TSLP/TSLPR promotes renal fibrosis by activating STAT3 in renal fibroblasts.

Previous studies have demonstrated the importance of TSLP-TSLPR in inflammatory, allergic, and fibrotic diseases. However, their exact molecular mechanism in regulating renal fibrosis has not been fully explored yet. The current study identified the high expression levels of TSLP and TSLPR in human and mouse hydronephrotic tissues. In addition, immunofluorescence staining showed that TSLP was highly expressed in renal tubular cells, while TSLPR was mainly co-localized with α-SMA, a marker of fibroblasts. Knocking out TSLPR in the UUO model could alleviate the severity of renal fibrosis. Most importantly, the application of antibody blockade of TSLP reduced the fibrotic level in the UUO model. The functional analysis revealed that the hypoxic exposure could induce the overexpression of TSLP in renal tubular cells via HIF-1α. The tubular cell-derived TSLP could bind to the TSLPR of fibroblasts in a paracrine manner to activate them. Specifically, the HIF-1α/TSLP/TSLPR-axis could activate fibroblasts through the STAT3 signaling pathway. This study revealed a mechanistic interaction of HIF-1α/TSLP/TSLPR and STAT3 signaling pathways in the activation and proliferation of human and murine kidney fibroblasts; these pathways might be exploited as a therapeutic target in renal fibrosis.

KLF2-induced circZKSCAN1 potentiates the tumorigenic properties of clear cell renal cell carcinoma by targeting the miR-1294/PIM1 axis.

Clear cell renal cell carcinoma (ccRCC) is one of the most common and lethal types of urologic cancer. With low survival rates among patients in advanced stages of disease, and increasing rate of morbidity and mortality worldwide, novel therapeutic targets for ccRCC clinical intervention are necessary. In this study, we investigated the functional role of circZKSCAN1 in ccRCC progression. Our results suggested that circZKSCAN1 was abundantly expressed in ccRCC tumor tissues and cells. CircZKSCAN1 knockdown significantly inhibited cell proliferation, migration, invasion, and epithelial-to-mesenchymal transition of renal cell carcinoma (RCC) cells, whereas potentiated Natural Killer (NK) cell-mediated cytotoxicity against RCC cells in vitro and repressed tumor growth in vivo. Furthermore, we identified a novel circZKSCAN1/miR-1294/PIM1 axis was identified in RCC progression, showing that the expression of circZKSCAN1 expression in RCC cells was transcriptionally regulated by Kruppel-like factor 2. The results of our study may provide new insights for ccRCC basic research.Abbreviations: ccRCC: clear cell renal cell carcinoma; ChIP: chromatin immunoprecipitation; circRNA: circular RNA; EDU: 5-ethynyl-2'-deoxyuridine; EMT: epithelial-mesenchymal transition; FBS: fetal bovine serum; FISH: RNA fluorescent in situ hybridization; KLF2: Kruppel-like factor 2; NC: normal control; NK cell: natural killer cell; NOD/SCID: nonobese severe diabetic/severe combined immunodeficiency; PIM1: Pim-1 proto-oncogene, serine/threonine kinase; RCC: renal cell carcinoma; ZKSCAN1: zinc finger with KRAB and SCAN domains 1.

Diagnostic Accuracy of Donor-derived Cell-free DNA in Renal-allograft Rejection: A Meta-analysis.

BACKGROUND: Donor-derived cell-free DNA (dd-cfDNA) is a potential noninvasive molecular marker of graft rejection after kidney transplant, whose diagnostic accuracy remains controversial. METHODS: We performed a systematic review and metaanalysis to evaluate the diagnostic accuracy of dd-cfDNA. Relevant literature was searched from online databases, and the data on the diagnostic accuracy of discriminating main rejection episodes (MRE) and antibody-mediated rejection (AMR) were merged, respectively. RESULTS: Nine studies were included in the metaanalysis, of which 6 were focused on the diagnostic accuracy of dd-cfDNA for MRE, whose pooled sensitivity, specificity, area under the receiver operating characteristics curve, diagnostic odds ratio, overall positive likelihood ratio, and negative likelihood ratio with 95% confidence intervals were 0.70 (0.57-0.81), 0.78 (0.70-0.84), 0.81 (0.77-0.84), 8.18 (5.11-13.09), 3.15 (2.47-4.02), and 0.39 (0.27-0.55), respectively. Five tests were focused on discriminating AMR, whose pooled indicators were 0.84 (0.75-0.90), 0.80 (0.74-0.84), 0.89 (0.86-0.91), 20.48 (10.76-38.99), 4.13(3.21-5.33), and 0.20(0.12-0.33), respectively. CONCLUSIONS: Donor-derived cell-free DNA can be a helpful marker for the diagnosis of AMR among those recipients suspected of renal dysfunction. Its diagnostic accuracy on the MRE remains uncertain, which requires further prospective, large-scale, multicenter, and common population research.

Reconstruction of a Transplant Recipient's External Iliac Artery Using Donor's Inferior Vena Cava in Renal Transplantation: 2 Case Reports.

Iliac atherosclerosis is common in renal transplant recipients. In severe cases, it affects intraoperative renal arterial anastomosis and increases the risk of postanastomosis complications. At present, safe and efficient vascular replacement methods are relatively limited. In the 2 renal transplant cases at our center, described here, the donors' iliac arteries were unavailable. We therefore attempted to replace the recipients' diseased external iliac artery with the donors' inferior vena cava and then performed an end-to-side grafting with the attachment in arterial reconstruction. One patient received a single kidney transplantation, while the other received a dual kidney transplantation. Antiplatelet/anticoagulation drug application was avoided, and both patients were observed for more than 6 months. Stable renal graft function was achieved without any vascular complications. During this study, all procedures were in compliance with the Helsinki Congress and the Declaration of Istanbul. For end-stage renal disease patients with severe iliac atherosclerosis who are waiting for kidney transplantation, a donor's vena cava graft could potentially be a promising replacement option to restore external iliac artery patency and reconstruct renal blood flow, without the necessity of harvesting a recipient's autologous vessels or looking for costly artificial ones.

BAP1 maintains chromosome stability by stabilizing DIDO1 in renal cell carcinoma.

BRCA1-associated protein 1 (BAP1) is a member of the ubiquitin C-terminal hydrolase family of deubiquitinating enzymes and is implicated in transcriptional regulation. The BAP1 gene is mutated in 5%-15% of patients with clear cell renal cell carcinoma (ccRCC), the most common form of renal cancer, which suggests that BAP1 is a tumor suppressor. However, whether BAP1 influences the progression of ccRCC tumors expressing wildtype (WT) BAP1 is unclear. Here, we identified DIDO1 as a bona fide substrate for BAP1. DIDO1 is a component of the centrosome proteins and plays an essential role in spindle assembly. BAP1 binds to DIDO1 and stabilizes DIDO1 through de-ubiquitination. BAP1 contributes to chromosome stability partially via DIDO1. A positive correlation was identified between BAP1 and DIDO1 expression in ccRCC tissues. Downregulation of both BAP1-loss and DIDO1 protein expression in ccRCC was associated with adverse clinicopathological features. This study revealed a novel mechanism involving BAP1 in the regulation of DIDO1 stability, and the results also provide insight into the relationship between BAP1 mutations and chromosome instability in ccRCC.

Identification of Kidney Transplant Recipients with Coronavirus Disease 2019.

Coronavirus disease 2019 (COVID-19) is a novel and lethal infectious disease, posing a threat to global health security. The number of cases has increased rapidly, but no data concerning kidney transplant (KTx) recipients infected with COVID-19 are available. To present the epidemiological, clinical, and therapeutic characteristics of KTx recipients infected with COVID-19, we report on a case series of five patients who were confirmed as having COVID-19 through nucleic acid testing (NAT) from January 1, 2020 to February 28, 2020. The most common symptoms on admission to hospital were fever (five patients, 100%), cough (five patients, 100%), myalgia or fatigue (three patients, 60%), and sputum production (three patients, 60%); serum creatinine or urea nitrogen levels were slightly higher than those before symptom onset. Four patients received a reduced dose of maintenance immunosuppressive therapy during hospitalization. As of March 4, 2020 NAT was negative for COVID-19 in three patients twice in succession, and their computed tomography scans showed improved images. Although greater patient numbers and long-term follow-up data are needed, our series demonstrates that mild COVID-19 infection in KTx recipients can be managed using symptomatic support therapy combined with adjusted maintenance immunosuppressive therapy.

Overexpression of PPT2 Represses the Clear Cell Renal Cell Carcinoma Progression by Reducing Epithelial-to-mesenchymal Transition.

Clear cell renal cell carcinoma (ccRCC) is one of the most common malignant tumors of the urinary system and has a poor response to radiotherapy and chemotherapy. To date, it is urgent to find effective biomarkers for the prevention and treatment of ccRCC. The occurrence and development of ccRCC is closely related to metabolic disturbances. Palmitoyl protein thioesterase 2 (PPT2) is a lysosomal thioesterase which is highly associated with metabolism, and it has never been studied in ccRCC. In this study, we first revealed PPT2 is significantly downregulated in ccRCC, and its expression level is highly correlated with clinicopathological parameters of ccRCC patients. Our ROC curve analyses evaluated the potential of PPT2 as a novel diagnostic marker and prognostic factor. Functional experiment results showed overexpression of PPT2 represses the proliferation, migration and invasion of ccRCC cells in vitro. Mechanistic investigations demonstrated that overexpression of PPT2 represses the ccRCC progression by reducing epithelial-to-mesenchymal transition (EMT). In conclusion, PPT2 is downregulated in ccRCC. Decreased PPT2 expression may be considered as a novel diagnostic marker and prognostic factor and serve as a therapeutic target for ccRCC.

Downregulation of the lncRNA ASB16-AS1 Decreases LARP1 Expression and Promotes Clear Cell Renal Cell Carcinoma Progression via miR-185-5p/miR-214-3p.

Clear cell renal cell carcinoma (ccRCC) comprises approximately 75% of renal cell carcinomas, which is one of the most common and lethal urologic cancers, with poor quality of life for patients and is a huge economic burden to health care systems. It is imperative we find novel prognostic and therapeutic targets for ccRCC clinical intervention. In this study, we found that the expression of the long noncoding RNA (lncRNA) ASB16-AS1 was downregulated in ccRCC tissues compared with non-diseased tissues and was also associated with advanced tumor stage and larger tumors. By constructing cell and mouse models, it was found that downregulated lncRNA ASB16-AS1 enhanced cell proliferation, migration, invasion, and promoted tumor growth and metastasis. Furthermore, by performing bioinformatics analysis, biotinylated RNA pull-downs, AGO2-RIP, and luciferase reporter assays, our findings showed that downregulated ASB16-AS1 decreased La-related protein 1 (LARP1) expression by inhibiting miR-185-5p and miR-214-3p. Furthermore, it was found that overexpression of LARP1 reversed the promotive effects of downregulated ASB16-AS1 on ccRCC cellular progression. Our results revealed that downregulated ASB16-AS1 promotes ccRCC progression via a miR-185-5p-miR-214-3p-LARP1 pathway. We suggest that this pathway could be used to monitor prognosis and presents therapeutic targets for ccRCC clinical management.

SPOP promotes ATF2 ubiquitination and degradation to suppress prostate cancer progression.

BACKGROUND: Next-generation sequencing of the exome and genome of prostate cancers has identified numerous genetic alterations. SPOP (Speckle-type POZ Protein) is one of the most frequently mutated genes in primary prostate cancer, suggesting that SPOP may be a potential driver of prostate cancer. The aim of this work was to investigate how SPOP mutations contribute to prostate cancer development and progression. METHODS: To identify molecular mediators of the tumor suppressive function of SPOP, we performed a yeast two-hybrid screen in a HeLa cDNA library using the full-length SPOP as bait. Immunoprecipitation and Western Blotting were used to analyze the interaction between SPOP and ATF2. Cell migration and invasion were determined by Transwell assays. Immunohistochemistry were used to analyze protein levels in patients' tumor samples. RESULTS: Here we identified ATF2 as a bona fide substrate of the SPOP-CUL3-RBX1 E3 ubiquitin ligase complex. SPOP recognizes multiple Ser/Thr (S/T)-rich degrons in ATF2 and triggers ATF2 degradation via the ubiquitin-proteasome pathway. Strikingly, prostate cancer-associated mutants of SPOP are defective in promoting ATF2 degradation in prostate cancer cells and contribute to facilitating prostate cancer cell proliferation, migration and invasion. CONCLUSION: SPOP promotes ATF2 ubiquitination and degradation, and ATF2 is an important mediator of SPOP inactivation-induced cell proliferation, migration and invasion.

Shizukaol D, a Dimeric Sesquiterpene Isolated from Chloranthus serratus, Represses the Growth of Human Liver Cancer Cells by Modulating Wnt Signalling Pathway.

Natural products have become sources of developing new drugs for the treatment of cancer. To seek candidate compounds that inhibit the growth of liver cancer, components of Chloranthus serratus were tested. Here, we report that shizukaol D, a dimeric sesquiterpene from Chloranthus serratus, exerted a growth inhibition effect on liver cancer cells in a dose- and time-dependent manner. We demonstrated that shizukaol D induced cells to undergo apoptosis. More importantly, shizukaol D attenuated Wnt signalling and reduced the expression of endogenous Wnt target genes, which resulted in decreased expression of ß-catenin. Collectively, this study demonstrated that shizukaol D inhibited the growth of liver cancer cells by modulating Wnt pathway.

High TXNDC5 expression predicts poor prognosis in renal cell carcinoma.

Clear cell renal cell carcinoma (ccRCC) is the most common primary kidney cancer in adults, and the identification of biomarkers involved in the pathogenesis and prognosis of ccRCC is crucial for early diagnosis and anticancer treatment. In this study, we demonstrate that thioredoxin domain-containing protein 5 (TXNDC5) expression is markedly upregulated in ccRCC tissues in comparison with adjacent non-cancerous tissues through quantitative RT-PCR, Western blotting, and immunohistochemical analyses. Importantly, TXNDC5 expression is negatively correlated with the overall survival of patients. Knockdown of TXNDC5 by siRNAs inhibits the cell growth, migration, and invasion of ccRCC cells as well as sensitizes ccRCC cells to chemotherapeutic drugs, such as Camptothecin and 5-Fluorouracil. Moreover, we used complementary DNA (cDNA) microarray analyses to explore the underlying molecular mechanisms of TXNDC5 in the pathogenesis of ccRCC. We demonstrate that knockdown of TXNDC5 affects the messenger RNA (mRNA) and protein levels of numerous important genes associated with tumorigenesis. In summary, our findings indicate that TXNDC5 performs an essential function in ccRCC pathogenesis and can serve as a novel prognostic marker of ccRCC.

Stabilization of MCRS1 by BAP1 prevents chromosome instability in renal cell carcinoma.

Characterization of the exome and genome of carcinoma (ccRCC) by next-generation sequencing identified numerous genetic alternations. BRCA1-associated protein-1 (BAP1) was identified as one of the most frequently mutated genes in ccRCC, suggesting that BAP1 is a potential key driver for ccRCC cancer initiation and progression. However, how BAP1 mutations contribute to ccRCC remains to be elucidated. BAP1 is a nuclear de-ubiquitinating enzyme and cleaves the ubiquitin chain from the substrates. Here, we identified MCRS1 as a bona fide substrate for BAP1. MCRS1 is a component of the centrosome proteins, and plays an essential role in spindle assembly. BAP1 binds to MCRS1 and stabilizes MCRS1 by de-ubiquitination. BAP1 contributes to chromosome stability partially via MCRS1. A positive correlation was identified between BAP1 and MCRS1 expression in ccRCC tissues. Both BAP1 loss and MCRS1 down-regulation in ccRCC were associated with adverse clinicopathological features. This study revealed a novel mechanism for BAP1 involved in MCRS1 stability regulation, and provided insight in understanding the relationship between BAP1 mutations and chromosome instability in ccRCC.

Ubiquitin E3 ligase UHRF1 regulates p53 ubiquitination and p53-dependent cell apoptosis in clear cell Renal Cell Carcinoma.

Ubiquitin-like with PHD and RING finger domain 1 (UHRF1) is a multi-domain ubiquitin E3 ligase that plays critical roles in regulation of DNA methylation and histone ubiquitination. In this study, we found UHRF1 is frequently overexpressed in human clear cell Renal Cell Carcinoma (ccRCC) tissues both at mRNA and protein levels. We showed that UHRF1 directly interacts with p53 both in vivo and in vitro. A new domain (PD) in UHRF1 was required for interaction with p53. We found that UHRF1 down-regulates p53 transactivation activity which was depends on the ubiquitin E3 ligase function. UHRF1 can promote non-degradative ubiquitination of p53, suppress p53 pathway activation and p53-dependent apoptosis in ccRCC cells. Together, our study suggests that UHRF1, which overexpressed ccRCC, may act as a p53 regulator, suppress p53 pathway activation and help ccRCC cells to escape from p53-dependent apoptosis.

let-7b and let-7c are determinants of intrinsic chemoresistance in renal cell carcinoma.

BACKGROUND: Renal cell carcinoma (RCC) is characterized by inherent resistance to chemotherapy. Earlier studies demonstrated that microRNAs (miRNAs) might be involved in the chemosensitivity of cancers. MicroRNA let-7, a putative tumor suppressor, is dysregulated in many cancers. Our study aims to investigate the exact role of let-7 in chemotherapy sensitivity of 5-fluorouracil (5-FU) in RCC. METHODS: The clinical significance of let-7b and let-7c expression in surgically resected specimens was assessed by qRT-PCR. Cell proliferation assay and colony formation assay were used to assess the survival of 786-O cells treated with let-7b or let-7c combined with 5-FU. Western blot was used to detect the expression of Akt2 and caspase-7. Luciferase assay was used to detect the direct binding of let-7b and let-7c to the 3'-untranslated region (UTR) of Akt2. RESULTS: Expression of let-7b and let-7c was significantly decreased in 32 paired clear cell renal cell carcinoma tissue specimens and the dysregulation of let-7b was associated with pathological grade. Transfection of let-7b or let-7c combined with 5-FU inhibited proliferation and potentiated the antitumor efficacies of 5-FU at tolerated concentration. let-7b and let-7c suppressed the luciferase activity of reporter plasmid containing the 3'-UTR of Akt2. Overexpression of let-7b and let-7c reduced Akt2 expression, and Akt2 inhibition enhanced the sensitivity to 5-FU by affecting apoptotic pathway. CONCLUSIONS: Expression of let-7b and let-7c was frequently decreased in clear cell renal cell carcinoma tissues. The dysregulation of let-7b and let-7c may be involved in chemoresistance of RCC cells to 5-FU by down-regulating Akt2.

The tumor suppressor proteins ASPP1 and ASPP2 interact with C-Nap1 and regulate centrosome linker reassembly.

Centrosome linker tethers interphase centrosomes together allowing them to function as a single microtubule organization center. The centrosome linker is disrupted at the onset of mitosis to ensure timely centrosome disjunction and bipolar spindle formation and is reassembled at the end of mitosis. While the mechanism controlling centrosome linker disassembly at early mitosis has been well explored, little is known about how the linker is subsequently reassembled before mitotic exit. Here we report that ASPP1 and ASPP2, two members of the apoptosis stimulating proteins of p53 (ASPP) family, are involved in centrosome linker reassembly. We showed that ASPP1/2 interacted with centrosome linker protein C-Nap1. Co-depletion of ASPP1 and ASPP2 inhibited re-association of C-Nap1 with centrosome at the end of mitosis. Moreover, ASPP1/2 facilitated the interaction between C-Nap1 and PP1α, and this interaction was significantly reduced by co-depletion of ASPP1/2. ASPP1/2 antagonized the NEK2A-mediated C-Nap1 Ser2417/2421 phosphorylation in a PP1-dependent manner. Co-depletion of ASPP1 and ASPP2 inhibited dephosphorylation of C-Nap1 (Ser2417/2421) at the end of mitosis. Based on these findings, we propose that ASPP1/2 act as PP1-targeting subunits to facilitate C-Nap1 dephosphorylation and centrosome linker reassembly at the end of mitosis.

HDGF-related protein-2 (HRP-2) acts as an oncogene to promote cell growth in hepatocellular carcinoma.

HDGFRP2 (HRP-2) belongs to the Hepatoma-derived growth factor (HDGF)-related proteins (HRPs) family, which are characterized by a conserved HATH/PWWP domain at a well-conserved region of the N-terminus. However, the cellular function of HRP-2 remains unknown. In this study, we showed for the first time that HRP-2 is frequently overexpressed in human HCC tissues at mRNA and protein levels. We further showed that HRP-2 can promote HCC cells growth in vitro and xenograft tumors in vivo. Using protein affinity purification methods, we searched for functional partners of HRP-2, and found that HRP-2 interacts with various proteins known to be involved in transcription elongation and processing. Furthermore, we demonstrate HRP-2 interacts and co-localizes with RNA processing regulator IWS1, and positively regulated the mRNA level of Cyclin D1. Together, our study suggests HRP-2 may act as an mRNA processing co-factor to promote cells growth by regulating the mRNA of key oncogenes, which can be explored further for cancer treatment.

The E3 ubiquitin ligase Itch and Yap1 have antagonistic roles in the regulation of ASPP2 protein stability.

ASPP2 is an important tumor suppressor protein promoting p53-dependent and-independent apoptosis. However, it has been unclear how ASPP2 protein is regulated. Here, we identified Itch as the E3 ubiquitin ligase for ASPP2. Itch interacts with ASPP2 and mediates its degradation and ubiquitination in vivo. The PPXY motif of ASPP2 interacts with the WW domains of Itch. Yap1 competes with Itch for binding to ASPP2, and prevents Itch-mediated degradation and ubiquitination of ASPP2. Together, these observations reveal that Itch and Yap1 have antagonistic roles in the regulation of ASPP2 protein stability through competing post-translational regulatory mechanism of ASPP2.

[Temporal-spatial variations of total nitrogen in the degraded grassland of Three-River Headwaters region in Qinghai Province].

Based on the data of the second soil survey and field sampling in 2009 and 2010, temporal-spatial variations of total nitrogen (TN) in the degraded grassland 0-10 cm, 10-20 cm and 30-50 cm beneath the surface soil at the Three-River Headwaters region in Qinghai Province for a 30-year period (1980-2010) were evaluated using geostatistics and geographic information system (GIS). After exclusion of the outliers, the results showed a downward trend from the surface to the bottom in the mean TN values measured in the samples collected during the two periods. For the same soil layers, the average TN contents and the coefficient of variation in 1980 were higher than those in 2010. The TN contents of the two periods showed a log-normal distribution. Semivariograms analysis of the experiments indicated that the nugget effect in the same soil layer was lower in 2010 than in 1980; suggesting that the spatial distribution autocorrelation of TN in the Three-River Headwaters region in Qinghai Province was strengthened and structural factors played a more and more important role on the spatial distribution of TN. The results of ordinary kriging showed that there were regional differences in variations of the total nitrogen content. There were significant decreases in the southern, central and eastern regions, while the increase mainly occurred in the western areas.