Is resistance to anti-tuberculosis drugs associated with type 2 diabetes mellitus? A register review in Beijing, China

Background: China has a high burden of drug-resistant tuberculosis (TB) and diabetes mellitus (DM). Objective: The objectives of this study were to determine the following in patients with culture-confirmed TB: 1) demographic characteristics and disease patterns in relation to the presence or absence of type 2 diabetes and 2) presence or absence of drug resistance to isoniazid (INH), rifampicin (RMP) or both in relation to duration of diabetes and control of diabetes. Design: This is a cross-sectional and retrospective study involving record reviews. Results: There were 621 patients with culture-positive TB, of whom 187 (30%) had previously known or new type 2 diabetes. In those with diabetes, there was a significantly higher proportion of males, persons aged ≥35 years and patients registered with new TB (p<0.05). Prevalence of multidrug-resistant TB (MDR-TB) was 6.2% in new patients (N=422) and 62.3% in previously treated patients (N=199), with no significant differences between those with and without diabetes. In patients with diabetes, there was no association of drug resistance with diabetes duration or disease control [assessed by fasting blood glucose (FBG) at 1 week]. Conclusion: A high proportion of patients with TB in a tertiary health facility, Beijing, China, had diabetes, but there was no association between type 2 diabetes and drug-resistant TB. Further prospective studies are needed to confirm these findings

PIKE is essential for oligodendroglia development and CNS myelination

Oligodendrocyte (OL) differentiation and myelin development are complex events regulated by numerous signal transduction factors. Here, we report that phosphoinositide-3 kinase enhancer L (PIKE-L) is required for OL development and myelination. PIKE-L expression is up-regulated when oligodendrocyte progenitor cells commit to differentiation. Conversely, depleting phosphoinositide- 3 kinase enhancer (PIKE) expression by shRNA prevents oligodendrocyte progenitor cell differentiation. In both conventional PIKE knockout (PIKE-/-) and OL-specific PIKE knockout mice, the number of OLs is reduced in the corpus callosum. PIKE-/- OLs also display defects when forming myelin sheath on neuronal axons during neonatal development, which is partially rescued when PTEN is ablated. In addition, Akt/mTOR signaling is impaired in OL-enriched tissues of the PIKE-/- mutant, leading to reduced expression of critical proteins for myelin development and hypomyelination. Moreover, myelin repair of lysolecithin-induced lesions is delayed in PIKE-/- brain. Thus, PIKE plays pivotal roles to advance OL development and myelinogenesis through Akt/mTOR activation.Link_to_subscribed_fulltex

HuD promotes BDNF expression in brain neurons via selective stabilization of the BDNF long 3'UTR mRNA.

Complex regulation of brain-derived neurotrophic factor (BDNF) governs its intricate functions in brain development and neuronal plasticity. Besides tight transcriptional control from multiple distinct promoters, alternative 3'end processing of the BDNF transcripts generates either a long or a short 3'untranslated region (3'UTR). Previous reports indicate that distinct RNA sequence in the BDNF 3'UTRs differentially regulates BDNF production in the brain to accommodate neuronal activity changes, conceivably through differential interactions with undefined trans-acting factors that regulate stability and translation of these BDNF mRNA isoforms. In this study, we report that the neuronal RNA-binding protein (RBP) HuD interacts with a highly conserved AU-rich element (ARE) specifically located in the BDNF long 3'UTR. Such interaction is necessary and sufficient for selective stabilization of mRNAs that contain the BDNF long 3'UTR in vitro and in vivo. Moreover, in a HuD transgenic mouse model, the BDNF long 3'UTR mRNA is increased in the hippocampal dentate granule cells (DGCs), leading to elevated expression of BDNF protein that is transported and stored in the mossy fiber (MF) terminals. Our results identify HuD as the first trans-acting factor that enhances BDNF expression specifically through the long 3'UTR and a novel mechanism that regulates BDNF protein production in selected neuronal populations by HuD abundance

Identification of sulfhydryl-containing proteins and further evaluation of the selenium-tagged redox homeostasis-regulating proteins

Chemoproteomic profiling of sulfhydryl-containing proteins has consistently been an attractive research hotspot. However, there remains a dearth of probes that are specifically designed for sulfhydryl-containing proteins, possessing sufficient reactivity, specificity, distinctive isotopic signature, as well as efficient labeling and evaluation capabilities for proteins implicated in the regulation of redox homeostasis. Here, the specific selenium-containing probes (Se-probes) in this work displayed high specificity and reactivity toward cysteine thiols on small molecules, peptides and purified proteins and showed very good competitive effect of proteins labeling in gel-ABPP. We identified more than 6000 candidate proteins. In TOP-ABPP, we investigated the peptide labeled by Se-probes, which revealed a distinct isotopic envelope pattern of selenium in both the primary and secondary mass spectra. This unique pattern can provide compelling evidence for identifying redox regulatory proteins and other target peptides. Furthermore, our examiation of post-translational modification (PTMs) of the cysteine site residues showed that oxidation PTMs was predominantly observed. We anticipate that Se-probes will enable broader and deeper proteome-wide profiling of sulfhydryl-containing proteins, provide an ideal tool for focusing on proteins that regulate redox homeostasis and advance the development of innovative selenium-based pharmaceuticals

An Indole-3-Acetic Acid Carboxyl Methyltransferase Regulates Arabidopsis Leaf Development

Auxin is central to many aspects of plant development; accordingly, plants have evolved several mechanisms to regulate auxin levels, including de novo auxin biosynthesis, degradation, and conjugation to sugars and amino acids. Here, we report the characterization of an Arabidopsis thaliana mutant, IAA carboxyl methyltransferase1-dominant (iamt1-D), which displayed dramatic hyponastic leaf phenotypes caused by increased expression levels of the IAMT1 gene. IAMT1 encodes an indole-3-acetic acid (IAA) carboxyl methyltransferase that converts IAA to methyl-IAA ester (MeIAA) in vitro, suggesting that methylation of IAA plays an important role in regulating plant development and auxin homeostasis. Whereas both exogenous IAA and MeIAA inhibited primary root and hypocotyl elongation, MeIAA was much more potent than IAA in a hypocotyl elongation assay, indicating that IAA activities could be effectively regulated by methylation. IAMT1 was spatially and temporally regulated during the development of both rosette and cauline leaves. Changing expression patterns and/or levels of IAMT1 often led to dramatic leaf curvature phenotypes. In iamt1-D, the decreased expression levels of TCP genes, which are known to regulate leaf curvature, may partially account for the curly leaf phenotype. The identification of IAMT1 and the elucidation of its role in Arabidopsis leaf development have broad implications for auxin-regulated developmental process

Forced expression of exogenous HuD selectively enhanced expression of BDNF long 3′UTR mRNA in primary cultured neurons.

<p>E17 cortical neurons were cultured for 2 days and then infected with HSV-HuD or HSV-lacZ virus. Following 3 days in culture, the levels of long 3′UTR BDNF mRNA and pan BDNF mRNA were determined by qRT-PCR using primers specific in the long 3′UTR (A) and primers in the coding region that detects the pan BDNF mRNA (B). *p<0.05 (Student's t-test, n = 4).</p

HuD enhances luciferase reporter expression through an ARE in the BDNF long 3′UTR.

<p>(A) A highly conserved cluster of Class I ARE in the BDNF long 3′UTR, with a consensus core sequence of <i>AUUUA</i> flanked by symmetric A or U (underlined). Triangles indicate alternative polyadenylation sites in the BDNF primary transcript. Primers used for RT-PCR to detect reporter mRNAs are illustrated underneath. (B) RT-PCR using multiple primers illustrated in (A) confirms expression of the expected RNA sequence from each transfected reporter construct. (C) Immunoblot (IB) showing expression of myc-HuD in the input (Inp) of transfected CAD cells and successful immunoprecipitation (IP) of myc-HuD. Two different anti-myc antibodies were used for IP and IB. (D) CLIP-qRT-PCR quantification of reporter mRNAs co-immunoprecipitated with HuD relative to the corresponding mRNA levels in the input. * indicates P<0.05 by Student's t-test (n = 3). Due to the presence of endogenous BDNF mRNA, primers specific for the luciferase coding region were used to detect reporter mRNAs. BDNF long 3′UTR reporter mRNA is preferentially enriched over short 3′UTR mRNA in immunoprecipitated HuD complex. Deletion of the ARE in the long 3′UTR significantly reduced the association or reporter mRNA with HuD.</p

HuD knockdown reduced the levels of endogenous BDNF long 3′UTR mRNA.

<p>(A) siRNA knockdown of HuD in transfected CAD cells measured by qRT-PCR using a HuD-specific primer flanking the target site by the siRNA. (B) Reduction of endogenous BDNF long 3′UTR mRNA in CAD cells measured by qRT-PCR as a result of HuD knockdown. For (A) and (B), results were derived from 3 independent experiments (n = 3), * indicates P<0.05. (C) Representative confocal images of L-BDNF FISH (red) in E17 hippocampal neurons transfected with either pEGFP control vector or pEGFP-shHuD plasmid. The transfected cells was marked by the green fluorescence and the number of FISH grains were counted in the cell bodies and processes (n = 6 for each condition) and graphically displayed in (D). Arrows mark the FISH grains in the processes. Note that the number of ISH grains in the shHuD- treated cells decreased throughout the soma and neurite relative to control GFP-vector treated cells.</p