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DHHC3 is a DHHC-family palmitoyl acyltransferase that is responsible for many mammalian palmitoylation events. By regulating the posttranslational modification of its specific substrates, DHHC3 has shown a strong protumor effect in various cancers. In this review, the authors introduce the research progress of DHHC3 as a new antitumor target through the expression of DHHC3 in patients with tumors, substrate proteins and potential mechanisms. Recent advances in the search for protein structures and inhibitors are also reviewed. Several design strategies to facilitate the optimization of the process of drug design based on DHHC3 are also discussed.

Vasculogenic mimicry (VM) describes a new tumor microvascular paradigm of non-endothelial cells, where aggressive cancer cells independent of angiogenesis acquire the ability to fluid-conducting vessels. VM shows worse 5-year overall survival in cancer that suggesting that VM could be a promising surgical and effective adjuvant therapy strategy in prognostics of metastatic cancer patients. The current chapter is a comprehensive review on "Main Staining Methods and Protocols in Vasculogenic Mimicry." Here, we provide most up-to-date and detailed information upon microscopy and histology protocols for the identification and understanding of VM process in both in vitro and in vivo.

Background Regenerative endodontic procedures (REPs) have achieved clinical success on the immature permanent teeth with pulp necrosis, and can promote root development. However, preoperative factors and their effects on root development of REPs have not been definitely concluded. The aim of this study was to investigate the preoperative factors that may influence the root development of REPs. Methods A total of 116 teeth in 110 patients treated with REPs in the Paediatric Dentistry Department and Endodontics Department from 2013 to 2017 were included in this study. Preoperative factors including aetiology, age, diagnosis and initial root morphology were collected retrospectively, and the associations between these factors and root development after REPs were analysed by Fisher's exact test and multivariate logistic regression model. Results The overall rate of root development after REPs was 89.7%. The dens evaginatus group showed a higher rate (98.8%) in root development than the trauma group (67.6%) (P P > 0.05). And it showed in the trauma group that the teeth with apical foramen sizes larger than 3 mm significantly promoted root development than those smaller than 3 mm (P P Conclusions The REPs promoted more root developments in the dens evaginatus group than the trauma group, indicating that aetiology may be correlated with the root development of REPs.

BRAF and NRAS are the most reported mutations associated to melanomagenesis. The lack of accurate diagnostic markers in response to therapeutic treatment in BRAF/NRAS-driven melanomagenesis is one of the main challenges in melanoma personalized therapy. In order to assess the diagnostic value of phosphatidylserine-specific phospholipase A1-alpha (PLA1A), a potent lysophospholipid mediating the production of lysophosphatidylserine, PLA1A mRNA and serum levels were compared in subjects with malignant melanoma (n = 18), primary melanoma (n = 13), and healthy subjects (n = 10). Additionally, the correlation between histopathological subtypes of BRAF/NRAS-mutated melanoma and PLA1A was analyzed. PLA1A expression was significantly increased during melanogenesis and positively correlated to disease severity and histopathological markers of metastatic melanoma. PLA1A mRNA and serum levels were significantly higher in patients with BRAF-mutated melanoma compared to the patients with NRAS-mutated melanoma. Notably, PLA1A can be used as a diagnostic marker for an efficient discrimination between naïve melanoma samples and advanced melanoma samples (sensitivity 91%, specificity 57%, and AUC 0.99), as well as BRAF-mutated melanoma samples (sensitivity 62%, specificity 61%, and AUC 0.75). Our findings suggest that PLA1A can be considered as a potential diagnostic marker for advanced and BRAF-mutated melanoma.

Objective To estimate the prognostic efficacy of several systemic hemato-immunological indices for the treatment of cervical cancer as well as to determine whether the systemic hemato-immunological indices are associated with an increased risk of cervical collision cancer. Methods A systematic search was conducted to identify studies that evaluated the prognostic impact of neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), lymphocyte-to-monocyte ratio (LMR), thrombocyte-to-lymphocyte ratio (TLR), C-reactive protein/albumin ratio (CAR), and systemic immune-inflammation index (SII) in cervical cancer patients. The endpoints were overall survival (OS) or progression-free survival (PFS) and clinicopathologic parameters. A meta-analysis using random-effect models was performed to calculate hazard ratios (HRs) or odds ratios with 95% confidence intervals. Results Twenty-two retrospective cohort studies involving 9558 patients were included. Our results show that high NLR, PLR, TLR, and CAR indicated poor prognosis for patients with cervical cancer (HRs = 2.46, 1.88, 3.70, and 3.94, respectively; all P ≤ 0.001). Subgroup analysis suggested that the highest NLR and PLR were more precise biomarkers in patients who were diagnosed with FIGO stage I-III cervical cancer after treatment with chemo-radiotherapy. High TLR and high LMR displayed significant prognostic value in late-FIGO stage III-IV cervical cancer (HRs = 4.33 and 2.032, respectively). Additionally, CAR was associated with poor survival in patients with advanced-FIGO stage cervical cancer and larger tumor size. According to the difference of NLR, the younger (43–51 years old) cervical cancer patients had a tendency of increased collision risk. However, cervical cancer patients in the 52–61 years age group were more vulnerable than their respective counterparts using the pooled estimate for PLR. Conclusion Our findings support a prognostic role for elevated CAR and TLR besides that of NLR and PLR in advanced-FIGO stage cervical cancer.

Long non-coding RNA (LncRNA) contributes to the occurrence and development of osteosarcoma (OS), although the underlying mechanism is not clear. In the present study, we showed that lncRNA MRPL23-AS1 was remarkably increased in OS tissues and cell lines. Stable knockdown of MRPL23-AS1 evidently attenuated cell viability and invasive ability, meanwhile inhibited in vivo tumor growth and dissemination. In terms of mechanism, luciferase reporter, RNA pull-down and fluorescence in situ hybridization (FISH) assays showed that MRPL23-AS1 competitively interacted with miR-30b, increasing myosin heavy chain 9 (MYH9) expression, a trans- activator of β-catenin, resulting in the activation of Wnt/β-catenin pathway, thereby promoting OS tumorigenesis and metastasis. Importantly, high MRPL23-AS1 was positively correlated with MYH9, while conversely correlated with miR-30b, suggesting that the regulatory axis of MRPL23-AS1/miR-30b/MYH9 does exist in OS. Clinically, OS patients with high MRPL23-AS1 had larger tumor size, higher stage and easier metastasis than those with low MRPL23-AS1, moreover, MRPL23-AS1 was identified as an adverse prognostic factor for OS survival. In conclusion, our results show that MRPL23-AS1 is a key oncogenic lncRNA in OS, targeting of MRPL23-AS1 may be a promising treatment for OS patients., GRAPHICAL ABSTRACT

Current therapeutic strategies for Alzheimer's disease (AD) mainly focus on amyloid β oligomer (AβO) formation or clearance. However, most of them have failed to yield good clinical results. There is an urgent need to explore an alternative therapeutic target for AD treatments. Recent studies have indicated that the cellular prion protein (PrP

The glomerular filtration barrier (GFB) produces primary urine and is composed of a fenestrated endothelium, a glomerular basement membrane (GBM), podocytes, and a slit diaphragm. Impairment of the GFB leads to albuminuria and microhematuria. The GBM is generated via secreted proteins from both endothelial cells and podocytes and is supposed to majorly contribute to filtration selectivity. While genetic mutations or variations of GBM components have been recently proposed to be a common cause of glomerular diseases, pathways modifying and stabilizing the GBM remain incompletely understood. Here, we identified prolyl 3-hydroxylase 2 (P3H2) as a regulator of the GBM in an a cohort of patients with albuminuria. P3H2 hydroxylates the 3' of prolines in collagen IV subchains in the endoplasmic reticulum. Characterization of a P3h2ΔPod mouse line revealed that the absence of P3H2 protein in podocytes induced a thin basement membrane nephropathy (TBMN) phenotype with a thinner GBM than that in WT mice and the development of microhematuria and microalbuminuria over time. Mechanistically, differential quantitative proteomics of the GBM identified a significant decrease in the abundance of collagen IV subchains and their interaction partners in P3h2ΔPod mice. To our knowledge, P3H2 protein is the first identified GBM modifier, and loss or mutation of P3H2 causes TBMN and focal segmental glomerulosclerosis in mice and humans.

The genome‑wide copy number analysis of circulating tumor cells (CTCs) provides a promising prognostic biomarker for survival in breast cancer liver metastasis (BCLM) patients. The present study aimed to confirm the prognostic value of the presence of CTCs in BCLM patients. We previously developed an assay for the genome‑wide pattern differences in copy number variations (CNVs) as an adjunct test for the routine imaging and histopathologic diagnosis methods to distinguish newly diagnosed liver metastases and recurrent liver metastases. Forty‑three breast cancer patients were selected for this study in which 23 newly diagnosed and 20 recurrent liver metastases were diagnosed by histopathology and 18F‑FDG PET/CT imaging. CTCs were counted from all patients using the CellSearch system and were confirmed by cytomorphology and three‑color immunocytochemistry. Genomic DNA of single CTCs was amplified using multiple annealing and looping based amplification cycles (MALBAC). Then, we compared the CTC numbers of newly diagnosed and recurrent BCLM patients using Illumina platforms. A high CTC frequency (>15 CTCs/7.5 ml blood) was found to be correlated with disease severity and metastatic progression, which suggests the value for CTCs in the diagnosis of BCLM in comparison with pathohistology and PET/CT imaging (P>0.05). Moreover, CTCs isolated from BCLM patients remained an independent prognostic detection factor associated with overall survival (P=0.0041). Comparison between newly diagnosed and recurrent liver metastases revealed different frequencies of CNVs (P>0.05). Notably, the CNV pattern of isolated CTCs of recurrent BCLM patients was similar to recurrent liver metastases (nearly 82% of the gain/loss regions). Functional enrichment analysis identified 25 genes as a CNV signature of BCLM. Among them, were defensin and β‑defensin genes, which are significantly associated with anti‑angiogenesis and immunomodulation signaling pathways. High CTC frequencies are effective in the evaluation and differentiation between newly diagnosed liver metastases from recurrent liver metastases. Future clinical studies will be necessary to fully determine the prognostic potential of CTC cluster signatures in patients with BCLM.

International audience; While constant basal levels of macroautophagy/autophagy are a prerequisite to preserve long-lived podocytes at the filtration barrier, MTOR regulates at the same time podocyte size and compensatory hypertrophy. Since MTOR is known to generally suppress autophagy, the apparently independent regulation of these two key pathways of glomerular maintenance remained puzzling. We now report that long-term genetic manipulation of MTOR activity does in fact not influence high basal levels of autophagy in podocytes either in vitro or in vivo. Instead we present data showing that autophagy in podocytes is mainly controlled by AMP-activated protein kinase (AMPK) and ULK1 (unc-51 like kinase 1). Pharmacological inhibition of MTOR further shows that the uncoupling of MTOR activity and autophagy is time dependent. Together, our data reveal a novel and unexpected cell-specific mechanism, which permits concurrent MTOR activity as well as high basal autophagy rates in podocytes. Thus, these data indicate manipulation of the AMPK-ULK1 axis rather than inhibition of MTOR as a promising therapeutic intervention to enhance autophagy and preserve podocyte homeostasis in glomerular diseases.Abbreviations: AICAR: 5-aminoimidazole-4-carboxamide ribonucleotide; AMPK: AMP-activated protein kinase; ATG: autophagy related; BW: body weight; Cq: chloroquine; ER: endoplasmic reticulum; ESRD: end stage renal disease; FACS: fluorescence activated cell sorting; GFP: green fluorescent protein; i.p.: intra peritoneal; MAP1LC3/LC3: microtubule-associated protein 1 light chain 3; MTOR: mechanistic target of rapamycin kinase; NPHS1: nephrosis 1, nephrin; NPHS2: nephrosis 2, podocin; PLA: proximity-ligation assay; PRKAA: 5'-AMP-activated protein kinase catalytic subunit alpha; RPTOR/RAPTOR: regulatory associated protein of MTOR, complex 1; RFP: red fluorescent protein; TSC1: tuberous sclerosis 1; ULK1: unc-51 like kinase 1.

Sonodynamic therapy (SDT) has the advantages of high penetration, non-invasiveness, and controllability, and it is suitable for deep-seated tumors. However, there is still a lack of effective sonosensitizers with high sensitivity, safety, and penetration. Now, ultrasound (US) and glutathione (GSH) dual responsive vesicles of Janus Au-MnO nanoparticles (JNPs) were coated with PEG and a ROS-sensitive polymer. Upon US irradiation, the vesicles were disassembled into small Janus Au-MnO nanoparticles (NPs) with promoted penetration ability. Subsequently, GSH-triggered MnO degradation simultaneously released smaller Au NPs as numerous cavitation nucleation sites and Mn2+ for chemodynamic therapy (CDT), resulting in enhanced reactive oxygen species (ROS) generation. This also allowed dual-modality photoacoustic imaging in the second near-infrared (NIR) window and T1 -MR imaging due to the released Mn2+ , and inhibited orthotopic liver tumor growth via synergistic SDT/CDT.

cited By 1 Skeletal muscle wasting is commonly associated with chronic kidney disease (CKD), resulting in increased morbidity and mortality. However, the link between kidney and muscle function remains poorly understood. Here, we took a complementary interorgan approach to investigate skeletal muscle wasting in CKD. We identified increased production and elevated blood levels of soluble pro-cachectic factors, including activin A, directly linking experimental and human CKD to skeletal muscle wasting programs. Single-cell sequencing data identified the expression of activin A in specific kidney cell populations of fibroblasts and cells of the juxtaglomerular apparatus. We propose that persistent and increased kidney production of procachectic factors, combined with a lack of kidney clearance, facilitates a vicious kidney/muscle signaling cycle, leading to exacerbated blood accumulation and, thereby, skeletal muscle wasting. Systemic pharmacological blockade of activin A using soluble activin receptor type IIB ligand trap as well as muscle-specific adeno-associated virus-mediated downregulation of its receptor ACVR2A/B prevented muscle wasting in different mouse models of experimental CKD, suggesting that activin A is a key factor in CKD-induced cachexia. In summary, we uncovered a crosstalk between kidney and muscle and propose modulation of activin signaling as a potential therapeutic strategy for skeletal muscle wasting in CKD.

The prevalence of type 2 diabetes mellitus (T2DM) and by association diabetic nephropathy (DN) will continuously increase in the next decades. Nevertheless, the underlying molecular mechanisms are largely unknown and studies on the role of new actors like long non-coding RNAs (lncRNAs) barely exist. In the present study, the inherently insulin-resistant mouse strain “black and tan, brachyuric” (BTBR) served as T2DM model. While wild-type mice do not exhibit pathological changes, leptin-deficient diabetic animals develop a severe T2DM accompanied by a DN, which closely resembles the human phenotype. We analyzed the glomerular expression of lncRNAs from wild-type and diabetic BTBR mice (four, eight, 16, and 24 weeks) applying the “GeneChip Mouse Whole Transcriptome 1.0 ST” array. This microarray covered more lncRNA gene loci than any other array before. Over the observed time, our data revealed differential expression patterns of 1746 lncRNAs, which markedly differed from mRNAs. We identified protein-coding and non-coding genes, that were not only co-located but also co-expressed, indicating a potentially cis-acting function of these lncRNAs. In vitro-experiments strongly suggested a cell-specific expression of these lncRNA-mRNA-pairs. Additionally, protein-coding genes, being associated with significantly regulated lncRNAs, were enriched in various biological processes and pathways, that were strongly linked to diabetes.

Multiorgan and Renal Tropism of SARS-CoV-2 In this autopsy series, the authors found that SARS-CoV-2 has an organotropism beyond the respiratory tract, including the kidneys, heart, liver, and brai...

Background In this study, the ovariectomized rat model was used to explore the impact of menopause on rats' dorsal lingual epithelium; at the same time, the curative effects of Remifemin and estradiol were also observed. Methods 28 adult female Sprague-Dawley rats were divided into four groups randomly, including sham-operated group (SHAM), an ovariectomized group (OVX), an ovariectomized treated with estradiol (OVX + E), an ovariectomized treated with Remifemin (OVX + iCR). Variation and possible mechanisms were studied via morphology, immunohistochemistry and electron microscope. Results The results showed that the dorsal lingual epithelium became thinner significantly in the apex part in OVX group, as well as the levels of proliferating cell nuclear antigen (PCNA) and the epidermal growth factor (EGF) were lower than that in other three groups. However, they could reverse close to normal after estradiol and Remifemin treatment respectively. Conclusion The thinning in the apex of dorsal lingual epithelium might be due to the reduced proliferation in the germinal layer led by the abating of estrogen level, instead of apoptosis. This might play an important role in the pathogenesis of the menopause female tongue burning sensation. Remifemin had certain curative effect on the dorsal lingual mucosa, but a little more inferior than estrogen.

Multiplex detection of tumor markers in blood with high specificity and high sensitivity is critical to cancer diagnosis, treatment, and prognosis. Herein, we demonstrate a strategy for simultaneous detection of multiple tumor markers in blood by functional liquid crystal (LC) sensors assisted with target-induced dissociation (TID) of an aptamer for the first time. Magnetic beads (MBs) coated with an aptamer (apt1) are employed to specifically capture target proteins in blood. After incubation of the obtained protein-coated MBs with duplexes of another aptamer (apt2) and signal DNA, sandwich complexes of apt1/protein/apt2 are formed on the MBs due to specific recognition of target proteins by apt2, which induces release of signal DNA into the aqueous solution. Subsequently, signal DNA is specifically recognized by highly sensitive DNA-laden LC sensors. Using this strategy, a 3D printed optical cell was employed to enable simultaneous detection of multiple tumor markers such as carcinoembryonic antigen (CEA), alpha-fetoprotein (AFP), and prostate specific antigen (PSA) with high specificity and high sensitivity. Overall, this effective and low-cost multiplex approach takes advantage of the easy separation of MBs, high specificity of aptamer-based recognition, and high sensitivity of functional LC sensors. Plus, it offers a performance that is competitive to that of commercial ELISA kits without potential interference from hemolysis, which makes it very promising in multiplex detection of tumor markers in clinical applications.

Mucociliary clearance through coordinated ciliary beating is a major innate defense removing pathogens from the lower airways, but the pathogen sensing and downstream signaling mechanisms remain unclear. We identified virulence-associated formylated bacterial peptides that potently stimulated ciliary-driven transport in the mouse trachea. This innate response was independent of formyl peptide and taste receptors but depended on key taste transduction genes. Tracheal cholinergic chemosensory cells expressed these genes, and genetic ablation of these cells abrogated peptide-driven stimulation of mucociliary clearance. Trpm5-deficient mice were more susceptible to infection with a natural pathogen, and formylated bacterial peptides were detected in patients with chronic obstructive pulmonary disease. Optogenetics and peptide stimulation revealed that ciliary beating was driven by paracrine cholinergic signaling from chemosensory to ciliated cells operating through muscarinic M3 receptors independently of nerves. We provide a cellular and molecular framework that defines how tracheal chemosensory cells integrate chemosensation with innate defense.

The visualization of glycosylation states of specific proteins in vivo is of great importance for uncovering their roles in disease development. However, the ubiquity of glycosylation makes probing the glycans on a certain protein as difficult as looking for a needle in a haystack. Herein, we demonstrate a proximity-induced hybridization chain reaction (HCR) strategy for amplified visualization of protein-specific glycosylation. The strategy relies on designing two kinds of DNA probes, glycan conversion probes and protein recognition probes, which are attached to glycans and target proteins, respectively. Upon sequential binding to the targets, the proximity-induced hybridization between two probes occurs, which leads to the structure-switching of protein recognition probes, followed by triggering of HCR assembly. This strategy has been used to visualize tyrosine-protein kinase 7-specific sialic acid in living CEM cells and zebrafish and to monitor its variation during drug treatment. It provides a potential tool for investigating protein-specific glycosylation and researching the relation between dynamic glycans state and disease process.

Cholesterol is an essential compound for maintaining cellular homeostasis and human healthy. Sensitive detection of cholesterol and efficient elimination of excess cholesterol have become the essential manipulations in clinical diagnosis and health management. To date, it is still quite challenging that cholesterol detection and elimination tasks are carried out simultaneously. In this study, bifunctional magnetic nanoparticles (Fe3O4@PDA-PBA-CD) are designed and fabricated to overcome this difficulty. Taking advantages of competitive host-guest interaction and magnetic separation, highly efficient, reusable and simultaneous cholesterol detection and elimination can be achieved. The limit of detection is determined to be 4.3 nM, which is comparable or even lower than existing methods. The distinguished performance may attribute to the high loading efficiency and magnetic enrichment of nanoparticles. Besides, this efficient strategy is resistant to interfering substances, thus realizing sensitive cholesterol detection in real sample. Simultaneously, the bifunctional magnetic nanoparticles also have up to 95% cholesterol elimination efficiency, which is higher than previous reported methods. Furthermore, the nanoparticles are turned out to be reusable within 5 times without noticeable loss in cholesterol elimination efficiency. Therefore, the bifunctional magnetic nanoparticles fabricated here could hold great potential for simultaneous cholesterol detection and elimination in practical applications.

BACKGROUND Neuromodulation devices have the potential to transform modern day treatments for patients with medicine-resistant neurological disease. For instance, the NeuroPace System (NeuroPace Inc, Mountain View, California) is a Food and Drug Administration (FDA)-approved device developed for closed-loop direct brain neurostimulation in the setting of drug-resistant focal epilepsy. However, current methods require placement either above or below the skull in nonanatomic locations. This type of positioning has several drawbacks including visible deformities and scalp pressure from underneath leading to eventual wound healing difficulties, micromotion of hardware with infection, and extrusion leading to premature explantation. OBJECTIVE To introduce complete integration of a neuromodulation device within a customized cranial implant for biocompatibility optimization and prevention of visible deformity. METHODS We report a patient with drug-resistant focal epilepsy despite previous seizure surgery and maximized medical therapy. Preoperative imaging demonstrated severe resorption of previous bone flap causing deformity and risk for injury. She underwent successful responsive neurostimulation device implantation via complete integration within a clear customized cranial implant. RESULTS The patient has recovered well without complication and has been followed closely for 180 d. Device interrogation with electrocorticographic data transmission has been successfully performed through the clear implant material for the first time with no evidence of any wireless transmission interference. CONCLUSION Cranial contour irregularities, implant site infection, and bone flap resorption/osteomyelitis are adverse events associated with implantable neurotechnology. This method represents a novel strategy to incorporate all future neuromodulation devices within the confines of a low-profile, computer-designed cranial implant and the newfound potential to eliminate contour irregularities, improve outcomes, and optimize patient satisfaction.

Chronic glomerular diseases, associated with renal failure and cardiovascular morbidity, represent a major health issue. However, they remain poorly understood. Here we have reported that tightly controlled mTOR activity was crucial to maintaining glomerular podocyte function, while dysregulation of mTOR facilitated glomerular diseases. Genetic deletion of mTOR complex 1 (mTORC1) in mouse podocytes induced proteinuria and progressive glomerulosclerosis. Furthermore, simultaneous deletion of both mTORC1 and mTORC2 from mouse podocytes aggravated the glomerular lesions, revealing the importance of both mTOR complexes for podocyte homeostasis. In contrast, increased mTOR activity accompanied human diabetic nephropathy, characterized by early glomerular hypertrophy and hyperfiltration. Curtailing mTORC1 signaling in mice by genetically reducing mTORC1 copy number in podocytes prevented glomerulosclerosis and significantly ameliorated the progression of glomerular disease in diabetic nephropathy. These results demonstrate the requirement for tightly balanced mTOR activity in podocyte homeostasis and suggest that mTOR inhibition can protect podocytes and prevent progressive diabetic nephropathy.

The aim of this study was to investigate the effects of verapamil on the pharmacokinetics of pristimerin in rats. A sensitive and reliable LC-MS/MS method was developed and applied for the determination of pristimerin in rat plasma. The pharmacokinetics of orally administered pristimerin with and without verapamil pretreatment was investigated. The results indicated that, when the rats were pretreated with verapamil, the peak concentration of pristimerin increased from 189.13 to 277.53 ng/mL (46.7%), and the AUC0-t increased by approximately 82.0%. Additionally, the effects of verapamil on the absorption and metabolic stability of pristimerin were investigated using the Caco-2 cell transwell model and rat liver microsomes. A markedly higher transport of pristimerin across the Caco-2 cells was observed in the basolateral-to-apical direction and was abrogated in the presence of the P-gp inhibitor, verapamil. These results indicated that P-gp might be involved in the absorption of pristimerin. Of note, the metabolic half-life of pristimerin was prolonged by the pretreatment with verapamil. In conclusion, verapamil could affect the pharmacokinetics of pristimerin, and it might work through increasing the absorption of pristimerin by inhibiting P-gp, or through slowing down the metabolism of pristimerin in the rat liver. Copyright © 2015 John WileySons, Ltd.

Loss of kidney function in renal ischemia/reperfusion injury is due to programmed cell death, but the contribution of necroptosis, a newly discovered form of programmed necrosis, has not been evaluated. Here, we identified the presence of death receptor–mediated but caspase-independent cell death in murine tubular cells and characterized it as necroptosis by the addition of necrostatin-1, a highly specific receptor-interacting protein kinase 1 inhibitor. The detection of receptor-interacting protein kinase 1 and 3 in whole-kidney lysates and freshly isolated murine proximal tubules led us to investigate the contribution of necroptosis in a mouse model of renal ischemia/reperfusion injury. Treatment with necrostatin-1 reduced organ damage and renal failure, even when administered after reperfusion, resulting in a significant survival benefit in a model of lethal renal ischemia/reperfusion injury. Unexpectedly, specific blockade of apoptosis by zVAD, a pan-caspase inhibitor, did not prevent the organ damage or the increase in urea and creatinine in vivo in renal ischemia/reperfusion injury. Thus, necroptosis is present and has functional relevance in the pathophysiological course of ischemic kidney injury and shows the predominance of necroptosis over apoptosis in this setting. Necrostatin-1 may have therapeutic potential to prevent and treat renal ischemia/reperfusion injury.

Injury and loss of podocytes are leading factors of glomerular disease and renal failure. The postmitotic podocyte is the primary glomerular target for toxic, immune, metabolic, and oxidant stress, but little is known about how this cell type copes with stress. Recently, autophagy has been identified as a major pathway that delivers damaged proteins and organelles to lysosomes in order to maintain cellular homeostasis. Here we report that podocytes exhibit an unusually high level of constitutive autophagy. Podocyte-specific deletion of autophagy-related 5 (Atg5) led to a glomerulopathy in aging mice that was accompanied by an accumulation of oxidized and ubiquitinated proteins, ER stress, and proteinuria. These changes resulted ultimately in podocyte loss and late-onset glomerulosclerosis. Analysis of pathophysiological conditions indicated that autophagy was substantially increased in glomeruli from mice with induced proteinuria and in glomeruli from patients with acquired proteinuric diseases. Further, mice lacking Atg5 in podocytes exhibited strongly increased susceptibility to models of glomerular disease. These findings highlight the importance of induced autophagy as a key homeostatic mechanism to maintain podocyte integrity. We postulate that constitutive and induced autophagy is a major protective mechanism against podocyte aging and glomerular injury, representing a putative target to ameliorate human glomerular disease and aging-related loss of renal function.