Microbial Reprogramming Inhibits Western Diet-Associated Obesity

A recent epidemiological study showed that eating ‘fast food’ items such as potato chips increased likelihood of obesity, whereas eating yogurt prevented age-associated weight gain in humans. It was demonstrated previously in animal models of obesity that the immune system plays a critical role in this process. Here we examined human subjects and mouse models consuming Westernized ‘fast food’ diet, and found CD4[superscript +] T helper (Th)17-biased immunity and changes in microbial communities and abdominal fat with obesity after eating the Western chow. In striking contrast, eating probiotic yogurt together with Western chow inhibited age-associated weight gain. We went on to test whether a bacteria found in yogurt may serve to lessen fat pathology by using purified Lactobacillus reuteri ATCC 6475 in drinking water. Surprisingly, we discovered that oral L. reuteri therapy alone was sufficient to change the pro-inflammatory immune cell profile and prevent abdominal fat pathology and age-associated weight gain in mice regardless of their baseline diet. These beneficial microbe effects were transferable into naïve recipient animals by purified CD4[superscript +] T cells alone. Specifically, bacterial effects depended upon active immune tolerance by induction of Foxp3[superscript +] regulatory T cells (Treg) and interleukin (Il)-10, without significantly changing the gut microbial ecology or reducing ad libitum caloric intake. Our finding that microbial targeting restored CD4[superscript +] T cell balance and yielded significantly leaner animals regardless of their dietary ‘fast food’ indiscretions suggests population-based approaches for weight management and enhancing public health in industrialized societies.National Institutes of Health (U.S.) (Grant P30-ES002109)National Institutes of Health (U.S.) (Grant RO1CA108854)National Institutes of Health (U.S.) (Grant P01 AI045757)National Institutes of Health (U.S.) (Grant U19 AI046130)National Institutes of Health (U.S.) (Grant U19 AI070352)National Institutes of Health (U.S.) (Grant P01 AI039671)National Institute of Neurological Disorders and Stroke (U.S.) (Jacob Javits Merit Award NS2427)The Penates FoundationNancy Taylor Foundation for Chronic Diseases, Inc

SecA, a remarkable nanomachine

Biological cells harbor a variety of molecular machines that carry out mechanical work at the nanoscale. One of these nanomachines is the bacterial motor protein SecA which translocates secretory proteins through the protein-conducting membrane channel SecYEG. SecA converts chemically stored energy in the form of ATP into a mechanical force to drive polypeptide transport through SecYEG and across the cytoplasmic membrane. In order to accommodate a translocating polypeptide chain and to release transmembrane segments of membrane proteins into the lipid bilayer, SecYEG needs to open its central channel and the lateral gate. Recent crystal structures provide a detailed insight into the rearrangements required for channel opening. Here, we review our current understanding of the mode of operation of the SecA motor protein in concert with the dynamic SecYEG channel. We conclude with a new model for SecA-mediated protein translocation that unifies previous conflicting data

Psychometric Evaluation of a New Patient-Reported Outcome (PRO) Symptom Diary for Varicose Veins: VVSymQ(®) Instrument.

OBJECTIVE To evaluate the psychometric properties of the VVSymQ(®) instrument, a new 5-item patient-reported outcome (PRO) measure for symptoms of varicose veins. METHOD The VVSymQ(®) electronic daily diary was administered to outpatients who received routine treatment for varicose veins (N = 40). Compliance with diary administration and item score variability, reliability, construct validity, sensitivity to change, and clinically meaningful change were evaluated. RESULTS Patients completed >97 % of scheduled diary assessments (at screening, baseline, and week 8). The VVSymQ(®) instrument captured patients' pre-treatment symptoms (all VVSymQ(®) symptoms were endorsed by ≥75 % of patients at baseline), and the change post-treatment (mean change in score -6.1), with a large Cohen effect size (1.6). Test-retest reliability was high (intraclass correlation coefficient 0.96); internal consistency was good (Cronbach's alpha ≥0.76; baseline, week 8). VVSymQ(®) scores were more strongly associated with PRO scores that reflect symptoms and symptom impact (the Venous Insufficiency Epidemiological and Economic Study-Quality of Life/Symptoms [VEINES-QOL/Sym] instrument and the Chronic Venous Insufficiency Quality-of-Life Questionnaire [CIVIQ-20]) than with PRO scores that reflect appearance (the Patient Self-Assessment of Appearance of Visible Varicose Veins [PA-V(3)]) or clinician-reported outcome scores (the Clinical-Etiology-Anatomy-Pathophysiology [CEAP] Classification of Venous Disorders and Venous Clinical Severity Score [VCSS]), demonstrating construct validity. Patients reporting that symptoms were "moderately" or "much improved" on the Patient Global Impression of Change (PGIC) anchor (i.e., >97 % of patients) had mean improvements of -6.3 VVSymQ(®) points, while a cumulative distribution curve showed that 50 % of patients improved by ≥-5.8 points; thus, a score change of approximately -6 demonstrated a clinically meaningful change in this study. The clinically meaningful change in the VVSymQ(®) score was greater in patients with a greater baseline VVSymQ(®) symptom burden, and the VVSymQ(®) instrument captured clinically meaningful treatment benefit even in patients with a low baseline symptom burden. CONCLUSION The 5-item VVSymQ(®) instrument is a brief, psychometrically sound, useful tool for evaluating patient-reported varicose veins symptoms

Preprotein-controlled catalysis in the helicase motor of SecA

The cornerstone of the functionality of almost all motor proteins is the regulation of their activity by binding interactions with their respective substrates. In most cases, the underlying mechanism of this regulation remains unknown. Here, we reveal a novel mechanism used by secretory preproteins to control the catalytic cycle of the helicase ‘DEAD' motor of SecA, the preprotein translocase ATPase. The central feature of this mechanism is a highly conserved salt-bridge, Gate1, that controls the opening/closure of the nucleotide cleft. Gate1 regulates the propagation of binding signal generated at the Preprotein Binding Domain to the nucleotide cleft, thus allowing the physical coupling of preprotein binding and release to the ATPase cycle. This relay mechanism is at play only after SecA has been previously ‘primed' by binding to SecYEG, the transmembrane protein-conducting channel. The Gate1-controlled relay mechanism is essential for protein translocase catalysis and may be common in helicase motors