Increased hepatic putrescine levels as a new potential factor related to the progression of metabolic dysfunction-associated steatotic liver disease.

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a chronic liver condition that often progresses to more advanced stages, such as metabolic dysfunction-associated steatohepatitis (MASH). MASH is characterized by inflammation and hepatocellular ballooning, in addition to hepatic steatosis. Despite the relatively high incidence of MASH in the population and its potential detrimental effects on human health, this liver disease is still not fully understood from a pathophysiological perspective. Deregulation of polyamine levels has been detected in various pathological conditions, including neurodegenerative diseases, inflammation, and cancer. However, the role of the polyamine pathway in chronic liver disorders such as MASLD has not been explored. In this study, we measured the expression of liver ornithine decarboxylase (ODC1), the rate-limiting enzyme responsible for the production of putrescine, and the hepatic levels of putrescine, in a preclinical model of MASH as well as in liver biopsies of patients with obesity undergoing bariatric surgery. Our findings reveal that expression of ODC1 and the levels of putrescine, but not spermidine nor spermine, are elevated in hepatic tissue of both diet-induced MASH mice and patients with biopsy-proven MASH compared with control mice and patients without MASH, respectively. Furthermore, we found that the levels of putrescine were positively associated with higher aspartate aminotransferase concentrations in serum and an increased SAF score (steatosis, activity, fibrosis). Additionally, in in vitro assays using human HepG2 cells, we demonstrate that elevated levels of putrescine exacerbate the cellular response to palmitic acid, leading to decreased cell viability and increased release of CK-18. Our results support an association between the expression of ODC1 and the progression of MASLD, which could have translational relevance in understanding the onset of this disease. © 2024 The Pathological Society of Great Britain and Ireland.

The role of PCSK9 in metabolic dysfunction-associated steatotic liver disease and its impact on bariatric surgery outcomes.

BACKGROUND: Metabolic dysfunction-associated steatotic liver disease (MASLD) is closely tied to obesity. The degree ranges from steatosis (MASL) and steatohepatitis (MASH) to liver cirrhosis. PCSK9 controls cholesterol and lipid particle transport to the liver. PCSK9 might interfere with the pathophysiology of MASLD and bariatric surgery (BS) outcomes of patients with MASLD. OBJECTIVES: Evaluate the relationship between serum and hepatic PCSK9 levels with the degree of MASLD and the metabolic outcome of BS. SETTING: University Hospital, Spain. METHODS: A total of 110 patients with obesity undergoing BS were classified according to liver histology as controls, MAS, and MASH. PCSK9 levels in serum were measured before and 6 months after BS using enzyme-linked immunosorbent assay. PCSK9 protein and mRNA levels in liver tissue were analyzed by immunohistochemistry and reverse transcriptase-polymerase chain reaction, respectively. RESULTS: Hepatic PCSK9 protein levels were diminished in MASL and MASH compared with patients without MASLD and showed a strong negative association with MASLD severity scores. Liver PCSK9 mRNA was higher in MASH compared with controls and MASL and showed positive associations with MASLD severity scores. There were no differences in serum PCSK9 pre or postBS between the groups. Pre- and postsurgery serum PCSK9 positively correlated with cholesterol fold-changes and body mass index (BMI), cholesterol, and low-density lipoprotein -cholesterol fold-changes, respectively. PCSK9 fold-change positively correlated with BMI changes and was the sole variable explaining BMI fold changes in a regression model. CONCLUSIONS: PCSK9 mRNA and protein in the liver might be associated with the degree of MASLD. Serum PCSK9 may be associated with cholesterol and/or BMI fold changes. Serum changes of PCSK9 after BS could explain BMI loss outcome.

Role of Kupffer cells in the progression of CRC liver metastases after the first stage of ALPPS.

Associated liver partition and portal vein ligation for staged hepatectomy (ALPPS) has been suggested as a potential therapy for extensive bilobar liver tumors, although in some circumstances this technique may induce tumor progression, a fact still not well studied. Our aim was to study tumor hepatic progression induced by the first step of ALPPS in a WAG/Rij rat syngenic model of metastatic colorectal carcinoma by subcapsular CC531 cell line inoculation. ALPPS induced: tumor progression on deportalized lobe and metastases; expression of hepatic vasculogenic factors (HIF1-α and VEGF); and a dramatic increase of Kupffer cells (KCs) and tumor-associated macrophages (TAMs). Interestingly, KCs expressed COX-2 (M1 polarization), while TAMs expressed mainly arginase-1 (M2 polarization). ALPPS also induced a decrease of tumor-infiltrating lymphocytes and an increase of intrahepatic T lymphocytes. Thus, ALPPS technique seems to induce a hypoxic environment, which enhances hepatic HIF1-α and VEGF expression and may promote KCs and TAMs polarization. Consequently, the regenerative stimulus seems to be driven by a pro-inflammatory and hypoxic environment, in which M1 intrahepatic macrophages expressing COX-2 and T-Lymphocytes play a key role, facts which may be related with the tumor progression observed.

Las relaciones interdisciplinarias entre la Educación Física y la Medicina Natural y Tradicional / The interdisciplinary relationships between Physical Education and Natural and Traditional Medicine

En un análisis realizado al programa de Educación Física y a la Estrategia Curricular de Medicina Natural y Tradicional, de la Universidad de Ciencias Médicas de la Habana, se pudo apreciar que la Educación Física tiene más potencialidades para vincular elementos básicos de la Medicina Natural y Tradicional, de los que tiene asignado, y, por lo tanto, se limita su desarrollo en esta esfera. También se comprobó que asignaturas como la Morfofisiología, tienen un mayor protagonismo en la Estrategia Curricular de Medicina Natural y Tradicional, y que abarcan contenidos que se pueden adecuar a los objetivos de la Educación Física. Estos pueden contribuir a elevar el nivel científico de esta disciplina y a la vez tener una mayor incidencia en la formación profesional de los estudiantes de medicina. Para lograr lo antes expuesto, se está aplicando una estrategia interdisciplinaria que permita integrar elementos básicos de la Medicina Natural y Tradicional con la Educación Física.

Influence of menopause on adipose tissue clock gene genotype and its relationship with metabolic syndrome in morbidly obese women.

Menopausal women exhibit a loss of circadian coordination, a process that runs parallel with a redistribution of adipose tissue. However, the specific genetic mechanisms underlying these alterations have not been studied. Thus, the aim of the present study was to determine whether the development of menopause induces an alteration of the genes that control biological rhythms in human subcutaneous (SAT) and visceral (VAT) adipose tissue, and whether changes in clock gene expression are involved in the increased risk of developing metabolic syndrome (MetS), which is frequently associated with menopause. To this end, VAT and SAT biopsies were taken in pre- (n = 7) and postmenopausal (n = 7) women at similar hours in the morning. RNA was extracted, and a microarray analysis was made. Data were confirmed by quantitative real-time polymerase chain reaction. Western blot and immunohistochemical analysis were also performed. When clock gene expression was compared between both groups of women, data in SAT showed that expression of the core clock gene period3 was significantly higher in postmenopausal women, while casein kinase-1δ, E1A-binding protein and cAMP-responsive element were preferentially expressed in the premenopausal group. In VAT, period2 (PER2) and v-myc myelocytomatosis viral oncogene expressions were significantly higher in the postmenopausal group. Western blot analysis indicated that PER2 and PER3 protein expression was also increased in postmenopausal women. In addition, several genes, including PER2, were differentially expressed depending on whether or not the patient met the MetS criteria. We conclude that menopause transition induces several changes in the genotype of the adipose tissue chronobiological machinery related to an increased risk of developing MetS.

Profile of adipose tissue gene expression in premenopausal and postmenopausal women: site-specific differences.

OBJECTIVES: Menopause increases the risk of several pathologies, probably due to enlarged levels of visceral fat. Apart from morphological and endocrine changes, a cluster of genes, still not fully defined, may be involved in these alterations. The objectives of the present study, therefore, were to analyze differences in adipose tissue gene expression between premenopausal and postmenopausal women and to ascertain whether any differences were depot specific. METHODS: Visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) biopsies were taken from 7 premenopausal and 7 postmenopausal women undergoing surgery because of morbid obesity. RNA was extracted, and the overall gene expression profile was analyzed by microarray analysis. RESULTS: In general, SAT genes were overexpressed, whereas VAT genes were down-regulated in premenopausal compared with postmenopausal women. We found 724 differentially expressed genes in SAT and 327 in VAT. These differences suggest that several biological processes, such as the immune system and other metabolic processes, were altered based on menopause status. Regarding individual genes, neurexin 3, metallothionein 1E, and keratyn 7 showed the most pronounced differences. Interestingly, the expression of these genes was related to body fat distribution. CONCLUSIONS: Our results reveal that menopause influences the adipose tissue expression of many genes, especially of neurexin 3, metallothionein 1E, and keratyn 7, which are associated with the alteration of several key biological processes, such as the immune system and cell metabolism. Gene expression in adipose tissue could be used for diagnosis and the development of new therapeutic strategies against obesity and related alterations, depending on menopause status.