Neurobehavioral deficits of mice expressing a low level of G127V mutant frataxin.

Friedreich’s ataxia (FRDA) is a neurodegenerative disease caused by reduced expression of the mitochondrial protein frataxin (FXN). Most FRDA patients are homozygous for large expansions of GAA repeats in intron 1 of FXN, while some are compound heterozygotes with an expanded GAA tract in one allele and a missense or nonsense mutation in the other. A missense mutation, changing a glycine to valine at position 130 (G130V), is prevalent among the clinical variants. We and others have demonstrated that levels of mature FXN protein in FRDA G130V samples are reduced below those detected in samples harboring homozygous repeat expansions. Little is known regarding expression and function of endogenous FXN-G130V protein due to lack of reagents and models that can distinguish the mutant FXN protein from the wild-type FXN produced from the GAA-expanded allele. We aimed to determine the effect of the G130V (murine G127V) mutation on Fxn expression and to define its multi-system impact in vivo. We used CRISPR/Cas9 to introduce the G127V missense mutation in the Fxn coding sequence and generated homozygous mice (FxnG127V/G127V). We also introduced the G127V mutation into a GAA repeat expansion FRDA mouse model (FxnGAA230/KO; KIKO) to generate a compound heterozygous strain (FxnG127V/GAA230). We performed neurobehavioral tests on cohorts of WT and Fxn mutant animals at three-month intervals for one year, and collected tissue samples to analyze molecular changes during that time. The endogenous Fxn G127V protein is detected at much lower levels in all tissues analyzed from FxnG127V/G127V mice compared to age and sex-matched WT mice without differences in Fxn transcript levels. FxnG127V/G127V mice are significantly smaller than WT counterparts, but perform similarly in most neurobehavioral tasks. RNA sequencing analysis revealed reduced expression of genes in oxidative phosphorylation and protein synthesis, underscoring the metabolic consequences in our mouse model expressing extremely low levels of Fxn. Results of these studies provide insight into the unique pathogenic mechanism of the FXN G130V mechanism and the tolerable limit of Fxn/FXN expression in vivo

Los residuos químicos de la producción de pulque. Etnoarqueometría y arqueología experimental

Pulque was one of the most important beverages in the Central Plateau of Mesoamerica. Its consumption continued during the Colonial period and the beverage is still popular in some places, although its cultural survival is at risk in others. In this paper we present the results of experimental and ethnoarchaeological studies aimed at recognizing the chemical residues produced by pulque production and consumption in the archaeological record. Two kinds of investigations were carried out to identify the residues of pulque: first, experimental work producing "bricks" of lime mortar, simulating archaeological plastered floors that were gradually enriched with pulque during a month; second, an ethnoarchaeometrical study involved the analysis of the samples obtained from the floors of a residence in the state of Hidalgo where pulque is produced and sold. The analyses were carried out with spot tests aimed at identifying the presence of carbohydrates, phosphates, fatty acids and protein residues in the samples. The results show that the enrichment of pulque can be recognized through high values of carbohydrates. We also show the results obtained through gas chromatography/mass spectrometry (GC/MS) analysis of one sample from the experimental brick of plaster

Oxytocin Deficiency Mediates Hyperphagic Obesity of Sim1 Haploinsufficient Mice

Single-minded 1 (Sim1) encodes a transcription factor essential for formation of the hypothalamic paraventricular nucleus (PVN). Sim1 haploinsufficiency is associated with hyperphagic obesity and increased linear growth in humans and mice, similar to the phenotype of melanocortin 4 receptor (Mc4r) mutations. PVN neurons in Sim1+/− mice are hyporesponsive to the melanocortin agonist melanotan II. PVN neuropeptides oxytocin (Oxt), TRH and CRH inhibit feeding when administered centrally. Consequently, we hypothesized that altered PVN neuropeptide expression mediates the hyperphagia of Sim1+/− mice. To test this hypothesis, we measured hypothalamic expression of PVN neuropeptides in Sim1+/− and wild-type mice. Oxt mRNA and peptide were decreased by 80% in Sim1+/− mice, whereas TRH, CRH, arginine vasopressin (Avp), and somatostatin mRNAs were decreased by 20–40%. Sim1+/− mice also showed abnormal regulation of Oxt but not CRH mRNA in response to feeding state. A selective Mc4r agonist activated PVN Oxt neurons in wild-type mice, supporting involvement of these neurons in melanocortin feeding circuits. To test whether Oxt itself regulates feeding, we measured the effects of central administration of an Oxt receptor antagonist or repeated doses of Oxt on food intake of Sim1+/− and wild-type mice. Sim1+/− mice were hypersensitive to the orexigenic effect of the Oxt receptor antagonist. Oxt decreased the food intake and weight gain of Sim1+/− mice at a dose that did not affect wild-type mice. Our results support the importance of Oxt neurons in feeding regulation and suggest that reduced Oxt neuropeptide is one mechanism mediating the hyperphagic obesity of Sim1+/− mice