Although increased predisposition to cardiac fibrosis and cardiac dysfunction has been demonstrated in the perinatally nicotine exposed heart, the underlying mechanisms remain unclear. Using a well-established rat model and cultured primary neonatal rat cardiac fibroblasts, the effect of perinatal nicotine exposure on offspring heart extracellular matrix deposition and the likely underlying mechanisms were investigated. Perinatal nicotine exposure resulted in increased collagen type I (COL1A1) and III (COL3A1) deposition along with a decrease in miR-29 family and an increase in long non-coding RNA myocardial infarction associated transcript (MIAT) levels in offspring heart. Nicotine treatment of isolated primary neonatal rat cardiac fibroblasts suggested that these effects were mediated via nicotinic acetylcholine receptors including α7 and the induced collagens accumulation was reversed by a gain-of function of miR-29 family. Knockdown of MIAT resulted in increased miR-29 family and decreased COL1A1 and COL3A1 levels, suggesting nicotine-mediated MIAT induction as the underlying mechanism for nicotine-induced collagen deposition. Luciferase reporter assay and RNA immunoprecipitation studies showed an intense physical interaction between MIAT, miR-29 family, and argonaute 2, corroborating the mechanistic link between perinatal nicotine exposure and increased extracellular matrix deposition. Overall, perinatal nicotine exposure resulted in lower miR-29 family levels in offspring heart, while it elevated cardiac MIAT and collagen type I and III levels. These findings provide mechanistic basis for cardiac dysfunction in perinatal nicotine exposed offspring and offer multiple novel potential therapeutic targets.

We report a rare case of juvenile cobalamin deficiency who presented at the age of seventeen years. He was underweight and had skin changes, normocytic anemia and autonomic dysfunction which lead to adynamic ileus and acute post-renal failure. The expected macrocytosis was masked by an underlying alpha thalassemia trait. The patient had an excellent response to parenteral cobalamin treatment.

We report a rare case of juvenile cobalamin deficiency who presented at the age of seventeen years. He was underweight and had skin changes, normocytic anemia and autonomic dysfunction which lead to adynamic ileus and acute post-renal failure. The expected macrocytosis was masked by an underlying alpha thalassemia trait. The patient had an excellent response to parenteral cobalamin treatment.