RESUMEN
Leigh syndrome is a neurodegenerative mitochondrial disorder of childhood characterized by symmetrical spongiform lesions in the brain. The clinical presentation of Leigh's syndrome can vary significantly. However, in the majority of cases, it usually presents as a progressive neurological disease involving motor and cognitive development. It is common to see signs and symptoms of the midbrain and brainstem involvement. Limited data are present on the brain processes occurring in Leigh's syndrome which can be attributed to fatal respiratory failure. Raised lactate levels in the blood and/or cerebrospinal fluid are noted. Magnetic resonance imaging (MRI) findings such as necrotic, symmetrical lesions in the BG/brain stem are helpful in arriving at the diagnosis of Leigh's syndrome. It's of utmost importance to determine whether fatal respiratory failure can be predicted based on clinical characteristics and findings on MRI. In our report, we presented 3 cases from rural India, including a 2-year-old male child presenting with UMN lesion signs, a 3-month-old female infant with delayed developmental milestones with lab results suggestive of Leigh's disease, and a 12-year-old female child with epistaxis and generalized weakness. As discussed above, all 3 cases presented differently with a variety of signs and symptoms and would have gone undiagnosed without the use of brain imaging. The study concluded with the impression that while MRI is essential to the initial diagnosis of Leigh's disease, MRI alone cannot be used to predict fatal respiratory failure in patients with Leigh's disease. In any dilemma regarding diagnosis even with MRI, molecular studies remain the gold standard.
RESUMEN
Menopause is associated with bone loss and enhanced visceral adiposity. A polyclonal antibody that targets the ß-subunit of the pituitary hormone follicle-stimulating hormone (Fsh) increases bone mass in mice. Here, we report that this antibody sharply reduces adipose tissue in wild-type mice, phenocopying genetic haploinsufficiency for the Fsh receptor gene Fshr. The antibody also causes profound beiging, increases cellular mitochondrial density, activates brown adipose tissue and enhances thermogenesis. These actions result from the specific binding of the antibody to the ß-subunit of Fsh to block its action. Our studies uncover opportunities for simultaneously treating obesity and osteoporosis.
Asunto(s)
Tejido Adiposo/metabolismo , Adiposidad , Hormona Folículo Estimulante de Subunidad beta/antagonistas & inhibidores , Termogénesis , Adipocitos/efectos de los fármacos , Adipocitos/metabolismo , Tejido Adiposo/efectos de los fármacos , Tejido Adiposo Beige/efectos de los fármacos , Tejido Adiposo Beige/metabolismo , Tejido Adiposo Blanco/efectos de los fármacos , Tejido Adiposo Blanco/metabolismo , Adiposidad/efectos de los fármacos , Animales , Anticuerpos/inmunología , Anticuerpos/farmacología , Dieta Alta en Grasa/efectos adversos , Femenino , Hormona Folículo Estimulante de Subunidad beta/inmunología , Haploinsuficiencia , Masculino , Ratones , Mitocondrias/efectos de los fármacos , Mitocondrias/metabolismo , Obesidad/tratamiento farmacológico , Obesidad/prevención & control , Osteoporosis/tratamiento farmacológico , Ovariectomía , Consumo de Oxígeno/efectos de los fármacos , Receptores de HFE/antagonistas & inhibidores , Receptores de HFE/genética , Receptores de HFE/metabolismo , Termogénesis/efectos de los fármacos , Proteína Desacopladora 1/biosíntesisRESUMEN
Congenital adrenal hyperplasia (CAH), resulting from mutations in CYP11B1, a gene encoding 11ß-hydroxylase, represents a rare autosomal recessive Mendelian disorder of aberrant sex steroid production. Unlike CAH caused by 21-hydroxylase deficiency, the disease is far more common in the Middle East and North Africa, where consanguinity is common often resulting in identical mutations. Clinically, affected female newborns are profoundly virilized (Prader score of 4/5), and both genders display significantly advanced bone ages and are oftentimes hypertensive. We find that 11-deoxycortisol, not frequently measured, is the most robust biochemical marker for diagnosing 11ß-hydroxylase deficiency. Finally, computational modeling of 25 missense mutations of CYP11B1 revealed that specific modifications in the heme-binding (R374W and R448C) or substrate-binding (W116C) site of 11ß-hydroxylase, or alterations in its stability (L299P and G267S), may predict severe disease. Thus, we report clinical, genetic, hormonal, and structural effects of CYP11B1 gene mutations in the largest international cohort of 108 patients with steroid 11ß-hydroxylase deficiency CAH.
Asunto(s)
Hiperplasia Suprarrenal Congénita/genética , Esteroide 11-beta-Hidroxilasa/genética , Hiperplasia Suprarrenal Congénita/patología , África del Norte , Consanguinidad , Femenino , Hormonas Esteroides Gonadales/biosíntesis , Hormonas Esteroides Gonadales/genética , Humanos , Masculino , Medio Oriente , Mutación Missense , Linaje , Esteroide 11-beta-Hidroxilasa/químicaRESUMEN
Prior studies show that oxytocin (Oxt) and vasopressin (Avp) have opposing actions on the skeleton exerted through high-affinity G protein-coupled receptors. We explored whether Avp and Oxtr can share their receptors in the regulation of bone formation by osteoblasts. We show that the Avp receptor 1α (Avpr1α) and the Oxt receptor (Oxtr) have opposing effects on bone mass: Oxtr(-/-) mice have osteopenia, and Avpr1α(-/-) mice display a high bone mass phenotype. More notably, this high bone mass phenotype is reversed by the deletion of Oxtr in Oxtr(-/-):Avpr1α(-/-) double-mutant mice. However, although Oxtr is not indispensable for Avp action in inhibiting osteoblastogenesis and gene expression, Avp-stimulated gene expression is inhibited when the Oxtr is deleted in Avpr1α(-/-) cells. In contrast, Oxt does not interact with Avprs in vivo in a model of lactation-induced bone loss in which Oxt levels are high. Immunofluorescence microscopy of isolated nucleoplasts and Western blotting and MALDI-TOF of nuclear extracts show that Avp triggers Avpr1α localization to the nucleus. Finally, a specific Avpr2 inhibitor, tolvaptan, does not affect bone formation or bone mass, suggesting that Avpr2, which primarily functions in the kidney, does not have a significant role in bone remodeling.