Huntington's and Kennedy's disease are autosomal dominant neurodegenerative diseases caused by pathogenic expansion of polyglutamine tracts. Expansion of glutamine repeats must in some way confer a gain of pathological function that disrupts an essential cellular process and leads to loss of affected neurons. Association of huntingtin with vesicular structures raised the possibility that axonal transport might be altered. Here we show that polypeptides containing expanded polyglutamine tracts, but not normal N-terminal huntingtin or androgen receptor, directly inhibit both fast axonal transport in isolated axoplasm and elongation of neuritic processes in intact cells. Effects were greater with truncated polypeptides and occurred without detectable morphological aggregates.

A cure for prostate cancer (CaP) will be possible only after a complete understanding of the mechanisms causing this disease to progress from androgen dependence to androgen independence. To carry on a careful characterization of the phenotypes of CaP cell lines before and after acquisition of androgen independence, we used two human CaP LNCaP sublines: LNCaP nan , which is androgen dependent (AD), and LNCaP-HP, which is androgen independent (AI). In AD LNCaP nan cells, dihydrotestosterone (

We report the isolation of a cDNA that encodes the complete human androgen receptor. The cDNA predicts a protein of 917 amino acids with a molecular weight of 98,918. Introduction of the cDNA into heterologous mammalian cells caused expression of high levels of a protein that binds dihydrotestosterone with the affinity, specificity, and sedimentation properties characteristic of the native human androgen receptor. Comparisons with the amino acid sequence of previously cloned steroid hormone receptors revealed a high degree of sequence conservation with the progesterone, glucocorticoid, and mineralocorticoid receptors in the putative hormone and DNA-binding domain regions.

OBJECTIVE The 2019 Standards of Medical Care in Diabetes suggested that patients with nonalcoholic fatty liver disease (NAFLD) should be evaluated for liver fibrosis. However, the performance of noninvasive clinical models/scores and plasma biomarkers for the diagnosis of nonalcoholic steatohepatitis (NASH) and advanced fibrosis has not been carefully assessed in patients with type 2 diabetes mellitus (T2DM). RESEARCH DESIGN AND METHODS In this cross-sectional study, patients (n = 213) had a liver MRS, and those with a diagnosis of NAFLD underwent a percutaneous liver biopsy. Several noninvasive clinical models/scores and plasma biomarkers were measured to identify NASH and advanced fibrosis (NASH: ALT, cytokeratin-18, NashTest 2, HAIR, BARD, and OWLiver; advanced fibrosis: AST, fragments of propeptide of type III procollagen [PRO-C3], FIB-4, APRI, NAFLD fibrosis score, and FibroTest). RESULTS None of the noninvasive tools assessed for the diagnosis of NASH in patients with T2DM had an optimum performance (all areas under the curve [AUCs] <0.80). Of note, none of the panels or biomarkers was able to outperform plasma ALT (AUC 0.78 [95% CI 0.71–0.84]). Performance was better to diagnose advanced fibrosis, in which plasma PRO-C3, AST, and APRI showed better results than the other approaches (AUC 0.90 [0.85–0.95], 0.85 [0.80–0.91], and 0.86 [0.80–0.91], respectively). Again, none of the approaches did significantly better than plasma AST. Sequential use of plasma AST and other noninvasive tests may help in limiting the number of liver biopsies required to identify patients with advanced fibrosis. CONCLUSIONS Performance of noninvasive clinical models/scores and plasma biomarkers for the diagnosis of NASH or advanced fibrosis was suboptimal in patients with T2DM. Combination of multiple tests may provide an alternative to minimize the need for liver biopsies to detect fibrosis in these patients.

IMPORTANCE Male sex is a risk factor for developing severe COVID-19 illness. It is not known whether sex hormones contribute to this predisposition. OBJECTIVE To investigate the association of concentrations of serum testosterone, estradiol, and insulinlike growth factor 1 (IGF-1, concentrations of which are regulated by sex hormone signaling) with COVID-19 severity. DESIGN, SETTING, AND PARTICIPANTS This prospective cohort study was conducted using serum samples collected from consecutive patients who presented from March through May 2020 to the Barnes Jewish Hospital in St Louis, Missouri, with COVID-19 (diagnosed using nasopharyngeal swabs).EXPOSURES Testosterone, estradiol, and IGF-1 concentrations were measured at the time of presentation (ie, day 0) and at days 3, 7, 14, and 28 after admission (if the patient remained hospitalized). MAIN OUTCOMES AND MEASURES Baseline hormone concentrations were compared amongpatients who had severe COVID-19 vs those with milder COVID-19 illness. RNA sequencing was performed on circulating mononuclear cells to understand the mechanistic association of altered circulating hormone concentrations with cellular signaling pathways. RESULTSAmong 152 patients (90 [59.2%] men; 62 [40.8%] women; mean [SD] age, 63 [16] years), 143 patients (94.1%) were hospitalized. Among 66 men with severe COVID-19, median [interquartile range] testosterone concentrations were lower at day 0 (53 [18 to 114] ng/dL vs 151 [95 to 217] ng/dL;

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The androgen receptor (AR) is a ligand-regulated member of the nuclear receptor superfamily. The cyclin D1 gene product, which encodes the regulatory subunit of holoenzymes that phosphorylate the retinoblastoma protein (pRB), promotes cellular proliferation and inhibits cellular differentiation in several different cell types. Herein the cyclin D1 gene product inhibited ligand-induced AR- enhancer function through a pRB-independent mechanism requiring the cyclin D1 carboxyl terminus. The histone acetyltransferase activity of P/CAF (p300/CBP associated factor) rescued cyclin D1-mediated AR trans-repression. Cyclin D1 and the AR both bound to similar domains of P/CAF, and cyclin D1 displaced binding of the AR to P/CAF in vitro. These studies suggest cyclin D1 binding to the AR may repress ligand-dependent AR activity by directly competing for P/CAF binding.

The isolation and cloning of a full-length cDNA insert complementary to mRNA encoding human aromatase system cytochrome P-450 is reported. The insert contains an open reading frame encoding a protein of 503 amino acids. This gene is clearly a member of the cytochrome P450 gene superfamily, because the sequence contains regions of marked homology to those of other members, notably a putative membrane-spanning region, I helix, Ozols, and hemebinding regions. The cDNA was inserted into a modified pCMV vector and expressed in COS-1 monkey kidney tumor cells. The expressed protein was similar in size to human placental aromatase system cytochrome P-450, as detected by immunoblot analysis, and catalyzed the aromatization of androstenedione, testosterone, and 16a-hydroxyandrostenedione. This activity was inhibited by the known aromatase inhibitors, 4-hydroxyandrostenedione and econazole. Thus the several steps involved in the aromatization reaction appear to be catalyzed by a single polypeptide chain, which can metabolize the three major physiological substrates.