Efficacy of GalNAc C3 siRNAs in factor H-deficient mice with C3 glomerulopathy.

Complement alternative pathway (AP) dysregulation drives C3 glomerulopathy (C3G), a rare renal disorder characterized by glomerular C3 deposition and glomerular damage, for which no effective treatments are available. Blockade of complement C3 is emerging as a viable therapeutic option. In an earlier study we showed that SLN500, a small interfering RNA targeting liver C3 synthesis, was able to limit AP dysregulation and glomerular C3d deposits in mice with partial factor H (FH) deficiency (Cfh mice).

Endothelial Glycocalyx of Peritubular Capillaries in Experimental Diabetic Nephropathy: A Target of ACE Inhibitor-Induced Kidney Microvascular Protection.

Peritubular capillary rarefaction is a recurrent aspect of progressive nephropathies. We previously found that peritubular capillary density was reduced in BTBR / mice with type 2 diabetic nephropathy. In this model, we searched for abnormalities in the ultrastructure of peritubular capillaries, with a specific focus on the endothelial glycocalyx, and evaluated the impact of treatment with an angiotensin-converting enzyme inhibitor (ACEi).

Hypoimmunogenic Human Pluripotent Stem Cells as a Powerful Tool for Liver Regenerative Medicine.

Induced pluripotent stem cells (iPSC) have huge potential as cell therapy for various diseases, given their potential for unlimited self-renewal and capability to differentiate into a wide range of cell types. Although autologous iPSCs represents the ideal source for patient-tailored regenerative medicine, the high costs of the extensive and time-consuming production process and the impracticability for treating acute conditions hinder their use for broad applications. An allogeneic iPSC-based strategy may overcome these issues, but it carries the risk of triggering an immune response.

Long-term adaptive response in COVID-19 vaccine recipients and the effect of a booster dose.

We examined the immune response in subjects previously infected with SARS-CoV2 and infection-naïve 9 months after primary 2-dose COVID-19 mRNA vaccination and 3 months after the booster dose in a longitudinal cohort of healthcare workers. Nine months after primary vaccination, previously infected subjects exhibited higher residual antibody levels, with significant neutralizing activity against distinct variants compared to infection-naïve subjects. The higher humoral response was associated with higher levels of receptor binding domain (RBD)-specific IgG and IgA memory B cells.

Imaging the Kidney with an Unconventional Scanning Electron Microscopy Technique: Analysis of the Subpodocyte Space in Diabetic Mice.

Transmission electron microscopy (TEM) remains the gold standard for renal histopathological diagnoses, given its higher resolving power, compared with light microscopy. However, it imposes several limitations on pathologists, including longer sample preparation time and a small observation area. To overcome these, we introduced a scanning electron microscopy (SEM) technique for imaging resin-embedded semi-thin sections of renal tissue.

Empagliflozin protects glomerular endothelial cell architecture in experimental diabetes through the VEGF-A/caveolin-1/PV-1 signaling pathway.

In addition to having blood glucose-lowering effects, inhibitors of sodium glucose cotransporter 2 (SGLT2) afford renoprotection in diabetes. We sought to investigate which components of the glomerular filtration barrier could be involved in the antiproteinuric and renoprotective effects of SGLT2 inhibition in diabetes. BTBR (black and tan, brachyuric) ob/ob mice that develop a type 2 diabetic nephropathy received a standard diet with or without empagliflozin for 10 weeks, starting at 8 weeks of age, when animals had developed albuminuria.

Unravelling the Role of PAX2 Mutation in Human Focal Segmental Glomerulosclerosis.

No effective treatments are available for familial steroid-resistant Focal Segmental Glomerulosclerosis (FSGS), characterized by proteinuria due to ultrastructural abnormalities in glomerular podocytes. Here, we studied a private PAX2 mutation identified in a patient who developed FSGS in adulthood. By generating adult podocytes using patient-specific induced pluripotent stem cells (iPSC), we developed an in vitro model to dissect the role of this mutation in the onset of FSGS.

Post-translational modifications by SIRT3 de-2-hydroxyisobutyrylase activity regulate glycolysis and enable nephrogenesis.

Abnormal kidney development leads to lower nephron number, predisposing to renal diseases in adulthood. In embryonic kidneys, nephron endowment is dictated by the availability of nephron progenitors, whose self-renewal and differentiation require a relatively repressed chromatin state. More recently, NAD-dependent deacetylase sirtuins (SIRTs) have emerged as possible regulators that link epigenetic processes to the metabolism.

Generation of a homozygous CIITA knockout iPS cell line using the CRISPR-Cas9 system.

Human induced pluripotent stem cells (iPSCs) have great promise in regenerative medicine. However, several limitations, including immune-incompatibility, have raised concerns regarding their clinical application. Recent studies have shown that human iPSCs and their derivatives lose their immunogenicity when major histocompatibility complex (MHC) class I and II genes are inactivated and CD47 is over-expressed.

COVID-19 and lombardy: TESTing the impact of the first wave of the pandemic.

Background: Italy was the first western country to experience a large Coronavirus Disease 2019 (COVID-19) outbreak and the province of Bergamo experienced one of the deadliest COVID-19 outbreaks in the world. Following the peak of the epidemic in mid-March, the curve has slowly fallen thanks to the strict lockdown imposed by the Italian government on 9th March 2020.

Methods: We performed a cross-sectional study to assess the prevalence of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection in 423 workers in Bergamo province who returned to the workplace after the end of the Italian lockdown on 5th May 2020.

Role of ultrastructural determinants of glomerular permeability in ultrafiltration function loss.

The epithelial filtration slit is a crucial component of the glomerular capillary membrane, which is essential for maintaining glomerular filtration function. Though chronic kidney diseases are an immense clinical problem, the mechanisms through which structural alterations reduce glomerular water filtration have not yet been understood completely. To investigate the mechanisms underlying filtration function loss, we studied rats with spontaneously occurring progressive kidney disease, either treated with angiotensin II antagonist or untreated, combining high-resolution electron microscopy of the glomerular capillary wall with theoretical water filtration modeling.

Generation of PKD1 mono-allelic and bi-allelic knockout iPS cell lines using CRISPR-Cas9 system.

Autosomal dominant polycystic kidney disease (ADPKD) is the most common hereditary kidney disease, characterised by the development of multiple fluid-filled cysts in the kidneys and other organs. PKD1 and PKD2 are the two major causative genes encoding for polycystin-1 and polycystin-2, respectively. Here, we report the generation of two isogenic induced pluripotent stem cell (iPSC) lines with either heterozygous or compound heterozygous mutations in the PKD1 gene using CRISPR-Cas9 technology.

Generation of two isogenic knockout PKD2 iPS cell lines, IRFMNi003-A-1 and IRFMNi003-A-2, using CRISPR/Cas9 technology.

Autosomal dominant polycystic kidney disease (ADPKD) is the most prevalent inherited renal disease, characterized by multiple cysts that can lead to kidney failure resulting in end-stage renal disease. ADPKD is mainly caused by mutations in either the PKD1 and PKD2 genes, encoding for polycystin-1 and polycystin-2, respectively. In order to clarify the disease mechanisms, here we describe the generation of two isogenic induced pluripotent stem cell (iPSC) lines in which the PKD2 gene was deleted using CRISPR/Cas9 technology.

Deficiency Shortens Life Span and Impairs Cardiac Mitochondrial Function Rescued by Gene Transfer.

Sirtuins, a family of NAD-dependent deacetylases, are recognized as nondispensable regulators of aging processes. Sirtuin 3 (SIRT3) is the main mitochondrial deacetylase that maintains mitochondrial bioenergetics, an essential prerequisite for healthy aging. In this study, using knockout () mice, we sought to establish whether deficiency affected life span, an endpoint that has never been tested formally in mammals, and uncover the mechanisms involved in organ damage associated with aging.

Engineering the vasculature of decellularized rat kidney scaffolds using human induced pluripotent stem cell-derived endothelial cells.

Generating new kidneys using tissue engineering technologies is an innovative strategy for overcoming the shortage of donor organs for transplantation. Here we report how to efficiently engineer the kidney vasculature of decellularized rat kidney scaffolds by using human induced pluripotent stem cell (hiPSCs)-derived endothelial cells (hiPSC-ECs). In vitro, hiPSC-ECs responded to flow stress by acquiring an alignment orientation, and attached to and proliferated on the acellular kidney sections, maintaining their phenotype.

CRISPR-Cas9-Mediated Correction of the G189R-PAX2 Mutation in Induced Pluripotent Stem Cells from a Patient with Focal Segmental Glomerulosclerosis.

Focal segmental glomerulosclerosis (FSGS) is defined by focal (involving few glomeruli) and segmental sclerosis of the glomerular tuft that manifests with nephrotic syndrome. Mutations in genes involved in the maintenance of structure and function of podocytes have been found in a minority of these patients. A family with adult-onset autosomal dominant FSGS was recently found to carry a new germline missense heterozygous mutation (p.

Generation of two isogenic iPS cell lines (IRFMNi002-A and IRFMNi002-B) from a patient affected by Focal Segmental Glomerulosclerosis carrying a heterozygous c.565G>A mutation in PAX2 gene.

Focal Segmental Glomerulosclerosis (FSGS) is the typical renal histologic lesion in familial steroid-resistant nephrotic syndrome, for which there is currently no treatment. Dysfunction of the glomerular podocyte, a specialized cell that forms the glomerular filtration barrier, is central in the pathogenesis of FSGS. Here, we reported the generation of two isogenic iPS cell lines from a patient affected by FSGS, carrying the c.

Engineered Kidney Tubules for Modeling Patient-Specific Diseases and Drug Discovery.

The lack of engineering systems able to faithfully reproduce complex kidney structures in vitro has made it difficult to efficiently model kidney diseases and development. Using polydimethylsiloxane (PDMS) scaffolds and a kidney-derived cell line we developed a system to rapidly engineer custom-made 3D tubules with typical renal epithelial properties. This system was successfully employed to engineer patient-specific tubules, to model polycystic kidney disease (PKD) and test drug efficacy, and to identify a potential new pharmacological treatment.

Extracellular vesicles derived from T regulatory cells suppress T cell proliferation and prolong allograft survival.

We have previously shown that rat allogeneic DC, made immature by adenoviral gene transfer of the dominant negative form of IKK2, gave rise in-vitro to a unique population of CD4CD25 regulatory T cells (dnIKK2-Treg). These cells inhibited Tcell response in-vitro, without needing cell-to-cell contact, and induced kidney allograft survival prolongation in-vivo. Deep insight into the mechanisms behind dnIKK2-Treg-induced suppression of Tcell proliferation remained elusive.

MicroRNA-184 is a downstream effector of albuminuria driving renal fibrosis in rats with diabetic nephropathy.

Aims/hypothesis: Renal fibrosis is a common complication of diabetic nephropathy and is a major cause of end-stage renal disease. Despite the suggested link between renal fibrosis and microRNA (miRNA) dysregulation in diabetic nephropathy, the identification of the specific miRNAs involved is still incomplete. The aim of this study was to investigate miRNA profiles in the diabetic kidney and to identify potential downstream targets implicated in renal fibrosis.

AAV9-mediated engineering of autotransplanted kidney of non-human primates.

Ex vivo gene transfer to the graft before transplantation is an attractive option for circumventing systemic side effects of chronic antirejection therapy. Gene delivery of the immunomodulatory protein cytotoxic T-lymphocyte-associated protein 4-immunoglobulin (CTLA4-Ig) prevented chronic kidney rejection in a rat model of allotransplantation without the need for systemic immunosuppression. Here we generated adeno-associated virus type 2 (AAV2) and AAV9 vectors encoding for LEA29Y, an optimized version of CTLA4-Ig.

Generation of functional podocytes from human induced pluripotent stem cells.

Generating human podocytes in vitro could offer a unique opportunity to study human diseases. Here, we describe a simple and efficient protocol for obtaining functional podocytes in vitro from human induced pluripotent stem cells. Cells were exposed to a three-step protocol, which induced their differentiation into intermediate mesoderm, then into nephron progenitors and, finally, into mature podocytes.

Functional Human Podocytes Generated in Organoids from Amniotic Fluid Stem Cells.

Generating kidney organoids using human stem cells could offer promising prospects for research and therapeutic purposes. However, no cell-based strategy has generated nephrons displaying an intact three-dimensional epithelial filtering barrier. Here, we generated organoids using murine embryonic kidney cells, and documented that these tissues recapitulated the complex three-dimensional filtering structure of glomerular slits in vivo and accomplished selective glomerular filtration and tubular reabsorption.

Regression of Renal Disease by Angiotensin II Antagonism Is Caused by Regeneration of Kidney Vasculature.

Chronic renal insufficiency inexorably progresses in patients, such as it does after partial renal ablation in rats. However, the progression of renal diseases can be delayed by angiotensin II blockers that stabilize renal function or increase GFR, even in advanced phases of the disease. Regression of glomerulosclerosis can be induced by angiotensin II antagonism, but the effect of these treatments on the entire vascular tree is unclear.