Pink1, Parkin and Fbxo7, three autosomal recessive familial genes of Parkinson's disease (PD), have been implicated in mitophagy pathways for quality control and clearance of damaged mitochondria, but the interplay of these three genes still remains unclear. Here we present that Fbxo7 and Pink1 play a reciprocal role in the regulation of their protein levels. Regardless of the genotypes of Fbxo7, the wild type and the PD familial mutants of Fbxo7 stabilize the processed form of Pink1, supporting the prior study that none of the PD familial mutations in Fbxo7 have an effect on the interaction with Pink1. On the other hand, the interaction of Fbxo7 with Bag2 further facilitates its capability to stabilize Pink1. Intriguingly, the stabilization of Fbxo7 by Pink1 is specifically observed in substantial nigra pars compacta but striatum and cerebral cortex. Taken together, our findings support the notion that Fbxo7 as a scaffold protein has a chaperon activity in the stabilization of proteins.

Advanced age and apolipoprotein E (APOE) ε4 allele are both associated with increased risk of the Alzheimer's disease (AD). However, the extent of the joint contribution of APOE ε4 allele and age on the brain white matter integrity, cognition and their relationship are unclear. We assessed the age-related variation differences of major cognitions in 846 non-demented elderly, and brain major white matter tracts in an MRI sub-cohort of 111 individuals between ε4 carriers and noncarriers. We found that: (i) carriers showed a steeper age-related decline after age 50 in general mental status, attention, language, and executive function and performed worse than noncarriers at almost all ages; (ii) main effect of age on anterior fibers, but main effect of APOE ε4 on posterior fibers, and the interactive effect of them existed on anterior and posterior fibers; (iii) carriers showed an accelerated age-related integrity reduction of these fibers compared to noncarriers who had a slight decrease but not significant; and (iv) significant associations of the higher white matter integrity with better multi-cognitive performance in old ε4 carriers. Overall, combining APOE status with age may be useful in assessing possible mechanisms of disease development in AD.

Parkinson's disease (PD) is one of the most common neurodegenerative diseases with complex etiology in sporadic cases. Accumulating evidence suggests that oxidative stress and defects in mitochondrial dynamics are associated with the pathogenesis of PD. The oxidative stress and mitochondrial dynamics are regulated strictly by peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α). We investigated whether acetylation and phosphorylation of PGC-1α contribute to protecting neuronal cell against oxidative stress.

Hypothalamic astrocytes are important contributors that activate gonadotropin-releasing hormone (GnRH) neurons and promote GnRH/LH (luteinizing hormone) surge. However, the potential roles and mechanisms of astrocytes during the early reproductive decline remain obscure. The current study reported that, in intact middle-aged female mice, astrocytes within the hypothalamic RP3V accumulated senescence-related markers with increasing age. It employed an ovariectomized animal model and a cell model receiving estrogen intervention to confirm the estrogen-induced senescence of hypothalamic astrocytes. It found that estrogen metabolites may be an important factor for the estrogen-induced astrocyte senescence. In vitro molecular analysis revealed that ovarian estradiol activated PKA and up-regulated CYPs expression, metabolizing estradiol into 2-OHE2 and 4-OHE2. Of note, in middle-aged mice, the progesterone synthesis and the ability to promote GnRH release were significantly reduced. Besides, the expression of growth factors decreased and the mRNA levels of proinflammatory cytokines significantly increased in the aging astrocytes. The findings confirm that ovarian estradiol induces the senescence of hypothalamic astrocytes and that the senescent astrocytes compromise the regulation of progesterone synthesis and GnRH secretion, which may contribute to the aging-related declines in female reproductive function.

Mitochondrial dysfunction and oxidative stress are closely associated with the pathogenesis of Parkinson's disease. Peroxisome proliferator-activated receptor γ coactivator 1 alpha (PGC-1α) is thought to play multiple roles in the regulation of mitochondrial biogenesis and cellular energy metabolism. We recently reported that altering PGC-1α gene expression modulates mitochondrial functions in N-methyl-4-phenylpyridinium ion (MPP+) treated human SH-SY5Y neuroblastoma cells, possibly via the regulation of Estrogen-related receptor α (ERRα), nuclear respiratory factor 1 (NRF-1), nuclear respiratory factor 2 (NRF-2) and peroxisome proliferator-activated receptor γ (PPARγ) expression. In the present study, we aimed to further investigate the potential beneficial effects of PGC-1α in the substantia nigra of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) treated C57BL mice.