Zhi-Xing Yao

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In developing ovarian follicles, the regulation of cell proliferation and differentiation is tightly coordinated. Precisely how this coordination is achieved is unknown, but recent observations have suggested that molecules emitted by the oocyte are involved in the process. The newly discovered oocyte-specific growth factor, bone morphogenetic protein-15(More)
Hormone-induced steroid biosynthesis begins with the transfer of cholesterol from intracellular stores into mitochondria. Steroidogenic acute regulatory protein (StAR) and peripheral-type benzodiazepine receptor (PBR) have been implicated in this rate-determining step of steroidogenesis. MA-10 mouse Leydig tumor cells were treated with and without(More)
Teas represent a large family of plants containing high amounts of polyphenols that may confer health benefits in various diseases. Recently, it has been hypothesized that tea consumption may also reduce the risk of age-related neurodegenerative pathologies. Considering the deleterious role of beta-amyloid (Abeta) in the aetiology of Alzheimer's disease(More)
In this study, we hypothesized that many of the reported effects of phthalate esters and other peroxisome proliferators (PPs) in the testis are mediated by members of the PP- activated receptor (PPAR) family of transcription factors through alterations in proteins involved in steroidogenesis. Exposure of Leydig cells to PPs prevented cholesterol transport(More)
In this study, we hypothesized that many of the reported effects of phthalate esters and other peroxisome proliferators (PPs) in the testis are mediated by members of the PPactivated receptor (PPAR) family of transcription factors through alterations in proteins involved in steroidogenesis. Exposure of Leydig cells to PPs prevented cholesterol transport(More)
We previously defined a cholesterol recognition/interaction amino acid consensus sequence [CRAC: L/V-X (1-5)-Y-X (1-5)-R/K] in the carboxyl terminus of the peripheral-type benzodiazepine receptor (PBR), a high-affinity drug and cholesterol-binding protein present in the outer mitochondrial membrane protein. This protein is involved in the regulation of(More)
22R-Hydroxycholesterol is an intermediate in the steroid biosynthesis pathway shown to exhibit a neuroprotective property against beta-amyloid (1-42) (Abeta) toxicity in rat PCl2 and human NT2N neuronal cells by binding and inactivating Abeta. In search of potent 22R-hydroxycholesterol derivatives, we assessed the ability of a series of naturally occurring(More)
Peripheral-type benzodiazepine receptor (PBR) is an 18 kDa high-affinity drug ligand and cholesterol binding protein involved in various cell functions. Antisera for distinct PBR areas identified immunoreactive proteins of 18, 40, and 56 kDa and occasionally 72, 90, and 110 kDa in testicular Leydig and breast cancer cells. These sizes may correspond to PBR(More)
22R-hydroxycholesterol, a steroid intermediate in the pathway of pregnenolone formation from cholesterol, was found at lower levels in Alzheimer's disease (AD) hippocampus and frontal cortex tissue specimens compared to age-matched controls. beta-Amyloid (Abeta) peptide has been shown to be neurotoxic and its presence in brain has been linked to AD(More)
Ginkgo biloba extract (EGb 761) can improve cognitive function in patients with Alzheimer's disease, but the molecular mechanisms underlying this effect remain undefined. Because free cholesterol may be involved in the production of beta-amyloid precursor protein and amyloid beta-peptide, key events in the development of Alzheimer's disease, we examined EGb(More)