Decreased Macrophage Autophagy Promotes Liver Injury and Inflammation from Alcohol.

BACKGROUND: One mechanism underlying the development of alcoholic liver disease is overactivation of the innate immune response. Recent investigations indicate that the lysosomal pathway of autophagy down-regulates the inflammatory state of hepatic macrophages, suggesting that macrophage autophagy may regulate innate immunity in alcoholic liver disease. The function of macrophage autophagy in the development of alcoholic liver disease was examined in studies employing mice with a myeloid-specific decrease in autophagy. METHODS: Littermate control and Atg5Δmye mice lacking Atg5-dependent myeloid autophagy were administered a Lieber-DeCarli control (CD) or ethanol diet (ED) alone or together with lipopolysaccharide (LPS) and examined for the degree of liver injury and inflammation. RESULTS: Knockout mice with decreased macrophage autophagy had equivalent steatosis but increased mortality and liver injury from ED alone. Increased liver injury and hepatocyte death also occurred in Atg5Δmye mice administered ED and LPS in association with systemic inflammation as indicated by elevated serum levels of proinflammatory cytokines. Hepatic macrophage and neutrophil infiltration were unaffected by decreased autophagy, but levels of proinflammatory cytokine gene induction were significantly increased in the livers but not adipose tissue of knockout mice treated with ED and LPS. Inflammasome activation was increased in ED/LPS-treated knockout mice resulting in elevated interleukin (IL)-1ß production. Increased IL-1ß promoted alcoholic liver disease as liver injury was decreased by the administration of an IL-1 receptor antagonist. CONCLUSIONS: Macrophage autophagy functions to prevent liver injury from alcohol. This protection is mediated in part by down-regulation of inflammasome-dependent and inflammasome-independent hepatic inflammation. Therapies to increase autophagy may be effective in this disease through anti-inflammatory effects on macrophages.

Pentamidine blocks hepatotoxic injury in mice.

Toxin-induced liver diseases lack effective therapies despite increased understanding of the role factors such as an overactive innate immune response play in the pathogenesis of this form of hepatic injury. Pentamidine is an effective antimicrobial agent against several human pathogens, but studies have also suggested that this drug inhibits inflammation. This potential anti-inflammatory mechanism of action, together with the development of a new oral form of pentamidine isethionate VLX103, led to investigations of the effectiveness of this drug in the prevention and treatment of hepatotoxic liver injury. Pretreatment with a single injection of VLX103 in the d-galactosamine (GalN) and lipopolysaccharide (LPS) model of acute, fulminant liver injury dramatically decreased serum alanine aminotransferase levels, histological injury, the number of terminal deoxynucleotide transferase-mediated deoxyuridine triphosphate nick end-labeling (TUNEL)-positive cells and mortality compared with vehicle-injected controls. VLX103 decreased GalN/LPS induction of tumor necrosis factor (TNF) but had no effect on other proinflammatory cytokines. VLX103 prevented the proinflammatory activation of cultured hepatic macrophages and partially blocked liver injury from GalN/TNF. In GalN/LPS-treated mice, VLX103 decreased activation of both the mitochondrial death pathway and downstream effector caspases 3 and 7, which resulted from reduced c-Jun N-terminal kinase activation and initiator caspase 8 cleavage. Delaying VLX103 treatment for up to 3 hours after GalN/LPS administration was still remarkably effective in blocking liver injury in this model. Oral administration of VLX103 also decreased hepatotoxic injury in a second more chronic model of alcohol-induced liver injury, as demonstrated by decreased serum alanine and aspartate aminotransferase levels and numbers of TUNEL-positive cells. CONCLUSION: VLX103 effectively decreases toxin-induced liver injury in mice and may be an effective therapy for this and other forms of human liver disease. (Hepatology 2017;66:922-935).

Primary Ewing Sarcoma of the Mastoid: A Novel Case Mimicking Acute Mastoiditis.

Ewing sarcoma (EWS) is a primitive neuroectodermal tumor arising in bone or soft tissue. It is the second most common primary bone malignancy of children and adolescents, with a peak incidence in the second decade of life. It most often arises in the long bones of the extremities and pelvis. Here, we present a novel case of EWS arising from the mastoid bone in a 5-year-old African American male who presented with symptoms of acute mastoiditis. This unique presentation highlights the importance of considering EWS in a patient who presents with atypical mastoiditis or a rapidly growing mass in the postauricular region.

Macrophage autophagy limits acute toxic liver injury in mice through down regulation of interleukin-1ß.

BACKGROUND & AIMS: Overactivation of the innate immune response underlies many forms of liver injury including that caused by hepatotoxins. Recent studies have demonstrated that macrophage autophagy regulates innate immunity and resultant tissue inflammation. Although hepatocyte autophagy has been shown to modulate hepatic injury, little is known about the role of autophagy in hepatic macrophages during the inflammatory response to acute toxic liver injury. Our aim therefore was to determine whether macrophage autophagy functions to down regulate hepatic inflammation. METHODS: Mice with a LysM-CRE-mediated macrophage knockout of the autophagy gene ATG5 were examined for their response to toxin-induced liver injury from D-galactosamine/lipopolysaccharide (GalN/LPS). RESULTS: Knockout mice had increased liver injury from GalN/LPS as determined by significant increases in serum alanine aminotransferase, histological evidence of liver injury, positive terminal deoxynucleotide transferase-mediated deoxyuridine triphosphate nick end-labeling, caspase activation and mortality as compared to littermate controls. Levels of proinflammatory tumor necrosis factor and interleukin (IL)-6 hepatic mRNA and serum protein were unchanged, but serum IL-1ß was significantly increased in knockout mice. The increase in serum IL-1ß was secondary to elevated hepatic caspase 1 activation and inflammasome-mediated cleavage of pro-IL-1ß to its active form. Cultured hepatic macrophages from GalN/LPS-treated knockout mice had similarly increased IL-1ß production. Dysregulation of IL-1ß was the mechanism of increased liver injury as an IL-1 receptor antagonist prevented injury in knockout mice in concert with decreased neutrophil activation. CONCLUSIONS: Macrophage autophagy functions to limit acute toxin-induced liver injury and death by inhibiting the generation of inflammasome-dependent IL-1ß.

Autophagy confers resistance to lipopolysaccharide-induced mouse hepatocyte injury.

During sepsis, bacterial products, particularly LPS, trigger injury in organs such as the liver. This common condition remains largely untreatable, in part due to a lack of understanding of how high concentrations of LPS cause cellular injury. In the liver, the lysosomal degradative pathway of autophagy performs essential hepatoprotective functions and is induced by LPS. We, therefore, examined whether hepatocyte autophagy protects against liver injury from septic levels of LPS. Mice with an inducible hepatocyte-specific knockout of the critical autophagy gene Atg7 were examined for their sensitivity to high-dose LPS. Increased liver injury occurred in knockout mice, as determined by significantly increased serum alanine aminotransferase levels, histological evidence of liver injury, terminal deoxynucleotide transferase-mediated deoxyuridine triphosphate nick end-labeling, and effector caspase-3 and -7 activation. Hepatic inflammation and proinflammatory cytokine induction were unaffected by the decrease in hepatocyte autophagy. Although knockout mice had normal NF-κB signaling, hepatic levels of Akt1 and Akt2 phosphorylation in response to LPS were decreased. Cultured hepatocytes from knockout mice displayed a generalized defect in Akt signaling in response to multiple stimuli, including LPS, TNF, and IL-1ß. Akt activation mediates hepatocyte resistance to TNF cytotoxicity, and anti-TNF antibodies significantly decreased LPS-induced liver injury in knockout mice, indicating that the loss of autophagy sensitized to TNF-dependent liver damage. Hepatocyte autophagy, therefore, protects against LPS-induced liver injury. Conditions such as aging and steatosis that impair hepatic autophagy may predispose to poor outcomes from sepsis through this mechanism.

Comprehensive evaluation of cytomorphologic, histologic, and molecular features of DICER1-altered thyroid lesions on FNA: A multipractice experience.

BACKGROUND: DICER1 mutations, though infrequent, are encountered on preoperative molecular testing of indeterminate adult and pediatric thyroid fine-needle aspiration (FNA) specimens. Yet, published cytomorphologic features of DICER1-altered thyroid lesions are limited. Cytomorphological features of DICER1-altered thyroid lesions were examined in a multipractice FNA cohort with clinical, radiological, and histologic data. METHODS: The cohort comprised 18 DICER1-altered thyroid FNAs, with 14 having slides available and eight having corresponding surgical resections. Smears, ThinPrep, and formalin-fixed cell block slides were reviewed and correlated with histology, when available. Clinical and radiologic data were obtained from the medical record. RESULTS: Most DICER1-altered FNAs were classified as atypia of undetermined significance (94.4%). DICER1 mutations occurred in codons 1709 (50%), 1810 (27.8%), and 1813 (22.2%). One patient had an additional DICER1 p.D1822N variant in both of their FNAs. Lesions were often hypoechoic (35.3%) and solid (47.1%) on ultrasound. Notable cytomorphologic features include mixed but prominent microfollicular or crowded component, variable colloid, and insignificant nuclear atypia. On resection (n = 10), histologic diagnoses ranged from benign follicular adenoma and low-risk follicular thyroid carcinoma to high-grade follicular-derived nonanaplastic thyroid carcinoma. Subcapsular infarct-type change was the most common histologic change. There was no evidence of recurrence or metastasis in eight patients on limited follow-up. CONCLUSION: DICER1-altered thyroid lesions occurred frequently in young females and FNAs show RAS-like cytomorphology including crowded, mixed macro-/microfollicular pattern, and bland nuclear features. On resection, DICER1-altered thyroid lesions include benign (50%), low-risk lesions (30%), or high-risk malignancies (20%).

Screening Colonoscopy Unmasking Colonic Metastasis from an Occult Breast Ductal Carcinoma: A Case Report and Review of the Literature.

Metastatic spread from breast cancer to the gastrointestinal tract is rare. Such cases are predominantly lobular carcinomas and they usually occur later on during the course of disease progression with the stomach being the most common site involved. Furthermore, occult breast primary tumor is extremely uncommon. To the best of our knowledge, we describe here the first case of incidental colonic metastasis as first presentation of an occult breast ductal carcinoma. We also provide a review of the literature on gastrointestinal-and specifically colonic-involvement from breast ductal carcinoma.

Primary renal angiosarcoma: a diagnostic and therapeutic challenge.

Primary renal angiosarcoma is an exceedingly rare and aggressive neoplasm. Although it may occur in youth, this tumour is frequently reported in the sixth and seventh decades of life. The clinical presentation is frequently varied. Pathogenesis remains largely unknown and it has overlapping features with other tumours of the kidney. Current treatment options include variable combinations of surgery, chemotherapy and radiotherapy. Reports regarding the disease prognosis and natural history are limited. In this article, we chronicle the case of a patient with primary renal angiosarcoma presenting at an advanced stage as a widely metastasised tumour. Additionally, we undertake here a brief literature review highlighting the rarity and aggressiveness of this condition, its poor prognosis, and the lack of specific management guidelines.

Lafora Disease Masquerading as Hepatic Dysfunction.

Lafora disease is fatal intractable progressive myoclonic epilepsy. It is frequently characterized by epileptic seizures, difficulty walking, muscle spasms, and dementia in late childhood or adolescence. We chronicle here an unusual case of an asymptomatic young male soccer player who presented with elevated liver enzymes. Neurological examination was unremarkable. The diagnostic workup for hepatitis, infectious etiologies, autoimmune disorders, hemochromatosis, Wilson's disease, alpha-1 antitrypsin deficiency, and other related diseases was inconclusive. He subsequently underwent an uneventful percutaneous liver biopsy. Based on the pathognomonic histopathological findings, Lafora disease was considered the likely etiology. The present study is a unique illustration of this rare disorder initially manifesting with abnormal liver enzymes. It underscores the importance of clinical suspicion of Lafora disease in cases with unexplained hepatic dysfunction. Prompt liver biopsy and genetic testing should be performed to antedate the onset of symptoms in these patients.

Impaired macrophage autophagy increases the immune response in obese mice by promoting proinflammatory macrophage polarization.

Recent evidence that excessive lipid accumulation can decrease cellular levels of autophagy and that autophagy regulates immune responsiveness suggested that impaired macrophage autophagy may promote the increased innate immune activation that underlies obesity. Primary bone marrow-derived macrophages (BMDM) and peritoneal macrophages from high-fat diet (HFD)-fed mice had decreased levels of autophagic flux indicating a generalized impairment of macrophage autophagy in obese mice. To assess the effects of decreased macrophage autophagy on inflammation, mice with a Lyz2-Cre-mediated knockout of Atg5 in macrophages were fed a HFD and treated with low-dose lipopolysaccharide (LPS). Knockout mice developed systemic and hepatic inflammation with HFD feeding and LPS. This effect was liver specific as knockout mice did not have increased adipose tissue inflammation. The mechanism by which the loss of autophagy promoted inflammation was through the regulation of macrophage polarization. BMDM and Kupffer cells from knockout mice exhibited abnormalities in polarization with both increased proinflammatory M1 and decreased anti-inflammatory M2 polarization as determined by measures of genes and proteins. The heightened hepatic inflammatory response in HFD-fed, LPS-treated knockout mice led to liver injury without affecting steatosis. These findings demonstrate that autophagy has a critical regulatory function in macrophage polarization that downregulates inflammation. Defects in macrophage autophagy may underlie inflammatory disease states such as the decrease in macrophage autophagy with obesity that leads to hepatic inflammation and the progression to liver injury.