Proliferation Of Renal Epithelial Cells Research Articles

Human umbilical cord-derived mesenchymal stem cells conditioned medium attenuate interstitial fibrosis and stimulate the repair of tubular epithelial cells in an irreversible model of unilateral ureteral obstruction.

The growing number of patients suffering from chronic renal disease (CKD) is a challenge for the development of innovative therapies. Researchers have studied the therapeutic effects of cell therapy in acute kidney injury (AKI). However, the therapeutic effect of conditional medium (CM) in the CKD models have been rarely reported. Here, we examined the effects of umbilical cord derived-mesenchymal stem cells (hUC-MSCs) CM on renal fibrosis in a rat model of unilateral ureteral obstruction (UUO). Animals were randomly divided into three groups: sham-operated, UUO, UUO + CM. CM was administered via the left renal artery after total ligation of the left ureter. Rats were killed after 14 days of obstruction. Histological changes and oxidative stress parameters were assessed. Western blotting and immunohistochemistry analysis were used to measure epithelial-mesenchymal transition (EMT) markers, including epithelial cadherin (E-cadherin), α-smooth muscle actin (α-SMA), tumour necrosis factor-α (TNF-α), Collagen-I, and transforming growth factor β1 (TGF-β1). Proliferation and apoptosis of renal tubular epithelial cells (RTEs) were also measured. HucMSC-CM significantly reduced the levels of malondialdehyde (MDA) and reactive oxygen species (ROS), and increased the activity of glutathione (GSH) induced by UUO. Moreover, CM significantly reduced the expression of TGF-β1, α-SMA, TNF-α and Collagen-I in UUO kidney, promoted the proliferation of RTEs and inhibited its apoptosis. In addition, the increased expression of E-cadherin also reflects the effective improvement of renal interstitial fibrosis. This study shows that CM protects UUO-induced kidney damage and therefore could be a potential tool to prevent CKD progression.

Effect of lentiviral vector-mediated KSR1 gene silencing on the proliferation of renal tubular epithelial cells and expression of inflammatory factors in a rat model of ischemia/reperfusion injury

Renal ischemia/reperfusion (I/R) is a common cause of acute renal failure in many clinical settings. Our study aimed to elucidate the role of lentiviral vector-mediated KSR1 gene silencing in inflammatory factor expression and proliferation of renal tubular epithelial cells (RTECs) in a rat model of I/R injury. Male Sprague-Dawley (SD) rats were used for I/R model establishment and subject to different treatments, followed by the measurement of neurological severity score (NSS), tumor necrosis factor-α (TNF-α), interleukin (IL)-6, IL-1β, 47-kDa heat-shock protein (HSP47), KSR1, and factors related to the Ras/MAPK pathway, as well as cell apoptosis. As compared with the blank group, the neurologic impairment induced by I/R in the siKSR1, U0126, and siKSR1 + U0126 groups was alleviated. Compared with the control group, the other five groups showed increased levels of TNF-α, IL-6, IL-1β, HSP47, N-ras, Raf-1, c-fos, TNF-α, IL-6, p38 MAPK, and cell apoptosis, accompanied by a declined mRNA and protein level of Bcl-2. As compared with the blank and NC groups, the siKSR1, U0126, and siKSR1 + U0126 groups showed decreased levels of TNF-α, IL-6, IL-1β, HSP47, N-ras, Raf-1, c-fos, TNF-α, IL-6, p38 MAPK, cleaved caspase-3, cleaved caspase-9, p53, and cell apoptosis, accompanied by an increased mRNA and protein level of Bcl-2. Our findings demonstrated that KSR1 gene silencing might inhibit the expression of inflammatory factors in RTECs and promote their proliferation by inactivating the Ras/MAPK pathway in the rat model of I/R injury.

253 - Comparison of human adipose stromal vascular fraction and adipose-derived mesenchymal stem cells for the attenuation of acute renal ischemia/reperfusion injury

Stem cells therapy has been suggested as a promising option for the treatment of acute kidney injury (AKI). This study was performed to compare the abilities of xenogenic transplantation of human adipose stromal vascular fraction (SVF) and adipose-derived mesenchymal stem cells (AdMSCs) to facilitate the recovery of renal function and structure in a rat model of ischemia/reperfusion (IR) induced AKI. SVF or AdMSCs were transplanted to the injured kidney through intra-parenchymal injection. Significantly improved renal function and reduced tubular injury were observed in SVF and AdMSCs groups. Administration of SVF or AdMSCs contributed to significantly improved cell proliferation and markedly reduced cell apoptosis in parallel with reduced microvascular rarefaction in injured kidney. IR injury resulted in higher levels of inflammatory cytokines, whereas xenogenic transplantation of SVF or AdMSCs reduced but not induced inflammatory cytokines expression. Additionally, in vitro study showed that administration of SVF or AdMSCs could also significantly promote the proliferation and survival of renal tubular epithelial cells underwent hypoxia/reoxygenation injury through secreting various growth factors. However, cell proliferation was significantly promoted in SVF group than in AdMSCs group. In conclusion, our study demonstrated that administration of SVF or AdMSCs was equally effective in attenuating acute renal IR injury.

Retracted: MicroRNA‐381‐induced down‐regulation of CXCR4 promotes the proliferation of renal tubular epithelial cells in rat models of renal ischemia reperfusion injury

This study aims to explore whether microRNA-381 (miR-381) mediating CXCR4 affects the renal tubular epithelial cells (RTEC) of renal ischemia reperfusion (I/R) injury. Forty-eight rats were assigned into the I/R (n = 24, successfully established as I/R model) and sham (n = 24) groups. After collecting kidney tissues, immunohistochemistry, and microvascular density (MVD) counting were conducted for CXCR4 positive expression and MVD numbers. RTECs were assigned into the sham, blank, negative control (NC), miR-381 mimics, miR-381 inhibitor, si-CXCR4, and miR-381 inhibitor + si-CXCR4 groups. RT-qPCR and Western blotting were performed for relative expressions in tissues and cells. Cell proliferation and apoptosis were measured by MTT assay and flow cytometry. Results showed that compared with the sham group, positive expression of CXCR4 and MVD number were higher in the I/R group, which exhibited decreased miR-381 and increased expression of CXCR4, stromal cell-derived factor-1 (SDF1), vascular endothelial growth factor (VEGF), hypoxia-inducible factor 1 (HIF-1α) and Tie-2. Dual luciferase reporter gene assay verified that CXCR4 is a target gene of miR-381. MiR-381 expression was lower in the miR-381 inhibitor + si-CXCR4 and miR-381 inhibitor groups and higher in the miR-381 mimics group than the blank and NC groups. Compared with the blank and NC groups, the miR-381 mimics and si-CXCR4 groups exhibited higher cell proliferation but lower cell apoptosis and expression of CXCR4, SDF1, VEGF, HIF-1α, and Tie-2, whereas the miR-381 inhibitor group exhibited the opposite trend. In conclusion, miR-381 may promote RTEC proliferation in rats with renal I/R injury by down-regulating CXCR4.

Lentivirus-Mediated Silencing of Src Homology 2 Domain-Containing Protein Tyrosine Phosphatase 2 Inhibits Release of Inflammatory Cytokines and Apoptosis in Renal Tubular Epithelial Cells Via Inhibition of the TLR4/NF-kB Pathway in Renal Ischemia-Reperfusion Injury

Renal reperfusion injury occurs after the blood flow to the ischemic kidney is re-established under various clinical conditions, such as organ transplantation, renal artery stenosis, embolic disease, and the repair of descending aortic. The current study aims to explore the effects of src homology 2 domain-containing protein tyrosine phosphatase 2 (SHP-2) on the release of inflammatory cytokines and the apoptosis of renal tubular epithelial cells by regulating the TLR4/NF-κB signaling pathway in rats with renal ischemia-reperfusion (I/R) injury. A total of 60 normal clean Sprague Dawley (SD) (WT) rats were used in this study. The levels of creatinine (Cr) and blood urea nitrogen (BUN) were determined using an automatic biochemical analyzer. The apoptosis in renal tissue was detected by TUNEL assay. The renal tubular epithelial cells of rats were cultured, infected and treated with different lentivirus vectors. The serum levels of interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), IL-1β and SHP27 were measured. Reverse transcription quantitative polymerases chain reaction and Western blot analysis were performed to measure the expression of relevant genes and proteins. Furthermore, the effect of SHP-2 on the proliferation, cell cycle and apoptosis of renal tubular epithelial cells was also investigated. In the serum of rats with renal I/R injury and prolonged reperfusion time, the contents of Cr and BUN were increased, the positive expression of SHP-2 was higher, the level of apoptosis was promoted, IL-6, TNF-α, IL-1β and SHP27 expression in the serum was increased, the expression of SHP2, TLR4, NF-κB, IL-6, TNF-α and Bax was up-regulated, and the expression of Bcl-2 was down-regulated. Lentivirus-mediated silencing of SHP-2 promoted the proliferation of renal tubular epithelial cells, inhibited their apoptosis, and reduced the expression of inflammatory factors in these cells by functionally suppressing the TLR4/NF-κB signaling pathway. The results indicated that lentivirus-mediated silencing of SHP-2 inhibited the release of inflammatory cytokines and the apoptosis of renal tubular epithelial cells, and promoted the proliferation of these cells by inhibiting the TLR4/NF-κB signaling pathway in rats with renal I/R injury.

Engineered extracellular matrices with controlled mechanics modulate renal proximal tubular cell epithelialization.

Acute kidney injury (AKI) is common and associated with significant morbidity and mortality. Recovery from many forms of AKI involves the proliferation of renal proximal tubular epithelial cells (RPTECs), but the influence of the microenvironment in which this recovery occurs remains poorly understood. Here we report the development of a poly(ethylene glycol) (PEG) hydrogel platform to study the influence of substrate mechanical properties on the proliferation of human RPTECs as a model for recovery from AKI. PEG diacrylate based hydrogels were generated with orthogonal control of mechanics and cell-substrate interactions. Using this platform, we found that increased substrate stiffness promotes RPTEC spreading and proliferation. RPTECs showed similar degrees of apoptosis and Yes-associated protein (YAP) nuclear localization regardless of stiffness, suggesting these were not key mediators of the effect. However, focal adhesion formation, cytoskeletal organization, focal adhesion kinase (FAK) activation, and extracellular signal-regulated kinase (ERK) activation were all enhanced with increasing substrate stiffness. Inhibition of ERK activation substantially attenuated the effect of stiffness on proliferation. In long-term culture, hydrogel stiffness promoted the formation of more complete epithelial monolayers with tight junctions, cell polarity, and an organized basement membrane. These data suggest that increased stiffness potentially may have beneficial consequences for the renal tubular epithelium during recovery from AKI.

Lysine methyltransferase SMYD2 promotes cyst growth in autosomal dominant polycystic kidney disease.

Autosomal dominant polycystic kidney disease (ADPKD) is driven by mutations in PKD1 and PKD2 genes. Recent work suggests that epigenetic modulation of gene expression and protein function may play a role in ADPKD pathogenesis. In this study, we identified SMYD2, a SET and MYND domain protein with lysine methyltransferase activity, as a regulator of renal cyst growth. SMYD2 was upregulated in renal epithelial cells and tissues from Pkd1-knockout mice as well as in ADPKD patients. SMYD2 deficiency delayed renal cyst growth in postnatal kidneys from Pkd1 mutant mice. Pkd1 and Smyd2 double-knockout mice lived longer than Pkd1-knockout mice. Targeting SMYD2 with its specific inhibitor, AZ505, delayed cyst growth in both early- and later-stage Pkd1 conditional knockout mouse models. SMYD2 carried out its function via methylation and activation of STAT3 and the p65 subunit of NF-κB, leading to increased cystic renal epithelial cell proliferation and survival. We further identified two positive feedback loops that integrate epigenetic regulation and renal inflammation in cyst development: SMYD2/IL-6/STAT3/SMYD2 and SMYD2/TNF-α/NF-κB/SMYD2. These pathways provide mechanisms by which SMYD2 might be induced by cyst fluid IL-6 and TNF-α in ADPKD kidneys. The SMYD2 transcriptional target gene Ptpn13 also linked SMYD2 to other PKD-associated signaling pathways, including ERK, mTOR, and Akt signaling, via PTPN13-mediated phosphorylation.

Sclt1 deficiency causes cystic kidney by activating ERK and STAT3 signaling.

Ciliopathies form a group of inherited disorders sharing several clinical manifestations because of abnormal cilia formation or function, and few treatments have been successful against these disorders. Here, we report a mouse model with mutated Sclt1 gene, which encodes a centriole distal appendage protein important for ciliogenesis. Sodium channel and clathrin linker 1 (SCLT1) mutations were associated with the oral-facial-digital syndrome (OFD), an autosomal recessive ciliopathy. The Sclt1-/- mice exhibit typical ciliopathy phenotypes, including cystic kidney, cleft palate and polydactyly. Sclt1-loss decreases the number of cilia in kidney; increases proliferation and apoptosis of renal tubule epithelial cells; elevates protein kinase A, extracellular signal-regulated kinases, SMAD and signal transducer and activator of transcription 3 (STAT3) pathways; and enhances pro-inflammation and pro-fibrosis pathways with disease progression. Embryonic kidney cyst formation of Sclt1-/- mice was effectively reduced by an anti-STAT3 treatment using pyrimethamine. Overall, we reported a new mouse model for the OFD; and our data suggest that STAT3 inhibition may be a promising treatment for SCLT1-associated cystic kidney.

Comparison of human adipose stromal vascular fraction and adipose-derived mesenchymal stem cells for the attenuation of acute renal ischemia/reperfusion injury

Stem cells therapy has been suggested as a promising option for the treatment of acute kidney injury (AKI). This study was performed to compare the abilities of xenogenic transplantation of human adipose stromal vascular fraction (SVF) and adipose-derived mesenchymal stem cells (AdMSCs) to facilitate the recovery of renal function and structure in a rat model of ischemia/reperfusion (IR) induced AKI. SVF or AdMSCs were transplanted to the injured kidney through intra-parenchymal injection. Significantly improved renal function and reduced tubular injury were observed in SVF and AdMSCs groups. Administration of SVF or AdMSCs contributed to significantly improved cell proliferation and markedly reduced cell apoptosis in parallel with reduced microvascular rarefaction in injured kidney. IR injury resulted in higher levels of inflammatory cytokines, whereas xenogenic transplantation of SVF or AdMSCs reduced but not induced inflammatory cytokines expression. Additionally, in vitro study showed that administration of SVF or AdMSCs could also significantly promote the proliferation and survival of renal tubular epithelial cells underwent hypoxia/reoxygenation injury through secreting various growth factors. However, cell proliferation was significantly promoted in SVF group than in AdMSCs group. In conclusion, our study demonstrated that administration of SVF or AdMSCs was equally effective in attenuating acute renal IR injury.

Poly(n-butyl methacrylate) with primary amine end groups for supporting cell adhesion and proliferation of renal epithelial cells

ABSTRACTPolymer coatings that support epithelial cell culture have been developed. Ozonolysis and subsequent workup of poly(butyl methacrylate-co-butadiene) copolymers is used to form oligomers with carboxylic acid end groups, which are then further reacted with diamines to provide poly(butyl methacrylate)s with primary amine end groups. The polymers are cast as films and used as cell culture substrates for human dermal fibroblasts and human renal epithelial cells. Fibroblast and epithelial cells adhere and proliferate on acid functional materials but on amine functional films epithelial cells show greater viability than fibroblasts.

Osteopontin improves adhesion and migration of human primary renal cortical epithelial cells during wound healing

The aim of the present study was to investigate the effect of osteopontin (OPN) on adhesion and migration in human primary renal cortical epithelial cells during wound healing and Transwell assays. MTT assay was used to examine the cell viability and western blot analysis was used to examine the expression of cytoskeletal proteins and cell adhesion molecules. The results showed that overexpression of OPN had positive effects on the viability, proliferation, adhesion and migration of the human primary renal cortical epithelial cells. In addition, the integrity of the cell membrane and cytoskeleton of the epithelial cells was negatively affected by knockdown of OPN expression. The Transwell migration and a wound healing assays performed using OPN-knockdown cells suggested that OPN had a significant impact on cell migration (P=0.0421) and wound healing (P=0.0333). Therefore, OPN may be a potential target for the therapeutic modulation of skin repair to improve the healing rate and quality of wound healing.

Cytosolic phospholipase A2α increases proliferation and de-differentiation of human renal tubular epithelial cells

The group IVA calcium-dependent cytosolic phospholipase A2 (cPLA2α) enzyme controls the release of arachidonic acid from membrane bound phospholipids and is the rate-limiting step in production of eicosanoids. A variety of different kidney injuries activate cPLA2α, therefore we hypothesized that cPLA2α activity would regulate pathologic processes in HK-2 cells, a human renal tubular epithelial cell line, by regulating cell phenotype and proliferation. In two lentiviral cPLA2α-silenced knockdowns, we observed decreased proliferation and increased apoptosis compared to control HK-2 cells. cPLA2α-silenced cells also demonstrated an altered morphology, had increased expression E-cadherin, and decreased expression of Ncadherin. Increased levels of E-cadherin were associated with increased promoter activity and decreased levels of SNAIL1, SNAIL2, and ZEB1, transcriptional repressors of E-cadherin expression. Addition of exogenous arachidonic acid, but not PGE2, reversed the phenotypic changes in cPLA2α-silenced cells. These data suggest that cPLA2α may play a key role in renal repair after injury through a PGE2-independent mechanism.

Biomimetic Porous PLGA Scaffolds Incorporating Decellularized Extracellular Matrix for Kidney Tissue Regeneration.

Chronic kidney disease is now recognized as a major health problem, but current therapies including dialysis and renal replacement have many limitations. Consequently, biodegradable scaffolds to help repairing injured tissue are emerging as a promising approach in the field of kidney tissue engineering. Poly(lactic-co-glycolic acid) (PLGA) is a useful biomedical material, but its insufficient biocompatibility caused a reduction in cell behavior and function. In this work, we developed the kidney-derived extracellular matrix (ECM) incorporated PLGA scaffolds as a cell supporting material for kidney tissue regeneration. Biomimetic PLGA scaffolds (PLGA/ECM) with different ECM concentrations were prepared by an ice particle leaching method, and their physicochemical and mechanical properties were characterized through various analyses. The proliferation of renal cortical epithelial cells on the PLGA/ECM scaffolds increased with an increase in ECM concentrations (0.2, 1, 5, and 10%) in scaffolds. The PLGA scaffold containing 10% of ECM has been shown to be an effective matrix for the repair and reconstitution of glomerulus and blood vessels in partially nephrectomized mice in vivo, compared with only PLGA control. These results suggest that not only can the tissue-engineering techniques be an effective alternative method for treatment of kidney diseases, but also the ECM incorporated PLGA scaffolds could be promising materials for biomedical applications including tissue engineered scaffolds and biodegradable implants.

Transcription Factor Trps1 Promotes Tubular Cell Proliferation after Ischemia-Reperfusion Injury through cAMP-Specific 3',5'-Cyclic Phosphodiesterase 4D and AKT.

Trichorhinophalangeal 1 (Trps1) is a transcription factor essential for epithelial cell morphogenesis during kidney development, but the role of Trps1 in AKI induced by ischemia-reperfusion (I/R) remains unclear. Our study investigated Trps1 expression during kidney repair after acute I/R in rats and explored the molecular mechanisms by which Trps1 promotes renal tubular epithelial cell proliferation. Trps1 expression positively associated with the extent of renal repair after I/R injury. Compared with wild-type rats, rats with knockdown of Trps1 exhibited significantly delayed renal repair in the moderate I/R model, with lower GFR levels and more severe morphologic injury, whereas rats overexpressing Trps1 exhibited significantly accelerated renal repair after severe I/R injury. Additionally, knockdown of Trps1 inhibited and overexpression of Trps1 enhanced the proliferation of renal tubular epithelial cells in rats. Chromatin immunoprecipitation sequencing assays and RT-PCR revealed that Trps1 regulated cAMP-specific 3',5'-cyclic phosphodiesterase 4D (Pde4d) expression. Knockdown of Trps1 decreased the renal protein expression of Pde4d and phosphorylated Akt in rats, and dual luciferase analysis showed that Trps1 directly activated Pde4d transcription. Furthermore, knockdown of Pde4d or treatment with the phosphatidylinositol 3 kinase inhibitor wortmannin significantly inhibited Trps1-induced tubular cell proliferation in vitro Trps1 may promote tubular cell proliferation through the Pde4d/phosphatidylinositol 3 kinase/AKT signaling pathway, suggesting Trps1 as a potential therapeutic target for kidney repair after I/R injury.

Preischemic Administration of Nonexpanded Adipose Stromal Vascular Fraction Attenuates Acute Renal Ischemia/Reperfusion Injury and Fibrosis.

: Ischemia/reperfusion (IR)-induced acute kidney injury (AKI) is a common clinical syndrome. Stem/progenitor cell therapy is a promising option to foster the intrinsic capacity for kidney regeneration. However, there are still several challenges to be resolved, including the potential risks during cell culture, low retention rate after transplantation, and unclear effect on the progression of chronic kidney disease (CKD). Recently, nonexpanded adipose stromal vascular fraction (SVF) has been regarded as an attractive cell source for cell-based therapy. Preconditioning with ischemia has been suggested as a useful method to promote the retention and survival of transplanted cells in vivo. In this study, freshly isolated autologous SVF was transplanted to the kidney of rats before ischemia, and then an IR-induced AKI model was established. Postischemic administration of SVF to the kidney was performed after renal IR injury was induced. A higher cell retention rate was detected in the preischemic group. Preischemic administration of SVF showed stronger functional and morphologic protection from renal IR injury than postischemic administration, through enhancing tubular cell proliferation and reducing apoptosis. Progression of kidney fibrosis was also significantly delayed by preischemic administration of SVF, which exhibited stronger inhibition of transforming growth factor-β1-induced epithelia-mesenchymal transition and microvascular rarefaction. In addition, in vitro study showed that prehypoxic administration of SVF could significantly promote the proliferation, migration, and survival of hypoxic renal tubular epithelial cells. In conclusion, our study demonstrated that preischemic administration of nonexpanded adipose SVF protected the kidney from both acute IR injury and long-term risk of developing CKD. Renal ischemia/reperfusion (IR) injury is a common clinical syndrome. Cell-based therapy provides a promising option to promote renal repair after IR injury. However, several challenges still remain because of the potential risks during cell culture, low retention rate after transplantation, and unclear effect on the progression of chronic kidney disease. Stromal vascular fraction (SVF) is considered as an attractive cell source. This study demonstrated that preischemic administration of uncultured SVF could increase cell retention and then improve renal function and structure at both early and long-term stage after IR, which may provide a novel therapeutic approach for IR injury.

Kidney-specific knockout of Sav1 in the mouse promotes hyperproliferation of renal tubular epithelium through suppression of the Hippo pathway.

We have previously reported that Salvador homologue 1 (SAV1), a component of the Hippo pathway, is significantly down-regulated in high-grade clear cell renal cell carcinoma (ccRCC) due to 14q copy number loss, and that this down-regulation contributes to the proliferation and survival of renal tubular epithelial cells through activation of Yes-associated protein 1 (YAP1), a downstream target of the Hippo pathway. However, the impact of SAV1 loss on the proliferation and survival of kidney cells in vivo remained to be determined. To address this issue, we generated kidney-specific Sav1-knockout (Cdh16-Cre;Sav1(fl/fl) ) mice. Sav1 deficiency enhanced the proliferation of renal tubular epithelial cells in Cdh16-Cre;Sav1(fl/fl) mice, accompanied by nuclear localization of Yap1, suggesting suppression of the Hippo pathway. Sav1 deficiency in renal tubules also caused structural and cellular abnormalities of the epithelial cells, including significant enlargement of their nuclei. Furthermore, Cdh16-Cre;Sav1(fl/fl) mice developed both glomerular and tubular cysts. Although lining cells of the glomerular cysts showed no atypia, those of the tubular cysts showed variations in cell size and nuclear shape, which became more severe as the mice aged. In aged Cdh16-Cre;Sav1(fl/fl) mice, we observed focal disruption of proximal tubules and perivascular lymphocytic infiltration. In conclusion, Sav1 is required for the maintenance of growth, nuclear size and structure of renal tubules under physiological conditions, and its deficiency leads to the acquisition of enhanced proliferation of renal epithelial cells through suppression of Hippo signalling.

Tumor necrosis factor receptor 2-signaling in CD133-expressing cells in renal clear cell carcinoma.

Compared to normal kidney, renal clear cell carcinomas (ccRCC) contain increased numbers of interstitial, non-hematopoietic CD133+cells that express stem cell markers and exhibit low rates of proliferation. These cells fail to form tumors upon transplantation but support tumor formation by differentiated malignant cells. We hypothesized that killing of ccRCC CD133+ (RCCCD133+) cells by cytotoxic agents might be enhanced by inducing them to divide. Since tumor necrosis factor-alpha (TNF), signalling through TNFR2, induces proliferation of malignant renal tubular epithelial cells, we investigated whether TNFR2 might similarly affect RCCCD133+cells. We compared treating organ cultures of ccRCC vs adjacent nontumour kidney (NK) and RCCCD133+ vs NK CD133+ (NKCD133+) cell cultures with wild-type TNF (wtTNF) or TNF muteins selective for TNFR1 (R1TNF) or TNFR2 (R2TNF). In organ cultures, R2TNF increased expression of TNFR2 and promoted cell cycle entry of both RCCCD133+ and NKCD133+ but effects were greater in RCCCD133+. In contrast, R1TNF increased TNFR1 expression and promoted cell death. Importantly, cyclophosphamide triggered much more cell death in RCCCD133+ and NKCD133+cells pre-treated with R2TNF as compared to untreated controls. We conclude that selective engagement of TNFR2 by TNF can drives RCCCD133+ proliferation and thereby increase sensitivity to cell cycle-dependent cytotoxicity.

Angiomotin promotes renal epithelial and carcinoma cell proliferation by retaining the nuclear YAP.

Renal cell carcinoma (RCC) is one of the common tumors in the urinary system without effective therapies. Angiomotin (Amot) can interact with Yes-associated protein (YAP) to either stimulate or inhibit YAP activity, playing a potential role in cell proliferation. However, the role of Amot in regulating the proliferation of renal epithelial and RCC cells is unknown. Here, we show that Amot is expressed predominantly in the nucleus of RCC cells and tissues, and in the cytoplasm and nucleus of renal epithelial cells and paracancerous tissues. Furthermore, Amot silencing inhibited proliferation of HK-2 and 786-O cells while Amot upregulation promoted proliferation of ACHN cells. Interestingly, the location of Amot and YAP in RCC clinical samples and cells was similar. Amot interacted with YAP in HK-2 and 786-O cells, particularly in the nucleus. Moreover, Amot silencing mitigated the levels of nuclear YAP in HK-2 and 786-O cells and reduced YAP-related CTGF and Cyr61 expression in 786-O cells. Amot upregulation slightly increased the nuclear YAP and YAP-related gene expression in ACHN cells. Finally, enhanced YAP expression restored proliferation of Amot-silencing 786-O cells. Together, these data indicate that Amot is crucial for the maintenance of nuclear YAP to promote renal epithelial and RCC proliferation.

Evaluation of autologous bone marrow-derived mesenchymal stem cells on renal regeneration after experimentally induced acute kidney injury in dogs.

To evaluate the usefulness of autologous bone marrow-derived mesenchymal stem cell (BM-MSC) therapy for the treatment of dogs with experimentally induced acute kidney injury. 6 healthy dogs. After induction of kidney injury (day 0) with cisplatin (5 mg/kg, IV), dogs immediately received saline (0.9% NaCl) solution (10 mL; n = 3) or BM-MSCs (1 × 10(6) cells/kg in 10 mL of saline solution; 3) IV. A CBC, serum biochemical analysis, and urinalysis were performed for each dog before administration of cisplatin and on days 1 through 4. Glomerular filtration rate was determined for all dogs on days -7 and 2; BM-MSC tracking by MRI was performed on BM-MSC-treated dogs on days -14 and 4. After sample collection and BM-MSC tracking on day 4, all dogs were euthanized; kidney tissue samples underwent histologic evaluation, immunohistochemical analysis, and cytokine profiling via reverse transcriptase PCR assays. Kidney tissue from both groups had mononuclear inflammatory cell infiltration, tubular necrosis, dilated tubules, and glomerular damage. However, there was less fibrotic change and increased proliferation of renal tubular epithelial cells in the BM-MSC-treated dogs, compared with findings for the control dogs. Expressions of tumor necrosis factor-α and transforming growth factor-β were lower in the BM-MSC-treated group, compared with findings for the control group. Laboratory data revealed no improvement in the renal function in BM-MSC-treated dogs. Results of this study suggested that autologous BM-MSCs may accelerate renal regeneration after experimentally induced acute kidney injury in dogs.

Effect of granulocyte colony-stimulating factor administration on renal regeneration after experimentally induced acute kidney injury in dogs.

To evaluate the effects of granulocyte colony-stimulating factor (GCSF) administration in dogs with experimentally induced acute kidney injury. 6 healthy dogs. After induction of kidney injury (day 0) with cisplatin (5 mg/kg, IV), the dogs were randomly assigned into 2 groups (n = 3 dogs/group). Then dogs immediately received GCSF (10 μg/kg) or 1 mL of saline (0.9% NaCl) solution (control group) SC; this treatment was repeated once daily for 4 additional days (days 1 through 4). A once-daily CBC (day 0 to 4), serum biochemical analysis (day 0 to 3), and urinalysis (day 0 to 3) were performed for each dog; samples were collected before administration of cisplatin (day 0) and before treatment with GCSF or saline solution (days 1 through 4). After sample collection and treatment on day 4, all dogs were euthanized; kidney tissue samples underwent histologic evaluation, immunohistochemical analyses, and cytokine profiling via reverse transcriptase PCR assay. In the GCSF-treated group, the histologic evaluation and immunohistochemical analyses of kidney tissue revealed less fibrotic change and greater proliferation of renal tubular epithelial cells, compared with findings in the control group. The mRNA profiles of kidney tissue from the GCSF-treated group indicated lower expression of tumor necrosis factor-α and tumor growth factor-β, compared with findings in the control group; however, concentrations of factors related to renal regeneration were not greater in the GCSF-treated group. Results indicated that GCSF treatment can impede renal fibrosis and increase proliferation of renal tubules after experimentally induced acute kidney injury in dogs.