Biallelic hypomorphic variants in ALDH1A2 cause a novel lethal human multiple congenital anomaly syndrome encompassing diaphragmatic, pulmonary, and cardiovascular defects.

This study shows a causal association between ALDH1A2 variants and a novel, severe multiple congenital anomaly syndrome in humans that is neonatally lethal due to associated pulmonary hypoplasia and respiratory failure. In two families, exome sequencing identified compound heterozygous missense variants in ALDH1A2. ALDH1A2 is involved in the conversion of retinol (vitamin A) into retinoic acid (RA), which is an essential regulator of diaphragm and cardiovascular formation during embryogenesis. Reduced RA causes cardiovascular, diaphragmatic, and associated pulmonary defects in several animal models, matching the phenotype observed in our patients. In silico protein modeling showed probable impairment of ALDH1A2 for three of the four substitutions. In vitro studies show a reduction of RA. Few pathogenic variants in genes encoding components of the retinoic signaling pathway have been described to date, likely due to embryonic lethality. Thus, this study contributes significantly to knowledge of the role of this pathway in human diaphragm and cardiovascular development and disease. Some clinical features in our patients are also observed in Fryns syndrome (MIM# 229850), syndromic microphthalmia 9 (MIM# 601186), and DiGeorge syndrome (MIM# 188400). Patients with similar clinical features who are genetically undiagnosed should be tested for recessive ALDH1A2-deficient malformation syndrome.

Stimulatory effects of (-)-epicatechin and its enantiomer (+)-epicatechin on mouse frontal cortex neurogenesis markers and short-term memory: proof of concept.

Consumption of (-)-epicatechin (Epi), a cacao flavanol improves cognition. The aim was to compare the effects of (-)-Epi or its stereoisomer (+)-Epi on mouse frontal cortex-dependent short-term working memory and modulators of neurogenesis. Three-month-old male mice (n = 7 per group) were provided by gavage either water (vehicle; Veh), (-)-Epi, at 1 mg kg-1 or (+)-Epi at 0.1 mg per kg of body weight for 15 days. After treatment, spontaneous alternation was evaluated by Y-maze. Brain frontal cortex was isolated for nitrate/nitrite measurements, Western blotting for nerve growth factor (NGF), microtubule associated protein 2 (MAP2), endothelial and neuronal nitric oxide synthase (eNOS and nNOS) and immunohistochemistry for neuronal specific protein (NeuN), doublecortin (DCX), capillary (CD31) and neurofilaments (NF200). Results demonstrate the stimulatory capacity of (-)-Epi and (+)-Epi on markers of neuronal proliferation as per increases in immunoreactive cells for NeuN (74 and 120% respectively), DCX (70 and 124%) as well as in NGF (34.4, 63.6%) and MAP2 (41.8, 63.8%). Capillary density yielded significant increases with (-)-Epi (∼80%) vs. (+)-Epi (∼160%). CD31 protein levels increased with (-)-Epi (∼70%) and (+)-Epi (∼140%). Effects correlated with nitrate/nitrite stimulation by (-)-Epi and (+)-Epi (110.2, 246.5%) and enhanced eNOS phosphorylation (Ser1177) with (-)-Epi and (+)-Epi (21.4, 41.2%) while nNOS phosphorylation only increased with (+)-Epi (18%). Neurofilament staining was increased in (-)-Epi by 135.6 and 84% with (+)-Epi. NF200 increased with (-)-Epi (116%) vs. (+)-Epi (84.5%). Frontal cortex-dependent short-term spatial working improved with (-)-Epi and (+)-Epi (15, 13%). In conclusion, results suggest that both enantiomers, but more effectively (+)-Epi, upregulate neurogenesis markers likely through stimulation of capillary formation and NO triggering, improvements in memory.

The role of inflammation in driving left ventricular remodeling in a pre-HFpEF model.

IMPACT STATEMENT: The incidence of HFpEF continues to increase and ∼2/3 of the patient population are post-menopausal women. Unfortunately, most studies focus on the use of male animal models of remodeling. In this study, however, using female rats to set a model of pre-HFpEF, we provide insights to possible mechanisms that contribute to HFpEF development in humans that will lead us to a better understanding of the underlying pathophysiology of HFpEF.