Management of complex pediatric and adolescent liver trauma: adult vs pediatric level 1 trauma centers.

PURPOSE: Management of high-grade pediatric and adolescent liver trauma can be complex. Studies suggest that variation exists at adult (ATC) vs pediatric trauma centers (PTC); however, there is limited granular comparative data. We sought to describe and compare the management and outcomes of complex pediatric and adolescent liver trauma between a level 1 ATC and two PTCs in a large metropolitan city. METHODS: A retrospective review of pediatric and adolescent (age < 21 years) patients with American Association for the Surgery of Trauma (AAST) Grade 4 and 5 liver injuries managed at an ATC and PTCs between 2016 and 2022 was performed. Demographic, clinical, and outcome data were obtained at the ATC and PTCs. Primary outcomes included rates of operative management and use of interventional radiology (IR). Secondary outcomes included packed red blood cell (pRBC) utilization, intensive care unit (ICU) length of stay (LOS), and hospital LOS. RESULTS: One hundred forty-four patients were identified, seventy-five at the ATC and sixty-nine at the PTC. The cohort was predominantly black (65.5%) males (63.5%). Six injuries (8.7%) at the PTC and forty-five (60%) injuries at the ATC were penetrating trauma. Comparing only blunt trauma, ATC patients had higher Injury Severity Score (median 37 vs 26) and ages (20 years vs 9 years). ATC patients were more likely to undergo operative management (26.7% vs 11.0%, p = 0.016) and utilized IR more (51.9% vs 4.8%, p < 0.001) compared to the PTC. The patients managed at the ATC required higher rates of pRBC transfusions though not statistically significant (p = 0.06). There were no differences in mortality, ICU, or hospital LOS. CONCLUSION: Our retrospective review of high-grade pediatric and adolescent liver trauma demonstrated higher rates of IR and operating room use at the ATC compared to the PTC in the setting of higher Injury Severity Score and age. While the PTC successfully managed > 95% of Grade 4/5 liver injuries non-operatively, prospective data are needed to determine the optimal algorithm for management in the older adolescent population. LEVEL OF EVIDENCE: Level IV.

miR-542-5p targets c-myc and negates the cell proliferation effect of SphK1 in intestinal epithelial cells.

Intestinal epithelial barrier defects occur commonly during a variety of pathological conditions, though their underlying mechanisms are not completely understood. Sphingosine-1-phosphate (S1P) has been shown to be a critical regulator of proliferation and of maintenance of an intact intestinal epithelial barrier, as is also sphingosine kinase 1 (SphK1), the rate-limiting enzyme for S1P synthesis. SphK1 has been shown to modulate its effect on intestinal epithelial proliferation through increased levels of c-myc. We conducted genome-wide profile analysis to search for differential microRNA expression related to overexpressed SphK1 demonstrating adjusted expression of microRNA 542-5p (miR-542-5p). Here, we show that miR-542-5p is regulated by SphK1 activity and is an effector of c-myc translation that ultimately serves as a critical regulator of the intestinal epithelial barrier. miR-542-5p directly regulates c-myc translation through direct binding to the c-myc mRNA. Exogenous S1P analogs administered in vivo protect murine intestinal barrier from damage due to mesenteric ischemia reperfusion, and damaged intestinal tissue had increased levels of miR-542-5p. These results indicate that miR-542-5p plays a critical role in the regulation of S1P-mediated intestinal barrier function, and may highlight a novel role in potential therapies.

Function and evolution of the aquaporin IsAQP1 in the Lyme disease vector Ixodes scapularis.

Ticks are important vectors of pathogenic viruses, bacteria, and protozoans to humans, wildlife, and domestic animals. Due to their life cycles, ticks face significant challenges related to water homeostasis. When blood-feeding, they must excrete water and ions, but when off-host (for stretches lasting several months), they must conserve water to avoid desiccation. Aquaporins (AQPs), a family of membrane-bound water channels, are key players in osmoregulation in many animals but remain poorly characterized in ticks. Here, we bioinformatically identified AQP-like genes from the deer tick Ixodes scapularis and used phylogenetic approaches to map the evolution of the aquaporin gene family in arthropods. Most arachnid AQP-like sequences (including those of I. scapularis) formed a monophyletic group clustered within aquaglycerolporins (GLPs) from bacteria to vertebrates. This gene family is absent from insects, revealing divergent evolutionary paths for AQPs in different hematophagous arthropods. Next, we sequenced the full-length cDNA of I. scapularis aquaporin 1 (IsAQP1) and expressed it heterologously in Xenopus oocytes to functionally characterize its permeability to water and solutes. Additionally, we examined IsAQP1 expression across different life stages and adult female organs. We found IsAQP1 is an efficient water channel with high expression in salivary glands prior to feeding, suggesting it plays a role in osmoregulation before or during blood feeding. Its functional properties are unique: unlike most GLPs, IsAQP1 has low glycerol permeability, and unlike most AQPs, it is insensitive to mercury. Together, our results suggest IsAQP1 plays an important role in tick water balance physiology and that it may hold promise as a target of novel vector control efforts.

The complementary roles of VAMP-2, -3, and -7 in platelet secretion and function.

Platelet secretion requires Soluble N-ethylmaleimide Sensitive Attachment Protein Receptors (SNAREs). Vesicle SNAREs/Vesicle-Associated Membrane Proteins (v-SNAREs/VAMPs) on granules and t-SNAREs in plasma membranes mediate granule release. Platelet VAMP heterogeneity has complicated the assessment of how/if each is used and affects hemostasis. To address the importance of VAMP-7 (V7), we analyzed mice with global deletions of V3 and V7 together or platelet-specific deletions of V2, V3, and global deletion of V7. We measured the kinetics of cargo release, and its effects on three injury models to define the context-specific roles of these VAMPs. Loss of V7 minimally affected dense and α granule release but did affect lysosomal release. V3-/-7-/- and V2Δ3Δ7-/- platelets showed partial defects in α and lysosomal release; dense granule secretion was unaffected. In vivo assays showed that loss of V2, V3, and V7 caused no bleeding or occlusive thrombosis. These data indicate a role for V7 in lysosome release that is partially compensated by V3. V7 and V3, together, contribute to α granule release, however none of these deletions affected hemostasis/thrombosis. Our results confirm the dominance of V8. When it is present, deletion of V2, V3, or V7 alone or in combination minimally affects platelet secretion and hemostasis.

What did we know? V8 is the primary VAMP isoform for platelet granule secretion, but V2 and V3 play compensatory roles.V3 is important for platelet endocytosis.V7 plays a minimal role in secretion and does not affect hemostasis.What did we discover? The loss of both V3 and V7 increases α and lysosomal secretion defects.Platelet-specific deletion of V2 and V3 with global V7-deletion causes defective α and lysosomal release.Secretion deficiencies in V3^−/−7^−/− and V2^Δ3^Δ7^−/− have no effect on hemostasis or thrombosis.What is the impact? We show that endosomal v-SNAREs (V3 and V7) play minor roles in secretion.V3^−/−7^−/− and platelet-specific V2^Δ3^Δ7^−/− mice are viable and will be valuable in in vivo studies of membrane trafficking.

α-Synuclein is the major platelet isoform but is dispensable for activation, secretion, and thrombosis.

Platelets play many roles in the vasculature ensuring proper hemostasis and maintaining integrity. These roles are facilitated, in part, by cargo molecules released from platelet granules via Soluble NSF Attachment Protein Receptor (SNARE) mediated membrane fusion, which is controlled by several protein-protein interactions. Chaperones have been characterized for t-SNAREs (i.e. Munc18b for Syntaxin-11), but none have been clearly identified for v-SNAREs. α-Synuclein has been proposed as a v-SNARE chaperone which may affect SNARE-complex assembly, fusion pore opening, and thus secretion. Despite its abundance and that it is the only isoform present, α-synuclein's role in platelet secretion is uncharacterized. In this study, immunofluorescence showed that α-synuclein was present on punctate structures that co-stained with markers for α-granules and lysosomes and in a cytoplasmic pool. We analyzed the phenotype of α-synuclein-/- mice and their platelets. Platelets from knockout mice had a mild, agonist-dependent secretion defect but aggregation and spreading in vitro were unaffected. Consistently, thrombosis/hemostasis were unaffected in the tail-bleeding, FeCl3 carotid injury and jugular vein puncture models. None of the platelet secretory machinery examined, e.g. the v-SNAREs, were affected by α-synuclein's loss. The results indicate that, despite its abundance, α-synuclein has only a limited role in platelet function and thrombosis.

What did we know? The N-terminus of α-Synuclein affects SNARE-complex assembly, fusion pore opening, and granule docking.Microvascular bleeding is seen in Parkinson Disease patients where α-synuclein has a pathological role.What did we discover? α-Synuclein colocalizes with P-selectin (α-granules) and LAMP-1 (lysosomes) in platelets.The loss of α-synuclein has only a mild, agonist-dependent effect on platelet secretion.The loss of α-synuclein had no effect on thrombosis/hemostasis in 3 injury models.What is the impact? Despite its abundance, α-synuclein is not required for platelet secretion.α-Synuclein is not required for hemostasis or thrombosis.

Nutrition and behavior change: a review of recent literature.

PURPOSE OF REVIEW: The current article will highlight recent trends and novel approaches to behavior change strategies in nutrition. Physicians, nurses, and other healthcare professionals play key roles in counseling patients on lifestyle change, which is critical for patients with chronic conditions. Nutrition science continues to advance, and new approaches to behavior change are needed for successful implementation at the individual and population level. RECENT FINDINGS: The solutions to obstacles around healthful eating patterns are varied, population-dependent, and require a multipronged approach. One area of focus is the language around behavior change, ensuring it is clear and emphasizes its multifactorial nature. For young adults, the careful use of video games and social media may be essential. For older adults, altering food consistency and ensuring proper nutrient intake are crucial factors. Vulnerable populations remain susceptible to malnutrition and need special attention. Despite significant advances in managing and treating diseases, there are still gaps in nutrition counseling and behavior change efforts. SUMMARY: Every age and stage of life needs a focus on healthful foods, and nutrition counseling at each stage has its unique nuances. Careful attention to the language of change and the phrasing used in counseling is vital for educating, connecting with, and empowering patients to change. Changing healthcare operations and provider behavior around nutrition counseling is a part of the solution to the worldwide problem of unhealthy eating patterns and practices.

A novel tick protein supports integrity of gut peritrophic matrix impacting existence of gut microbiome and Lyme disease pathogens.

The peritrophic matrix (PM) is an acellular membrane that covers the gut epithelium in arthropods and physically separates it from the lumen. The structure is thought to play an important role in tick biology. The PM is also known to impact the persistence of tick-borne pathogens like Borrelia burgdorferi, although limited information is available about its molecular constituents or their biological significance. Herein, we characterise a novel PM-associated gut protein in Ixodes scapularis ticks, annotated as Peritrophic Membrane Chitin Binding Protein (PM_CBP), for its role in the integrity and function of the matrix. The PM_CBP displays homology to the chitin deacetylase metalloenzyme, shows upregulation during tick feeding, and is localized at the luminal surface of the gut epithelium. The structural integrity of the PM was impaired both by the knock down of PM_CBP expression via RNA interference and by treatment with anti-PM_CBP antibodies, as revealed by its electron microscopic appearance. Additionally, the duration of tick engorgement on mice and the passage of experimentally-inoculated fluorescent dextran molecules across the PM are affected by the knock down of PM_CBP expression. The transfer of anti-PM_CBP antibodies into the tick gut impacted the overall composition of the resident microbiome, and also influenced B. burgdorferi acquisition in ticks and its transmission to mice. Taken together, these data highlight the biological significance of the Ixodes PM and suggest that the targeting of its molecular constituents may contribute to the development of novel interventions against tick-borne infections.

Correlates of bird collisions with buildings across three North American countries.

Collisions with buildings cause up to 1 billion bird fatalities annually in the United States and Canada. However, efforts to reduce collisions would benefit from studies conducted at large spatial scales across multiple study sites with standardized methods and consideration of species- and life-history-related variation and correlates of collisions. We addressed these research needs through coordinated collection of data on bird collisions with buildings at sites in the United States (35), Canada (3), and Mexico (2). We collected all carcasses and identified species. After removing records for unidentified carcasses, species lacking distribution-wide population estimates, and species with distributions overlapping fewer than 10 sites, we retained 269 carcasses of 64 species for analysis. We estimated collision vulnerability for 40 bird species with ≥2 fatalities based on their North American population abundance, distribution overlap in study sites, and sampling effort. Of 10 species we identified as most vulnerable to collisions, some have been identified previously (e.g., Black-throated Blue Warbler [Setophaga caerulescens]), whereas others emerged for the first time (e.g., White-breasted Nuthatch [Sitta carolinensis]), possibly because we used a more standardized sampling approach than past studies. Building size and glass area were positively associated with number of collisions for 5 of 8 species with enough observations to analyze independently. Vegetation around buildings influenced collisions for only 1 of those 8 species (Swainson's Thrush [Catharus ustulatus]). Life history predicted collisions; numbers of collisions were greatest for migratory, insectivorous, and woodland-inhabiting species. Our results provide new insight into the species most vulnerable to building collisions, making them potentially in greatest need of conservation attention to reduce collisions and into species- and life-history-related variation and correlates of building collisions, information that can help refine collision management.

Correlaciones de las Colisiones de Aves contra Edificios en Tres Países de América del Norte Resumen Las colisiones contra los edificios causan hasta mil millones de fatalidades de aves al año en los Estados Unidos y en Canadá. Sin embargo, los esfuerzos por reducir estas colisiones se beneficiarían con estudios realizados a grandes escalas espaciales en varios sitios de estudio con métodos estandarizados y considerando las variaciones relacionadas a la historia de vida y a la especie y las correlaciones de las colisiones. Abordamos estas necesidades de investigación por medio de una recolección coordinada de datos sobre las colisiones de aves contra edificios en los Estados Unidos (35), Canadá (3) y México (2). Recolectamos todos los cadáveres y los identificamos hasta especie. Después de retirar los registros de cadáveres no identificados, las especies sin estimaciones poblacionales a nivel distribución y las especies con distribuciones traslapadas en menos de diez sitios, nos quedamos con 269 cadáveres de 64 especies para el análisis. Estimamos la vulnerabilidad a colisiones para 40 especies con ≥2 fatalidades con base en la abundancia poblacional para América del Norte, el traslape de su distribución entre los sitios de estudio y el esfuerzo de muestreo. De las diez especies que identificamos como las más vulnerables a las colisiones, algunas han sido identificadas previamente (Setophaga caerulescens), y otras aparecieron por primera vez (Sitta carolinensis), posiblemente debido a que usamos una estrategia de muestreo más estandarizada que en los estudios previos. El tamaño del edificio y el área del vidrio estuvieron asociados positivamente con el número de colisiones para cinco de ocho especies con suficientes observaciones para ser analizadas independientemente. La vegetación alrededor de los edificios influyó sobre las colisiones solamente para una de esas ocho especies Catharus ustulatus). Las historias de vida pronosticaron las colisiones; el número de colisiones fue mayor para las especies migratorias, insectívoras y aquellas que habitan en las zonas boscosas. Nuestros resultados proporcionan una nueva perspectiva hacia las especies más vulnerables a las colisiones contra edificios, lo que las pone en una necesidad potencialmente mayor de atención conservacionista para reducir estas colisiones y de estudio de las variaciones relacionadas con la especie y la historia de vida y las correlaciones de las colisiones contra edificios, información que puede ayudar a refinar el manejo de colisiones.

Plasticity in early immune evasion strategies of a bacterial pathogen.

Borrelia burgdorferi is one of the few extracellular pathogens capable of establishing persistent infection in mammals. The mechanisms that sustain long-term survival of this bacterium are largely unknown. Here we report a unique innate immune evasion strategy of B. burgdorferi, orchestrated by a surface protein annotated as BBA57, through its modulation of multiple spirochete virulent determinants. BBA57 function is critical for early infection but largely redundant for later stages of spirochetal persistence, either in mammals or in ticks. The protein influences host IFN responses as well as suppresses multiple host microbicidal activities involving serum complement, neutrophils, and antimicrobial peptides. We also discovered a remarkable plasticity in BBA57-mediated spirochete immune evasion strategy because its loss, although resulting in near clearance of pathogens at the inoculum site, triggers nonheritable adaptive changes that exclude detectable nucleotide alterations in the genome but incorporate transcriptional reprograming events. Understanding the malleability in spirochetal immune evasion mechanisms that ensures their host persistence is critical for the development of novel therapeutic and preventive approaches to combat long-term infections like Lyme borreliosis.

Perceived Parameters of Christian Pharmacy Students' Faith-Sharing in Clinical Settings.

Our interdisciplinary team (which included professionals from nursing, pharmacy, allied health, and psychology) conducted in-depth, semi-structured interviews with pharmacy students (n = 14) who were presently in a clinical rotation. When conducting the phenomenological, qualitative research study, we explored how students framed their respective experiences of incorporating spirituality into their clinical work. Three themes emerged from the interviews: (1) The students reportedly viewed their main role as being more of a support person than an evangelist, (2) They framed their influence from the perspective of so-called faith flags, and (3) They perceived more opportunities for influence with their coworkers than with patients. We discuss the findings in light of published findings and also in terms of how health care workers frame the concept of "ministry."

Borrelia burgdorferi protein interactions critical for microbial persistence in mammals.

Borrelia burgdorferi is the causative agent of Lyme disease that persists in a complex enzootic life cycle, involving Ixodes ticks and vertebrate hosts. The microbe invades ticks and vertebrate hosts in spite of active immune surveillance and potent microbicidal responses, and establishes long-term infection utilising mechanisms that are yet to be unravelled. The pathogen can cause multi-system disorders when transmitted to susceptible mammalian hosts, including in humans. In the past decades, several studies identified a limited number of B. burgdorferi gene-products critical for pathogen persistence, transmission between the vectors and the host, and host-pathogen interactions. This review will focus on the interactions between B. burgdorferi proteins, as well as between microbial proteins and host components, protein and non-protein components, highlighting their roles in pathogen persistence in the mammalian host. A better understanding of the contributions of protein interactions in the microbial virulence and persistence of B. burgdorferi would support development of novel therapeutics against the infection.

Spontaneous Calcium-Independent Dimerization of the Isolated First Domain of Neural Cadherin.

Cadherins are calcium-dependent, transmembrane adhesion molecules that assemble through direct noncovalent association of their N-terminal extracellular modular domains. As the transmembrane component of adherens junctions, they indirectly link adherent cells' actin cytoskeletons. Here, we investigate the most distal extracellular domain of neural cadherin (N-cadherin), a protein required at excitatory synapses, the site of long-term potentiation. This domain is the site of the adhesive interface, and it forms a dimer spontaneously without binding calcium, a surprising finding given that calcium binding is required for proper physiological function. A critical tryptophan at position 2, W2, provides a spectroscopic probe for the "closed" monomer and strand-swapped dimer. Spectroscopic studies show that W2 remains docked in the two forms but has a different apparent interaction with the hydrophobic pocket. Size-exclusion chromatography was used to measure the levels of the monomer and dimer over time to study the kinetics and equilibria of the unexpected spontaneous dimer formation ( Kd = 130 µM; τ = 2 days at 4 °C). Our results support the idea that NCAD1 is missing critical contacts that facilitate the rapid exchange of the ßA-strand. Furthermore, the monomer and dimer have equivalent and exceptionally high intrinsic stability for a 99-residue Ig-like domain with no internal disulfides ( Tm = 77 °C; Δ H = 85 kcal/mol). Ultimately, a complete analysis of synapse dynamics requires characterization of the kinetics and equilibria of N-cadherin. The studies reported here take a reductionist approach to understanding the essential biophysics of an atypical Ig-like domain that is the site of the adhesive interface of N-cadherin.

Drugs of Abuse and Novel Psychoactive Substances at Outdoor Music Festivals in Colorado.

BACKGROUND: Drugs of abuse (DOA) are widely used in the United States and are ubiquitous at outdoor music festivals. Attendees at music festivals are at high-risk for novel psychoactive substance (NPS) use, which is becoming more prevalent worldwide. No U.S. studies have employed an qualitative approach to investigate the etiologies of both traditional DOA and NPS use amongst music festival attendees. OBJECTIVES: The objective of this study was to improve understanding of the knowledge, attitudes, beliefs, and practices of festival attendees using NPS and DOA. METHODS: We conducted semi-structured interviews of 171 attendees during the Sonic Bloom and Arise music festivals in Colorado in 2015 and 2016. Discrete variables were summarized with descriptive statistics. The anonymous, multi-domain interview documented the knowledge, attitudes beliefs, and practices underlying DOA use, which were analyzed with qualitative methods. RESULTS: We enrolled 171 participants that endorsed DOA use at the festivals. Most were experienced DOA users, who perceived minimal risks associated with DOA and NPS use. Nearly all unanimously reported normalization of DOA at music festivals. Participants popularly cited empathogenic, entactogenic, and entheogenic effects of DOA as their primary motivations for use. NPS use was endorsed by 39.8% (n = 68) of respondents, all of whom identified as being experienced DOA users. CONCLUSIONS: This population of novel psychoactive substance users is primarily composed of experienced drug users that endorsed use because of low cost, minimal perceived risk, accessibility, and normalization of drug use at music festivals.

Can time to healing in pediatric blunt splenic injury be predicted?

BACKGROUND: Current consensus guidelines do not recommend routine follow-up imaging for blunt splenic injury (BSI) in children. However, repeat imaging is recommended based on persistent symptoms. Wide variation of practice continues to exist among surgeons. By defining the natural evolution of BSI, we sought to identify patients at higher risk for delayed healing who could benefit from outpatient imaging. METHODS: A retrospective review of all children with BSI at a Level 1 Pediatric Trauma Center was completed. Grade of injury, hospital course, laboratory values and follow-up imaging results were obtained. Injured spleens were classified as 'healed', 'healing' (with echogenic scar), or 'non-healing' with persistence of parenchymal abnormalities. RESULTS: Between 2000 and 2014, 222 patients with BSI were identified. Seven patients (3%) underwent immediate splenectomy. Packed red blood cell transfusion was required in 13 (6%) of the 222 patients, and 3 (2%) of 145 with isolated splenic injuries. Seventy-one percent of patients underwent additional imaging 2-74 weeks post-injury. A receiver operating characteristics (ROC) curve was used to establish the relationship between sensitivity and specificity of capturing non-healing spleens over time. Optimal timing for post-injury imaging for grades I-II was 7-8 weeks; healing of higher-grade injuries could not accurately be predicted. CONCLUSIONS: If return to full physical activity, in particular contact sports, is contingent upon documented healing of the splenic parenchyma after blunt trauma in the pediatric population, follow-up imaging for low-grade injuries is best obtained around 7-8 weeks. No such recommendations can be made for high-grade splenic injuries, as the exact time to healing cannot be predicted based on initial data. LEVEL OF EVIDENCE: IV. Diagnostic test.

Borrelia burgdorferi BBI39 Paralogs, Targets of Protective Immunity, Reduce Pathogen Persistence Either in Hosts or in the Vector.

Borrelia burgdorferi genome harbors several paralogous gene families (pgf) that can encode immunogenic proteins of unknown function. Protein-protein interaction assays using a transmission-blocking vaccine candidate, BBA52, as bait identified an interacting partner in spirochetes-a member of pgf 54, annotated as BBI39. We show that BBI39 is a surface-exposed membrane antigen that is immunogenic during spirochete infection, despite the gene being primarily transcribed in the vector with a transient expression in the host only at tick-bite sites. Immunization of rodents with BBI39, or a diverse paralog, BBI36, or their combination impaired pathogen acquisition by the vector, transmission from ticks to hosts, or induction of disease. High-titer BBI39 immunoglobulin G antibodies, which have borreliacidal properties, could be generated through routine subcutaneous or oral immunization, further highlighting use of BBI39 proteins as novel Lyme disease vaccines that can target pathogens in the host or in ticks.

Characterization of the Pro-Inflammatory Cytokine IL-1ß on Butyrate Oxidation in Colorectal Cancer Cells.

Cancer, in part, is driven, by alterations in cellular metabolism that promote cell survival and cell proliferation. Identifying factors that influence this shift in cellular metabolism in cancer cells is important. Interleukin-1ß (IL-1ß) is a pro-inflammatory cytokine that has been reported to be elevated in colorectal cancer patients. While much is known toward the effect of dietary nutrients on regulating inflammation and the inflammatory response, which includes cytokines such as IL-1ß, far less is understood how cytokines impact nutrient fate to alter cancer cell metabolism. Butyrate, a nutrient derived from the fermentation of dietary fiber in the colon, is the preferential exogenous energetic substrate used by non-cancerous colonocytes, but is used less efficiently by colorectal cancer cells. To test whether IL-1ß alters colonocyte energy metabolism, we measured butyrate oxidation in HCT116 colorectal cancer cells with and without IL-1ß. We hypothesize that IL-1ß will push cancerous colonocytes away from the utilization and oxidation of butyrate. In this study, we demonstrate that pretreatment of colorectal cancer cells with IL-1ß diminished butyrate oxidation and NADH levels. This effect was blocked with the interleukin receptor antagonist A (IL-1RA). Moreover, IL-1ß suppressed basal mitochondrial respiration and lowered the mitochondrial spare capacity. By using inhibitors to block downstream targets of the interleukin-1 receptor pathway, we show that p38 is required for the IL-1ß-mediated decrease in butyrate oxidation. These data provide insight into the metabolic effects induced by IL-1ß in colorectal cancer, and identify relevant targets that may be exploited to block the effects of this cytokine. J. Cell. Biochem. 118: 1614-1621, 2017. © 2016 Wiley Periodicals, Inc.

A Borrelia burgdorferi Surface-Exposed Transmembrane Protein Lacking Detectable Immune Responses Supports Pathogen Persistence and Constitutes a Vaccine Target.

Borrelia burgdorferi harbors a limited set of transmembrane surface proteins, most of which constitute key targets of humoral immune responses. Here we show that BB0405, a conserved membrane-spanning protein of unknown function, fails to evoke detectable antibody responses despite its extracellular exposure. bb0405 is a member of an operon and ubiquitously expressed throughout the rodent-tick infection cycle. The gene product serves an essential function in vivo, as bb0405-deletion mutants are unable to transmit from ticks and establish infection in mammalian hosts. Despite the lack of BB0405-specific immunoglobulin M or immunoglobulin G antibodies during natural infection, mice immunized with a recombinant version of the protein elicited high-titer and remarkably long-lasting antibody responses, conferring significant host protection against tick-borne infection. Taken together, these studies highlight the essential role of an apparently immune-invisible borrelial transmembrane protein in facilitating infection and its usefulness as a target of protective host immunity blocking the transmission of B. burgdorferi.

HtrA, a Temperature- and Stationary Phase-Activated Protease Involved in Maturation of a Key Microbial Virulence Determinant, Facilitates Borrelia burgdorferi Infection in Mammalian Hosts.

High-temperature requirement protease A (HtrA) represents a family of serine proteases that play important roles in microbial biology. Unlike the genomes of most organisms, that of Borrelia burgdorferi notably encodes a single HtrA gene product, termed BbHtrA. Previous studies identified a few substrates of BbHtrA; however, their physiological relevance could not be ascertained, as targeted deletion of the gene has not been successful. Here we show that BbhtrA transcripts are induced during spirochete growth either in the stationary phase or at elevated temperature. Successful generation of a BbhtrA deletion mutant and restoration by genetic complementation suggest a nonessential role for this protease in microbial viability; however, its remarkable growth, morphological, and structural defects during cultivation at 37°C confirm a high-temperature requirement for protease activation and function. The BbhtrA-deficient spirochetes were unable to establish infection of mice, as evidenced by assessment of culture, PCR, and serology. We show that transcript abundance as well as proteolytic processing of a borrelial protein required for cell fission and infectivity, BB0323, is impaired in BbhtrA mutants grown at 37°C, which likely contributed to their inability to survive in a mammalian host. Together, these results demonstrate the physiological relevance of a unique temperature-regulated borrelial protease, BbHtrA, which further enlightens our knowledge of intriguing aspects of spirochete biology and infectivity.