study was designed to develop, for the first time, a method that allows long-term repeated measurements of renal cortical blood flow (CBF) and medullary blood flow (MBF) in conscious unanesthetized rats. The use of fiber-optic probes (0.5 mm diam) for the chronic measurement of renal CBF and MBF was evaluated. Basal renal cortical and medullary laser-Doppler flow (LDF) signals and the responses to intravenous bolus injections of angiotensin II (ANG II, 12.5 ng) were determined every other day for 11 days in conscious Sprague-Dawley rats (n = 9). A recovery period of 5-7 days after surgery was required before stable signals were obtained from the implanted probes. Thereafter, the fiber-optic probes gave reproducible laser-Doppler measurements of CBF and MBF for 11 days. The CBF and MBF responses to intravenous bolus injections of ANG II (12.5 ng) were also constant during this period. Chronic implantation of the fiber-optic probes caused minimal tissue damage and did not significantly alter urine concentrating ability or renal function. These findings suggest that LDF technique with chronically implanted optical fibers provides a new tool for the continuous long-term monitoring of regional blood flow in the kidney of conscious rats.