MicroRNAs (miRNAs) are endogenous short non-coding RNAs that regulate most of important cellular processes by inhibiting gene expression through the post-transcriptional repression of their target mRNAs. In kidneys, miRNAs have been associated in renal development, homeostasis, and physiological functions. Results from clinical and experimental animal studies demonstrate that miRNAs play essential roles in the pathogenesis of various renal diseases. Chronic kidney diseases (CKD) is characterized by renal fibrosis. Transforming growth factor beta (TGF-β) is recognized as a major mediator of renal fibrosis because it is able to stimulate the accumulation of extracellular matrix (ECM) proteins to impair normal kidney function. Recently, emerging evidence demonstrate the relationship between TGF-β signaling and miRNAs expression during renal diseases. TGF-β regulates expression of several microRNAs, such as miR-21, miR-192, miR-200, miR-433, and miR-29. MiR-21, miR-192, and miR-433 which are positively induced by TGF-β signaling play a pathological role in kidney diseases. In contrast, members in both miR-29 and miR-200 families which are inhibited by TGF-β signaling protect kidneys from renal fibrosis by suppressing the deposition of ECM and preventing epithelial-to-mesenchymal transition, respectively. Clinically, the presence of miRNAs in blood and urine has been examined to be early biomarkers for detecting renal diseases. From experimental animal studies of CKD, targeting microRNAs also provides evidence about therapeutic potential of miRNAs during renal diseases. Now, it comes to the stage to examine the exact mechanisms of miRNAs during the initiation and progression of renal diseases. Therefore, determining the function of miRNAs in renal fibrosis may facilitate the development of both early diagnosis and treatment of renal diseases.

(+)-Lingzhiol and (-)-lingzhiol, a pair of rotary door-shaped meroterpenoidal enantiomers, were isolated from Ganoderma lucidum. Their structures were identified by spectroscopic methods and X-ray diffraction crystallography. Lingzhiol bears an unusual 5/5/6/6 ring system characteristic of sharing a C-3'-C-7' axis. Biological evaluation showed that (+)-lingzhiol or (-)-lingzhiol could selectively inhibit the phosphorylation of Smad3 in TGF-β1-induced rat renal proximal tubular cells and activate Nrf2/Keap1 in mesangial cells under diabetic conditions.

C-reactive protein (CRP) is a risk factor or biomarker for cardiovascular diseases, including hypertension. The present study investigated the functional importance of human CRP in hypertensive cardiac remodeling by a chronic infusion of angiotensin II (Ang II) into mice that express human CRP. Compared with the wild-type mice, although Ang II infusion caused an equally high systolic blood pressure, levels of human CRP were further elevated, and cardiac remodeling was markedly exacerbated in mice that express human CRP, resulting in a significant reduction in the left ventricular ejection fraction and fractional shortening and an increase in cardiac fibrosis (collagen I and III and alpha-smooth muscle actin) and inflammation (interleukin 1beta and tumor necrosis factor-alpha). The enhancement in cardiac remodeling in mice that express human CRP was associated with further upregulation of the Ang II type I receptor and transforming growth factor-beta1 and overactivation of both transforming growth factor-beta/Smad and nuclear factor-kappaB signaling pathways. Furthermore, in vitro studies in cardiac fibroblasts revealed that CRP alone was able to significantly induce expression of the Ang II type I receptor, collagen I/III, and alpha-smooth muscle actin, as well as proinflammation cytokines (interleukin 1beta and tumor necrosis factor-alpha), which was further enhanced by addition of Ang II. In conclusion, CRP is not only a biomarker but also a mediator in Ang II-mediated cardiac remodeling. Enhanced upregulation of the Ang II type I receptor and activation of the transforming growth factor-beta/Smad and nuclear factor-kappaB signaling pathways may be the mechanisms by which CRP promotes cardiac fibrosis and inflammation under high Ang II conditions.