Case Report: Comprehensive Management of Pneumocystis Jiroveci Pneumonia (PJP) and Secondary Infections of Multiple-Drug Resistant Enterobacter cloacae complex and Pseudomonas aeruginosa in a Kidney Transplant Recipient with Sulfonamide Allergies.

We report a case of pneumocystis jiroveci pneumonia (PJP) in a 46-year-old woman, who previously underwent kidney transplant for chronic renal failure. She did not receive PJP prophylaxis treatment for the history of sulfonamide allergies. Four months after renal transplantation, the patient had cough, chest tightness, and shortness of breath. Procalcitonin (PCT) (0.06 ng/mL) and C-reactive protein (CRP) (5.33 mg/L) were normal, but the level of 1, 3-ß-D-glucan test (G test, 193.89 pg/mL) were elevated. Metagenomics next-generation sequencing (mNGS) using bronchoalveolar lavage fluid (BALF) rapidly and accurately identified P. jiroveci. Through sulfonamide desensitization and sulfamethoxazole-trimethoprim (TMP-SMX) combined with caspofungin (CAS) treatment, PJP was controlled. However, the patients' conditions were worsen for the hospital-acquired secondary pulmonary infection. A second BALF mNGS identified Enterobacter cloacae complex and Pseudomonas aeruginosa carrying carbapenem drug resistance genes, which were confirmed by subsequent culture and antimicrobial susceptibility test within 3 days. Finally, symptoms, such as chest tightness, cough, and shortness of breath, were improved and she was discharged after combined treatment with meropenem (MEM), polymyxin B (PMB), CAS, and TMP-SMX. In this case, mNGS, culture, and drug susceptibility testing were combined to monitor pathogenic microbial and adjust medication. At present, there are no case reports of mNGS use and sulfonamide desensitization in a kidney transplant recipient with sulfonamide allergies.

TRPC6 ameliorates renal ischemic reperfusion injury by inducing Zn2+ influx and activating autophagy to resist necrosis.

Background: Renal ischemic reperfusion injury (RIRI) is the most hackneyed cause of acute renal injury with high incidence. As a slit diaphragm (SD), TRPC6 (transient receptor potential channel 6) can maintain the structure and function of glomerular podocytes, and its activation has been reported to prominently alleviate ischemia reperfusion (I/R). However, the specific mechanism of TRPC6 in RIRI is uncertain. Methods: The TRPC6 specific shRNA or overexpressing plasmid was used to decrease or increase TRPC6 level in HK-2 cells, respectively. Subsequently, the OGD/R (oxygen-glucose deprivation and re-oxygenation) HK-2 cells and RIRI model rats was established to examine the effect of TRPC6 in RIRI in vitro. After processing, viability was confirmed with MTT; cell necrosis was analyzed with flow cytometry; necrosis and autophagy-related proteins were verified with Western blot; free Zn2+ was tested with an Zn2+ fluorescent probe; and cell autophagy was monitored with MDC (monodansylcadaverine) method. Furthermore, TRPC6 agonist (OGA) or TRPC6 inhibitor (SKF96365) were introduced to increase or inhibit the activity of TRPC6 in RIRI model rats, and the kidney injury was assessed with H&E staining and RIP1 and PARP-1 expressions were examined with IHC (immunohistochemistry) staining. Results: Our results verified TRPC6 could markedly enhance viability, Zn2+ influx, and autophagy, and suppressed necrosis in OGD/R HK-2 cells. In addition, increase of Zn2+ or autophagy activation produced similar results to TRPC6 overexpression in viability, autophagy, and necrosis of OGD/R HK-2 cells. Rescue experiment results also showed TRPC6 could prevent necrosis and facilitate Zn2+ influx and autophagy of OGD/R HK-2 cells by inducing Zn2+ influx and autophagy. Moreover, TRPC6 could ameliorate kidney injury, block necrosis, and enhance autophagy in RIRI model rats by promoting Zn2+ influx and autophagy. Conclusions: TRPC6 could prevent necrosis and induce autophagy to alleviate RIRI by accelerating Zn2+ influx and autophagy. This shows TRPC6/Zn2+ influx/autophagy might be a novel therapeutic strategy for RIRI.

Current Status of Ultrasound in Acute Rejection After Renal Transplantation: A Review with a Focus on Contrast-Enhanced Ultrasound.

Renal transplantation has developed into the best treatment for end-stage renal disease, but severe cases can even lead to loss of renal allograft function due to rejection and complications caused by surgical procedures. If a series of postoperative complications can be reduced or even avoided, the quality of life of recipients will be significantly improved. Acute rejection in a transplanted kidney is one of the main complications after renal transplantation. Early detection and diagnosis will significantly help the prognosis of transplanted kidney patients. As a seminal morphological and hemodynamic examination method, ultrasound can monitor the tissue structure and arteriovenous blood flow of the transplanted kidney, providing information on the transplanted kidney's gross shape and blood perfusion. Ultrasound is a commonly used detection method after renal transplantation. At present, two-dimensional ultrasound, color Doppler ultrasound, three-dimensional ultrasound, and contrast-enhanced ultrasound have been applied in the monitoring of complications after renal transplantation. Contrast-enhanced ultrasound, as a non-invasive, radiation-free, and easy to perform examination technique, can qualitatively and quantitatively evaluate the microcirculatory blood perfusion of the transplanted kidney. It can reflect the function of the transplanted kidney more objectively and sensitively. In recent years, contrast-enhanced ultrasound has attracted attention as a new technology that can quantitatively monitor the transplanted kidney's microcirculation perfusion. A large number of studies have shown that contrast-enhanced ultrasound has unique advantages in monitoring acute rejection after renal transplantation compared with other imaging methods, providing a reliable basis for clinical intervention. This article reviews the current status of and recent research on contrast-enhanced ultrasound in acute rejection after renal transplantation.

The long noncoding RNA Ptprd-IR is a novel molecular target for TGF-ß1-mediated nephritis.

The role of microRNAs (miRNAs) in chronic kidney disease (CKD) is relatively well established, but much less is known about the role(s) of long noncoding RNAs (lncRNAs). Transforming growth factor ß1 (TGF-ß1) mediates inflammatory and fibrogenic signaling in CKD via the transcription factor Smad3; however, the extent of lncRNAs-based regulation of TGF-ß1 signaling in CKD remains unknown. Herein, we identified np_4334, a lncRNA we named Ptprd-IR, whose promoter contains a highly-conserved site for Smad3 binding. Smad3 knockout (KO) eliminated Ptprd-IR upregulation in a murine model of obstructive nephropathy. Furthermore, Ptprd-IR KO in renal tubular epithelial cell cultures blocked TGF-ß1- and interleukin-1ß (IL-1ß)-mediated NF-κB inflammatory signaling but did not impact TGF-ß1-triggered Smad3 pathway activity and fibrosis. Accordingly, Ptprd-IR overexpression (OE) upregulated TGF-ß1- and IL-1ß-mediated NF-κB pathway activation and production of pro-inflammatory cytokines but did not influence TGF-ß1-mediated fibrogenic signaling. Additionally, transfection of obstructed kidneys with Ptprd-IR-directed shRNA attenuated the inflammatory response via NF-κB but did not impact TGF-ß1/Smad3-mediated fibrogenesis. Overall, our findings demonstrate that the lncRNA Ptprd-IR stimulates the inflammatory response in kidneys and advocate Ptprd-IR as a possible therapeutic target for CKD.

Necrostatin-1 Attenuates Renal Ischemia and Reperfusion Injury via Meditation of HIF-1α/mir-26a/TRPC6/PARP1 Signaling.

Necroptosis, oxidative stress, and inflammation are major contributors to the pathogenesis of ischemic acute kidney injury. Necrostatin-1 (Nec-1), an inhibitor of the kinase domain of receptor-interacting protein kinase-1 (RIP1), has been reported to regulate renal ischemia and reperfusion (I/R) injury; however, its underlying mechanism of action remains unclear. HK-2 cells were used to create an in vitro I/R model, in which the cells were subjected to hypoxia, followed by 2, 6, and 12 h of reoxygenation. For the in vivo study, a rat model of renal I/R was established in which samples of rat blood serum and kidney tissue were harvested after reperfusion to assess renal function and detect histological changes. Cell viability and necroptosis were analyzed using the Cell Counting Kit (CCK)-8 assay and flow cytometry, respectively. The expression levels of molecules associated with necroptosis, oxidative stress, and inflammation were determined by real-time PCR, western blotting, immunofluorescence staining, and ELISA. Luciferase and chromatin immunoprecipitation (ChIP) assays were performed to confirm the relevant downstream signaling pathway. We found that pretreatment with Nec-1 significantly decreased hypoxia-inducible factor-1α (HIF-1α) and miR-26a expression, as well as the levels of factors associated with necroptosis (RIP1, RIP3, and Sirtuin-2), oxidative stress (malondialdehyde [MDA], NADP+/NADPH ratio), and inflammation (interleukin [IL]-1ß, IL-10, and tumor necrosis factor alpha [TNF-α]) in I/R injury cells and the rat model. However, these effects could be reversed by miR-26a overexpression or TRPC6 knockdown. Mechanistic studies demonstrated that HIF-1α directly binds to the promoter region of miR-26a, and that TRPC6 is a potential target gene for miR-26a. Our findings indicate that Nec-1 can effectively protect against renal I/R injury by inhibiting necroptosis, oxidative stress, and inflammation, and may exert its effects through mediation of the HIF-1α/miR-26a/TRPC6/PARP1 signaling pathway.

Efficacy of N-Acetylcysteine in Preventing Acute Kidney Injury After Cardiac Surgery: A Meta-Analysis Study.

PURPOSE: To evaluate whether perioperative N-acetylcysteine (NAC) administration reduces the risk of cardiac surgery associated acute kidney injury (CSA-AKI). MATERIALS AND METHODS: A systematic literature review (Medline, PubMed, Cochrane, Biomedical central, Google Scholar) identified 10 studies (1391 patients; 695 NAC and 696 placebo) that compared the efficacy and adverse effects of perioperative NAC administration for CSA-AKI prevention in adults undergoing elective cardiac surgery. Meta-analysis was performed using Comprehensive Meta-Analysis statistical software. RESULTS: Patients in the NAC-treated and placebo groups had similar rate of CSA-AKI occurrence, change in creatinine levels, as well as the in-hospital mortality rate (RR = 0.841, 95% CI = 0.691 to 1.023, p = 0.083; pooled difference in means = -0.328, 95% CI = -0.712 to 0.056, p = 0.094; RR = 0.741, 95% CI = 0.388 to 1.418, p = 0.366, respectively). CONCLUSIONS: Our study does not support perioperative NAC administration as a mean to reduce the risk of CSA-AKI.