Induced pluripotent stem cells derived renal tubular cells from a patient with pseudohypoparathyroidism and its response to parathyroid hormone stimulation.

INTRODUCTION: Creating induced pluripotent stem cells (iPSCs) from somatic cells of patients with genetic diseases offers a pathway to generate disease-specific iPSCs carrying genetic markers. Differentiating these iPSCs into renal tubular cells can aid in understanding the pathophysiology of rare inherited renal tubular diseases through cellular experiments. MATERIALS AND METHODS: Two Japanese patients with Pseudohypoparathyroidism (PHP), a 49-year-old woman and a 71-year-old man, were studied. iPSC-derived tubular cells were established from their peripheral blood mononuclear cells (PBMCs). We examined changes in intracellular and extracellular cyclic adenosine monophosphate (cAMP) levels in these cells in response to parathyroid hormone (PTH) stimulation. RESULTS: Renal tubular cells, differentiated from iPSCs of a healthy control (648A1), showed a PTH-dependent increase in both intracellular and extracellular cAMP levels. However, the renal tubular cells derived from the PHP patients' iPSCs showed inconsistent changes in cAMP levels upon PTH exposure. CONCLUSION: We successfully created disease-specific iPSCs from PHP patients' PBMCs, differentiated them into tubular cells, and replicated the distinctive response of the disease to PTH in vitro. This approach could enhance our understanding of the pathophysiology of inherited renal tubular diseases and contribute to developing effective treatments.

Abnormal epigenetic memory of mesenchymal stem and progenitor cells caused by fetal malnutrition induces hypertension and renal injury in adulthood.

Fetal malnutrition has been reported to induce hypertension and renal injury in adulthood. We hypothesized that this hypertension and renal injury would be associated with abnormal epigenetic memory of stem and progenitor cells contributing to organization in offspring due to fetal malnutrition. We measured blood pressure (BP) for 60 weeks in offspring of pregnant rats fed a normal protein diet (Control), low-protein diet (LP), and LP plus taurine (LPT) in the fetal period. We used western blot analysis to evaluate the expression of αSMA and renin in CD44-positive renal mesenchymal stem cells (MSCs) during differentiation by TGF-ß1. We measured kidney label-retaining cells (LRCs) at 11 weeks of age and formation of endothelial progenitor cells (EPCs) at 60 weeks of age from the offspring with fetal malnutrition. Epigenetics of the renal MSCs at 14 weeks were investigated by ATAC-sequence and RNA-sequence analyses. BP was significantly higher in LP than that in Control and LPT after 45-60 weeks of age. Numbers of LRCs and EPC colonies were significantly lower in LP than in Control. Renal MSCs from LP already showed expression of h-caldesmon, αSMA, LXRα, and renin before their differentiation. Epigenetic analyses identified PAR2, Chac1, and Tspan6 genes in the abnormal differentiation of renal MSCs. These findings suggested that epigenetic abnormalities of stem and progenitor cell memory cause hypertension and renal injury that appear in adulthood of offspring with fetal malnutrition.

Development of multifunctional pyrrole-imidazole polyamides that increase hepatocyte growth factor and suppress transforming growth factor-ß1.

PURPOSE: The DNA recognition peptide compounds pyrrole-imidazole (PI) polyamides bind to the minor groove and can block the binding of transcription factors to target sequences. To develop more PI polyamides as potential treatments for fibrotic diseases, including chronic renal failure, we developed multifunctional PI polyamides that increase hepatocyte growth factor (HGF) and decrease transforming growth factor (TGF)-ß1. METHODS: We designed seven PI polyamides (HGF-1 to HGF-7) that bind to the chicken ovalbumin upstream promoter transcription factor-1 (COUP-TF1) binding site of the HGF promoter sequence. We selected PI polyamides that increase HGF and suppress TGF-ß1 in human dermal fibroblasts (HDFs). FINDINGS: Gel shift assays showed that HGF-2 and HGF-4 bound the appropriate dsDNAs. HGF-2 and HGF-4 significantly inhibited the TGF-ß1 mRNA expression in HDFs stimulated by phorbol 12-myristate 13-acetate. HGF-2 and HGF-4 significantly inhibited the TGF-ß1 protein expression in HDFs with siRNA targeting HGF, indicating that HGF-2 and HGF-4 directly inhibited the expression of TGF-ß1. CONCLUSION: The designed and synthetic HGF PI polyamides targeting the HGF promoter, which increased the expression of HGF and suppressed the expression of TGF-ß, will be a potential practical medicine for fibrotic diseases, including progressive renal diseases.