Chronic ethanol consumption plus an atherogenic diet cause metabolic steatohepatitis with advanced liver fibrosis in apolipoprotein E/low-density lipoprotein receptor double-knockout mice.

BACKGROUND: Nonalcoholic steatohepatitis is the inflammatory subtype of nonalcoholic fatty liver disease with a high risk of progression to liver fibrosis. We investigated metabolic steatohepatitis with advanced liver fibrosis in apolipoprotein E/low-density lipoprotein receptor double-knockout (AL) mice fed a co-diet of ethanol with a low-carbohydrate-high-protein-high-fat atherogenic diet (AD) for 16 weeks. We also examined the underlying mechanisms, especially hepatic sympathetic activation, involved in the effects. METHODS: We maintained 12-week-old male AL mice on AD and a standard chow diet (SCD) with or without ethanol treatment for 16 weeks. Age-matched male C57BL/6J mice on SCD without ethanol treatment served as controls. We conducted blood biochemical, histopathological, and fluorescence immunohistochemical, and reverse transcriptase polymerase chain reaction studies. RESULTS: AL mice showed significant hyperlipidemia. AD induced increased body weight, hepatic steatosis, and hepatic damage; ethanol and the AD co-diet resulted in hepatic sympathetic activation accompanied by hepatic steatosis, lobular inflammation, bridging fibrosis, and hepatic damage. Hepatic Kupffer cells (KCs) and hepatic stellate cells (HSCs), which showed sympathetic activation, produced 4.4- to 9.4-fold more inflammatory factors (KC and KC-derived tumor necrosis factor-α, and chemokine [C-C motif] ligand 2) and 2.0- to 32.0-fold more fibrosis factors (HSC and HSC-derived transforming growth factor ß1 and collagen 1a1); all p < 0.05 vs. controls. CONCLUSIONS: We created a model of metabolic steatohepatitis with advanced liver fibrosis from coexisting hyperlipidemia and hepatic sympathetic activation in AL mice on a co-diet of ethanol and AD. KCs and HSCs became the cellular targets of hepatic sympathetic activation, which could play a role in the initiation and progression of metabolic steatohepatitis with advanced liver fibrosis.

The Chemical Basis of Fungal Bioluminescence.

Many species of fungi naturally produce light, a phenomenon known as bioluminescence, however, the fungal substrates used in the chemical reactions that produce light have not been reported. We identified the fungal compound luciferin 3-hydroxyhispidin, which is biosynthesized by oxidation of the precursor hispidin, a known fungal and plant secondary metabolite. The fungal luciferin does not share structural similarity with the other eight known luciferins. Furthermore, it was shown that 3-hydroxyhispidin leads to bioluminescence in extracts from four diverse genera of luminous fungi, thus suggesting a common biochemical mechanism for fungal bioluminescence.

A New Non-Obese Steatohepatitis Mouse Model with Cardiac Dysfunction Induced by Addition of Ethanol to a High-Fat/High-Cholesterol Diet.

Non-obese metabolic dysfunction-associated steatotic liver disease (MASLD) has been associated with cardiovascular-related mortality, leading to a higher mortality rate compared to the general population. However, few reports have examined cardiovascular events in non-obese MASLD mouse models. In this study we created a mouse model to mimic this condition. In this study involving seven-week-old C57BL/6J male mice, two dietary conditions were tested: a standard high-fat/high-cholesterol diet (STHD-01) and a combined diet of STHD-01 and ethanol. Over periods of 6 and 12 weeks, we analyzed the effects on liver and cardiac tissues using various staining techniques and PCR. Echocardiography and blood tests were also performed to assess cardiac function and liver damage. The results showed that mice on the ethanol-supplemented STHD-01 diet developed signs of steatohepatitis and cardiac dysfunction, along with increased sympathetic activity, as early as 6 weeks. At 12 weeks, more pronounced exacerbations accompanied with cardiac dilation, advanced liver fibrosis, and activated myocardial fibrosis with sympathetic activation were observed. This mouse model effectively replicated non-obese MASLD and cardiac dysfunction over a 12-week period using a combined diet of STHD-01 and ethanol. This dietary approach highlighted that both liver inflammation and fibrosis, as well as cardiac dysfunction, could be significantly worsened due to the activation of the sympathetic nervous system. Our results indicate that alcohol, even when completely metabolized on the day of drinking, exacerbates the progression of non-obese MASLD and cardiac dysfunction.

Bitter compounds in two Tricholoma species, T. aestuans and T. virgatum.

Lascivol was identified as the bitter compound in two Tricholoma species, T. aestuans and T. virgatum, and was previously isolated from the European mushroom T. lascivum. The structure of lascivol was previously solved by X-ray crystallographical analysis but its stereochemistry at C3 remained ambiguous. We thus re-examined the absolute configuration of C3 bearing a hydroxy group using the modified Mosher's method.