Studies suggest that altered renal lipid metabolism plays a role in the pathogenesis of diabetic kidney disease and that genetic or pharmacological induction of cholesterol efflux protects from the development of diabetic kidney disease and focal segmental glomerulosclerosis (FSGS). Here we tested whether altered lipid metabolism contributes to renal failure in the Col4a3 knockout mouse model for Alport Syndrome. There was an eight fold increase in the cholesterol content in renal cortexes of mice with Alport Syndrome. This was associated with increased glomerular lipid droplets and cholesterol crystals. Treatment of mice with Alport Syndrome with hydroxypropyl-β-cyclodextrin (HPβCD) reduced cholesterol content in the kidneys of mice with Alport Syndrome and protected from the development of albuminuria, renal failure, inflammation and tubulointerstitial fibrosis. Cholesterol efflux and trafficking related genes were primarily affected in mice with Alport Syndrome and were differentially regulated in the kidney cortex and isolated glomeruli. HPβCD also protected from proteinuria and mesangial expansion in a second model of non-metabolic kidney disease; adriamycin-induced nephropathy. Consistent with our experimental findings, microarray analysis confirmed dysregulation of several lipid related genes in glomeruli isolated from kidney biopsies of patients with primary FSGS enrolled in the NEPTUNE study. Thus, lipid dysmetabolism occurs in non-metabolic glomerular disorders such as Alport Syndrome and FSGS, and HPβCD improves renal function in experimental Alport Syndrome and FSGS.

Nephrin belongs to a family of highly conserved proteins with a well characterized function as modulators of cell adhesion and guidance, and nephrin may have a role in metabolic pathways linked to podocyte and pancreatic b-cell survival. However, this role is incompletely characterized. In this study, we developed floxed nephrin mice for pancreatic b-cell-specific deletion of nephrin, which had no effect on islet size and glycemia. Nephrin deficiency, however, resulted in glucose intolerance in vivo and impaired glucose-stimulated insulin release ex vivo. Glucose intolerance was also observed in eight patients with nephrin mutations compared with three patients with other genetic forms of nephrotic syndrome or nine healthy controls. In vitro experiments were conducted to investigate if nephrin affects autocrine signaling through insulin receptor A (IRA) and B (IRB), which are both expressed in human podocytes and pancreatic islets. Coimmunoprecipitation of nephrin and IRB but not IRA was observed and required IR phosphorylation. Nephrin per se was sufficient to induce phosphorylation of p70S6K in an phosphatidylinositol 3-kinase-dependent but IR/Src-independent manner, which was not augmented by exogenous insulin. These results suggest a role for nephrin as an independent modulator of podocyte and pancreatic b-cell nutrient sensing in the fasting state and the potential of nephrin as a drug target in diabetes.

Patient: Male, 69Final Diagnosis: Spontaneous spinal subdural hematomaSymptoms: ParaplegiaMedication: RivaroxabanClinical Procedure: —Specialty: General Internal Medicine • Hospital Medicine • Cardiology • Hematology • NeurologyObjective:Diagnostic/therapeutic accidentsBackground:Spontaneous spinal subdural hematoma (SSDH) is a rare but disabling condition, accounting for only 4.1% of all intraspinal hematomas. Risk factors include arteriovenous malformations, coagulopathy, therapeutic anticoagulation, underlying neoplasms, or following spinal puncture. Vitamin K antagonists, antiplatelet agents, and heparinoids have been associated with SSDHs in prior reports. To the best of our knowledge, no cases have reported this association with the factor Xa inhibitor, rivaroxaban, and SSDHs.Case Report:We report the case of a 69-year-old Honduran man with a 5-year history of symptomatic palpitations due to non-valvular atrial fibrillation. He was initially refractory to pharmacologic therapy. He underwent cardioversion in February 2014. After cardioversion, he remained asymptomatic on flecainide. He was anticoagulated on rivaroxaban 20 mg daily without incident since early 2013 until presentation in August 2014. He presented with sudden onset of excruciating upper and lower back pain after minimal movement. This was immediately followed by bilateral lower extremity paresis rapidly progressing to paraplegia with bowel and bladder dysfunction over 15 minutes. Magnetic resonance imaging demonstrated an acute spinal subdural hematoma extending from T3 inferiorly to the conus medullaris. Six months after undergoing cervical and lumbar drainage procedures, he has not recovered bowel, bladder, or lower extremity neurologic function.Conclusions:Non-traumatic spontaneous spinal subdural hematoma is a rare neurological emergency that may occur during the use of rivaroxaban in patients with non-valvular atrial fibrillation. Physicians should suspect SSDH in patients on rivaroxaban with acute onset of severe back pain and neurologic symptoms to improve the odds of a favorable outcome.

Multiple Sclerosis (MS) is a highly polymorphic disease characterized by different neurologic signs and symptoms. In MS, racial and genetic factors may play an important role in the geographic distribution of this disease. Studies have reported the presence of several protective alleles against the development of autoimmune disorders. In the case of MS, however, they help define MS as a complex disease, and confirm the importance of environmental agents as an independent variable not associated with ethnicity. We carried out an on-site epidemiological study to confirm the absence of MS or NMO among Lacandonians, a pure Amerindian ethnic group in Mexico. We administered a structured interview to 5,372 Lacandonians to assess by family background any clinical data consistent with the presence of a prior demyelinating event. Every participating subject underwent a comprehensive neurological examination by a group of three members of the research team with experience in the diagnosis and treatment of demyelinating disorders to detect clinical signs compatible with a demyelinating disease. We did not find any clinical signs compatible with multiple sclerosis among study participants.