Losartan alleviates renal fibrosis by inhibiting the biomechanical stress-induced epithelial-mesenchymal transition of renal epithelial cells.

Angiotensin receptor blockers (ARBs) have been reported to be beneficial of renal fibrosis, but the molecular and cellular mechanisms are still unclear. In this study, we investigated the effectiveness and relevant mechanism of ARBs in alleviating renal fibrosis, especially by focusing on biomechanical stress-induced epithelial to mesenchymal transition (EMT) of renal epithelial cells. Unilateral ureteral obstruction (UUO) renal fibrosis model was established in mice by ligating the left ureter, and then randomly received losartan at a low dose (1 mg/kg) or a regular dose (3 mg/kg) for 2 weeks. Compared to the control, histological analysis showed that losartan treatment at either a low dose or a regular dose effectively attenuated renal fibrosis in the UUO model. To further understand the mechanism, we ex vivo loaded primary human renal epithelial cells to 50 mmHg hydrostatic pressure. Western blot and immunostaining analyses indicated that the loading to 50 mmHg hydrostatic pressure for 24 h significantly upregulated vimentin, ß-catenin and α-SMA, but downregulated E-cadherin in renal epithelial cells, suggesting the EMT. The addition of 10 or 100 nM losartan in medium effectively attenuated the EMT of renal epithelial cells induced by 50 mmHg hydrostatic pressure loading. Our in vivo and ex vivo experimental data suggest that losartan treatment, even at a low dose can effectively alleviate renal fibrosis in mouse UUO model, at least partly by inhibiting the biomechanical stress-induced EMT of renal epithelial cells. A low dose of ARBs may repurpose for renal fibrosis treatment.

Plasma exchange plus glucocorticoids in the treatment of immune checkpoint inhibitor-induced myocarditis: A case series and review.

Immune checkpoint inhibitors (ICIs), including antiprogrammed cell-death (PD)-1/anti-PD-ligand (PDL-1) monoclonal antibodies, are effective at improving the prognosis of patients with cancer. Among immune-related adverse events, myocarditis associated with anti-PD-1/anti-PD-L1 antibodies is rare but lacks effective treatment and mortality is very high. In this study, the authors extracted data from the previous 8 years from electronic medical records housed in the hospital information system to identify patients hospitalized with myocarditis putatively caused by anti-PD-1/anti-PD-L1 tumor therapy. Clinical data from these patients are reported. Four patients who developed myocarditis after undergoing treatment with anti-PD-1/anti-PD-L1 antibodies for malignant tumors, all of whom responded favorably to therapy consisting of plasma exchange and glucocorticoids for myocarditis, and all patients improved and were discharged from hospital. Plasma exchange plus systemic glucocorticoids may be effective for treating anti-PD-1/anti-PD-L1 antibody-induced myocarditis in patients with cancer.

CaMKII may regulate renal tubular epithelial cell apoptosis through YAP/NFAT2 in acute kidney injury mice.

AIM: Renal tubular epithelial cell (RTEC) apoptosis is important in acute kidney injury (AKI). Calcium/calmodulin-dependent protein kinase II (CaMKII) plays an important role in cell apoptosis, but its potential role in AKI remains unknown. METHODS: Using co-immunoprecipitation, immunofluorescence, immunohistochemistry, western blotting, flow cytometry, and cell transfection, this study aimed to verify whether CaMKII is involved in RTEC apoptosis and to explore the underlying mechanism. RESULTS: We found that CaMKII was involved in RTEC apoptosis. In adriamycin-induced AKI mice, serum creatinine levels, cell apoptosis, CaMKII activity, and nuclear factor of activated T cells 2 (NFAT2) levels increased, whereas nuclear Yes-associated protein (YAP) expression decreased; inhibition of CaMKII activity reversed these changes. Phosphorylated CaMKII could bind to phosphorylated YAP in the cytoplasm and block it from entering the nucleus, thereby failing to inhibit NFAT2-mediated cell apoptosis. Sequestrated phosphorylated YAP in the RTEC cytoplasm was finally degraded by ubiquitination. CONCLUSION: CaMKII may regulate RTEC apoptosis through YAP/NFAT2 in AKI mice. CaMKII may be a potent molecular target for AKI treatment.

The BACE1-Specific DNA Aptamer A1 Rescues Amyloid-ß Pathology and Behavioral Deficits in a Mouse Model of Alzheimer's Disease.

Amyloid-ß (Aß) plaque deposits in the brain are considered to be one of the main pathological markers of Alzheimer's disease (AD). The sequential proteolytic cleavage of amyloid precursor protein (APP) by the aspartyl proteases ß-site APP-cleaving enzyme 1 (BACE1) and γ-secretase produces Aß. Therefore, BACE1 inhibition is a very attractive target for the treatment of AD. Our previous work identified a DNA aptamer named A1 that can bind to BACE1 with high affinity and specificity and exhibits a distinct inhibitory effect on BACE1 activity in an AD cell model. The purpose of this research was to test the effect of aptamer A1 in Tg6799 mice. Four-month-old Tg6799 mice were randomly divided into two groups and treated with aptamer A1 and ineffective aptamer A1scr, respectively, by intracerebroventricular injection. Subsequent behavioral experiments showed that treatment with the aptamer A1 improved the cognitive abilities of the AD mice. Western blot indicated that BACE1 and soluble amyloid precursor protein ß (sAPPß) expression significantly decreased in the A1-treated mice. Moreover, aptamer A1 reduced the content of Aß42 and the number and density of senile plaques in AD mice. Therefore, our results indicate that aptamer A1 is a novel specific and potent BACE1 inhibitor and is a promising potential target for the treatment of AD.

Potential Role of the Resident Mesenchymal Stem-Like Cells in Renal Fibrogenesis after Ureteral Obstruction.

The mechanisms of renal fibrogenesis after ureteral obstruction remain unclear. We tried to primarily expand mesenchymal stem cells from renal tissues and then investigated their role in fibrogenesis after ureteral obstruction. Unilateral ureteral obstruction was induced by ligating the left ureteral duct of adult C57BL/6 mice. We collected the kidneys for experiments at 2, 7, and 14 days after operation. Histological analysis showed obviously fibrotic changes in the left kidney at 7 days and further increased at 14 days after ureteral obstruction. To expand mesenchymal stem cells, we minced the renal tissues into small explants (about 1 mm3) and cultured onto 10 cm dishes. Interestingly, the outgrowth of cells was observed significantly earlier from the explants of the obstructed left kidney than that of the unobstructed right kidney. These expanded cells showed the potency of adipogenic, osteogenic, and chondrogenic differentiations and positively expressed with CD44 and partly expressed with CD90, CD105, and CD106, but negatively expressed with CD34, CD45, and FSP1, suggesting the phenotype of mesenchymal stem-like cells (MSLCs). The mouse fibrosis RT2 profiler PCR array showed that many genes were changed over 2-fold in the MSLCs expanded from both kidneys at 2, 7, and 14 days after operation. Interestingly, profibrotic genes were prevalently enhanced in the left kidney with ureteral obstruction. Histological analysis also showed obviously infiltration of inflammatory cells in the left kidney at 14 days after operation. Our data indicate the potential role of resident MSLCs in renal fibrogenesis after ureteral obstruction, but further experiments are required to understand the relevant mechanisms.

RhoA protects the podocytes against high glucose-induced apoptosis through YAP and plays critical role in diabetic nephropathy.

BACKGROUND: Podocyte apoptosis is important mechanism that leading to proteinuria in Diabetic nephropathy (DN), but the underling mechanisms that cause podocyte apoptosis in DN are not very clear. We have recently demonstrated that RhoA, a small GTPase protein, effectively protected podocyte apoptosis induced by LPS and ADR in vitro. However, the potential role of RhoA in DN is unknown. METHODS AND RESULTS: Conditionally immortalized mouse podocyte cells, C57BL/KsJ, db/db diabetic mice, and renal biopsies from patients with DN were used for study. The treatment of podocytes with high glucose (HG) for 48h significantly induced cell apoptosis and decreased RhoA expression and its activity. The expression of RhoA was also decreased in glomerular podocytes of db/db mice and patients with DN. Knockdown of RhoA by siRNA contributed in the apoptosis of podocyte and induced proteinuria in db/db mice. Beyond the increased pro-apoptotic Bax and the decreased anti-apoptotic Bcl-2, RhoA knockdown also inhibited the expression of a nuclear protein of YAP in podocyte. Over expression active form of YAP completely abolished the apoptosis of podocyte induced by RhoA knockdown. CONCLUSION: RhoA plays a critical role in DN probably by mediating the podocyte apoptosis through YAP. RhoA may be a novel molecular target for the treatment of DN.

Recovery of renal function in a heart transplantation recipient with over 300 days of iatrogenic anuria: A case report.

RATIONALE: Anuria is a severe symptom indicating severe kidney damage. Patient recovery from prolonged anuria is rarely reported. PATIENT CONCERNS: A 15-year-old boy received gender- and weight-mismatch heart transplantation (HT) due to dilated cardiomyopathy. He developed severe hypotension, and heart failure 24 hours after surgery, which were relieved by preload reduction treatments. Although, routine examinations did not show any abnormalities in renal function before surgery, anuria occurred 4 days after preload reduction treatments (24-hour urine volume was 23 mL). DIAGNOSIS: The patient was diagnosed with acute kidney injury (AKI). INTERVENTIONS: He was admitted to continuous renal replacement therapy (CRRT) or hemodialysis. OUTCOMES: Surprisingly, his urine volume was gradually, and miraculously, restored to more than 1000 mL/24 hours after over 300 days of anuria. Hemodialysis was not needed in the twentieth month after surgery. Moreover, he partially, recovered renal function. LESSONS: This case indicates the likelihood of recovery from long-term anuria.

Inhibition of BACE1 Activity by a DNA Aptamer in an Alzheimer's Disease Cell Model.

An initial step in amyloid-ß (Aß) production includes amyloid precursor protein (APP) cleavage via ß-Site amyloid precursor protein cleaving enzyme 1 (BACE1). Increased levels of brain Aß have been implicated in the pathogenesis of Alzheimer's disease (AD). Thus, ß-secretase represents a primary target for inhibitor drug development in AD. In this study, aptamers were obtained from combinatorial oligonucleotide libraries using a technology referred to as systematic evolution of ligands by exponential enrichment (SELEX). A purified human BACE1 extracellular domain was used as a target to conduct an in vitro selection process using SELEX. Two DNA aptamers were capable of binding to BACE1 with high affinity and good specificity, with Kd values in the nanomolar range. We subsequently confirmed that one aptamer, A1, exhibited a distinct inhibitory effect on BACE1 activity in an AD cell model. We detected the effects of M17-APPsw cells that stably expressed Swedish mutant APP after aptamer A1 treatment. Aß40 and Aß42 concentrations secreted by M17-APPsw cells decreased intracellularly and in culture media. Furthermore, Western blot analysis indicated that sAPPß expression significantly decreased in the A1 treated versus control groups. These findings support the preliminary feasibility of an aptamer evolved from a SELEX strategy to function as a potential BACE1 inhibitor. To our knowledge, this is the first study to acquire a DNA aptamer that exhibited binding specificity to BACE1 and inhibited its activity.

[Application of the Oxford classification of IgA nephropathy to predict renal outcome].

OBJECTIVE: To validate the value of the Oxford classification of IgA nephropathy in predicting the renal outcome in Chinese population. METHODS: Retrospective study was done in patients with IgA nephropathy. All slides were re-assessed according to the Oxford classification of IgA nephropathy. The primary end point is doubling serum creatinine, or a 50% reduction in estimated glomerular filtration rate (eGFR), or end-stage renal disease. Pathologic predictors for the progression to the end point were determined by univariate and multivariate Cox regression. RESULTS: Totally 533 patients were enrolled in the study. During the follow-up (median: 39 months; range: 12-263 months), 5.07% of the patients reached the end point. While tubular atrophy and interstitial fibrosis and arterial/ arteriolar lesion were associated with the endpoint in univariate analysis, only the T score was predictive of the renal outcome in multivariate Cox regression. Combination of the patho- logic lesions had no impact on renal outcome. CONCLUSION: According to the Oxford classification of IgA nephropathy, the degree of tubulointerstitial fibrosis is the only feature independently predictive of renal outcome.

Differential patterns of neuronal activation in rostral versus caudal ventral tegmental area involved in behavioral sensitization induced by an escalating-dose morphine administration paradigm.

The transition to addiction often involves a gradual process of escalated drug intake. The purpose of the present study was to characterize neuronal activation in the ventral tegmental area (VTA) and substantia nigra (SN) following chronic escalating-dose morphine exposure (days 1-7, 2 mg/kg/d; days 8-21, beginning at 10 mg/kg/d, increasing by 2 mg/kg/d), with steady-dose morphine (2 mg/kg/d, i.p., for 21 days) as the comparison. Using immunohistochemical double-staining for tyrosine hydroxylase (TH) and Fos, we found that the number of Fos(+)TH(+) neurons in the rostral VTA and number of Fos(+)TH(-) neurons in the lateral SNr were significantly increased in escalating-dose morphine-treated rats compared with steady-dose morphine-treated rats and acute morphine-treated rats. Meanwhile, this increase was associated with robust expression of behavioral sensitization after a challenge with 10 mg/kg morphine. The number of Fos(+)TH(+) neurons was significantly increased by acute morphine in the caudal VTA and SNc, but this number did not increase further with morphine pretreatment. These results demonstrate that behavioral sensitization was associated with elevated activation of dopaminergic neurons in the rostral VTA and nondopaminergic neurons in the lateral SNr, which could only be induced by chronic escalating-dose morphine rather than chronic steady-dose morphine pretreatment.

Accuracy of single-shot autocorrelation measurements of petawatt laser pulses.

At the Shen Guang II (SGII) Petawatt Laser Facility, measurements of large-energy, single-shot laser pulses sometimes feature asymmetric autocorrelation signals, causing uncertainty in the measurement of compressed pulses. This study presents a method for defining and describing the asymmetry of autocorrelation signals. We discuss two sources of asymmetry: the nonuniform distribution of the near field excited by a beam, and the rotation of autocorrelator arms from the cylinder lens. The pulsewidth of an asymmetric autocorrelation signal is shorter than its real width. After updating the autocorrelator, the single-shot autocorrelator for the SGII petawatt laser exhibits a measurement uncertainty of below 12.3%. Recommendations on reducing asymmetry in large-energy, single-shot autocorrelation are discussed.

Gene expression of conditioned locomotion and context-specific locomotor sensitization controlled by morphine-associated environment.

The nucleus accumbens (NAc) is involved in contextual drug associations, which might be particularly important for environmental cue-induced relapse to drug seeking. In the present study, rats were first administered repeated morphine for 5 days (5 mg/kg, i.p.) in a contextually paired and unpaired design. After reexposure to the morphine-associated environment, which induced conditioned locomotor activity in the morphine-paired group, we performed a rat 27k 70-mer oligo array to profile gene expression in the NAc. One hundred fifty-five upregulated and 88 downregulated genes were found in the paired group compared with the unpaired group. Eight gene transcripts were then selected to confirm their alterations by quantitative real-time polymerase chain reaction (qRT-PCR). The identified genes generally play important roles in neuroactive receptor-ligand interactions, synapse plasticity, ion transport, and protein phosphorylation. Furthermore, the expression of the eight selected genes that were identified and confirmed to show significant fold changes in the first microarray experiment were again measured with qRT-PCR after morphine challenge (2 mg/kg, i.p.). As expected, 2 mg/kg morphine-induced context-specific sensitization. Meanwhile, mRNA expression of the selected genes showed marked upregulation in the morphine-paired group compared with the unpaired and acute groups. These results suggest that alterations in the expression of the identified genes in the NAc may contribute to the neuroplasticity underlying contextual cue-induced relapse to drug use.

Sulfation of tea polysaccharides: synthesis, characterization and hypoglycemic activity.

Neutral polysaccharides (NTPS) and acid polysaccharides (ATPS) from tea leaves were obtained on a D315 macroporous anion-exchange resin column chromatography. NTPS and ATPS were sulfated by the pyridine-sulfonic acid method to obtain NTPS-S and ATPS-S. It was found that NTPS was easier sulfated than ATPS. There are strong characteristic absorption peaks located in 1258 cm(-1), 1146 cm(-1), 832 cm(-1) and 617 cm(-1) in the FTIR spectra of sulfated polysaccharides. Sulfation of polysaccharides also affected the endothermic and exothermic peaks via the DSC scan analysis. The appearance of exothermic peaks in both NTPS-S and ATPS-S indicated that the redox reaction might happen. The comparative study of hypoglycemic effect on mice showed that the sulfation of polysaccharides significantly improved hypoglycemic activity.