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Found 37769 matches. Displaying 1001-1010
Lockhart A, Mucida D, Parsa R
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Immunity to enteric viruses

IMMUNITY 2022 MAY 10; 55(5):800-818
Pathogenic enteric viruses are a major cause of morbidity and mortality, particularly among children in developing countries. The host response to enteric viruses occurs primarily within the mucosa, where the intestinal immune system must balance protection against pathogens with tissue protection and tolerance to harmless commensal bacteria and food. Here, we summarize current knowledge in natural immunity to enteric viruses, highlighting specialized features of the intestinal immune system. We further discuss how knowledge of intestinal anti-viral mechanisms can be translated into vaccine development with particular focus on immunization in the oral route. Research reveals that the intestine is a complex interface between enteric viruses and the host where environmental factors influence susceptibility and immunity to infection, while viral infections can have lasting implications for host health. A deeper mechanistic understanding of enteric anti-viral immunity with this broader context can ultimately lead to better vaccines for existing and emerging viruses.
Chen Z, Ye ZQ, Soccio RE, Nakadai T, Hankey W, Zhao Y, Huang FR, Yuan FW, Wang HY, Cui ZF, Sunkel B, Wu DY, Dzeng RK, Thomas-Ahner JM, Huang THM, Clinton SK, Huang JT, Lazar MA, Jin VX, Roeder RG, Wang QB
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Phosphorylated MED1 links transcription recycling and cancer growth

NUCLEIC ACIDS RESEARCH 2022 MAY 6; 50(8):4450-4463
Mediator activates RNA polymerase II (Pol II) function during transcription, but it remains unclear whether Mediator is able to travel with Pol II and regulate Pol II transcription beyond the initiation and early elongation steps. By using in vitro and in vivo transcription recycling assays, we find that human Mediator 1 (MED1), when phosphorylated at the mammal-specific threonine 1032 by cyclin-dependent kinase 9 (CDK9), dynamically moves along with Pol II throughout the transcribed genes to drive Pol II recycling after the initial round of transcription. Mechanistically, MED31 mediates the recycling of phosphorylated MED1 and Pol II, enhancing mRNA output during the transcription recycling process. Importantly, MED1 phosphorylation increases during prostate cancer progression to the lethal phase, and pharmacological inhibition of CDK9 decreases prostate tumor growth by decreasing MED1 phosphorylation and Pol II recycling. Our results reveal a novel role of MED1 in Pol II transcription and identify phosphorylated MED1 as a targetable driver of dysregulated Pol II recycling in cancer.
Uitto J, Saeidian AH, Youssefian L, Saffarian Z, Casanova JL, Beziat V, Jouanguy E, Vahidnezhad H
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Recalcitrant Warts, Epidermodysplasia Verruciformis, and the Tree-Man Syndrome: Phenotypic Spectrum of Cutaneous Human Papillomavirus Infections at the Intersection of Genetic Variability of Viral and Human Genomes

JOURNAL OF INVESTIGATIVE DERMATOLOGY 2022 MAY; 142(5):1265-1269
Human papillomavirus (HPV) infections can cause common warts, which usually resolve spontaneously or become recalcitrant, resistant to multiple treatments. In rare cases, they transform into cutaneous giant horns resulting in the tree-man syndrome (TMS). Defective beta-HPVs can cause flat warts in epidermodysplasia verruciformis (EV), a genetic disorder. In typical EV, limited to the skin, the mutated genes are critical for keratinocyte-intrinsic immunity, whereas atypical, syndromic EV involves genes controlling T cells. Inborn errors of immunity due to mutations in distinct genes underlying recalcitrant warts and the alpha-HPV2-driven TMS have been identified, all disrupting T-cell immunity. Collectively, these observations attest to the wide phenotypic spectrum of cutaneous infections caused by different HPV types at the intersection of the genetic diversity of the viral and human genomes.
Jiang JY, Su YF, Zhang RL, Li HW, Tao L, Liu Q
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C. elegans enteric motor neurons fire synchronized action potentials underlying the defecation motor program

NATURE COMMUNICATIONS 2022 MAY 19; 13(1):? Article 2783
C. elegans neurons were thought to be non-spiking until our recent discovery of action potentials in the sensory neuron AWA; however, the extent to which the C. elegans nervous system relies on analog or digital coding is unclear. Here we show that the enteric motor neurons AVL and DVB fire synchronous all-or-none calcium-mediated action potentials following the intestinal pacemaker during the rhythmic C. elegans defecation behavior. AVL fires unusual compound action potentials with each depolarizing calcium spike mediated by UNC-2 followed by a hyperpolarizing potassium spike mediated by a repolarization-activated potassium channel EXP-2. Simultaneous behavior tracking and imaging in free-moving animals suggest that action potentials initiated in AVL propagate along its axon to activate precisely timed DVB action potentials through the INX-1 gap junction. This work identifies a novel circuit of spiking neurons in C. elegans that uses digital coding for long-distance communication and temporal synchronization underlying reliable behavioral rhythm. Most neurons in the nematode C. elegans communicate in an analog manner. Here, the authors demonstrate that enteric motor neurons can fire all-or-none action potentials, and that this digital communication is important for defecation.
Almeida ST, Paulo AC, de Lencastre H, Sa-Leao R
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Evaluation of Methicillin-Resistant Staphylococcus aureus Carriage in the Elderly in Portugal Using Selective Enrichment Followed by quantitative real-time PCR

MICROBIAL DRUG RESISTANCE 2022 MAY 1; 28(5):585-592
The prevalence of methicillin-resistant Staphylococcus aureus (MRSA) in hospitals in Portugal is worrisome and among the highest in Europe. Surprisingly, MRSA prevalence in the community was described as very low (<2%) based on studies that used classical culture-based methods (CCBM). We investigated whether the apparent limited spread of MRSA in the community in Portugal might result from low sensitivity of CCBM. Nasopharyngeal- and oropharyngeal-paired samples obtained from senior adults living in nursing (n = 299) or family homes (n = 300) previously characterized by CCBM were reanalyzed. Samples were inoculated in a semi-selective enrichment medium, and those showing visible growth were evaluated by qPCR targeting nuc, mecA, and mecC genes (SSE+qPCR). By SSE+qPCR, 34 of the 1,198 (2.8%) samples were MRSA positive compared with 21 (1.8%) by CCBM. SSE+qPCR improved non-significantly detection of MRSA carriers from 5.4% to 8.0% (p = 0.12) in the nursing home collection, and from 0.3% to 1.7% (p = 0.13) in the family home collection. MRSA isolates belonged to three HA-MRSA clones widely disseminated in Portuguese hospitals. In conclusion, use of semi-selective medium combined with qPCR did not change the overall scenario previously described. In Portugal, MRSA circulation in the community among senior adults is low.
Morse KW, Heinz NK, Abolade JM, Wright-Chisem J, Russell LA, Zhang M, Mirza S, Pearce-Fisher D, Orange DE, Figgie MP, Sculco PK, Goodman SM
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Factors Associated With Increasing Length of Stay for Rheumatoid Arthritis Patients Undergoing Total Hip Arthroplasty and Total Knee Arthroplasty

HSS JOURNAL 2022 MAY; 18(2):196-204
Background: Total hip arthroplasty (THA) and total knee arthroplasty (TKA) are cost-effective procedures that decrease pain and improve health-related quality of life for patients with advanced symptomatic arthritis, including rheumatoid arthritis (RA). Patients with RA have a longer length of stay (LOS) after THA or TKA than patients with osteoarthritis, yet the factors contributing to LOS have not been investigated. Purpose: We sought to identify the factors contributing to LOS for patients with RA undergoing THA and TKA at a single tertiary care orthopedic specialty hospital. Methods: We retrospectively reviewed data from a prospectively collected cohort of 252 RA patients undergoing either THA or TKA. Demographics, RA characteristics, medications, serologies, and disease activity were collected preoperatively. Linear regression was performed to explore the relationship between LOS (log-transformed) and possible predictors. A multivariate model was constructed through backward selection using significant predictors from a univariate analysis. Results: Of the 252 patients with RA, 83% were women; they had a median disease duration of 14 years and moderate disease activity at the time of arthroplasty. We had LOS data on 240 (95%) of the cases. The mean LOS was 3.4 +/- 1.5 days. The multivariate analysis revealed a longer LOS for RA patients who underwent TKA versus THA, were women versus men, required a blood transfusion, and took preoperative opioids. Conclusion: Our retrospective study found that increased postoperative LOS in RA patients undergoing THA or TKA was associated with factors both non-modifiable (type of surgery, sex) and modifiable (postoperative blood transfusion, preoperative opioid use). These findings suggest that preoperative optimization of the patient with RA might focus on improving anemia and reducing opioid use in efforts to shorten LOS. More rigorous study is warranted.
Wang ZQ, Koirala B, Hernandez Y, Zimmerman M, Brady SF
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Bioinformatic prospecting and synthesis of a bifunctional lipopeptide antibiotic that evades resistance

SCIENCE 2022 MAY 27; 376(6596):991-+
Emerging resistance to currently used antibiotics is a global public health crisis. Because most of the biosynthetic capacity within the bacterial kingdom has remained silent in previous antibiotic discovery efforts, uncharacterized biosynthetic gene clusters found in bacterial genome-sequencing studies remain an appealing source of antibiotics with distinctive modes of action. Here, we report the discovery of a naturally inspired lipopeptide antibiotic called cilagicin, which we chemically synthesized on the basis of a detailed bioinformatic analysis of the cil biosynthetic gene cluster. Cilagicin's ability to sequester two distinct, indispensable undecaprenyl phosphates used in cell wall biosynthesis, togethDer with the absence of detectable resistance in laboratory tests and among multidrug-resistant clinical isolates, makes it an appealing candidate for combating antibiotic-resistant pathogens.
Sorrells TR, Pandey A, Rosas-Villegas A, Vosshall LB
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A persistent behavioral state enables sustained predation of humans by mosquitoes

ELIFE 2022 MAY 12; 11(?):? Article e76663
Predatory animals pursue prey in a noisy sensory landscape, deciding when to continue or abandon their chase. The mosquito Aedes aegypti is a micropredator that first detects humans at a distance through sensory cues such as carbon dioxide. As a mosquito nears its target, it senses more proximal cues such as body heat that guide it to a meal of blood. How long the search for blood continues after initial detection of a human is not known. Here, we show that a 5 s optogenetic pulse of fictive carbon dioxide induced a persistent behavioral state in female mosquitoes that lasted for more than 10 min. This state is highly specific to females searching for a blood meal and was not induced in recently blood-fed females or in males, who do not feed on blood. In males that lack the gene fruitless, which controls persistent social behaviors in other insects, fictive carbon dioxide induced a long-lasting behavior response resembling the predatory state of females. Finally, we show that the persistent state triggered by detection of fictive carbon dioxide enabled females to engorge on a blood meal mimic offered up to 14 min after the initial 5 s stimulus. Our results demonstrate that a persistent internal state allows female mosquitoes to integrate multiple human sensory cues over long timescales, an ability that is key to their success as an apex micropredator of humans.
Hall KD, Farooqi IS, Friedman JM, Klein S, Loos RJF, Mangelsdorf DJ, O'Rahilly S, Ravussin E, Redman LM, Ryan DH, Speakman JR, Tobias DK
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The energy balance model of obesity: beyond calories in, calories out

AMERICAN JOURNAL OF CLINICAL NUTRITION 2022 MAY 1; 115(5):1243-1254
A recent Perspective article described the "carbohydrate-insulin model (CIM)" of obesity, asserting that it "better reflects knowledge on the biology of weight control" as compared with what was described as the "dominant energy balance model (EBM)," which fails to consider "biological mechanisms that promote weight gain." Unfortunately, the Perspective conflated and confused the principle of energy balance, a law of physics that is agnostic as to obesity mechanisms, with the EBM as a theoretical model of obesity that is firmly based on biology. In doing so, the authors presented a false choice between the CIM and a caricature of the EBM that does not reflect modern obesity science. Here, we present a more accurate description of the EBM where the brain is the primary organ responsible for body weight regulation operating mainly below our conscious awareness via complex endocrine, metabolic, and nervous system signals to control food intake in response to the body's dynamic energy needs as well as environmental influences. We also describe the recent history of the CIM and show how the latest "most comprehensive formulation" abandons a formerly central feature that required fat accumulation in adipose tissue to be the primary driver of positive energy balance. As such, the new CIM can be considered a special case of the more comprehensive EBM but with a narrower focus on diets high in glycemic load as the primary factor responsible for common obesity. We review data from a wide variety of studies that address the validity of each model and demonstrate that the EBM is a more robust theory of obesity than the CIM.
Kimani RW, Gatimu SM
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Child mortality in Africa and south Asia: a multidimensional research and policy framework

LANCET GLOBAL HEALTH 2022 MAY; 10(5):E594-E595