Expression of Niban in renal interstitial fibrosis

NIBAN1, Exploring its Roles in Cell Survival Under Stress Context

Cell survival must quickly activate specific mechanisms that enable to detect changes in the cellular microenvironment. The impact of these cell alteration has direct consequences on cellular homeostasis. Cellular stress, as well as its regulation and implication, has been studied in different pathologies. In this sense, the alteration in NIBAN1 expression seems to act in response to different cellular disturbances. Over the years, the knowledge of NIBAN1 functions has improved, demonstrating its important cell roles, favoring the cell survival under stress context. In response to the disturbances, NIBAN1 seems to be involved in the decision-making process between cell survival and death. The increase in NIBAN1 expression has been related to cellular mechanisms that seek to minimize the damage caused to cellular homeostasis. In this review, the main biological insights attributed to the NIBAN1 gene in different cellular contexts and its role as a mediator of cellular stress are discussed.

Differential microRNA Expression in Newcastle Disease Virus-Infected HeLa Cells and Its Role in Regulating Virus Replication

As an oncolytic virus, Newcastle disease virus (NDV) can specifically kill tumor cells and has been tested as an attractive oncolytic agent for cancer virotherapy. Virus infection can trigger the changes of the cellular microRNA (miRNA) expression profile, which can greatly influence viral replication and pathogenesis. However, the interplay between NDV replication and cellular miRNA expression in tumor cells is still largely unknown. In the present study, we compared the profiles of cellular miRNAs in uninfected and NDV-infected HeLa cells by small RNA deep sequencing. Here we report that NDV infection in HeLa cells significantly changed the levels of 40 miRNAs at 6 h post-infection (hpi) and 62 miRNAs at 12 hpi. Among 23 highly differentially expressed miRNAs, NDV infection greatly promoted the levels of 3 miRNAs and suppressed the levels of 20 miRNAs at both time points. These 23 miRNAs are predicted to target various genes involved in virus replication and antiviral immunity such as ErbB, Jak-STAT, NF-kB and RIG-I-like receptor. Verification of deep sequencing results by quantitative RT-PCR showed that 9 out of 10 randomly selected miRNAs chosen from this 23-miRNA pool were consistent with deep sequencing data, including 6 down-regulated and 3 up-regulated. Further functional research revealed that hsa-miR-4521, a constituent in this 23-miRNA pool, inhibited NDV replication in HeLa cells. Moreover, dual-luciferase and gene expression array uncovered that the member A of family with sequence similarity 129 (FAM129A) was directly targeted by hsa-miR-4521 and positively regulated NDV replication in HeLa cells, indicating that hsa-miR-4521 may regulate NDV replication via interaction with FAM129A. To our knowledge, this is the first report of the dynamic cellular miRNA expression profile in tumor cells after NDV infection and may provide a valuable basis for further investigation on the roles of miRNAs in NDV-mediated oncolysis.

miR-135a deficiency inhibits the AR42J cells damage in cerulein-induced acute pancreatitis through targeting FAM129A

Acute pancreatitis (AP) is a common clinical critical disease with high mortality and the exact pathogenesis is not fully elucidated. The present study aimed to uncover the function of miR-135a in the proliferation, apoptosis, and inflammatory characteristics of diseased pancreatic cells and the potential molecular mechanisms. The expression patterns of miR-135a and family with sequence similarity 129 member A (FAM129A) in patients with AP were analyzed on the basis of the GEO database. The transfection efficiency and expression level of miR-135a in AR42J cells were determined by qRT-PCR. The biological characteristics of AR42J cells treated with cerulein were detected by cell counting kit-8 (CCK-8), flow cytometry, and western blot assays. The potential interaction between miR-135a and FAM129A was confirmed by bioinformatics prediction softwares and luciferase reporter assay. MiR-135a inhibitor and pcDNA3.1-FAM129A were co-transfected to determine the regulation of miR-135a/FAM129A on inflammatory AR42J cell injury. We observed that miR-135a was highly expressed in AP samples. Depletion of miR-135a could alleviate the condition so that the AR42J cells proliferation increased, apoptosis decreased, and the expression of inflammatory cytokines enhanced. In addition, mRNA and protein expression of FAM129A were negatively regulated by miR-135a, and over-expression of FAM129A could strengthen the relief effect of miR-135a inhibitor in AP induced by cerulein. In summary, our data demonstrates that silencing miR-135a reduces AR42J cells injury and inflammatory response in AP induced by cerulein through targeting FAM129A.

Niban protein regulates apoptosis in HK-2 cells via caspase-dependent pathway

Purpose: To investigate whether Niban protein plays a role in renal interstitial fibrosis by regulating renal tubular epithelial cell apoptosis and explore the underlying mechanism. Methods: Unilateral ureteral obstruction (UUO) model was performed in C57B/6J mice, and divided into sham operation group and groups of days 3, days 7, and days 14. Niban expression was detected by immunohistochemistry and Western blot. TUNEL assays were used to detected apoptosis. Niban siRNA and overexpression Niban plasmid were transfected in HK-2 cells respectively to explore apoptosis related mechanisms of Niban during angiotensin II (AngII) - and endoplasmic reticulum (ER) stress-induced injury. Results: With the development of obstruction, Niban's expression decreased gradually while apoptosis increased. Silencing of Niban not only increased the AngII- and ER stress-induced apoptosis, but also promoted the expression of caspase 8, caspase 9, Bip, and Chop. Overexpression of Niban reduced AngII-induced apoptosis and the expression of caspase 8 and caspase 9. Conclusions: Niban protein is involved in apoptosis regulation in HK-2 cells, and most likely via caspase-dependent pathway.

miR-4521-FAM129A axial regulation on ccRCC progression through TIMP-1/MMP2/MMP9 and MDM2/p53/Bcl2/Bax pathways

Clear cell renal cell carcinoma (ccRCC) is the most aggressive RCC subtype with high metastasis, chemotherapy and radiotherapy resistance, and poor prognosis. This study attempted to establish the deregulations of miR-4521 and FAM129A together with their correlation to and mechanism of regulation of ccRCC development and progression. FAM129A acted as tumor promotor and miR-4521 acted as a suppressor in ccRCC. As measured in surgical tumorous tissues from ccRCC patients, FAM129A overexpression and miR-4521 deficiency together contributed to ccRCC progression by promoting advances in patients' TNM stage and Fuhrman grade. Both the FAM129A knockdown and miR-4521 overexpression could reduce the in vitro migration and invasion abilities of renal cancer cells 786-O and ACHN, through the TIMP-1/MMP2/MMP9 pathway and could decrease their proliferation by promoting their apoptosis through the MDM2/p53/Bcl2/Bax pathway. By directly targeting the 3'-UTR domain of FAM129A, miR-4521 was negatively correlated with FAM129A/FAM129A levels in ccRCC progression and renal cancer cell malignancies. This work establishes the miR-4521-FAM129A axial regulation mechanism in ccRCC. Micro-4521 deficiency leads to FAM129A/FAM129A upregulation, which synergistically enhances the migration and invasion of renal cancer cells due to the induced decrease of TIMP-1 and increases of MMP2 and MMP9, and increases their growth through escaping apoptosis by suppressing p53 by way of upregulation of induced MDM2. The current work provides new clues to assist fundamental research into the diagnosis and treatment of ccRCC.

P2X7R antagonism after subfailure overstretch injury of blood vessels reverses vasomotor dysfunction and prevents apoptosis

Human saphenous vein (HSV) is harvested and prepared prior to implantation as an arterial bypass graft. Injury and the response to injury from surgical harvest and preparation trigger cascades of molecular events and contribute to graft remodeling and intimal hyperplasia. Apoptosis is an early response after implantation that contributes the development of neointimal lesions. Here, we showed that surgical harvest and preparation of HSV leads to vasomotor dysfunction, increased apoptosis and downregulation of the phosphorylation of the anti-apoptotic protein, Niban. A model of subfailure overstretch injury in rat aorta (RA) was used to demonstrate impaired vasomotor function, increased extracellular ATP (eATP) release, and increased apoptosis following pathological vascular injury. The subfailure overstretch injury was associated with activation of p38 MAPK stress pathway and decreases in the phosphorylation of the anti-apoptotic protein Niban. Treatment of RA after overstretch injury with antagonists to purinergic P2X7 receptor (P2X7R) antagonists or P2X7R/pannexin (PanX1) complex, but not PanX1 alone, restored vasomotor function. Inhibitors to P2X7R and PanX1 reduced stretch-induced eATP release. P2X7R/PanX1 antagonism led to decrease in p38 MAPK phosphorylation, restoration of Niban phosphorylation and increases in the phosphorylation of the anti-apoptotic protein Akt in RA and reduced TNFα-stimulated caspase 3/7 activity in cultured rat vascular smooth muscle cells. In conclusion, inhibition of P2X7R after overstretch injury restored vasomotor function and inhibited apoptosis. Treatment with P2X7R/PanX1 complex inhibitors after harvest and preparation injury of blood vessels used for bypass conduits may prevent the subsequent response to injury that lead to apoptosis and represents a novel therapeutic approach to prevent graft failure.

Loss of the Protein Cystathionine β-Synthase During Kidney Injury Promotes Renal Tubulointerstitial Fibrosis

BACKGROUND/AIMS

Renal tubulointerstitial fibrosis (TIF) is the common pathway of progressive chronic kidney disease. Inflammation has been widely accepted as the major driving force of TIF. Cystathionine β-synthase (CBS) is the first and rate-limiting enzyme in the transsulfuration pathway. CBS is considered to play protective role in liver and pulmonary fibrosis, but its role in TIF remains unknown. The purpose of this study was to investigate the potential role and mechanism of CBS in renal inflammation and TIF.

METHODS

Renal function, tubulointerstitium damage index score, extracellular matrix (ECM) deposition, and the expressions of collagen I, collagen III, fibronectin, CD3, CD68, IL-1β, TNF-α were measured in sham operation and unilateral ureteral obstruction (UUO) rats. Proteomics and gene array analysis were performed to screen differentially expressed molecules in the development of renal inflammation and TIF in UUO rats. The expression of CBS was detected in patients with obstructive nephropathy and UUO rats. We confirmed the expression of CBS using western blot and real-time PCR in HK-2 cells. Overexpression plasmid and siRNA were transfected specifically to study the possible function of CBS in HK-2 cells.

RESULTS

Abundant expression of CBS, localized in renal tubular epithelial cells, was revealed in human and rat renal tissue, which correlated negatively with the progression of fibrotic disease. Expression of CBS was dramatically decreased in the obstructed kidney from UUO rats as compared with the sham group (SHM). In addition, knocking down CBS exacerbated extracellular matrix (ECM) deposition, whereas CBS overexpression attenuated TGF-β1-induced ECM deposition in vitro. Inflammatory and chemotactic factors were also increased in CBS knockdown HK-2 cells stimulated by IL-1β.

CONCLUSIONS

These findings establish CBS as a novel inhibitor in renal fibrosis and as a new therapeutic target in patients with chronic kidney disease.

miR-182-5p Inhibition Ameliorates Ischemic Acute Kidney Injury

Acute kidney injury (AKI) remains a major clinical event with high mortality rates. We previously identified renal miR-182 as the main driver of post-transplantation AKI. Therefore, we tested the causal inference of miR-182 by inhibiting its renal expression in vivo. In 45 rats AKI was induced by right nephrectomy and contralateral clamping of the renal pedicle for 40 minutes. Systemically administered antisense oligonucleotide (ASO) inhibited miR-182 in the kidneys up to 96 hours. The maximum creatinine elevation was on day 2 after injury (mg/dL; median and interquartile range): ASO 2.5mg/kg: 1.9 (1.3; 3.2), ASO 25mg/kg: 2.8 (0.7; 5.0), mismatch oligonucleotide (MM) 25mg/kg: 5.7 (5,0; 5.8), saline: 4.4 (3.5; 5.8) (P = 0.016, analysis of variance). Blinded semiquantitative histologic evaluation of renal biopsies showed better preserved morphology in both ASO groups than saline- and MM-treated kidneys (median and interquartile range of overall injury scores): ASO both concentrations 1 (1, 1), saline 3 (3, 3) and MM 3 (3, 3) (P< 0.001, analysis of variance). ASO facilitated cell proliferation, metabolism, and angiogenesis on a genome-wide level. ASO when applied in normothermic kidney machine perfusion reduced renal miR-182 expression by more than two magnitudes. In summary, we showed that in vivo inhibition of miR-182 by ASO improved kidney function and morphology after AKI. This technique may be applicable to reduce the high rate of AKI in the human renal transplantation setting.

The possible roles of B-cell novel protein-1 (BCNP1) in cellular signalling pathways and in cancer

B‐cell novel protein‐1 (BCNP1) or Family member of 129C (FAM129C) was identified as a B‐cell‐specific plasma‐membrane protein. Bioinformatics analysis predicted that BCNP1 might be heavily phosphorylated. The BCNP1 protein contains a pleckstrin homology (PH) domain, two proline‐rich (PR) regions and a Leucine Zipper (LZ) domain suggesting that it may be involved in protein‐protein interactions. Using The Cancer Genome Atlas (TCGA) data sets, we investigated the correlation of alteration of the BCNP1 copy‐number changes and mutations in several cancer types. We also investigated the function of BCNP1 in cellular signalling pathways. We found that BCNP1 is highly altered in some types of cancers and that BCNP1 copy‐number changes and mutations co‐occur with other molecular alteration events for TP53 (tumour protein P53), PIK3CA (Phosphatidylinositol‐4,5‐Bisphosphate 3‐Kinase, Catalytic Subunit Alpha), MAPK1 (mitogen‐activated protein kinase‐1; ERK: extracellular signal regulated kinase), KRAS (Kirsten rat sarcoma viral oncogene homolog) and AKT2 (V‐Akt Murine Thymoma Viral Oncogene Homolog 2). We also found that PI3K (Phoshoinositide 3‐kinase) inhibition and p38 MAPK (p38 mitogen‐activated protein kinase) activation leads to reduction in phosphorylation of BCNP1 at serine residues, suggesting that BCNP1 phosphorylation is PI3K and p38MAPK dependent and that it might be involved in cancer. Its degradation depends on a proteasome‐mediated pathway.