Potential application of Klotho as a prognostic biomarker for patients with diabetic kidney disease: a meta-analysis of clinical studies.

Background: Diabetic kidney disease (DKD) is a serious diabetic complication and the performance of serum Klotho in DKD's prognostic evaluation is controversial. Objective: To assess the association of serum Klotho with adverse kidney and non-kidney clinical outcomes in patients with DKD. Design: Clinical studies regarding the relationship of serum Klotho with DKD were included. Study quality was assessed using the Newcastle-Ottawa scale. Subgroup and sensitive analyses were performed to search for the source of heterogeneity. Data sources and methods: We comprehensively searched PubMed, Embase, Web of Science, and Cochrane library databases up to 27 September 2022. The associations of Klotho with albuminuria, such as the urinary albumin creatinine ratio (UACR), kidney outcomes such as persistent albuminuria, estimated glomerular filtration rate decline, and non-kidney outcomes such as diabetic retinopathy, cardiovascular morbidity, and mortality, were evaluated. The indicators, such as the correlation coefficient (r), odds ratio (OR), relative risk, and hazard ratio, were retrieved or calculated from the eligible studies. Results: In all, 17 studies involving 5682 participants fulfilled the inclusion criteria and were included in this meta-analysis. There was no significant association of serum Klotho with UACR in DKD patients [summary r, -0.28 (-0.55, 0.04)] with high heterogeneity. By contrast, a strong association was observed regarding serum Klotho with kidney outcomes [pooled OR, 1.60 (1.15, 2.23)], non-kidney outcomes [pooled OR, 2.78 (2.11, 3.66)], or combined kidney and non-kidney outcomes [pooled OR, 1.96 (1.45, 2.65)] with moderate heterogeneity. Subgroup analysis indicated that age, study design, and the estimated glomerular filtration rate may be the sources of heterogeneity. Conclusion: A decreased serum Klotho level is possibly associated with an increased risk of developing kidney and non-kidney clinical outcomes in DKD patients; thus, Klotho may be a possible biomarker to predict DKD clinical outcomes. Additional studies are needed to clarify and validate Klotho's prognostic value.

Upstream and downstream regulators of Klotho expression in chronic kidney disease.

Klotho is a critical protein that protects the kidney. Klotho is severely downregulated in chronic kidney disease (CKD), and its deficiency is implicated in the pathogenesis and progression of CKD. Conversely, an increase in Klotho levels results in improved kidney function and delays CKD progression, supporting the notion that modulating Klotho levels could represent a possible therapeutic strategy for CKD treatment. Nevertheless, the regulatory mechanisms responsible for the loss of Klotho remain elusive. Previous studies have demonstrated that oxidative stress, inflammation, and epigenetic modifications can modulate Klotho levels. These mechanisms result in a decrease in Klotho mRNA transcript levels and reduced translation, thus can be grouped together as upstream regulatory mechanisms. However, therapeutic strategies that aim to rescue Klotho levels by targeting these upstream mechanisms do not always result in increased Klotho, indicating the involvement of other regulatory mechanisms. Emerging evidence has shown that endoplasmic reticulum (ER) stress, the unfolded protein response, and ER-associated degradation also affect the modification, translocation, and degradation of Klotho, and thus are proposed to be downstream regulatory mechanisms. Here, we discuss the current understanding of upstream and downstream regulatory mechanisms of Klotho and examine potential therapeutic strategies to upregulate Klotho expression for CKD treatment.

The controversy of klotho as a potential biomarker in chronic kidney disease.

Klotho is an identified longevity gene with beneficial pleiotropic effects on the kidney. Evidence shows that a decline in serum Klotho level occurs in early chronic kidney disease (CKD) and continues as CKD progresses. Klotho deficiency is associated with poor clinical outcomes and CKD mineral bone disorders (CKD-MBD). Klotho has been postulated as a candidate biomarker in the evaluation of CKD. However, the evidence for the clinical significance of the relationship between Klotho and kidney function, CKD stage, adverse kidney and/or non-kidney outcomes, and CKD-MBD remains inconsistent and in some areas, contradictory. Therefore, there is uncertainty as to whether Klotho is a potential biomarker in CKD; a general consensus regarding the clinical significance of Klotho in CKD has not been reached, and there is limited evidence synthesis in this area. To address this, we have systematically assessed the areas of controversy, focusing on the inconsistencies in the evidence base. We used a PICOM strategy to search for relevant studies and the Newcastle-Ottawa Scale scoring to evaluate included publications. We reviewed the inconsistent clinical findings based on the relationship of Klotho with CKD stage, kidney and/or non-kidney adverse outcomes, and CKD-MBD in human studies. Subsequently, we assessed the underlying sources of the controversies and highlighted future directions to resolve these inconsistencies and clarify whether Klotho has a role as a biomarker in clinical practice in CKD.

Genome-wide identification of Tomato Golden 2-Like transcription factors and abiotic stress related members screening.

BACKGROUND: Golden 2-Like (G2-like) transcription factors play an important role in plant development. However, the roles of these G2-like regulatory genes in response to abiotic stresses in tomato are not well understood. RESULTS: In this study, we identified 66 putative G2-like genes in tomato (Solanum lycopersicum) and classified them into 5 groups (I to V) according to gene structure, motif composition and phylogenetic analysis. The G2-like genes were unevenly distributed across all 12 chromosomes. There were nine pairs of duplicated gene segments and four tandem duplicated SlGlk genes. Analysis of the cis-regulatory elements (CREs) showed that the promoter regions of SlGlks contain many kinds of stress- and hormone-related CREs. Based on RNA-seq, SlGlks were expressed in response to three abiotic stresses. Thirty-six differentially expressed SlGlks were identified; these genes have multiple functions according to Gene Ontology (GO) analysis and are enriched mainly in the zeatin biosynthesis pathway. Further studies exhibited that silencing SlGlk16 in tomato would reduce drought stress tolerance by earlier wilted, lower superoxide dismutase (SOD), peroxidase (POD) activities, less Pro contents and more MDA contents. CONCLUSIONS: Overall, the results of this study provide comprehensive information on G2-like transcription factors and G2-like genes that may be expressed in response to abiotic stresses.

Meta-analysis of the association between sclerostin level and adverse clinical outcomes in patients undergoing maintenance haemodialysis.

BACKGROUND: Studies regarding the relationship of sclerostin (Scl) with clinical outcomes in patients undergoing maintenance haemodialysis have yielded controversial findings. This meta-analysis was performed to investigate the predictive role of Scl in this patient population. METHODS: Several electronic medical databases (e.g. PubMed, Embase, Web of Science and Cochrane Library) were searched for eligible studies through December 20, 2019. Summary hazard ratios (HRs) with 95% confidence intervals (CIs) were calculated based on Scr level (high or low) using a random or fixed effects model. RESULTS: From among 641 initially screened publications, 16 eligible studies were included in this meta-analysis. A high Scl level was not associated with cardiovascular events [HR = 0.8 (95% CI, 0.42-1.35)] or all-cause mortality [HR = 0.93 (95% CI, 0.56-1.54)]. There was high heterogeneity, but no evidence of publication bias. Interestingly, a high Scl level was associated with reduced cardiovascular events [HR = 0.44 (95% CI, 0.29-0.69)] in the subgroup by shorter follow-up period or all-cause mortality [pooled HR = 0.58 (95% CI, 0.36-0.91)] by shorter dialysis vintage. CONCLUSION: This meta-analysis indicated that a high Scl level did not predict total clinical outcomes in patients undergoing maintenance haemodialysis despite survival benefits in the subgroups. The predictive role of Scl in these patients should be further evaluated in large prospective studies.

Association of Soluble Klotho Level with Adverse Outcomes in Patients on Maintenance Hemodialysis.

BACKGROUND: The predictive value of soluble Klotho (sKlotho) for adverse outcomes in patients on maintenance hemodialysis (MHD) is controversial. In this study, we aimed to clarify the potential association of sKlotho levels with adverse outcomes in this patient population. MATERIALS: A total of 211 patients on MHD were identified and stratified according to the median sKlotho level. Patients were followed up for adverse outcomes including cardiovascular (CV) morbidity and all-cause mortality. RESULTS: During the 36-month follow-up, 75 patients [51 CV events (including 16 CV deaths) and 40 deaths] experienced adverse outcomes. After stratification according to median sKlotho level, patients with a lower sKlotho level had a greater risk of CV events (38.2% vs. 19.5%, p = 0.006), all-cause mortality (28.4% vs. 11.6%, p = 0.003), and combined adverse outcomes (51.0% vs. 24.2%, p < 0.001). Similar observations were made from analyses using Kaplan-Meier survival curves. Cox regression analysis showed that a low sKlotho level was strongly correlated with CV morbidity [1.942 (1.030-3.661), p = 0.040)], all-cause mortality [2.073 (1.023-4.203), p = 0.043], and combined adverse outcomes [1.818 (1.092-3.026), p = 0.021] in fully adjusted models. CONCLUSIONS: The sKlotho level was an independent predictive factor of adverse outcomes including CV morbidity and mortality in patients on MHD.

The prognostic value of soluble Klotho in patients with haemodialysis: a systematic review and meta-analysis.

AIM: The correlation between soluble Klotho (sKlotho) levels and clinical outcomes remains inconclusive for patients undergoing maintenance haemodialysis (MHD). We aimed to evaluate the potential predictive significance of sKlotho in this population by conducting a meta-analysis. METHODS: PubMed, Embase, Web of Science and Cochrane Library were comprehensively searched for studies concerning the association between sKlotho level and clinical outcomes including cardiovascular (CV) events and all-cause mortality. The pooled hazard ratios (HR) and 95% confidence intervals (CI) were generated using either random or fixed effects models. Sensitivity and subgroup analyses were used to explore heterogeneity sources. RESULTS: Eight prospective studies with 992 MHD participants were included and reduced sKlotho levels predicted more adverse outcomes in this meta-analysis. The pooled HRs and 95% CIs related to CV events, mortality, or composite outcomes were 1.73 (95% CI 1.08-2.76, p = 0.02), 2.34 (95% CI 1.34-2.07, p = 0.003) or 1.75 (95% CI 1.19-2.57, p = 0.005). Moderate heterogeneity was observed in the composite adverse outcomes (I 2 = 57%, p = 0.05). Age and sKlotho level were the main sources of heterogeneities in the subgroup analysis. CONCLUSION: Lower sKlotho levels were associated with more CV events and all-cause mortality, suggesting that sKlotho may have predictive value in CKD patients receiving haemodialysis.

The Prognostic Role of Klotho in Patients with Chronic Kidney Disease: A Systematic Review and Meta-analysis.

OBJECTIVE: The prognostic role of Klotho in patients with chronic kidney disease is still controversial. Therefore, we performed this meta-analysis to assess the relationship between the low sKlotho level and the risk of adverse kidney outcomes. MATERIALS AND METHODS: We systematically searched medical databases, such as PubMed, Embase, and the Cochrane Library, for eligible publications regarding the relationship between the low sKlotho level and risk of adverse kidney outcomes. The quality of included studies was assessed by using the Newcastle-Ottawa Scale. Combined hazard ratios (HRs) and its 95% confidence intervals (CIs) were calculated using a random- or fixed-effect model. Subgroup analysis was conducted with stratification by age, estimated glomerular filtration rate (eGFR), follow-up interval, region, and study quality. All data was analyzed by RevMan 5.3 analysis software. RESULTS: Eight cohort studies with 3586 participants from 3818 studies were included in our final analysis. Levels of sKlotho were significantly correlated with the eGFR, with a summary correlation coefficient r and 95% CI of 0.469 (0.226, 0.658). Additionally, low sKlotho levels were strongly associated with increased adverse kidney outcomes, and the pooled HR and its 95% CI were 1.64 (1.19, 2.26; P = 0.002), despite publication bias and statistical heterogeneity (I 2 = 52%, P = 0.07). Furthermore, this positive correlation was still observed in all of the subgroup analyses. However, heterogeneity was present in subgroup analyses stratified by the eGFR and follow-up interval. CONCLUSION: Levels of sKlotho are positively correlated with the eGFR, and low sKlotho levels are significantly associated with an increased risk of poor kidney outcomes. Therefore, sKlotho could be used as a novel biomarker for early diagnosis and prognostic assessment for patients with chronic kidney disease. Studies with a larger sample size and longer follow-up period are warranted to validate our results.

Quinoline's influence on nitrogen removal performance and microbial community composition of the anammox process.

This study aimed to evaluate the effects of quinoline on nitrogen removal performance and microbial community of an anaerobic biofilm reactor with anammox activity. Results showed that 20 mg L-1 quinoline addition leading the ammonia and nitrite removal efficiency of the ABR reduced from about 90% to 40%. Illumina MiSeq sequencing study indicated that microbial community structure and composition varied with the additive of quinoline. Planctomycetes and Bacteroidetes, decreased in abundance, suggested that quinoline adversely affects the anammox metabolism within the anammox reactor. The distribution of the anammox bacteria was affected by quinoline addition. Ca. Jettenia prevailed over the other two anammox bacteria (Brodica and Kuenenia) in the recovered phase.

Ginsenoside-Rg1 Protects against Renal Fibrosis by Regulating the Klotho/TGF-ß1/Smad Signaling Pathway in Rats with Obstructive Nephropathy.

Ginsenoside-Rg1 (G-Rg1) is an agent isolated from Panax ginseng that exerts anti-fibrotic effects; however, the mechanism is still unclear. Herein, we investigated whether G-Rg1 administration can mitigate or reverse unilateral ureteral obstruction (UUO)-induced renal fibrosis by regulating the Klotho/transforming growth factor (TGF)-ß1/Smad signaling pathway in rats. Sprague-Dawley male rats were subjected to UUO, and rats in the treatment group were administered G-Rg1 or G-Rg1 plus Klotho short hairpin RNA interference (shRNA), while rats in the control and model groups were administered vehicle for 14 d. Epithelial-mesenchymal transition (EMT) biomarkers and Klotho/TGF-ß1 signaling molecules were examined by immunohistochemistry, quantitative real-time PCR and Western blotting. Immunohistochemistry showed that UUO induced increased pro-fibrotic TGF-ß1 expression, overexpression of the mesenchymal marker, α-smooth muscle actin (α-SMA), and suppression of the epithelial marker, E-cadherin. Moreover, Western blotting analysis indicated that UUO promoted TGF-ß1 and phosphorylated Smad3 (p-Smad3) expression (p<0.01), but blocked Klotho and Smad7 expression (p<0.01). After G-Rg1 administration, the UUO-induced TGF-ß1 and p-Smad3 expression was suppressed (p<0.01), whereas the reduced Klotho and Smad7 expression was reversed (p<0.05), followed by amelioration of the EMT process. Intriguingly, the G-Rg1 effects were largely abrogated by Klotho knockdown. Furthermore, Klotho expression was upregulated by G-Rg1 treatment at the mRNA and protein levels. Our results suggest that G-Rg1 may be beneficial for ameliorating renal fibrosis by targeting Klotho/TGF-ß1/Smad signaling in UUO rats.

Plasma s-Klotho is related to kidney function and predicts adverse renal outcomes in patients with advanced chronic kidney disease.

To investigate whether the soluble Klotho (s-Klotho) level in patients with chronic kidney disease (CKD) is related to kidney function and whether a low s-Klotho level can predict adverse renal outcomes or CKD progression in patients with advanced CKD. 112 patients with CKD stages 3-5 and 30 healthy volunteers were enrolled. Blood samples were collected to measure serum creatinine, calcium, phosphorus, intact parathyroid hormone, and hemoglobin. s-Klotho and fibroblast growth factor 23 (FGF23) were determined by ELISA. We first conducted a cross-sectional study to investigate correlations between s-Klotho and estimated glomerular filtration rate (eGFR) and other parameters. Patients were then followed prospectively for 20.1±10.1 months according to s-Klotho median level until serum creatinine doubled, or initiation of renal replacement therapy, or death. s-Klotho levels inpatients with CKD were significantly lower than that in the control group. For patients with CKD, there were no differences in age distribution among subgroups. However, s-Klotho level differed significantly across CKD stages, and it was lower in the advanced CKD group compared with the moderate CKD group. Correlation analysis revealed that s-Klotho was positively associated with eGFR, but inversely associated with FGF23. During the follow-up of 20.1±10.1 months, patients with higher s-Klotho levels showed a reduced risk of kidney adverse outcomes, including serum creatinine doubling and initiation of renal replacement therapy. Cox regression analysis revealed that low s-Klotho was an independent risk factor for CKD progression. s-Klotho level was closely correlated with kidney function, further, low s-Klotho level could predict adverse kidney disease outcomes in patients with progressive CKD.

Klotho mitigates cyclosporine A (CsA)-induced epithelial-mesenchymal transition (EMT) and renal fibrosis in rats.

PURPOSE: Klotho deficiency is implicated in various kidney diseases, including renal fibrosis. The aim of this study was to investigate the effect of Klotho administration on epithelial-mesenchymal transition (EMT) and renal fibrosis induced by cyclosporine A (CsA) in rats. METHODS: CsA-induced renal fibrosis was established by oral administration of CsA (30 mg/kg) to rats on a low-salt diet for 28 days. Klotho was administered to rats by intraperitoneal injection. Renal pathological changes were evaluated by hematoxylin and eosin and Masson's trichrome staining. The EMT response was assessed by measuring the level of TGF-ß1, E-cadherin and α-SMA by immunohistochemistry and Western blot. RESULTS: Administration of CsA for 28 days induced renal damage, decreased Klotho expression and activated the EMT response (demonstrated as increased TGF-ß1 and α-SMA expression accompanied by decreased in E-cadherin expression). Treatment with Klotho significantly ameliorated pathological lesions of the kidney by modulating the expression of EMT-associated proteins in the kidney. CONCLUSIONS: Klotho inhibits CsA-induced EMT and renal fibrosis in rats. Klotho may serve as a therapeutic agent to minimize CsA-induced renal fibrosis.

Apelin-13 upregulates Egr-1 expression in rat vascular smooth muscle cells through the PI3K/Akt and PKC signaling pathways.

Previous studies have shown that Apelin-13 upregulates early growth response factor-1 (Egr-1) via the extracellular signal-regulated protein kinase (ERK) signaling pathway. Apelin-13 induces proliferation and migration of vascular smooth muscle cells (VSMCs) as well as the upregulation of osteopontin (OPN) via the upregulation of Egr-1. This study was designed to further explore the activity of Apelin-13 in VSMCs by investigating members of the mitogen-activated protein kinase (MAPK) family, in particular Jun kinase (JNK) and p38 mitogen-activated protein kinase (P38). We also examined whether the phosphatidylinositol 3 kinase (PI3K)/protein kinase B (Akt) and protein kinase C (PKC) signaling pathways were involved in the regulation of Egr-1 by Apelin-13. We treated rat aortic VSMCs with Apelin-13 and examined the expression of JNK, p-JNK, P38, and p-P38 to investigate whether Apelin-13-mediated increases in Egr-1 occurred through the JNK and P38 signaling pathways. We then pretreated VSMCs with the Gi protein inhibitor pertussis toxin (PTX) and the Gq inhibitor YM254890, added Apelin-13 and looked for changes in Egr-1 expression. Finally, we pretreated with the PI3K inhibitor LY294002 and the PKC inhibitor GF109203X, and treated with Apelin-13. Our results showed that JNK and P38 did not participate in Apelin-13-mediated increase in Egr-1. Instead, Apelin-13 upregulation of Egr-1 was mediated by a PTX-sensitive Gi protein. Apelin-13 did increase ERK phosphorylation through the PI3K/Akt and PKC signaling pathways, resulting in changes in Egr-1 expression. These data provide important targets for future studies to modulate vascular remodeling.

Ameliorating effect of Klotho on endoplasmic reticulum stress and renal fibrosis induced by unilateral ureteral obstruction.

INTRODUCTION: Expression of Klotho is decreased and endoplasmic reticulum (ER) stress is activated in patients with chronic kidney disease. This study aimed to investigate the effect of Klotho protein on ER stress-related apoptosis and renal fibrosis in rates with unilateral ureteral obstruction (UUO). MATERIALS AND METHODS: Twenty-four rats were divided into the sham, UUO, and Klotho treatment groups. Renal interstitial fibrosis model was induced by UUO in the rats of the latter two groups. Soluble Klotho protein was injected into the abdominal cavity. Serum and kidney samples were collected 14 days after the UUO surgery for examination of renal injury and renal interstitial fibrosis using hematoxylin-eosin and Masson trichrome staining methods. The level of apoptotic cells was assessed by the terminal deoxynucleotidyl transferase dUTP nick end labeling assay. Expression of 3 ER stress-related proteins including glucose-regulated protein 78, CCAAT/enhancer-binding protein homologous protein, and caspase-12 were measured. RESULTS: Kidney dysfunction, increased renal injury index, and aggravated renal fibrosis were documented in the UUO group. Expression of Klotho in the UUO rats was remarkably decreased (P < .05) and expression of all three ER stress-related proteins were significantly upregulated, accompanied by increasing numbers of apoptotic cells (P < .05). Soluble Klotho administration improved kidney function, ameliorated pathological changes, decreased expressions of ER-stress related-proteins, and reduced the number of apoptotic cells. CONCLUSION: Unilateral ureteral obstruction decreased Klotho expression and activated ER stress and related apoptosis. Klotho administration ameliorated UUO-induced ER stress, inhibited apoptotic process, and attenuated renal fibrosis.

Ginsenoside-Rg1 inhibits endoplasmic reticulum stress-induced apoptosis after unilateral ureteral obstruction in rats.

AIM: Endoplasmic reticulum (ER) stress and unfolded protein response (UPR) are implicated in many fibrotic diseases, including renal fibrosis. Whether Ginsenoside-Rg1 (G-Rg1) could attenuate renal fibrosis via suppression of ER stress and UPR has not been reported. The aim of this study was to explore the effect of G-Rg1 on ER stress and UPR-induced apoptosis in kidneys with unilateral ureteral obstruction (UUO) rat model. METHODS: Twenty-four male Sprague-Dawley rats were randomly divided into control group, model group and G-Rg1 treatment group. G-Rg1 was administered to rats by intraperitoneal injection. Renal interstitial fibrosis in the model group was developed by UUO in rats. Renal function was estimated by the levels of serum creatinine (Scr) and blood urea nitrogen (BUN). Renal pathological damage was evaluated by hematoxylin and eosin (HE) and Masson's trichrome staining. The ER stress was assessed with glucose-regulated protein (GRP) 78 expression, and the proapoptotic response was detected with CCAAT/enhancer-binding protein homologous protein (CHOP) and caspase-12 expressions by Western Blot. The number of apoptotic cells was determined by Terminal-deoxynucleotidyl Transferase Mediated Nick End Labeling (TUNEL) analysis. RESULTS: UUO for 14 days aggravated renal function, renal damage and renal interstitial fibrosis, activated ER stress response (induction of GRP78 protein), enhanced the proapoptotic response (increase in CHOP and caspase-12 proteins) and increased the number of apoptotic cells (shown by the TUNEL assay). Treatment with G-Rg1 significantly ameliorates the renal pathological lesions and decreases expressions of ER stress-associated proteins and the level of apoptotic cells in kidneys. CONCLUSION: G-Rg1 suppresses renal cell apoptotic and fibrotic process partly through inhibition of ERS- and UPR-related apoptotic pathway in the kidneys after UUO.

'Cool and quiet' therapy for malignant hyperthermia following severe traumatic brain injury: A preliminary clinical approach.

Malignant hyperthermia increases mortality and disability in patients with brain trauma. A clinical treatment for malignant hyperthermia following severe traumatic brain injury, termed 'cool and quiet' therapy by the authors of the current study, was investigated. Between June 2003 and June 2013, 110 consecutive patients with malignant hyperthermia following severe traumatic brain injury were treated using mild hypothermia (35-36°C) associated with small doses of sedative and muscle relaxant. Physiological parameters and intracranial pressure were monitored, and the patients slowly rewarmed following the maintenance of mild hypothermia for 3-12 days. Consecutive patients who had undergone normothermia therapy were retrospectively analyzed as the control. In the mild hypothermia group, the recovery rate was 54.5%, the mortality rate was 22.7%, and the severe and mild disability rates were 11.8 and 10.9%, respectively. The mortality rate of the patients, particularly that of patients with a Glasgow Coma Scale (GCS) score of between 3 and 5 differed significantly between the hypothermia group and the normothermia group (P<0.05). The mortality of patients with a GCS score of between 6 and 8 was not significantly different between the two groups (P> 0.05). The therapy using mild hypothermia with a combination of sedative and muscle relaxant was beneficial in decreasing the mortality of patients with malignant hyperthermia following severe traumatic brain injury, particularly in patients with a GCS score within the range 3-5 on admission. The therapy was found to be safe, effective and convenient. However, rigorous clinical trials are required to provide evidence of the effectiveness of 'cool and quiet' therapy for hyperthermia.

Tranilast attenuates TGF-ß1-induced epithelial-mesenchymal transition in the NRK-52E cells.

We previously reported that tranilast can halt the pathogenesis of chronic cyclosporine nephrotoxicity in rats via the transforming growth factor-ß (TGF-ß) /Smad pathway, an important signaling system involved in epithelial-mesenchymal transition (EMT), but the exact underlying cellular mechanisms are not yet clear. Thus, by selecting TGF-ß1-induced normal rat kidney proximal tubular epithelial cells (NRK-52E) as a model, we demonstrated potential modifying effect of tranilast on EMT-induced by TGF-ß1 in vitro. NRK-52E cells were incubated with the blank vehicle (Dulbecco's modified Eagle's medium and F-12 (DMEM/F12) added with 10% fetal bovine serum (FBS)), 10 ng/ml TGF-ß1 alone or together with 100, 200 or 400µM tranilast for 48 h after incubation in medium containing 1% FBS for 24 h. Cell morphological changes were observed to confirm occurrence of EMT. Protein expressions of two typical markers of EMT, E-cadherin and α-smooth muscle actin (α-SMA), were assessed by western blotting and flow cytometry, respectively. Our results showed that TGF-ß1 induced spindle-like morphological transition, the loss of E-cadherin protein and upregulation of expression of α-SMA. However, the TGF-ß1-produced changes in cellular morphology, E-cadherin and α-SMA were inversed by tranlilast in concentration-dependent manner. Our findings indicate that tranilast can directly inhibit EMT. Thus, it may be implied that regulation of EMT be the target to prevent renal tubulointerstitial fibrosis.

Apelin-13-induced proliferation and migration induced of rat vascular smooth muscle cells is mediated by the upregulation of Egr-1.

Apelin-13 plays an important role in the migration and proliferation of vascular smooth muscle cells (VSMCs); however, the underlying mechanisms are still unclear. Egr-1 is a nuclear transcription factor, which is considered to be the critical initiating factor of the processes of VSMC proliferation and migration. Egr-1 is known to regulate the expression of osteopontin (OPN), which is a marker of the phenotypic modulation that is a necessary condition of VSMC proliferation and migration. We hypothesized that the role of Apelin-13 is mediated via upregulation of Egr-1. To test this hypothesis, we analyzed the effects of Apelin-13 treatment on Egr-1 mRNA and protein expression in A10 rat aortic VSMCs by RT-PCR and Western blotting, respectively. Results showed that, Apelin-13 upregulated the expression of Egr-1. Furthermore, treatment with the extracellular-regulated protein kinase (ERK) inhibitor, PD98059, inhibited the upregulation of Egr-1 by Apelin-13. In addition, this upregulation was inhibited by treatment of VSMCs with the Egr-1 specific deoxyribozyme ED5 (DNAenzyme/10-23 DRz). Furthermore, ED5 treatment was found to significantly inhibit Apelin-13-induced migration and proliferation of VSMCs using transwell and MTT assays, respectively. The evaluation of OPN mRNA and protein expression levels by RT-PCR and Western blot analyses revealed that ED5 treatment also inhibited Apelin-13-induced OPN upregulation. The results of this study indicated that Apelin-13 upregulates Egr-1 via ERK. Furthermore, Apelin-13 induced the proliferation and migration of VSMCs as well as the upregulation of OPN via the upregulation of Egr-1. These results will provide an important theoretical and experimental basis for the control of inappropriate remodeling of vessel walls, and will hopefully lead to the prevention and treatment of vascular remodeling diseases.

[Clinicopathologic characteristics and prognosis in young Chinese women with breast cancer].

OBJECTIVE: To analyze the clinicopathologic characteristics and evaluate the prognosis in young Chinese women with breast cancer. METHODS: A total of 1538 female patients with operable primary breast cancer (stage I-III) treated at our hospital from December 1994 to December 2003 were analyzed retrospectively. Among them, 1075 patients (≤ 60 yrs) with the complete follow-up data were divided into two groups according to age: young breast cancer group (≤ 40 yrs, n = 208) and control group (41 - 60 yrs, n = 867) to analyze the differences in their clinicopathologic characteristics and evaluate the prognosis of both groups. RESULTS: The patients with young breast cancer were more likely to have positive lymph nodes (P = 0.016), a negative expression of ER (estrogen receptor) (P = 0.016) and a positive expression of HER2 (P = 0.001). The 5-year disease-free survival (DFS) rates of young breast cancer group and control group were 73.3% and 84.1% (P < 0.001) and the 5-year overall survival (OS) rates 83.5% and 89.1% (P = 0.004) respectively. Moreover, the patients with young breast cancer had a worse DFS than control group in patients with stage I-II disease but not in those with stage III disease. And ≤ 40 years was an independent unfavorable prognostic factor of DFS (HR = 1.78, 95%CI: 1.19 - 2.66, P = 0.005) and OS (HR = 1.71, 95%CI: 1.01 - 2.90, P = 0.046) in the patients with stage I-II disease. CONCLUSION: Chinese women with young breast cancer have a worse prognosis, particularly in those with stage I-II disease.

Positive regulation of the Egr-1/osteopontin positive feedback loop in rat vascular smooth muscle cells by TGF-beta, ERK, JNK, and p38 MAPK signaling.

Previous studies identified a positive feedback loop in rat vascular smooth muscle cells (VSMCs) in which early growth response factor-1 (Egr-1) binds to the osteopontin (OPN) promoter and upregulates OPN expression, and OPN upregulates Egr-1 expression via the extracellular signal-regulated protein kinase (ERK) signaling pathway. The current study examined whether transforming growth factor-beta (TGF-beta) activity contributes to Egr-1 binding to the OPN promoter, and whether other signaling pathways act downstream of OPN to regulate Egr-1 expression. ChIP assays using an anti-Egr-1 antibody showed that amplification of the OPN promoter sequence decreased in TGF-beta DNA enzyme-transfected VSMCs relative to control VSMCs. Treatment of VSMCs with PD98059 (ERK inhibitor), SP600125 (JNK inhibitor), or SB203580 (p38 MAPK inhibitor) significantly inhibited OPN-induced Egr-1 expression, and PD98059 treatment was associated with the most significant decrease in Egr-1 expression. OPN-stimulated VSMC cell migration was inhibited by SP600125 or SB203580, but not by PD98059. Furthermore, MTT assays showed that OPN-mediated cell proliferation was inhibited by PD98059, but not by SP600125 or SB203580. Taken together, the results of the current study show that Egr-1 binding to the OPN promoter is positively regulated by TGF-beta, and that the p38 MAPK, JNK, and ERK pathways are involved in OPN-mediated Egr-1 upregulation.