P2Y2 purinergic receptor gene deletion protects mice from bacterial endotoxin and sepsis-associated liver injury and mortality

The liver plays a significant role in regulating a wide range of metabolic, homeostatic, and host-defense functions. However, the impact of liver injury on the host's ability to control bacteremia and morbidity in sepsis is not well understood. Leukocyte recruitment and activation lead to cytokine and chemokine release, which, in turn, trigger hepatocellular injury and elevate nucleotide levels in the extracellular milieu. P2Y2 purinergic receptors, G protein-coupled and activated by extracellular ATP/UTP, are expressed at the cell surface of hepatocytes and nonparenchymal cells. We sought to determine whether P2Y2 purinergic receptor function is necessary for the maladaptive host response to bacterial infection and endotoxin-mediated inflammatory liver injury and mortality in mice. We report that P2Y2 purinergic receptor knockout mice (P2Y2-/-) had attenuated inflammation and liver injury, with improved survival in response to LPS/galactosamine (LPS/GalN; inflammatory liver injury) and cecal ligation and puncture (CLP; polymicrobial sepsis). P2Y2-/- livers had attenuated c-Jun NH2-terminal kinase activation, matrix metallopeptidase-9 expression, and hepatocyte apoptosis in response to LPS/GalN and attenuated inducible nitric oxide synthase and nucleotide-binding oligomerization domain, leucine-rich repeat and pyrin domain containing 3 protein expression in response to CLP. Implicating liver injury in the disruption of amino acid homeostasis, CLP led to lower serum arginine and higher bacterial load and morbidity in the WT mice, whereas serum arginine levels were comparable to sham-operated controls in P2Y2-/- mice, which had attenuated bacteremia and improved survival. Collectively, our studies highlight the pathophysiological relevance of P2Y2 purinergic receptor function in inflammatory liver injury and dysregulation of systemic amino acid homeostasis with implications for sepsis-associated immune dysfunction and morbidity in mice.NEW & NOTEWORTHY Our studies provide experimental evidence for P2Y2 purinergic receptor-mediated potentiation of inflammatory liver injury, morbidity, and mortality, in two well-established animal models of inflammatory liver injury. Our findings highlight the potential to target P2Y2 purinergic signaling to attenuate the induction of "cytokine storm" and prevent its deleterious consequences on liver function, systemic amino acid homeostasis, host response to bacterial infection, and sepsis-associated morbidity and mortality.

A Case of Pediatric Alcohol-Associated Hepatitis Evaluated for Liver Transplant Listing

Alcohol-associated hepatitis (AH) refers to liver injury from alcoholic intake that usually occurs after years of heavy alcohol abuse. Frequent, heavy alcohol consumption causes hepatic inflammation, fibrosis, and cirrhosis. Some patients develop severe AH, which carries high short-term mortality and is the second most common reason for adult liver transplants (LTs) worldwide. We present one of the first cases of a teenager diagnosed with severe AH that led to LT evaluation. Our patient was a 15-year-old male who presented with epistaxis and 1 month of jaundice after 3 years of heavy daily alcohol abuse. In collaboration with our adult transplant hepatologist colleagues, we initiated a management plan that consisted of treating acute alcohol withdrawal, steroid utilization, mental health support, and LT evaluation.

Special Population: Pediatric Nonalcoholic Fatty Liver Disease

Pediatric nonalcoholic fatty liver disease represents the most common liver disease in children and has been shown to carry significant morbidity. Widespread heterogeneity of disease, as well as the limitation of indirect screening modalities, has made true prevalence of disease difficult to estimate as well as hindered ability to identify optimal prognostic factors in the pediatric population. Current therapeutic options are limited in pediatric patients with current mainstay of therapy, lifestyle modifications, has proven to have a limited efficacy in current clinical application. Current research remains needed in improved screening modalities, prognosticating techniques, and therapeutic options in the pediatric population.

Trends and Disparities in Pediatric Nonalcoholic Fatty Liver Disease-Associated Hospitalizations in the United States

OBJECTIVE

Non-alcoholic fatty liver disease (NAFLD) represents a spectrum of disease characterized by accumulation of fat in the liver and is associated with co-morbidities linked to metabolic syndrome. The prevalence of NAFLD in children has increased in the United States over time and with marked racial differences observed in geographically limited studies. This study aims to provide a current, nation-wide analysis of temporal trends of pediatric NAFLD-related hospitalizations and associated co-morbidities as well as assess for racial/ethnic disparities.

METHODS

A cross-sectional study was conducted using the National Inpatient Sample (NIS) from 2004 to 2018 and included NAFLD-associated hospitalizations of children ages 0-17 years of age based on ICD-9/10 diagnosis codes. Rates and patient characteristics analyzed via descriptive statistics and associations via survey logistic regression. Temporal trends assessed via joinpoint regression.

RESULTS

There was an overall increase in pediatric NAFLD-associated hospitalizations with an average annual percent change (AAPC) of 6.6 with highest rates among Hispanic patients (AAPC = 11.1) compared to NH-White (AAPC = 4.1) and NH-Black (AAPC = 2.1). Analysis of race/ethnicity and NAFLD hospitalization showed an increased association in Hispanic patients (odds ratio [OR] = 1.64, 95% confidence interval [CI] = 1.51-1.77) and a decreased association in non-Hispanic (NH)-Black patients (OR = 0.49, 95% CI = 0.45-0.54) when compared to NH-White patients.

CONCLUSION

Utilizing a nation-wide database we demonstrated significant increases in NAFLD-associated hospitalizations with highest prevalence and rates seen in Hispanic patients. In addition, sex and comorbidities showed notable correlation to these hospitalization rates displaying the need for further studies on these relationships and highlights the potential for interventions aimed at high-risk groups.

Online learning in a dermatology clerkship: piloting the new American Academy of Dermatology Medical Student Core Curriculum

BACKGROUND

Multiple studies have shown that both current and future primary care providers have insufficient education and training in dermatology. To address the limitations and wide variability in medical student dermatology instruction, the American Academy of Dermatology (AAD) created a standardized, online curriculum for both dermatology learners and educators.

OBJECTIVE

We sought to determine the impact of the integration of the AAD online curriculum into a 2-week introductory dermatology clerkship for fourth-year medical students.

METHODS

In addition to their clinical duties, we assigned 18 online modules at a rate of 1 to 3 per day. We evaluated knowledge acquisition using a 50-item, multiple-choice pretest and posttest. Postmodule and end-of-course questionnaires contained both closed and open-ended items soliciting students' perceptions about usability and satisfaction.

RESULTS

All 51 participants significantly improved in their dermatology knowledge (P < .001). The majority of students found the modules easy to navigate (95%) and worth their time (93%). All respondents supported the continuation of the modules as part of the dermatology clerkship.

LIMITATIONS

Without a control group who did not experience the online curriculum, we are unable to isolate the specific impact of the online modules on students' learning.

CONCLUSION

This study demonstrates the successful integration of this educational resource into a 2-week, university-based dermatology clerkship. Students' perceptions regarding usability and satisfaction were overwhelmingly positive, suggesting that the online curriculum is highly acceptable to learners. Widespread use of this curriculum may be a significant advancement in standardized dermatology learning for medical students.

Validation of a diagnostic microarray for human papillomavirus: coverage of 102 genotypes

Papillomaviruses have been implicated in a variety of human diseases ranging from common warts to invasive carcinoma of the anogenital mucosa. Existing assays for genotyping human papillomavirus are restricted to a small number of types. Here, we present a comprehensive, accurate microarray strategy for detection and genotyping of 102 human papillomavirus types and validate its use in a panel of 91 anal swabs. This array has equal performance to traditional dot blot analysis with the benefits of added genotype coverage and the ability to calibrate readout over a range of sensitivity or specificity values.

Transcriptome sequencing demonstrates that human papillomavirus is not active in cutaneous squamous cell carcinoma

Beta-papillomavirus (β-HPV) DNA is present in some cutaneous squamous cell carcinomas (cuSCC), but no mechanism of carcinogenesis has been determined. We used ultra-high throughput sequencing of the cancer transcriptome to assess whether papillomavirus transcripts are present in these cancers. Sixty-seven cuSCC samples were assayed for β-HPV DNA by PCR, and viral loads were measured with type-specific qPCR. Thirty-one SCCs were selected for whole transcriptome sequencing. Transcriptome libraries were prepared in parallel from the HPV18 positive HeLa cervical cancer cell line and HPV16 positive primary cervical and periungual SCC. Thirty percent (20/67) of the tumors were positive for β-HPV DNA, but there was no difference in β-HPV viral load between tumor and normal tissue (p=0.310). Immunosuppression and age were significantly associated with higher viral load (p=0.016 for immunosuppression; p=0.0004 for age). Transcriptome sequencing failed to identify papillomavirus expression in any of the skin tumors. In contrast, HPV 16 and 18 mRNA transcripts were readily identified in primary cervical and periungual cancers and HeLa cells. These data demonstrate that papillomavirus mRNA expression is not a factor in the maintenance of cuSCC.