Many features of chronic kidney disease may be reversed, but it is unclear whether advanced lesions, such as adhesions of sclerotic glomerular tufts to Bowman's capsule (synechiae), can resolve during treatment. We previously showed, using a renal ablation model, that the renoprotective effect of the AT-1 receptor blocker, losartan, is dose-dependent. Here we determined if moderate and advanced glomerular lesions, associated with streptozotocin-induced diabetes, regress with conventional or high-dose losartan treatment. Using daily insulin injection for 10 months, we maintained diabetic adult male Munich-Wistar rats in a state of moderate hyperglycemia. Following this period, some rats continued to receive insulin with or without conventional or high-dose losartan for an additional 2 months. Diabetic rats pretreated with insulin for 10 months and age-matched non-diabetic rats served as controls. Mesangial expansion was found in the control diabetic rats and was exacerbated in those rats maintained on only insulin for an additional 2 months. Conventional and high-dose losartan treatments reduced this mesangial expansion and the severity of synechiae lesions below that found prior to treatment; however, the frequency of the latter was unchanged. There was no dose-response effect of losartan. Our results show that regression of mesangial expansion and contraction of sclerotic lesions is feasible in the treatment of diabetes, but complete resolution of advanced glomerulosclerosis may be hard to achieve.

Background: Inflammatory events antecede established renal injury in rats with 5/6 renal ablation (Nx), as indicated by the beneficial effects of early, uninterrupted treatment with mycophenolate mofetil (MMF). Angiotensin II also exerts a major pathogenic role at this initial phase. We investigated whether losartan (L) or L+MMF treatment, started early, and L+MMF treatment, started late, would exert lasting renoprotection in Nx even after being discontinued. Methods: Adult male Munich-Wistar rats underwent Nx and were divided into three groups: Nx (untreated), Nx_L (given L), and Nx_LMMF (given L and MMF). Protocol 1: treatments began on day 1, and ceased on day 30, after Nx. Protocol 2: L+MMF treatment began on day 30 and ceased on day 60. Results: Protocol 1: on day 30, hypertension, albuminuria and renal injury were strongly attenuated in Groups Nx_L and Nx_LMMF. On day 120, these abnormalities were still attenuated in group Nx_LMMF. Protocol 2: on day 120, all parameters were similar between this late Nx_LMMF group and untreated Nx. Conclusion: In Nx, temporary suppression of early, transitory hemodynamic/inflammatory phenomena affords relatively durable renoprotection even after treatment discontinuation. This effect is not obtained with similar temporary treatment initiated later in the course of renal disease.

Introduction: The CDH2 gene encodes a transmembrane protein responsible for calcium-dependent cell-cell adhesion that participates in the process of embrionic development. Neural development is achieved by neuronal neurulation, migration and differentiation, as well as axon growth and synapse formation. During pituitary development, CDH2 was associated to the epithelium-to-mesenchymal transition, with cell migration from the marginal zone to the anterior pituitary gland, followed by terminal differentiation. Thus, a dysfunction in n-cadherins disrupts the architecture of the neural tube, cortical architecture of the embryonic brain and pituitary development. In a previous study in our laboratory, a patient was diagnosed with a homozygous variant located in the N-terminal region of CDH2 (p.Val289IIe) that culminated in congenital hypopituitarism and pituitary hypoplasia. Together, these observations indicate that cadherins, especially N-cadherin, play an indispensable role in the organization of neuroepithelial layers. Zebrafish has been widely used as a model for studies of gene functionality, as it has 70% genetic homology to humans, besides being a small animal with rapid development. Our goal was to generate a zebrafish knockout for the CDH2 gene, using CRISPR Cas9 genomic edition to study its importance during development and analyze this gene in patients with characteristics similar to those observed in zebrafish. Material and methods: Three guides were drawn for the CDH2 gene using crispor program. sgRNA, produced by in vitro transcription, and Cas9 protein were injected into one cell stage. All developmental parameters were observed under a microscope up to 96 hours post fertilization (hpf). Mortality rate were calculated at 24, 48, 72 and 96 hpf. The embryos were genotyped to confirm the deleterious allelic variant. CDH2 coding region was evaluated in 3 female siblings, born from consanguineous parents, presenting micro/anophtalmia and short stature. Exons 2 to 16 were sequenced by the Sanger method. Results: 352 eggs were injected and several deformities such as absence of somites, cardiac edema, spinal curvature, cranial malformation and microphthalmia or total absence of eyes were observed. The mortality rates were 26%, 31%, 40% and 62% at 24, 48, 72 and 96 hpf, respectively. The Sanger sequencing from DNA extracted from the whole animal presented deleterious effect classified as insertions, deletions and missense changes. No deleterious allelic variant was observed in the 15 analyzed exons in the 3 patients. Conclusion: The CDH2 gene is important for neurodevelopment and eyes formation in the zebrafish although pathogenic allelic variants in this gene was not found in the studied patients with short stature and eye abnormalities.