CRISPR-Cas9-Mediated Correction of SLC12A3 Gene Mutation Rescues the Gitelman's Disease Phenotype in a Patient-Derived Kidney Organoid System.

The aim of this study is to explore the possibility of modeling Gitelman's disease (GIT) with human-induced pluripotent stem cell (hiPSC)-derived kidney organoids and to test whether gene correction using CRISPR/Cas9 can rescue the disease phenotype of GIT. To model GIT, we used the hiPSC line CMCi002 (CMC-GIT-001), generated using PBMCs from GIT patients with SLC12A3 gene mutation. Using the CRISPR-Cas9 system, we corrected CMC-GIT-001 mutations and hence generated CMC-GIT-001corr. Both hiPSCs were differentiated into kidney organoids, and we analyzed the GIT phenotype. The number of matured kidney organoids from the CMC-GIT-001corr group was significantly higher, 3.3-fold, than that of the CMC-GIT-001 group (12.2 ± 0.7/cm2 vs. 3.7 ± 0.2/cm2, p < 0.05). In qRT-PCR, performed using harvested kidney organoids, relative sodium chloride cotransporter (NCCT) mRNA levels (normalized to each iPSC) were increased in the CMC-GIT-001corr group compared with the CMC-GIT-001 group (4.1 ± 0.8 vs. 2.5 ± 0.2, p < 0.05). Consistently, immunoblot analysis revealed increased levels of NCCT protein, in addition to other tubular proteins markers, such as LTL and ECAD, in the CMC-GIT-001corr group compared to the CMC-GIT-001 group. Furthermore, we found that increased immunoreactivity of NCCT in the CMC-GIT-001corr group was colocalized with ECAD (a distal tubule marker) using confocal microscopy. Kidney organoids from GIT patient-derived iPSC recapitulated the Gitelman's disease phenotype, and correction of SLC12A3 mutation utilizing CRISPR-Cas9 technology provided therapeutic insight.

Effect of dual inhibition of DPP4 and SGLT2 on tacrolimus-induced diabetes mellitus and nephrotoxicity in a rat model.

Sodium/glucose co-transporter-2 inhibitor (SGLT2i) or dipeptidyl peptidase IV inhibitor (DPP4i) is a newer anti-diabetic drug in type II diabetes mellitus (DM), but their use in tacrolimus (TAC)-induced DM is still undetermined. We performed this study to evaluate the effect of these two drugs in TAC-induced DM and nephrotoxicity in ex vivo and in vivo. In the experimental Sprague Dawley rat model of TAC-induced DM and nephrotoxicity, dual inhibition of DPP4 and SGLT2 significantly decreased blood glucose level, HbA1C and increased plasma insulin levels and pancreatic islet size compared with each drug. In the kidney, dual inhibition improved renal function decreased interstitial fibrosis and profibrotic cytokines compared with DPP4i and SGLT2i alone. Increased oxidative stress by TAC was remarkably decreased with DPP4i or SGLT2i in serum, pancreatic and renal tissues and this decrease was much more significant in the combination group. In in vitro study, TAC decreased the cell viability of human kidney-2(HK-2) cells and insulin-secreting beta-cell-derived line(INS-1) cells. SGLT2i protected TAC-induced cell death in HK-2 cells, but not in INS-1 cells. The addition of DPP4i to SGLT2i compensated for a lack of protective effect of SGLT2i on INS-1 cells. This finding provides the rationale for the combined treatment of SGLG2i and DPP4i in TAC-induced DM and nephrotoxicity.

Clinical significance of heart rate variability for the monitoring of cardiac autonomic neuropathy in end-stage renal disease patients.

BACKGROUND AND AIMS: The aim of this study is to determine whether the measurement of continuous heart rate variability (HRV) is useful in the evaluation of cardiac autonomic neuropathy (CAN) in end-stage renal disease (ESRD) patients. METHODS AND RESULTS: This cross-sectional study was performed at Seoul St. Mary's hospital between June 2017 and February 2018. Seventy-seven ESRD patients, and 29 healthy controls (HCs) were asked to wear a continuous ambulatory HRV monitor for 24 h. General cardiac function was evaluated using transthoracic echocardiogram (TTE), pulse wave velocity (PWV), coronary calcium scoring (CCS), and 24-h ambulatory blood pressure monitoring (ABPM). HRV parameters of ESRD patients and HCs, and the correlation of HRV parameters with cardiovascular screening methods were observed. All HRV parameters were significantly decreased in ESRD patients compared to HCs (P < 0.001). In the correlation analysis between TTE results and HRV parameters, 24-h standard deviation of all N-N intervals (24SDNN), 24-h standard deviation of sequential 5-min N-N interval means (24DANN) and Low Frequency Power/High Frequency Power (LF/HF) ratio showed negative correlations with E/e', LAVI and TR velocity which are representative indices for the diastolic function of the heart (P < 0.05). HRV parameters showed negative correlations with baPWV, CCS, and 24-h ABPM results as well (P < 0.05). Hemoglobin and serum albumin showed positive correlations with HRV parameters, and glucose, BUN, creatinine, and iPTH levels showed negative correlations (P < 0.05). CONCLUSION: Continuous HRV monitoring may be a useful tool for the evaluation of CAN in ESRD.

Host cell in vivo production of the synthetic drug anti-CD25/IL-10 using minicircle vector.

Synthetic biologic drugs are highly successful for induction therapy in transplantation, but the development of novel biologics is limited because of the high cost of synthesis and purification. In this study, we developed a novel strategy for the production of synthetic protein drugs in vivo by the host itself. We utilized minicircle (MC) technology, which can robustly express a target molecule and secrete it from cells, as an indirect method to produce a protein of interest in vivo. We designed an MC vector containing the sequences of basiliximab (anti-CD25 mAb) and IL-10. We verified the substantial production of the anti-CD25/IL-10 protein from the MC in vitro and in vivo. The therapeutic effect of MC-derived anti-CD25/IL-10 was evaluated in a skin allograft mouse model by single intravenous infusion. Mice treated with the MC encoding anti-CD25/IL-10 exhibited prolonged skin allograft survival times accompanied by improved histologic changes and immunologic regulation. These findings indicate that the anti-CD25/IL-10 protein drug obtained by MC technology is functionally active and relevant for reducing allograft rejection. This self-reproducible strategy for synthetic protein drugs using MCs is a promising tool for transplantation.-Lim, S. W., Shin, Y. J., Luo, K., Quan, Y., Ko, E. J., Chung, B. H., Yang, C. W. Host cell in vivo production of the synthetic drug anti-CD25/IL-10 using minicircle vector.

Effect of Klotho on autophagy clearance in tacrolimus-induced renal injury.

Recently, we showed that tacrolimus-induced renal injury was closely associated with impairment of autophagy clearance, and Klotho deficiency aggravated tacrolimus-induced renal injury. In this study, we evaluated the effect of Klotho treatment on autophagy clearance in tacrolimus-induced renal injury. We evaluated the effect of Klotho on tacrolimus-induced renal injury in an experimental mouse model and in vitro by treatment with tacrolimus and/or recombinant mouse Klotho. In vivo and in vitro studies showed that tacrolimus treatment impaired lysosomal acidification and decreased cathepsin B activity, expression of lysosome-associated membrane protein 2, and expression of transcription factor EB (TFEB), a master regulator for lysosomal biogenesis. These results were improved by Klotho treatment. Moreover, addition of bafilomycin A1, an inhibitor of lysosomal function, abolished the protective effect of Klotho, indicating that the protective effect of Klotho was closely associated with lysosome function. Klotho induced nuclear translocation of TFEB through inhibition of phosphorylation of glycogen synthase kinase 3ß (GSK3ß) by confirming using CHIR99021, a GSK3ß inhibitor. Collectively, our data suggest that Klotho improves autophagy clearance via activation of lysosomal function in tacrolimus-induced nephrotoxicity.-Lim, S. W., Shin, Y. J., Luo, K., Quan, Y., Ko, E. J., Chung, B. H., Yang, C. W. Effect of Klotho on autophagy clearance in tacrolimus-induced renal injury.

Coenzyme Q10 alleviates tacrolimus-induced mitochondrial dysfunction in kidney.

The major side effect of tacrolimus (Tac) is nephrotoxicity. We studied whether supplementation of coenzyme Q10, (CoQ10) a potent antioxidant, can reduce Tac-induced nephrotoxicity via improving mitochondrial function. In an in vitro study, CoQ10 reduced the production of Tac-induced mitochondrial reactive oxygen species and abolished the loss of mitochondrial membrane potential in proximal tubular cell line. Assessment of mitochondrial function revealed that CoQ10 decreased oxygen consumption and mitochondrial respiration rate increased by Tac, suggesting improvement of mitochondrial function to synthesize ATP with CoQ10 treatment. The effect of the CoQ10in vitro study was observed in an experimental model of chronic Tac-induced nephropathy. CoQ10 attenuated Tac-induced oxidative stress and was accompanied by function and histologic improvement. On electron microscopy, addition of CoQ10 increased not only the number but also the volume of mitochondria compared with Tac treatment only. Our data indicate that CoQ10 improves Tac-induced mitochondrial dysfunction in kidney. Supplementary CoQ10 treatment may be a promising approach to reduce Tac-induced nephrotoxicity.-Yu, J. H., Lim, S. W., Luo, K., Cui, S., Quan, Y., Shin, Y. J., Lee, K. E., Kim, H. L., Ko, E. J., Chung, B. H., Kim, J. H., Chung, S. J., Yang, C. W. Coenzyme Q10 alleviates tacrolimus-induced mitochondrial dysfunction in kidney.

The impact of cytomegalovirus infection on clinical severity and outcomes in kidney transplant recipients with Pneumocystis jirovecii pneumonia.

Cytomegalovirus (CMV) infection is associated with Pneumocystis jirovecii pneumonia (PJP) in kidney transplant recipients (KTRs), but its impact on clinical severity and outcomes in KTRs with PJP is unknown. We reviewed 1994 medical records of KTRs from January 1997 to March 2019. PJP or CMV infection was diagnosed by polymerase chain reaction or culturing using blood or respiratory specimens. We divided patients into PJP and PJP+CMV groups, and evaluated the clinical severity and outcomes. Fifty two patients had PJP (2.6%) in the whole study cohort. Among patients with PJP, 38 (73.1%) had PJP alone and 14 (26.9%) had combined PJP and CMV co-infection. The PJP+CMV group showed worse laboratory findings (serum albumin and C-reactive protein, P = 0.010 for both) and higher requirement of continuous renal replacement therapy than the PJP group (P = 0.050). The pneumonia severity was worse in the PJP+CMV group than in the PJP group (P < 0.05), and CMV infection was a high risk factor of pneumonia severity (odds ratio 16.0; P = 0.002). The graft function was worse in the PJP+CMV group (P < 0.001), and the incidence of graft failure was higher in the PJP+CMV group than in the PJP group (85.7% vs 36.8%; P < 0.001). Mortality was double in the PJP+CMV group than in the PJP group, but not statistically significant (21.4% vs 10.5%; P = 0.370). Our results show that approximately one in four patients with PJP after kidney transplantation develops CMV with increased clinical severity and risk of graft failure. The possibility of increased clinical severity and worse clinical outcomes by CMV co-infection should be considered in KTRs with PJP.

Moving closer to death: understanding psychosocial distress among older veterans with advanced cancers.

BACKGROUND: Early identification of psychosocial distress is important to address the needs of vulnerable populations and influence symptom management. Older veterans diagnosed with life-limiting cancers are particularly vulnerable because they often have unmet needs, experiencing psychological or emotional problems and gaps in healthcare communication, which extends suffering. Lack of emotional support, ongoing physical pain, and unresolved symptom control can further increase distress among older veterans, contributing to complexity of decision-making for end of life (EOL) care. OBJECTIVE: We explored older veterans' experiences and identification of psychosocial distress in cancer care to better understand how they describe distress while facing the end of life. METHODS: Guiding this study is a conceptual framework from psychosocial oncology with the multifactorial experience of distress indicated by NCCN guidelines for distress screening. We use a phenomenological approach to explore the experience of psychosocial distress among older veterans diagnosed with advanced cancers at risk for dying within a year. INCLUSION CRITERIA: Provider response of "no" to, "Would you be surprised if your patient died within a year?" and "yes", to the question, "Have you talked with your patient about the severity of their illness as being life-limiting, terminal?" RESULTS: Five themes emerged: (1) the meaning of distress: "It's hard to explain"; (2) severity of advanced cancer: "There's no stage five"; (3) distressing thoughts about the possibility of dying: "Either way, it's life limiting"; (4) coping: "Deal with it and hope for a better day"; and (5) personal factors: "I don't want to be anything but a man who can handle adversity." Findings suggest older veterans may have unique cancer experiences different from other populations. CONCLUSION: Older veterans in this study exhibited distressing symptoms which demonstrate they are at risk for declining health and in need of support for their distress. Healthcare providers are urged to understand the complexity of distress to provide the best possible treatment for older veterans.

Development of End Stage Renal Disease after Long-Term Ingestion of Chaga Mushroom: Case Report and Review of Literature.

Chaga mushrooms are widely used in folk remedies and in alternative medicine. Contrary to many beneficial effects, its adverse effect is rarely reported. We here report a case of end-stage renal disease after long-term taking Chaga mushroom. A 49-year-old Korean man with end stage renal disease (ESRD) was transferred to our hospital. Review of kidney biopsy finding was consistent with chronic tubulointerstitial nephritis with oxalate crystal deposits and drug history revealed long-term exposure to Chaga mushroom powder due to intractable atopic dermatitis. We suspected the association between Chaga mushroom and oxalate nephropathy, and measured the oxalate content of remained Chaga mushroom. The Chaga mushroom had extremely high oxalate content (14.2/100 g). Estimated daily oxalate intake of our case was 2 times for four years and 5 times for one year higher than that of usual diet. Chaga mushroom is a potential risk factor of chronic kidney disease considering high oxalate content. Nephrologist should consider oxalate nephropathy in ESRD patients exposed to Chaga mushrooms.

Therapeutic Challenge of Minicircle Vector Encoding Klotho in Animal Model.

BACKGROUND: Klotho treatment is a promising approach against kidney injury, but its clinical application is still undetermined. We developed a novel strategy to allow self-production of Klotho protein, using minicircle (MC) technology, and evaluated its feasibility in therapeutic Klotho delivery. METHODS: We engineered MC vectors to carry cassette sequences of Klotho and verified the self-production of Klotho protein from in HEK293T cells. We evaluated the location and persistence of delivered MC in vivo, and the duration of Klotho protein production from MCs by serial measurement of Klotho protein in blood. We subsequently evaluated the therapeutic potential of Klotho-encoding MCs in experimental model of renal injury. RESULTS: We confirmed the production of Klotho from MC by its significant availability in cells transfected with the MC, as well as in its conditioned medium, compared to that in cells transfected with parent vector. MCs were delivered in vivo by hydrodynamic injection via tail vein. After a single injection of MCs, red fluorescence protein was detected until 30 days in liver, and Klotho protein was maintained until 10 days in the blood, suggesting the production of Klotho protein from MCs via protein synthesis machinery in liver. Therapeutic effect of MC was confirmed by functional and histological improvement seen in mouse model of acute ischemia-reperfusion injury and unilateral ureteral obstruction. CONCLUSION: Together, these findings implied that self-generated Klotho protein, using MC technology, is functionally active and relevant as a therapeutic approach in renal injury.