Wnts compose a family of signaling proteins that play an essential role in kidney development, but their expression in adult kidney is thought to be silenced. Here, we analyzed the expression and regulation of Wnts and their receptors and antagonists in normal and fibrotic kidneys after obstructive injury. In the normal mouse kidney, the vast majority of 19 different Wnts and 10 frizzled receptor genes was expressed at various levels. After unilateral ureteral obstruction, all members of the Wnt family except Wnt5b, Wnt8b, and Wnt9b were upregulated in the fibrotic kidney with distinct dynamics. In addition, the expression of most Fzd receptors and Wnt antagonists was also induced. Obstructive injury led to a dramatic accumulation of beta-catenin in the cytoplasm and nuclei of renal tubular epithelial cells, indicating activation of the canonical pathway of Wnt signaling. Numerous Wnt/beta-catenin target genes (c-Myc, Twist, lymphoid enhancer-binding factor 1, and fibronectin) were induced, and their expression was closely correlated with renal beta-catenin abundance. Delivery of the Wnt antagonist Dickkopf-1 gene significantly reduced renal beta-catenin accumulation and inhibited the expression of Wnt/beta-catenin target genes. Furthermore, gene therapy with Dickkopf-1 inhibited myofibroblast activation; suppressed expression of fibroblast-specific protein 1, type I collagen, and fibronectin; and reduced total collagen content in the model of obstructive nephropathy. In summary, these results establish a role for Wnt/beta-catenin signaling in the pathogenesis of renal fibrosis and identify this pathway as a potential therapeutic target.

Infection with SARS-CoV-2, the cause of coronavirus infectious disease-19 , has caused a pandemic with >850,000 cases worldwide and increasing. Several studies report outcomes of COVID-19 in predominately well persons. There are also some data on COVID-19 in persons with predominately solid cancer but controversy whether these persons have the same outcomes. We conducted a cohort study at two centres in Wuhan, China, of 128 hospitalised subjects with haematological cancers, 13 (10%) of whom developed COVID-19. We also studied 226 health care providers, 16 of whom developed COVID-19 and 11 of whom were hospitalised. Co-variates were compared with the 115 subjects with haematological cancers without COVID-19 and with 11 hospitalised health care providers with COVID-19. There were no significant differences in baseline co-variates between subjects with haematological cancers developing or not developing COVID-19. Case rates for COVID-19 in hospitalised subjects with haematological cancers was 10% (95% Confidence Interval [CI], 6, 17%) compared with 7% (4, 12%; P = 0.322) in health care providers. However, the 13 subjects with haematological cancers had more severe COVID-19 and more deaths compared with hospitalised health care providers with COVID-19. Case fatality rates were 62% (32, 85%) and 0 (0, 32%; P = 0.002). Hospitalised persons with haematological cancers have a similar case rate of COVID-19 compared with normal health care providers but have more severe disease and a higher case fatality rate. Because we were unable to identify specific risk factors for COVID-19 in hospitalised persons with haematological cancers, we suggest increased surveillance and possible protective isolation.

Recent studies implicate Wnt/␤-catenin signaling in podocyte dysfunction. Because vitamin D analogs can inhibit ␤-catenin in other tissues, we tested whether the vitamin D analog paricalcitol could ameliorate podocyte injury, proteinuria, and renal fibrosis in adriamycin (ADR) nephropathy. Compared with vehicle-treated controls, paricalcitol preserved expression of nephrin, podocin, and WT1; prevented proteinuria; and reduced glomerulosclerotic lesions induced by ADR. Paricalcitol also inhibited expression of proinflammatory cytokines, reduced renal infiltration of monocytes/macrophages, hampered activation of renal myofibroblasts, and suppressed expression of the fibrogenic TGF-␤1, CTGF, fibronectin, and types I and III collagen. Selective suppression of renal Wnt4, Wnt7a, Wnt7b, and Wnt10a expression after ADR accompanied these renoprotective effects of paricalcitol. Significant upregulation of ␤-catenin, predominantly in podocytes and tubular epithelial cells, accompanied renal injury; paricalcitol largely abolished this induction of renal ␤-catenin and inhibited renal expression of Snail, a downstream effector of Wnt/␤-catenin signaling. Administration of paricalcitol also ameliorated established proteinuria. In vitro, paricalcitol induced a physical interaction between the vitamin D receptor and ␤-catenin in podocytes, which led to suppression of ␤-catenin-mediated gene transcription. In summary, these findings suggest that paricalcitol prevents podocyte dysfunction, proteinuria, and kidney injury in adriamycin nephropathy by inhibiting Wnt/␤-catenin signaling.