Nuclear receptor 4A1 ameliorates renal fibrosis by inhibiting vascular endothelial growth factor A induced angiogenesis in UUO rats.

INTRODUCTION: Angiogenesis is closely related to renal fibrosis; however, its basic mechanism remains unclear. In our study, we found that nuclear receptor 4A1 (NR4A1) inhibits vascular endothelial growth factor A (VEGFA)-induced angiogenesis, ameliorating renal fibrosis. METHODS: We prepared a renal fibrosis animal model with unilateral ureteral obstruction (UUO) and NR4A1 knockdown UUO mice model, Using Human umbilical vein endothelial cells (HUVECs) to conduct all in vitro experiments. We then detected and analyzed the expression levels of NR4A1 and other genes related to angiogenesis and fibrosis. RESULTS: The angiogenesis related genes, such as VEGFA, vascular endothelial growth factor receptor-2 (VEGFR-2), endoglin (CD105), as well as the expression of fibrosis related genes that included, α-smooth muscle actin (α-SMA), Vimentin, and Collagen I are all significantly increased in the UUO rat model. In addition, the expression of NR4A1 of the kidney tissue of UUO rats was significantly reduced. Therefore, according to the above results, we speculated that angiogenesis may exacerbate renal fibrosis and NR4A1 may repress renal fibrosis by inhibiting angiogenesis. To further verify the above results, we used VEGFA to stimulate HUVECs with (or without) overexpression or knockdown of NR4A1. The results showed that with prolonged stimulation using VEGFA, the expression of NR4A1 decreases. Overexpression of NR4A1 significantly inhibits the expression of related indicators of angiogenesis and renal fibrosis. Furthermore, knockdown of NR4A1 induces endothelial cell proliferation and migration; therefore, exacerbating angiogenesis and fibrosis. Finally, the results of NR4A1 knockdown UUO mice showed that knockdown of NR4A1 can aggravating kidney damage and induce the expression of angiogenesis and renal fibrosis related indicators, while UUO can significantly induce kidney damage, angiogenesis and renal fibrosis. When knockdown of NR4A1, renal kidney damage, angiogenesis and fibrosis becomes more severe than UUO. Thus, all of these results indicate that NR4A1 can ameliorate renal fibrosis by inhibiting angiogenesis. CONCLUSIONS: NR4A1 can inhibit angiogenesis to ameliorate renal fibrosis.

The roles of orphan nuclear receptor 4 group A1 and A2 in fibrosis.

Fibrosis is not a disease but rather an outcome of the pathological tissue repair response. Many myofibroblasts are activated which lead to the excessive accumulation of extracellular matrix components such as collagen and fibronectin with fibrosis. A variety of organs, including kidney, liver, lung, heart and skin, can undergo fibrosis under the stimulation of exogenous or endogenous pathogenic factors. The orphan nuclear receptor 4 group A1 (NR4A1) and nuclear receptor 4 group A2（NR4A2）are belong to the nuclear receptor subfamily and inhibit the occurrence and development of fibrosis. NR4A1 is an inhibitory factor of TGF-ß signaling transduction. Overexpression of NR4A1 in fibroblasts can reduce TGF-ß induced collagen deposition and fibrosis related gene expression. Here, we summarize the current research progress on the NR4A1/2 and fibrosis, providing reference for the treatment of fibrosis.

Losartan ameliorates renal fibrosis by inhibiting tumor necrosis factor signal pathway.

Losartan is widely used in the treatment of chronic kidney disease (CKD) and has achieved good clinical efficacy, but its exact mechanism is not clear. We performed high-throughput sequencing (HTS) technology to screen the potential target of losartan in treating CKD. According to the HTS results, we found that the tumor necrosis factor (TNF) signal pathway was enriched. Therefore, we conducted in vivo and in vitro experiments to verify it. We found that TNF signal pathway was activated in both unilateral ureteral obstruction (UUO) rats and human proximal renal tubular epithelial cells (HK-2) treated with transforming growth factor-ß1 (TGF-ß1), while losartan can significantly inhibit TNF signal pathway as well as the expression of fibrosis related genes (such as COL-1, α-SMA and Vimentin). These data suggest that losartan may ameliorate renal fibrosis through modulating the TNF pathway.

Losartan ameliorates renal fibrosis by inhibiting tumor necrosis factor signal pathway / Losartán mejora la fibrosis renal al inhibir la vía de señalización del factor de necrosis tumoral

Losartan is widely used in the treatment of chronic kidney disease (CKD) and has achieved good clinical efficacy, but its exact mechanism is not clear. We performed high-throughput sequencing (HTS) technology to screen the potential target of losartan in treating CKD. According to the HTS results, we found that the tumor necrosis factor (TNF) signal pathway was enriched. Therefore, we conducted in vivo and in vitro experiments to verify it. We found that TNF signal pathway was activated in both unilateral ureteral obstruction (UUO) rats and human proximal renal tubular epithelial cells (HK-2) treated with transforming growth factor-β1 (TGF-β1), while losartan can significantly inhibit TNF signal pathway as well as the expression of fibrosis related genes (such as COL-1, α-SMA and Vimentin). These data suggest that losartan may ameliorate renal fibrosis through modulating the TNF pathway.(AU)

El Losartán es ampliamente utilizado en el tratamiento de la enfermedad renal crónica (CKD) y ha logrado buenos resultados clínicos, pero su mecanismo exacto aún no está claro. Utilizamos la técnica de secuenciación de alto rendimiento (HTS) para detectar posibles dianas de losartán para el tratamiento de la CKD. Según los resultados de HTS, encontramos un enriquecimiento de la vía de señalización del factor de necrosis tumoral (TNF). Así, realizamos experimentos in vivo e in vitro para verificar esto. Encontramos que, tanto en ratas con obstrucción ureteral unilateral (uuo) como en células epiteliales tubulares renales proximal humanas (HK-2) tratadas con factor de crecimiento transformador β1 (TGF-β1), se activó la vía de señalización del TNF. El losartán inhibe significativamente la expresión de las vías de señalización del TNF y genes relacionados con la fibrosis, como COL-1, α-SMA y vicentin. Estos datos sugieren que el losartán puede mejorar la fibrosis renal regulando la vía del TNF.(AU)

The role of PI3K/Akt signaling pathway in chronic kidney disease.

Chronic kidney disease (CKD), including chronic glomerulonephritis, IgA nephropathy and diabetic nephropathy, are common chronic diseases characterized by structural damage and functional decline of the kidneys. The current treatment of CKD is symptom relief. Several studies have reported that the phosphatidylinositol 3 kinases (PI3K)/protein kinase B (Akt) signaling pathway is a pathway closely related to the pathological process of CKD. It can ameliorate kidney damage by inhibiting this signal pathway which is involved with inflammation, oxidative stress, cell apoptosis, epithelial mesenchymal transformation (EMT) and autophagy. This review highlights the role of activating or inhibiting the PI3K/Akt signaling pathway in CKD-induced inflammatory response, apoptosis, autophagy and EMT. We also summarize the latest evidence on treating CKD by targeting the PI3K/Akt pathway, discuss the shortcomings and deficiencies of PI3K/Akt research in the field of CKD, and identify potential challenges in developing these clinical therapeutic CKD strategies, and provide appropriate solutions.

The nuclear receptor subfamily 4 group A1 in human disease.

Nuclear receptor 4A1 (NR4A1), a member of the NR4A subfamily, acts as a gene regulator in a wide range of signaling pathways and responses to human diseases. Here, we provide a brief overview of the current functions of NR4A1 in human diseases and the factors involved in its function. A deeper understanding of these mechanisms can potentially improve drug development and disease therapy.

Early Research on COVID-19: A Bibliometric Analysis.

In December 2019, an outbreak of pneumonia, which was named COVID-2019, emerged as a global health crisis. Scientists worldwide are engaged in attempts to elucidate the transmission and pathogenic mechanisms of the causative coronavirus. COVID-19 was declared a pandemic by the World Health Organization in March 2020, making it critical to track and review the state of research on COVID-19 to provide guidance for further investigations. Here, bibliometric and knowledge mapping analyses of studies on COVID-19 were performed, including more than 1,500 papers on COVID-19 available in the PubMed and China National Knowledge Infrastructure databases from January 1, 2020 to March 8, 2020. In this review, we found that because of the rapid response of researchers worldwide, the number of COVID-19-related publications showed a high growth trend in the first 10 days of February; among these, the largest number of studies originated in China, the country most affected by pandemic in its early stages. Our findings revealed that the epidemic situation and data accessibility of different research teams have caused obvious difference in emphases of the publications. Besides, there was an unprecedented level of close cooperation and information sharing within the global scientific community relative to previous coronavirus research. We combed and drew the knowledge map of the SARS-CoV-2 literature, explored early status of research on etiology, pathology, epidemiology, treatment, prevention, and control, and discussed knowledge gaps that remain to be urgently addressed. Future perspectives on treatment, prevention, and control are also presented to provide fundamental references for current and future coronavirus research.