👤 Hayley C Furlong

Major depression (MD) is the most prevalent psychiatric disease in the population and is considered a prodromal stage of the Alzheimer's disease (AD). Despite both diseases having a robust genetic component, the common transcriptomic signature remains unknown. We investigated the cognitive and emotional behavioural responses in 3- and 6-month-old APP/PSEN1-Tg mice, before β-amyloid plaques were detected. We studied the genetic and pathway deregulation in the prefrontal cortex, striatum, hippocampus and amygdala of mice at both ages, using transcriptomic and functional data analysis. We found that depressive-like and anxiety-like behaviours, as well as memory impairments, are already present at 3-month-old APP/PSEN1-Tg mutant mice together with the deregulation of several genes, such as Ciart, Grin3b, Nr1d1 and Mc4r, and other genes including components of the circadian rhythms, electron transport chain and neurotransmission in all brain areas. Extending these results to human data performing GSEA analysis using DisGeNET database, it provides translational support for common deregulated gene sets related to MD and AD. The present study sheds light on the shared genetic bases between MD and AD, based on a comprehensive characterization from the behavioural to transcriptomic level. These findings suggest that late MD could be an early manifestation of AD. Show less

We previously demonstrated that cigarette smoke (CS) exposure decreases primordial follicle counts and induces autophagy in ovarian granulosa cells in preference to apoptosis. Therefore, the objective of this study was to investigate molecular targets underlying smoke-induced activation of the reparative autophagy pathway in the ovary. Briefly, ovarian homogenates were prepared from adult female mice exposed to mainstream CS twice daily for 8 wk, using a whole-body exposure system. A gene array revealed that CS exposure induced a greater than 2-fold significant increase in the expression of proautophagic genes Cdkn1b, Map1lc3a, Bad, and Sqstm1/p62. A significant increase in Prkaa2, Pik3c3, and Maplc31b expression, as well as a significant decrease in Akt1 and Mtor expression, was detected by quantitative PCR. The 5'-AMP-activated protein kinase catalytic subunit (AMPK) alpha1 + alpha2 and ATG7 protein expression was significantly increased, whereas AKT1, mTOR, CDKN1B/p27, and CXCR4 proteins were significantly decreased in CS exposed versus control ovaries. Up-regulation of AMPK alpha1 + alpha2, a known initiator of autophagic signaling, and ATG7 further suggests activation of the autophagy cascade. Two prosurvival factors, AKT and mTOR, were decreased in expression, an outcome that favors induction of the autophagy pathway, whereas decreased levels of CDKN1B is suggestive of cell cycle dysregulation. In summary, our data suggest that CS exposure induces ovarian follicle loss through induction of the autophagic cascade via the AMPK pathway together with inhibition of antiautophagic markers AKT and mTOR. We further postulate that toxicant-induced dysregulation of reparative autophagy is a novel pathway central to impaired follicle development and subfertility. Show less

Anomalies in neuropeptides and neuroactive amino acids have been postulated to play a role in neurodegeneration in a variety of diseases including the inherited neuronal ceroid lipofuscinoses (NCLs, Batten disease). These are often indicated by concentration changes in cerebrospinal fluid (CSF). Here we compare CSF neuropeptide concentrations in patients with the classical juvenile CLN3 form of NCL and the classical late infantile CLN2 form with neuropeptide and neuroactive amino acid concentrations in CSF from sheep with the late infantile variant CLN6 form. A marked disease related increase in CSF concentrations of neuron specific enolase and tau protein was noted in the juvenile CLN3 patients but this was not observed in an advanced CLN2 patient nor CLN6 affected sheep. No changes were noted in S-100b, GFAP or MBP in patients or of S-100b, GFAP or IGF-1 in affected sheep. There were no disease related changes in CSF concentrations of the neuroactive amino acids, aspartate, glutamate, serine, glutamine, glycine, taurine and GABA in these sheep. The changes observed in the CLN3 patients may be progressive markers of neurodegeneration, or of underlying metabolic changes perhaps associated with CLN3 specific changes in neuroactive amino acids, as have been postulated. The lack of changes in the CLN2 and CLN6 subjects indicate that these changes are not shared by the CLN2 or CLN6 forms and changes in CSF concentrations of these compounds are unreliable as biomarkers of neurodegeneration in the NCLs in general. Show less