The pathogenesis and treatment of nonalcoholic steatohepatitis (NASH) are not well established. Feeding a diet deficient in both methionine and choline (MCD) is one of the most common models of NASH, which is characterized by steatosis, mitochondrial dysfunction, hepatocellular injury, oxidative stress, inflammation, and fibrosis. However, the individual contribution of the lack of methionine and choline in liver steatosis, advanced pathology and impact on mitochondrial S-adenosyl-Lmethionine (SAM) and glutathione (GSH), known regulators of disease progression, has not been specifically addressed. Here, we examined the regulation of mitochondrial SAM and GSH and signs of disease in mice fed a MCD, methionine-deficient (MD), or choline-deficient (CD) diet. The MD diet reproduced most of the deleterious effects of MCD feeding, including weight loss, hepatocellular injury, oxidative stress, inflammation, and fibrosis, whereas CD feeding was mainly responsible for steatosis, characterized by triglycerides and free fatty acids accumulation. These findings were preceded by MCD-or MD-mediated SAM and GSH depletion in mitochondria due to decreased mitochondrial membrane fluidity associated with a lower phosphatidylcholine/phosphatidylethanolamine ratio. MCD and MD but not CD feeding resulted in increased ceramide levels by acid sphingomyelinase. Moreover, GSH ethyl ester or SAM therapy restored mitochondrial GSH and ameliorated hepatocellular injury in mice fed a MCD or MD diet. Thus, the depletion of SAM and GSH in mitochondria is an early event in the MCD model of NASH, which is determined by the lack of methionine. Moreover, therapy using permeable GSH prodrugs may be of relevance in NASH.

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To evaluate the bronchial inflammatory response and its relationship to bacterial colonization in bronchiectasis, we performed a bronchoalveolar lavage (BAL) in 49 patients in stable clinical condition and in nine control subjects. BAL was processed for differential cell count, quantitative bacteriologic cultures, and measurement of inflammatory mediators. An increase was observed in the percentage of neutrophils (37 [0 to 98]) (median[range]) versus 1[0 to 4]%, p = 0.01), in the concentration of elastase (90.5 [8 to 2,930] versus 34 [9 to 44], p = 0.03), myeloperoxidase (9.1 [0 to 376] versus 0.3 [0.1 to 1.4], p = 0.01), and in the levels of TNF-alpha (4 [0 to 186] versus 0 [0 to 7], p = 0.03), IL-8 (195 [0 to 5,520] versus 3 [0 to 31], p = 0.001), and IL-6 (6 [0 to 115] versus 0 [0 to 3], p = 0.001) in patients with bronchiectasis compared with control subjects. Noncolonized patients showed a more intense bronchial inflammatory reaction than did control subjects. This inflammatory reaction was exaggerated in patients colonized by microorganisms with potential pathogenicity (MPP), with a clear relationship with the bronchial bacterial load. Patients with bronchiectasis showed a slight systemic inflammatory response, with poor correlations between systemic and bronchial inflammatory mediators, suggesting that the inflammatory process was mostly compartmentalized. We conclude that patients with bronchiectasis in a stable clinical condition present an active neutrophilic inflammation in the airways that is exaggerated by the presence of MPP, and the higher the bacterial load the more intense the inflammation.

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Background & aims The pathogenesis of alcohol-induced liver disease (ALD) is poorly understood. Here, we examined the role of acid sphingomyelinase (ASMase) in alcohol induced hepatic endoplasmic reticulum (ER) stress, a key mechanism of ALD Methods We examined ER stress, lipogenesis, hyperhomocysteinemia, mitochondrial cholesterol (mChol) trafficking and susceptibility to LPS and concanavalin-A in ASMase−/− mice fed alcohol. Results Alcohol feeding increased SREBP-1c, DGAT-2 and FAS mRNA in ASMase+/+ but not in ASMase−/− mice. Compared to ASMase+/+ mice, ASMase−/− mice exhibited decreased expression of ER stress markers induced by alcohol, but the level of tunicamycin-mediated upregulation of ER stress markers and steatosis was similar in both types of mice. The increase in homocysteine levels induced by alcohol feeding was comparable in both ASMase+/+ mice and ASMase−/− mice. Exogenous ASMase, but not neutral SMase, induced ER stress by perturbing ER Ca2+ homeostasis. Moreover, alcohol-induced mChol loading and StARD1 overexpression were blunted in ASMase−/− mice. Tunicamycin upregulated StARD1 expression and this outcome was abrogated by tauroursodeoxycholic acid. Alcohol-induced liver injury and sensitization to LPS and concanavalin-A were prevented in ASMase−/− mice. These effects were reproduced in alcohol-fed TNFR1/R2−/− mice. Moreover, ASMase does not impair hepatic regeneration following partial hepatectomy. Of relevance, liver samples from patients with alcoholic hepatitis exhibited increased expression of ASMase, StARD1 and ER stress markers. Conclusion Our data indicate that ASMase is critical for alcohol-induced ER stress, and provide a rationale for further clinical investigation in ALD.

Background & Aim Acid sphingomyelinase (ASMase) is activated in nonalcoholic steatohepatitis (NASH). However, ASMase’s contribution to NASH is poorly understood and limited to hepatic steatosis and glucose metabolism. Here we examined ASMase’s role in high fat diet (HFD)-induced NASH. Methods Autophagy, endoplasmic reticulum (ER) stress and lysosomal membrane permeabilization (LMP) were determined in ASMase−/− mice fed HFD. The impact of pharmacological ASMase inhibition on NASH was analyzed in wild type mice fed HFD. Results ASMase deficiency determined resistance to HFD or methionine and choline deficient diet-mediated hepatic steatosis. ASMase−/− mice were resistant to HFD-induced hepatic ER stress, but sensitive to tunicamycin-mediated ER stress and steatosis, indicating selectivity in the resistance of ASMase−/− mice to ER stress. Autophagic flux determined in the presence of rapamycin and/or chloroquine was lower in primary mouse hepatocytes (PMH) from ASMase−/− mice and accompanied by increased p62 levels, suggesting autophagic impairment. Moreover, autophagy suppression by chloroquine and brefeldinA caused ER stress in PMH from ASMase+/+ mice but not ASMase−/− mice. ASMase−/− PMH exhibited increased lysosomal cholesterol loading, decreased LMP and apoptosis resistance induced by O-methyl-serine dodecylamide hydrochloride or palmitic acid, effects that were reversed by decreasing cholesterol levels by the oxysterol 25-hydroxycholesterol. In vivo pharmacological ASMase inhibition by amitriptyline, a widely used tricyclic antidepressant, protected wild type mice against HFD-induced hepatic steatosis, fibrosis, and liver damage, effects indicative of early-stage NASH. Conclusions These findings underscore a critical role for ASMase in diet-induced NASH and suggest the potential of amitriptyline as a treatment for patients with NASH.

The emergence of an oligoclonal humoral response, resulting in the appearance of a different serum M-protein to that observed at diagnosis is a well-recognized event after autologous stem cell transplantation in multiple myeloma in complete response, and it has been considered to be a benign phenomenon. The aim of the present study was to investigate the incidence, biological characteristics and prognostic value of the oligoclonal bands in patients with myeloma who underwent autologous transplantation at our institution in the last 18 years. We proceed with a retrospective systematic review of all serum and urine immunofixation studies performed in the 211 patients with multiple myeloma who underwent melphalan-based autologous transplantation. Oligoclonal bands were observed in 34% of the patients, with a significantly higher prevalence with the use of novel agents versus conventional chemotherapy in induction (63% vs. 22%; P=0.0001). The incidence of oligoclonal bands was most frequent in non-IgG isotype, particularly in light chain only myeloma. The oligoclonal phenomenon was almost exclusive to patients in complete remission compared to other degrees of response (87% vs. 13%; P=0.0001), and lasted for a median of 1.35 years, persisting during follow up in all patients except in those who relapsed. In prognostic terms, the presence of oligoclonality resulted in a significantly longer progression-free and overall survival. Patients with oligoclonal humoral response lasting for more than one year after transplantation had a significantly longer clinical progression-free and overall survival than those with shorter duration (P=0.008 and P=0.0001, respectively), likely reflecting the importance of a robust humoral immune response.Natural history and prognostic impact of oligoclonal humoral response in patients with multiple myeloma after autologous stem cell transplantation: long-term results from a single institution

Running title: Cholesterol and hepatic ischemia-reperfusion injury.Key words: Hepatic steatosis; ischemia/reperfusion; liver transplantation; triglycerides; cholesterol; statins; squalene synthase.