The mitotic regulator RCC2 promotes glucose metabolism through BACH1-dependent transcriptional upregulation of hexokinase II in glioma.

Weighted gene co-expression network analysis (WGCNA) identified a cell-cycle module that is associated with poor prognosis and aggressiveness of glioma. One of the core members, Regulator of chromatin condensation 2 (RCC2) is a component of the chromosome passenger complex. Accumulating evidence suggests that RCC2 plays a vital role in the mitotic process and that abnormal RCC2 expression is involved in cancer development. Gene silencing experiments show that RCC2 is required for glioma cell proliferation and migration. RNA-Sequencing analysis reveals a dual role of RCC2 in both the cell cycle and metabolism. Specifically, RCC2 regulates G2/M progression via CDC2 phosphorylation at Tyrosine 15. Metabolomic analysis identifies a role for RCC2 in promoting the glycolysis and pentose phosphate pathway. RCC2 exerts effects on metabolism by stabilizing the transcription factor BACH1 at its C-terminus leading to the transcriptional upregulation of hexokinase 2 (HK2). These findings elucidate a novel PTEN/RCC2/BACH1/HK2 signaling axis that drives glioma progression through the dual regulation of mitotic cell cycle and glycolytic events.

Autism-associated PTEN missense mutation leads to enhanced nuclear localization and neurite outgrowth in an induced pluripotent stem cell line.

Germline mutation in the PTEN gene is the genetic basis of PTEN hamartoma tumor syndrome with the affected individuals harboring features of autism spectrum disorders. Characterizing a panel of 14 autism-associated PTEN missense mutations revealed reduced protein stability, catalytic activity, and subcellular distribution. Nine out of 14 (64%) PTEN missense mutants had reduced protein expression with most mutations confined to the C2 domain. Selected mutants displayed enhanced polyubiquitination and shortened protein half-life, but that did not appear to involve the polyubiquitination sites at lysine residues at codon 13 or 289. Analyzing their intrinsic lipid phosphatase activities revealed that 78% (11 out of 14) of these mutants had twofold to 10-fold reduction in catalytic activity toward phosphatidylinositol phosphate substrates. Analyzing the subcellular localization of the PTEN missense mutants showed that 64% (nine out of 14) had altered nuclear-to-cytosol ratios with four mutants (G44D, H123Q, E157G, and D326N) showing greater nuclear localization. The E157G mutant was knocked-in to an induced pluripotent stem cell line and recapitulated a similar nuclear targeting preference. Furthermore, iPSCs expressing the E157G mutant were more proliferative at the neural progenitor cell stage but exhibited more extensive dendritic outgrowth. In summary, the combination of biological changes in PTEN is expected to contribute to the behavioral and cellular features of this neurodevelopmental disorder.

NMR-based metabolomic urinalysis: a rapid screening test for urinary tract infection.

BACKGROUND: Urinary tract infection (UTI) is one of the most common bacterial infections in humans; however, there is no accurate and fast quantitative test to detect UTI. Dipstick urinalysis is semi-quantitative with a limited diagnostic accuracy, while urine culture is accurate but takes time. We described a quantitative biochemical method for the diagnosis of bacteriuria using a single marker. METHODS: We compared the urine metabolomes from 88 patients with bacterial UTI and 61 controls using (1)H NMR spectroscopy followed by principal component analysis (PCA) and orthogonal partial least squares-discriminant analysis (OPLS-DA). The biomarker identified was subsequently validated using independent samples. RESULTS: The urine acetic acid/creatinine (mmol/mmol) level was determined to be the most discriminatory marker for bacterial UTI with an area-under-receiver operating characteristic curve=0.97, sensitivity=91% and specificity=95% at the optimal cutoff 0.03 mmol/mmol. For validation, 60 samples were recruited prospectively. Using the optimal cutoff for acetic acid/creatinine, this method showed sensitivity=96%, specificity=94%, positive predictive value=92%, negative predictive value=97% and an overall accuracy=95%. The diagnostic performance was superior to dipstick urinalysis or microscopy. In addition, we also observed an increase of urinary trimethylamine (TMA) in patients with Escherichia coli-associated UTI. TMA is a mammalian-microbial co-metabolite and the high level of TMA generated is related to the bacterial enzyme, trimethylamine N-oxide (TMAO) reductase which reduces TMAO to TMA. CONCLUSIONS: Urine acetic acid is a neglected metabolite that can be used for rapid diagnosis of UTI and TMA can be used for etiologic diagnosis of UTI. With the introduction of NMR-based clinical analyzers to clinical laboratories, NMR-based urinalysis can be translated for clinical use.

Effects of 17-allylamino-17-demethoxygeldanamycin (17-AAG) in transgenic mouse models of frontotemporal lobar degeneration and Alzheimer's disease.

Alzheimer's disease (AD), the most common dementia, is characterized by potentially neurotoxic aggregation of Aß peptide and tau protein, and their deposition as amyloid plaques and neurofibrillary tangles (NFTs). Tau aggregation also occurs in other common neurodegenerative diseases. Frontotemporal dementia (FTD) can be caused by tau mutations that increase the susceptibility of tau to hyperphosphorylation and aggregation, which may cause neuronal dysfunction and deposition of NFTs. 17-allylamino-17-demethoxygeldanamycin (17-AAG) is a potent inhibitor of heat shock protein 90 (Hsp90), a cytosolic chaperone implicated in the proper folding and functions of a repertoire of client proteins. 17-AAG binds to Hsp90 and enhances degradation of Hsp90 client protein. We sought to determine whether 17-AAG can reduce Aß and tau pathology in the brains of AD and FTD model mice expressing Aß or P301L mutant tau, respectively. Mice were randomized to receive 25, 5, or 0 mg/kg 17-AAG thrice weekly from age eight to 11 months. Analysis was performed by rotarod test on motor function, on the area occupied by plaques in hippocampus or NFTs in medulla tissue sections, and on mortality. A high dose of 17-AAG tended to decrease NFTs in male mice (p = 0.08). Further studies are required to confirm the effect of 17-AAG in diseases of tau aggregation.

Serum zinc is decreased in Alzheimer's disease and serum arsenic correlates positively with cognitive ability.

Zinc, copper, and iron aggregate Abeta and accumulate in Alzheimer's disease (AD) plaques. Some metals are increased in AD vs. control serum. The authors examined levels of 12 metals in serum of 44 AD and 41 control subjects. Zinc decreased from 12.3 to 10.9 micromol/L (means, p = 0.0007). Arsenic positively correlated with Mini-Mental State Examination score (p < 0.0001). Zinc deposition in brain amyloid might deplete zinc from other body compartments, such as serum. The arsenic correlation might be caused by the major contribution of seafood consumption to intake of both arsenic and docosahexaenoic acid, of which the latter may delay AD.