Ube4A maintains metabolic homeostasis and facilitates insulin signaling in vivo.

OBJECTIVE: Defining the regulators of cell metabolism and signaling is essential to design new therapeutic strategies in obesity and NAFLD/NASH. E3 ubiquitin ligases control diverse cellular functions by ubiquitination-mediated regulation of protein targets, and thus their functional aberration is associated with many diseases. The E3 ligase Ube4A has been implicated in human obesity, inflammation, and cancer. However, its in vivo function is unknown, and no animal models are available to study this novel protein. METHODS: A whole-body Ube4A knockout (UKO) mouse model was generated, and various metabolic parameters were compared in chow- and high fat diet (HFD)-fed WT and UKO mice, and in their liver, adipose tissue, and serum. Lipidomics and RNA-Seq studies were performed in the liver samples of HFD-fed WT and UKO mice. Proteomic studies were conducted to identify Ube4A's targets in metabolism. Furthermore, a mechanism by which Ube4A regulates metabolism was identified. RESULTS: Although the body weight and composition of young, chow-fed WT and UKO mice are similar, the knockouts exhibit mild hyperinsulinemia and insulin resistance. HFD feeding substantially augments obesity, hyperinsulinemia, and insulin resistance in both sexes of UKO mice. HFD-fed white and brown adipose tissue depots of UKO mice have increased insulin resistance and inflammation and reduced energy metabolism. Moreover, Ube4A deletion exacerbates hepatic steatosis, inflammation, and liver injury in HFD-fed mice with increased lipid uptake and lipogenesis in hepatocytes. Acute insulin treatment resulted in impaired activation of the insulin effector protein kinase Akt in liver and adipose tissue of chow-fed UKO mice. We identified the Akt activator protein APPL1 as a Ube4A interactor. The K63-linked ubiquitination (K63-Ub) of Akt and APPL1, known to facilitate insulin-induced Akt activation, is impaired in UKO mice. Furthermore, Ube4A K63-ubiquitinates Akt in vitro. CONCLUSION: Ube4A is a novel regulator of obesity, insulin resistance, adipose tissue dysfunction and NAFLD, and preventing its downregulation may ameliorate these diseases.

Enhancing Hepatic MBOAT7 Expression in Mice With Nonalcoholic Steatohepatitis.

BACKGROUND AND AIMS: Polymorphisms near the membrane bound O-acyltransferase domain containing 7 (MBOAT7) genes are associated with worsened nonalcoholic fatty liver (NASH), and nonalcoholic fatty liver disease (NAFLD)/NASH may decrease MBOAT7 expression independent of these polymorphisms. We hypothesized that enhancing MBOAT7 function would improve NASH. METHODS: Genomic and lipidomic databases were mined for MBOAT7 expression and hepatic phosphatidylinositol (PI) abundance in human NAFLD/NASH. Male C57BL6/J mice were fed either choline-deficient high-fat diet or Gubra Amylin NASH diet and subsequently infected with adeno-associated virus expressing MBOAT7 or control virus. NASH histological scoring and lipidomic analyses were performed to assess MBOAT7 activity, hepatic PI, and lysophosphatidylinositol (LPI) abundance. RESULTS: Human NAFLD/NASH decreases MBOAT7 expression and hepatic abundance of arachidonate-containing PI. Murine NASH models display subtle changes in MBOAT7 expression, but significantly decreased activity. After MBOAT7 overexpression, liver weights, triglycerides, and plasma alanine and aspartate transaminase were modestly improved by MBOAT7 overexpression, but NASH histology was not improved. Despite confirmation of increased activity with MBOAT7 overexpression, content of the main arachidonoylated PI species was not rescued by MBOAT7 although the abundance of many PI species was increased. Free arachidonic acid was elevated but the MBOAT7 substrate arachidonoyl-CoA was decreased in NASH livers compared to low-fat controls, likely due to the decreased expression of long-chain acyl-CoA synthetases. CONCLUSION: Results suggest decreased MBOAT7 activity plays a role in NASH, but MBOAT7 overexpression fails to measurably improve NASH pathology potentially due to the insufficient abundance of its arachidonoyl-CoA substrate.

Adipose-targeted SWELL1 deletion exacerbates obesity- and age-related nonalcoholic fatty liver disease.

Healthy expansion of adipose tissue is critical for the maintenance of metabolic health, providing an optimized reservoir for energy storage in the form of triacylglycerol-rich lipoproteins. Dysfunctional adipocytes that are unable to efficiently store lipid can result in lipodystrophy and contribute to nonalcoholic fatty liver disease (NAFLD) and metabolic syndrome. Leucine-rich repeat containing protein 8a/SWELL1 functionally encodes the volume-regulated anion channel complex in adipocytes, is induced in early obesity, and is required for normal adipocyte expansion during high-fat feeding. Adipose-specific SWELL1 ablation (Adipo KO) leads to insulin resistance and hyperglycemia during caloric excess, both of which are associated with NAFLD. Here, we show that Adipo-KO mice exhibited impaired adipose depot expansion and excess lipolysis when raised on a variety of high-fat diets, resulting in increased diacylglycerides and hepatic steatosis, thereby driving liver injury. Liver lipidomic analysis revealed increases in oleic acid-containing hepatic triacylglycerides and injurious hepatic diacylglyceride species, with reductions in hepatocyte-protective phospholipids and antiinflammatory free fatty acids. Aged Adipo-KO mice developed hepatic steatosis on a regular chow diet, and Adipo-KO male mice developed spontaneous, aggressive hepatocellular carcinomas (HCCs). These data highlight the importance of adipocyte SWELL1 for healthy adipocyte expansion to protect against NAFLD and HCC in the setting of overnutrition and with aging.

Solitary Intracranial Plasmacytoma of the Brain Treated With Primary Radiation Therapy.

We present a rare case of a solitary intracranial plasmacytoma of the brain parenchyma in a 49-year-old female who presented with neck pain/headache, paresthesias, and auditory hallucinations. A workup revealed a solitary left parietal lobe brain lesion and a biopsy demonstrated a plasma cell infiltrate consistent with an extramedullary plasmacytoma. A complete workup for multiple myeloma was negative. As opposed to surgical resection and adjuvant radiation therapy (RT), as described in prior case reports in the literature, this patient was managed with definitive local RT alone to 50 Gy in 25 fractions. Six months following primary RT completion, the patient's presenting symptoms completely resolved and follow-up imaging revealed regression of the primary tumor. To our knowledge, this is the first reported case of a solitary extramedullary plasmacytoma of the brain treated with localized definitive RT alone.

Asymptomatic Hepatic Leiomyoma in an Immunocompetent Middle-Aged Woman.

Primary hepatic leiomyomas are rare tumors most commonly in immunosuppressed individuals who are coinfected with Epstein-Barr virus (EBV). From our literature review, there have been 50 published cases, of which 24 were immunocompetent individuals and only 5 were negative for EBV infection. We report a case of primary hepatic leiomyomas in an asymptomatic middle-aged woman without a history of immunosuppression or EBV infection.

Metastatic Hepatocellular Carcinoma Masquerading as Acute Diverticulitis.

Colorectal cancer may masquerade as acute diverticulitis. Our case is a 71-year-old man who presented to the emergency department with abdominal pain and was diagnosed with acute diverticulitis. He was ultimately found to have metastatic hepatocellular carcinoma to the colon without any evidence of diverticular disease on colonoscopy. Although the most common malignancy to masquerade as diverticulitis is colorectal cancer, metastatic deposits should also be considered, especially in patients with a history of extracolonic malignancy.

A Rare Cause of Upper Gastrointestinal Bleeding: Sarcina ventriculi.

We describe a patient who presented with hematemesis and was found to have unusually well-demarcated erythematous mucosa with a 2-3 cm irregular nonbleeding necrotic ulcer in the gastric body on esophagogastroduodenoscopy. Biopsy and pathologic examination of the tissue indicated infection with a rare bacterium, Sarcina ventriculi, prompting treatment with an unproven combination of 4 agents: metronidazole, ciprofloxacin, sucralfate, and pantoprazole. Repeat esophagogastroduodenoscopy 8 weeks later revealed complete resolution of the ulceration and surrounding erythema. These results may contribute toward establishing an appropriate therapeutic regimen for future S. ventriculi infections.

ENhAncing Lifestyle Behaviors in EndometriaL CancEr (ENABLE): A Pilot Randomized Controlled Trial.

PURPOSE: Endometrial cancer is associated with the highest comorbid disease burden of any cancer. The aim of this trial was to assess the feasibility and safety of an allied health intervention during adjuvant treatment. METHODS: A mixed-methods pilot randomized (2:1) controlled trial with concealed allocation and assessor-blinding. Eligibility criteria: adjuvant endometrial cancer treatment scheduled, disease stage I-IIIC1, ECOG 0-2 and able to perform unsupervised physical activity (PA). Participants received usual care and 8 sessions of weekly, individualized, lifestyle education (diet and PA) with behavior change and social support (intervention group), delivered predominantly by telehealth, or usual care alone. Feasibility outcomes: recruitment and consent rates, decline reasons, program acceptability, intervention adherence and retention. RESULTS: 22/44 eligible patients (50%, 95%CI: 36%, 64%) were recruited over 10 months (14 intervention, 8 usual care). The recruitment rate was 2.2 patients/month (95%CI: 1.4, 3.3). Patients who declined had too much going on (7/22, 32%) or were not interested (6/22, 27%). Mean (SD) age and BMI were 63.2 years (6.8) and 31.9 kg/m2 (6.7). A majority were FIGO stage I (15/22, 68%) and received vaginal brachytherapy (14/22, 64%). Adherence was high, 11/14 (79%, 95%CI: 52%, 92%) participants attended >70% of scheduled sessions. Retention was 100% (95%CI: 85%, 100%) at 9 weeks, however completion of objective measures was impacted by COVID-19 restrictions. Telehealth and online questionnaires enabled participation. No serious adverse events occurred. CONCLUSION: The intervention was acceptable to participants with high levels of adherence and retention. Trial findings will be used to design a future RCT. TRIAL REGISTRATION: The trial was registered on www.anzctr.org.au (ACTRN12619000631101) 29/04/2019.

A Unique Presentation of Metastatic Gallbladder Carcinoma.

Gallbladder carcinoma can be challenging to diagnose and treat and usually leads to poor outcome, due to its aggressive nature and the nonspecific clinical presentation at early stage. We describe an interesting case of a 60-year-old female who presented with stage 3 appendiceal carcinoma after appendectomy was performed outside hospital. Further imaging workup demonstrated enlarged ovarian cysts and porcelain gallbladder. Upon exploration, she was found to have carcinomatosis and we proceeded with cytoreductive surgery (CRS) and hyperthermic intraperitoneal therapy (HIPEC). Final pathology demonstrated carcinoma from gallbladder primary.

PPARα agonist fenofibrate attenuates iron-induced liver injury in mice by modulating the Sirt3 and ß-catenin signaling.

Iron accumulation is frequently associated with chronic liver diseases. However, our knowledge on how iron contributes to the liver injury is limited. Aberrant Wnt/ß-catenin signaling is a hallmark of several hepatic pathologies. We recently reported that peroxisome proliferator-activated receptor α (PPARα) agonist, fenofibrate, prevents iron-induced oxidative stress and ß-catenin signaling by chelating the iron. Sirtuin3 (Sirt3), a type of NAD+-dependent deacetylase, that plays a critical role in metabolic regulation was found to prevent ischemia reperfusion injury (IRI) by normalizing the Wnt/ß-catenin pathway. In the present study, we explored if fenofibrate prevents iron-induced liver injury by regulating the Sirt3 and ß-catenin signaling. In vitro and in vivo iron treatment resulted in the downregulation of PPARα, Sirt3, active ß-catenin, and its downstream target gene c-Myc in the mouse liver. Pharmacological activation of Sirt3, both in vitro and in vivo, by Honokiol (HK), a known activator of Sirt3, abrogated the inhibitory effect of iron overload on active ß-catenin expression and prevented the iron-induced upregulation of α smooth muscle actin (αSMA) and TGFß expression. Intrinsically, PPARα knockout mice showed significant downregulation of hepatic Sirt3 levels. In addition, treatment of iron overload mice with PPARα agonist fenofibrate reduced hepatic iron accumulation and prevented iron-induced downregulation of liver Sirt3 and active ß-catenin, mitigating the progression of fibrosis. Thus, our results establish a novel link between hepatic iron and PPARα, Sirt3, and ß-catenin signaling. Further exploration on the mechanisms by which fenofibrate ameliorates iron-induced liver injury likely has significant therapeutic impact on iron-associated chronic liver diseases.NEW & NOTEWORTHY Hepatic intracellular iron accumulation has been implicated in the pathophysiology of chronic liver diseases. In this study, we identified a novel mechanism involved in the progression of fibrosis. Excess iron accumulation in liver caused downregulation of PPARα-Sirt3-Wnt signaling leading to fibrosis. This work has significant translational potential as PPARα agonist fenofibrate could be an attractive therapeutic drug for the treatment of liver disorders associated with iron overload.

A Rare Case of Pancreatic Endometriosis Masquerading as Pancreatic Mucinous Neoplasm.

Endometriosis is a relatively common condition among women, and pancreatic endometriosis has been reported on rare occasions. Such pancreatic lesions are difficult to diagnose and distinguish from other cystic lesions of the pancreas preoperatively. This report describes a case of pancreatic endometriosis in a 51-year-old female patient. Imaging demonstrated an enlarging cyst with findings concerning for a mucinous neoplasm. The patient underwent robotic distal pancreatectomy and splenectomy. Histopathology revealed an endometriotic cyst. Pancreatic endometriosis can be difficult to distinguish from other lesions of the pancreas. Surgical resection should be undertaken in cases where malignancy is suspected.

NAFLD: Reporting Histologic Findings in Clinical Practice.

The role of liver biopsy in NASH has evolved along with the increased recognition of the significance of this disease, and the unmet medical need it presents. Drug development and clinical trials are rapidly growing, as are noninvasive tests for markers of steatosis, inflammation, injury, and fibrosis. Liver biopsy evaluation remains necessary for both drug development and clinical trials as the most specific means of diagnosis and patient identification for appropriate intervention. This White Paper, sponsored by the American Association for the Study of Liver Disease NASH Task Force, is a focused review of liver biopsy evaluation in fatty liver disease in subjects with presumed NAFLD for practicing clinical hepatologists and pathologists. The goal is to provide succinct and specific means for reporting the histopathologic elements of NASH, distinguishing NASH from nonalcoholic fatty liver without steatohepatitis, and from alcohol-associated steatohepatitis when possible. The discussion includes the special situations of NASH in advanced fibrosis or cirrhosis, and in the pediatric population. Finally, there is discussion of semiquantitative methods of evaluation of lesions of "disease activity" and fibrosis. Tables are presented for scoring and a suggested model for final reporting. Figures are presented to highlight the histopathologic elements of NASH.

Expression of CDX2 and Thyroid Transcription Factor-1 in Oropharyngeal Undifferentiated Carcinomas: A Potential Diagnostic Pitfall.

Oropharyngeal undifferentiated carcinomas are rare and most are human papillomavirus related. Morphologically, they overlap with undifferentiated carcinomas from other organ sites, including the nasopharynx, lung, and gastrointestinal tract. Most have lymph node metastases at presentation and, especially when initially encountered in a lymph node, immunostains may be performed to determine the most likely primary site. We recently reviewed a case in consultation that strongly and diffusely expressed both thyroid transcription factor-1 (TTF-1, SPT24 clone) and CDX2, 2 widely used markers that are considered relatively lineage specific for lung/thyroid and intestinal differentiation, respectively. Unexpected expression of these markers could be misleading. However, they have not been previously assessed in oropharyngeal undifferentiated carcinoma. Here, we performed immunohistochemistry for CDX2 and TTF-1 (8G7G3/1 clone) on primary tumors and/or lymph node metastases from 11 in-house patients with previously characterized undifferentiated carcinoma of the oropharynx from 1992 to 2008. All were male with an average age of 56.7 years, and 5 (46%) initially presented with a neck mass. All were Epstein-Barr virus negative and 9 (82%) were human papillomavirus and p16 positive. CDX2 was positive in 6 of the 11 (55%) cases. However, staining was generally weak to moderate and/or nondiffuse. TTF-1 was negative in all the in-house cases and showed only rare, weakly positive cells in the consult case when TTF-1 was repeated using the 8G7G3/1 clone. Thus, CDX2 immunoreactivity is common, whereas TTF-1 expression is rare in oropharyngeal undifferentiated carcinomas. As a result, one should not rely on CDX2 as evidence of intestinal differentiation or origin in metastatic undifferentiated carcinomas in the neck, particularly when staining is not strong and diffuse. In addition, TTF-1 should be interpreted with caution especially when using the SPT24 clone.

Pancreatic Neuroendocrine Tumors: Computed Tomography Enhancement, But Not Histological Grade, Correlates With Tumor Aggression.

OBJECTIVES: The aims of this study were to assess computed tomography enhancement of pancreatic neuroendocrine tumors (NETs), determine correlation with histological vascularity and fibrosis, and identify a biomarker for tumor aggression. METHODS: The arterial and venous enhancement of NET was calculated on computed tomography for 56 patients. Tumor size and vascularity/fibrosis were assessed. Tumor aggression was grouped by World Health Organization and Hochwald grade and the presence of metastases. Variables were assessed for correlation. Groups were compared using t test/Wilcoxon rank sum test. RESULTS: Arterial enhancement and dynamic washout (r = 0.35, P = 0.02; r = 0.34, P = 0.02, respectively) correlate with vascularity. There is inverse correlation between vascularity and fibrosis (r = -0.62, P < 0.001), but no correlation between enhancement and fibrosis. Metastatic NET had less arterial (mean, -2 [standard deviationi {SD}, 27.1] Hounsfield unit [HU]; 35.7 [SD, 57.5] HU; P = 0.01) and venous (12.6 [SD, 14.4] HU; 29.2 [SD, 38.3] HU; P = 0.04) enhancement and less washout (8.5 [SD, 18.5] HU; 26.8 [SD, 30] HU, P = 0.02) compared with nonmetastatic NET. These differences were not present when comparing by tumor grade. Arterial hypoenhancement was the only significant predictor of metastases. CONCLUSIONS: Aggressive tumors, as determined by metastases, but not histological grade, enhance less than nonmetastatic tumors.

Assessment of disease aggression in cystic pancreatic neuroendocrine tumors: A CT and pathology correlation study.

BACKGROUND/OBJECTIVES: There are inconsistencies in the literature regarding the clinical significance of cystic components in pancreatic neuroendocrine tumors (NET). This may be related to differences in the identification of cystic NET through imaging and/or pathology. Tumors may also be microscopically or macroscopically cystic. Our primary objective is to determine radiology-pathology correlation for the identification of cystic components. Our secondary objective is to determine if cystic components are associated with indices of tumor aggression. METHODS: 60 tumors with correlative surgical pathology were assessed retrospectively for cystic components on CT and pathology. Tumor was categorized as solid or cystic on CT and pathology. If cystic on pathology, cystic components were categorized as macroscopic or microscopic. Cystic components were estimated as <50% and ≥50% tumor volume. WHO/Hochwald grade and presence of metastases were used to stratify disease aggression. Associations were tested with Chi square/Fisher's exact test and differences were tested with t-test/Wilcoxon rank sums test. RESULTS: There is moderate agreement between CT and histology for presence of cystic components. Discrepancies were mostly attributable to the presence of microscopic cystic components in tumors appearing solid on CT. There was no difference in size between cystic and solid tumors on CT or pathology. No association between CT-determined cystic components and tumor grade was found. Tumors with cystic components (cystic by CT, and macroscopically cystic by pathology) demonstrated less association with metastases than solid tumors. CONCLUSIONS: Cystic components, comprising ≥50% of the tumor by CT and observed macroscopically on pathology, are associated with less aggressive disease.

Clinical T2N0 Esophageal Cancer: Identifying Pretreatment Characteristics Associated With Pathologic Upstaging and the Potential Role for Induction Therapy.

BACKGROUND: Although studies have suggested standard therapy for clinical T2N0 esophageal cancer should be primary surgery, we hypothesize there is a subgroup for whom induction therapy may result in improved overall survival. METHODS: Patients with cT2N0 esophageal cancer receiving induction therapy or upfront esophagectomy (UE) were identified in the National Cancer Data Base. The UE patients were dichotomized as (1) pathologically upstaged, or (2) same-staged or downstaged. Logistic regression models identified variables associated with upstaging, and Kaplan-Meier analysis compared median overall survival. RESULTS: From 2006 to 2012, 932 cT2N0 patients (52.2%) received UE, and 853 (47.8%) received induction therapy first. In all, 326 of 713 UE patients (45.7%) were upstaged: 87 of 326 (26.7%) had T upstaging; 98 of 326 (30.1%) had N upstaging; and 141 of 326 (43.3%) had both. Patients upstaged after UE had a higher tumor grade (35.1% versus 57.1% grade 3), and a higher rate of lymphovascular invasion (57.1% versus 17.7%; both p < 0.001). Variables associated with upstaging included lymphovascular invasion (odds ratio 6.0, 95% confidence interval: 2.9 to 12.5, p < 0.001) and tumor grade 3 (odds ratio 9.4, 95% confidence interval: 1.8 to 48.4, p = 0.007). Of upstaged UE patients, only 144 (44.2%) received adjuvant therapy. The median overall survival for cT2N0 patients upstaged after UE was 27.5 ± 2.5 months versus 43.9 ± 2.9 months for induction therapy patients (any resultant pathologic stage, p < 0.001). CONCLUSIONS: Half of all cT2N0 patients were pathologically upstaged after UE, with worse survival compared with patients receiving induction therapy. Refining an upstaging model would help select patients for induction therapy and increase the rate of chemotherapy in patients at risk for systemic disease.