1J and fig
1J and fig. Introduction Tuberculosis (TB) pathogenesis is driven by a complex interplay between the host immune system and the survival strategies of the bacterium (1). The ability of (infection (4), and this is intimately linked to the metabolic programs of the host (5). The engagement of cellular immunometabolic circuits is predominantly regulated by sensors, including mTOR (mammalian target of rapamycin), AMPK (adenosine monophosphateCactivated protein kinase), and the sirtuins (silent mating type information regulation 2 homologs) (6C8). Perturbations in mTOR and AMPK signaling have been associated with virulence (9, 10). Targeting the mTOR pathway with specific inhibitors has been shown to stimulate autophagy induction, leading to increased mycobacterial clearance (3, 11). Similarly, activation of AMPK using the antidiabetic drug metformin leads to improved control (12). This highlights the potential of targeting functional connections between host immune defense and metabolism to modulate pathogenicity. The sirtuins are a family of nicotinamide adenine dinucleotide (NAD+)Cdependent class III histone deacetylases, consisting of seven members present in nearly all subcellular compartments (8). Among these, sirtuin 1 (SIRT1) is involved in a range of cellular processes important for the maintenance of human health, including stress response, cellular metabolism, and aging (13, 14). SIRT1 is known to be important in the prevention of viral diseases (13, 15); however, its role in chronic bacterial infections is unknown. In the present study, we show that SIRT1 expression is down-regulated during active infection and that enhancement of SIRT1 activity using specific activators inhibits the intracellular growth of infection down-regulates SIRT1 expression Understanding evasion strategies is warranted for the advancement of TB HDTs (1, 3). This led us to investigate the effect of infection on sirtuins, an important family of host energy sensors. A comparison of gene (fig. NPB S1A and Fig. 1A) and protein (Fig. 1B). This is consistent with published microarray data sets of mRNA expression was also observed in the lung tissues of Infection down-regulates SIRT1 expression(A) mRNA NPB was assessed by qRT-PCR in mRNA expression in the lungs of Rabbit polyclonal to ANG4 = 4). (D) mRNA expression in the lungs of macaques with active or latent TB. Fold change of expression in lesions versus normal lung tissue is shown (= 10 to 12). (E) Immunostaining of lung NPB tissue of a representative uninfected and = 8 to 20). (G to J) Raw intensity values for mRNA expression in the data set of different cohorts, that is, UK 2010, South Africa 2010, South Africa 2014, and China 2014. Red bars in (G) to (J) indicate the median. Data in (A) to (C) are representative of three to four independent experiments, expressed as means SEM, and analyzed by two-tailed Student’s test. Data in (D) and (F) to (I) are analyzed by Mann-Whitney test. Data in (J) are analyzed by paired Wilcoxon signed-rank test. * 0.05, ** 0.01, *** 0.001, **** 0.0001. Exact values are provided in table S7. To evaluate the clinical significance of mRNA expression profiles derived from peripheral blood of active TB (ATB) patients, latent TB individuals, and healthy controls from seven different cohorts (table S1) (17C22). In the UK 2010, South Africa 2010 (17), and South Africa 2013 (22) cohorts, mRNA levels were lowest in ATB patients compared with healthy and latent TB individuals (Fig. 1, G and H, and fig. S1D). mRNA levels were also reduced in HIV patients with TB as co-morbidity compared with those with HIV alone (South Africa 2014 cohort; Fig..