Jordan S. Pober

Clear-cell renal cell carcinoma (ccRCC), a tubular epithelial malignancy, secretes tumor necrosis factor (TNF), which signals ccRCC cells in an autocrine manner via two cell surface receptors, TNFR1 and TNFR2, to activate shared and distinct signaling pathways. Selective ligation of TNFR2 was shown to drive cell cycle entry of malignant cells via a signaling pathway involving epithelial tyrosine kinase, vascular endothelial cell growth factor receptor type 2, phosphatidylinositol-3-kinase, Akt, pSer727-Stat3, and mammalian target of rapamycin. In this study, phosphorylated 4E binding protein-1 (4EBP1) serine 65 (pSer65-4EBP1) is identified as a downstream target of this TNFR2 signaling pathway. pSer65-4EBP1 expression is significantly elevated relative to total 4EBP1 in ccRCC tissue compared with normal kidneys, with signal intensity increasing with malignant grade. Selective ligation of TNFR2 with the …

Clear cell renal cell carcinoma (ccRCC), a tubular epithelial malignancy, secretes tumor necrosis factor (TNF) which signals ccRCC cells in an autocrine manner via two cell surface receptors, TNFR1 and TNFR2, to activate shared and distinct signalling pathways. Selective ligation of TNFR2 was shown to drive cell cycle entry of malignant cells via a signalling pathway involving Etk, VEGFR2, PI3K, Akt, pSer727-Stat3 and mTOR. In this study, phosphorylated-4EBP1 serine 65 (pSer65-4EBP1) is identified as a downstream target of this TNFR2 signalling pathway. pSer65-4EBP1 expression is significantly elevated relative to total 4EBP1 in ccRCC tissue compared to normal kidneys, signal intensity increasing with malignant grade. Selective ligation of TNFR2 with the mutein R2TNF increases pSer65-4EBP1 expression in organ cultures that co-localises with internalised TNFR2 in mitochondria and increases expression of mitochondrially-encoded COX (cytochrome c oxidase subunit) Cox1, as well as nuclear-encoded Cox4/5b subunits. Pharmacological inhibition of mTOR reduces both R2TNF-mediated phosphorylation of 4EBP1 and cell cycle activation in tumor cells while increasing cell death. These results signify the importance of pSer65-4EBP1 in mediating TNFR2-driven cell-cycle entry in tumor cells in ccRCC and implicate a novel relationship between the TNFR2/pSer65-4EBP1/COX axis and mitochondrial function.

Background Acute tubulointerstitial nephritis (AIN) is one of the few causes of acute kidney injury with diagnosis-specific treatment options. However, due to the need to obtain a kidney biopsy for histological confirmation, AIN diagnosis can be delayed, missed, or incorrectly assumed. Here, we identify and validate urinary CXCL9, an IFN-γ-induced chemokine involved in lymphocyte chemotaxis, as a diagnostic biomarker for AIN. Methods In a prospectively enrolled cohort with pathologist-adjudicated histological diagnoses, termed the discovery cohort, we tested the association of 180 immune proteins measured by an aptamer-based assay with AIN and validated the top protein, CXCL9, using sandwich immunoassay. We externally validated these findings in 2 cohorts with biopsy-confirmed diagnoses, termed the validation cohorts, and examined mRNA expression differences in …

2023-05-18 Assigned to YALE UNIVERSITY, ALEXION PHARMACEUTICALS, INC. reassignment YALE UNIVERSITY ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: JANE-WIT, Daniel, POBER, JORDAN S., QIN, Lingfeng, WANG, YI

Purpose: Cardiac primary graft dysfunction (PGD) is a contributor to organ under-utilization, and post-transplant complications. Phase separation in biological systems offers critical therapeutic insight into the impact of mineralocorticoid receptor (MR) rearrangement to form membraneless compartments on donor heart function.Methods: We examined mice, pig and human hearts. Ex-situ perfusion and murine transplants were used for reperfusion after extended cold static preservation with HTK. MR function loss was induced via drug and genetic approaches. Adeno-associated viruses expressed MR mutants with impaired phase separation into hearts.Results: MR expression was increased in human and mouse donor hearts during cold static preservation. Inhibiting MR with water-soluble canrenone improved the contraction and relaxation of mice donor hearts after ex vivo perfusion and heterotopic transplant with 16 …

Internalization of complement membrane attack complexes (MACs) assembles NLRP3 inflammasomes in endothelial cells (EC) and promotes IL-β-mediated tissue inflammation. Informed by proteomics analyses of FACS-sorted inflammasomes, we identify a protein complex modulating inflammasome activity on endosomes. ZFVYE21, a Rab5 effector, partners with Rubicon and RNF34, forming a “ZRR” complex that is stabilized in a Rab5- and ZFYVE21-dependent manner on early endosomes. There, Rubicon competitively disrupts inhibitory associations between caspase-1 and its pseudosubstrate, Flightless I (FliI), while RNF34 ubiquitinylates and degradatively removes FliI from the signaling endosome. The concerted actions of the ZRR complex increase pools of endosome-associated caspase-1 available for activation. The ZRR complex is assembled in human tissues, its associated signaling responses occur …

Donor-recipient (D-R) mismatches outside of human leukocyte antigens (HLAs) contribute to kidney allograft loss, but the mechanisms remain unclear, specifically for intronic mismatches. We quantified non-HLA mismatches at variant-, gene-, and genome-wide scales from single nucleotide polymorphism (SNP) data of D-Rs from 2 well-phenotyped transplant cohorts: Genomics of Chronic Allograft Rejection (GoCAR; n = 385) and Clinical Trials in Organ Transplantation-01/17 (CTOT-01/17; n = 146). Unbiased gene-level screening in GoCAR uncovered the LIMS1 locus as the top-ranked gene where D-R mismatches associated with death-censored graft loss (DCGL). A previously unreported, intronic, LIMS1 haplotype of 30 SNPs independently associated with DCGL in both cohorts. Haplotype mismatches showed a dosage effect, and minor-allele introduction to major-allele-carrying recipients showed greater …

Preservation quality of donor hearts is a key determinant of transplant success. Preservation duration beyond 4 hours is associated with primary graft dysfunction (PGD). Given transport time constraints, geographical limitations exist for donor-recipient matching, leading to donor heart underutilization. Here, we showed that metabolic reprogramming through up-regulation of the enzyme immune response gene 1 (IRG1) and its product itaconate improved heart function after prolonged preservation. Irg1 transcript induction was achieved by adding the histone deacetylase (HDAC) inhibitor valproic acid (VPA) to a histidine-tryptophan-ketoglutarate solution used for donor heart preservation. VPA increased acetylated H3K27 occupancy at the IRG1 enhancer and IRG1 transcript expression in human donor hearts. IRG1 converts aconitate to itaconate, which has both anti-inflammatory and antioxidant properties …