Insulin-like Growth Factor Binding Proteins and Cellular Senescence Are Involved in the Progression of Non-Alcoholic Fatty Liver Disease and Fibrosis in a Mouse Model.

Background and Objectives: Non-alcoholic fatty liver disease (NAFLD) is highly prevalent worldwide. It progresses from simple steatosis to non-alcoholic steatohepatitis (NASH). Fibrosis is often present during NAFLD progression; however, factors determining which subjects develop NASH or fibrosis are unclear. Insulin-like growth factor binding proteins (IGFBPs) are a family of secreted proteins involved in senescence and scarring, mainly synthetized in the liver. Here, we aimed to study the association of IGFBPs and their induced senescence with the progression of NAFLD and liver fibrosis. Materials and Methods: A total of 16-week-old male C57BL/6 mice weighing 23 ± 3 g were fed either methionine/choline-deficient (MCD) or control diet for 2, 8, or 12 weeks. Blood and liver samples were collected, and a histological assessment of NAFLD and fibrosis was performed. Fat contents were measured. Cellular senescence was evaluated in the liver. IGFBP levels were assessed in the liver and serum. Data were expressed as mean ± SD and analyzed by a one-way ANOVA followed by Tukey's test. Lineal regression models were applied for NAFLD and fibrosis progression. p < 0.05 was considered significant. Results: IGFBP-1 and -2 were increased in serum during NAFLD. IGFBP-7 was significantly increased in the serum in NASH compared with the controls. Senescence increased in NAFLD. Serum and liver IGFBP-7 as well as SA-ß-gal activity increased as fibrosis progressed. Both IGFBP-7 and cellular senescence were significantly higher during NAFLD and fibrosis in MCD-fed mice. Conclusions: IGFBP-1, -2, and -7, through their consequent senescence, have a role in the progression of NAFLD and its associated fibrosis, being a plausible determinant in the progression from steatosis to NASH.

In Vitro Lipid Overload Affects Cellular Proliferation, Apoptosis, and Senescence in a Time-Dependent Manner in HepG2 Hepatocytes and LX-2 Hepatic Stellate Cells.

Different cellular mechanisms influence steatotic liver disease (SLD) progression. The influence of different levels of steatogenic inputs has not been studied in hepatocytes and hepatic stellate cells (HSCs). METHODS: HepG2 hepatocytes and LX-2 HSCs were cultured in mild (MS) and severe (SS) steatogenic conditions. TGF-ß stimulation was also tested for HSCs in control (T) and steatogenic conditions (MS-T and SS-T). Steatosis was stained with Oil Red, and the proliferation was assayed via WST-8 reduction, apoptosis via flow cytometry, and senescence via SA-ß-galactosidase activity. RESULTS: Regarding hepatocytes, steatosis progressively increased; proliferation was lower in MS and SS; and the viability of both conditions significantly decreased at 72 h. Apoptosis increased in MS at 72 h, while it decreased in SS. Senescence increased in MS and diminished in SS. Regarding HSCs, the SS and SS-T groups showed no proliferation, and the viability was reduced in MS at 72 h and in SS and SS-T. The LX-2 cells showed increased apoptosis in SS and SS-T at 24 h, and in MS and MS-T at 72 h. Senescence decreased in MS, SS, and SS-T. CONCLUSIONS: Lipid overload induces differential effects depending on the cell type, the steatogenic input level, and the exposure time. Hepatocytes are resilient to mild steatosis but susceptible to high lipotoxicity. HSCs are sensitive to lipid overload, undergoing apoptosis and lowering senescence and proliferation. Collectively, these data may help explain the development of steatosis and fibrosis in SLD.

Collagen matrix scaffolds: Future perspectives for the management of chronic liver diseases.

Approximately 1.5 billion chronic liver disease (CLD) cases have been estimated worldwide, encompassing a wide range of liver damage severities. Moreover, liver disease causes approximately 1.75 million deaths per year. CLD is typically characterized by the silent and progressive deterioration of liver parenchyma due to an incessant inflammatory process, cell death, over deposition of extracellular matrix proteins, and dysregulated regeneration. Overall, these processes impair the correct function of this vital organ. Cirrhosis and liver cancer are the main complications of CLD, which accounts for 3.5% of all deaths worldwide. Liver transplantation is the optimal therapeutic option for advanced liver damage. The liver is one of the most common organs transplanted; however, only 10% of liver transplants are successful. In this context, regenerative medicine has made significant progress in the design of biomaterials, such as collagen matrix scaffolds, to address the limitations of organ transplantation (e.g., low donation rates and biocompatibility). Thus, it remains crucial to continue with experimental and clinical studies to validate the use of collagen matrix scaffolds in liver disease.

Pancreatic Cancer: Genetic Conditions and Epigenetic Alterations.

BACKGROUND: Pancreatic cancer is a lethal proliferative disease driven by multiple genetic and epigenetic alterations. Microarrays and omics-based sequencing techniques are potent tools that have facilitated a broader understanding of the complex biological processes that drive pancreatic ductal adenocarcinoma (PDAC). In turn, these tools have resulted in the identification of novel disease markers, prognostic factors, and therapeutic targets. Herein, we provide a review of the genetic and epigenetic drivers of PDAC relative to recent discoveries that impact patient management. METHODS: A review of PubMed, Medline, Clinical Key, and Index Medicus was conducted to identify literature from January 1995 to July 2022 that is related to PDAC genetics and epigenetics. Articles in Spanish and English were considered during selection. RESULTS: Molecular, genetic, and epigenetic diagnostic tools, novel biomarkers, and promising therapeutic targets have emerged in the treatment of pancreatic cancer. The implementation of microarray technology and application of large omics-based data repositories have facilitated recent discoveries in PDAC. Multiple molecular analyses based on RNA interference have been instrumental in the identification of novel therapeutic targets for patients with PDAC. Moreover, microarrays and next-generation omics-based discoveries have been instrumental in the characterization of subtypes of pancreatic cancer, thereby improving prognostication and refining patient selection for available targeted therapies. CONCLUSION: Advances in molecular biology, genetics, and epigenetics have ushered in a new era of discovery in the pathobiology of PDAC. Current efforts are underway to translate these findings into clinical tools and therapies to improve outcomes in patients with PDAC.

Xenoimplant of Collagen Matrix Scaffold in Liver Tissue as a Niche for Liver Cells.

Hepatitis C virus-induced liver damage, chronic liver damage due to alcohol, and non-alcoholic liver disease-induced cellular alterations promote fibrosis, cirrhosis, and/or hepatocellular carcinoma. The recommended therapeutic option for advanced liver damage is liver transplantation. Extracellular matrix scaffolds have been evaluated as an alternative for tissue restoration. Studies on the biocompatibility and rejection of synthetic and natural scaffolds as an alternative to organ transplantation have been evaluated. Our group has recently described the xenoimplant of collagen matrix scaffold (CMS) in a rat model. However, no complete macroscopic and histological description of the liver parenchyma at the initial (day 3), intermediate (day 14), and advanced (day 21) stages has been obtained. In this study, we described and compared liver tissue from the CMS zone (CZ, CMS, and liver parenchyma), liver tissue from the normal zone (liver parenchyma close to the CMS), and basal tissue (resected tissue from the CMS implantation site). Our data strongly suggest that the collagen matrix xenoimplant is a good niche for hepatocytes, with no rejection, and does not affect liver function tests. The liver can regenerate after damage, but this capacity is inhibited in a chronic injury. At present, the use of CMS after liver damage has not been reported. This biomaterial could be a novel alternative in the field of regenerative medicine for liver diseases.

Alcoholic Liver Disease.

Content available: Author Interview and Audio Recording.

Three-Dimensional Collagen Matrix Scaffold Implantation as a Liver Regeneration Strategy.

Liver diseases are the leading cause of death worldwide. Excessive alcohol consumption, a high-fat diet, and hepatitis C virus infection promote fibrosis, cirrhosis, and/or hepatocellular carcinoma. Liver transplantation is the clinically recommended procedure to improve and extend the life span of patients in advanced disease stages. However, only 10% of transplants are successful, with organ availability, presurgical and postsurgical procedures, and elevated costs directly correlated with that result. Extracellular matrix (ECM) scaffolds have emerged as an alternative for tissue restoration. Biocompatibility and graft acceptance are the main beneficial characteristics of those biomaterials. Although the capacity to restore the size and correct function of the liver has been evaluated in liver hepatectomy models, the use of scaffolds or some kind of support to replace the volume of the extirpated liver mass has not been assessed. Partial hepatectomy was performed in a rat liver with the xenoimplantation of a collagen matrix scaffold (CMS) from a bovine condyle. Left liver lobe tissue was removed (approximately 40%), and an equal proportion of CMS was surgically implanted. Liver function tests were evaluated before and after the surgical procedure. After days 3, 14, and 21, the animals were euthanized, and macroscopic and histologic evaluations were performed. On days 3 and 14, adipose tissue was observed surrounding the CMS, with no clinical evidence of rejection or infection, as was vessel neoformation and CMS reabsorption at day 21. There was histologic evidence of an insignificant inflammation process and migration of adjacent cells to the CMS, observed with the hematoxylin and eosin (H&E) and Masson's trichrome staining. The CMS was shown to perform well in liver tissue and could be a useful alternative for studying tissue regeneration and repair in chronic liver diseases.

Production and activity of matrix metalloproteinases during liver fibrosis progression of chronic hepatitis C patients.

BACKGROUND: Matrix metalloproteinases (MMPs) participate in the degradation of extracellular matrix compounds, maintaining the homeostasis between fibrogenesis and fibrolytic processes in the liver. However, there are few studies on the regulation of liver MMPs in fibrosis progression in humans. AIM: To assess the production activity and regulation of matrix metalloproteinases in liver fibrosis stages in chronic hepatitis C (CHC). METHODS: A prospective, cross-sectional, multicenter study was conducted. CHC patients were categorized in fibrosis grades through FibroTest ® and/or FibroScan ® . Serum MMP-2, -7, and -9 were determined by western blot and multiplex suspension array assays. Differences were validated by the Kruskal-Wallis and Mann-Whitney U tests. The Spearman correlation coefficient and area under the receiver operating characteristic curve were calculated. Collagenolytic and gelatinase activity was determined through the Azocoll substrate and zymogram test, whereas tissue inhibitor of metalloproteinase-1 production was determined by dot blot assays. RESULTS: Serum concentrations of the MMPs evaluated were higher in CHC patients than in healthy subjects. MMP-7 distinguished early and advanced stages, with a correlation of 0.32 (P < 0.001), and the area under the receiver operating characteristic displayed moderate sensitivity and specificity for MMP-7 in F4 (area under the receiver operating characteristic, 0.705; 95% confidence interval: 0.605-0.805; P < 0.001). Collagenolytic activity was detected at F0 and F1, whereas gelatinase activity was not detected at any fibrosis stage. Tissue inhibitor of metalloproteinase-1 determination showed upregulation in F0 and F1 but downregulation in F2 (P < 0.001). CONCLUSION: High concentrations of inactive MMPs were present in the serum of CHC patients, reflecting the impossibility to restrain liver fibrosis progression. MMPs could be good diagnostic candidates and therapeutic targets for improving novel strategies to reverse liver fibrosis in CHC.

Differential production of insulin-like growth factor-binding proteins in liver fibrosis progression.

Noninvasive methods for liver disease diagnoses offer great advantages over biopsy, but they cannot be utilized in all cases. Therefore, specific indicators for chronic liver disease management are necessary. The aim was to assess the production of insulin-like growth factor-binding proteins (IGFBPs) 1-7 and their correlation with the different stages of fibrosis in chronic hepatitis C (CHC). A prospective, cross-sectional, multicenter study was conducted. CHC patients were categorized by FibroTest® and/or FibroScan®. Serum concentrations of IGFBPs 1-7 were determined through multiple suspension arrangement array technology. Significant differences were validated by the Kruskal-Wallis and Mann-Whitney U tests. Logistic regression models were performed to assess the association between the IGFBPs and fibrosis stages. The association was determined utilizing odds ratios (ORs), and receiver operating characteristic (ROC) curves were constructed to distinguish the IGFBPs in relation to the diagnosis of fibrosis. IGFBP-1 and IGFBP-7 concentrations were higher in CHC than in the healthy individuals, whereas IGFBP-3, IGFBP-5, and IGFBP-6 were downregulated in the patients. An apparent increase of all the IGFBPs was found at fibrosis stage F4, but with different regulations. IGFBP-2, -4, -6, and -7 had the best OR, showing the relation to fibrosis progression. The ROC curves showed that IGFBP-7 was the only protein that distinguished F1 from F3 and F2 from F3. IGFBPs participate in liver fibrosis progression and could be employed as circulating novel protein panels for diagnosis and as possible therapeutic targets in liver fibrosis progression.

Assessment of urinary TWEAK levels in Mexican patients with untreated lupus nephritis: An exploratory study / Evaluación de los niveles urinarios de TWEAK en pacientes mexicanos con nefritis lúpica sin tratamiento farmacológico: Estudio exploratorio

Objectives: Urinary levels of TWEAK (uTWEAK) may be correlated with the degree of lupus nephritis (LN) activity. Our objective was to determine the sensitivity and specificity of uTWEAK in Mexican patients with untreated active lupus nephritis. Methods: An exploratory study was performed; four groups of patients were analyzed as follows: 1) patients with systemic lupus erythematosus (SLE) without renal activity (SLE-LN), 2) patients with SLE with renal activity (SLE+LN), 3) patients with other types of glomerulopathy (glomerulonephritis, GMN), 4) and healthy patients (controls). Results: In all, 44 patients, with an average age of 35.9±11.5 years, were evaluated. uTWEAK levels were higher in patients with SLE+LN compared with patients in the other groups: SLE+LN 12.88±8.33, SLE-LN 3.12±2.31, GMN 4.36±2.31 and controls 2.41±1.94pg/mg Cr (p=0.007). A total of 72.7% of the cases had renal activity index scores above 12, and 90.9% of the cases had scores of chronicity below 6 points. Receiver Operating Characteristic (ROC) curve analysis revealed that uTWEAK levels above 4.91pg/mg Cr had a sensitivity of 81% and a specificity of 75% for the diagnosis of renal activity due to lupus, with an area under the curve of 0.876 (95% CI: 0.75-0.99). However, no significant correlation was observed between the levels of uTWEAK and the histological findings specific to the activity and chronicity associated with SLE. Conclusions: Our study revealed that uTWEAK can adequately distinguish renal activity due to lupus, but cannot predict the degree of histological activity in Mexican patients with active lupus nephropathy (AU)

Objetivos: Los niveles urinarios de TWEAK (uTWEAK) pueden correlacionarse con el grado de actividad de nefritis lúpica (NL). Nuestro objetivo fue determinar la sensibilidad y especificidad de los uTWEAK en pacientes mexicanos con NL activa sin tratamiento farmacológico previo. Metodología: Se realizó un estudio exploratorio en el que se incluyeron 4 grupos de pacientes: 1) pacientes con lupus eritematoso sistémico sin actividad renal (LES-NL); 2) pacientes con lupus eritematoso sistémico con actividad renal (LES+NL); 3) pacientes con otras glomerulopatías y 4) controles sanos. Resultados: La edad promedio de los 44 pacientes fue de 35,9±11,5 años. Los uTWEAK fueron más elevados en pacientes con LES+NL comparados con los otros grupos: LES+NL (12,88±8,33), LES-NL (3,12±2,31), otras glomerulopatías (4,36±2,31) y grupo control (2,41±1,94pg/mgCr) (p=0,007). En el 72,7% de los casos se observó un índice de actividad renal mayor a 12 puntos y en el 90,9% de los casos los índices de cronicidad estaban por debajo de 6 puntos. La curva ROC reveló que los niveles urinarios por encima de 4,91pg/mg Cr tienen sensibilidad del 81% y especificidad del 75% para el diagnóstico de actividad renal secundaria a lupus, con área debajo de la curva de 0,876 (IC 95%: 0,75-0,99). Sin embargo, no se observó correlación significativa entre los uTWEAK y los hallazgos histológicos específicos de actividad y cronicidad asociados a LES. Conclusiones: Nuestro estudio revela que los uTWEAK pueden distinguir adecuadamente actividad renal secundaria a lupus, pero no predicen el grado de actividad histológica en pacientes mexicanos con NL activa (AU)

Assessment of urinary TWEAK levels in Mexican patients with untreated lupus nephritis: An exploratory study.

OBJECTIVES: Urinary levels of TWEAK (uTWEAK) may be correlated with the degree of lupus nephritis (LN) activity. Our objective was to determine the sensitivity and specificity of uTWEAK in Mexican patients with untreated active lupus nephritis. METHODS: An exploratory study was performed; four groups of patients were analyzed as follows: 1) patients with systemic lupus erythematosus (SLE) without renal activity (SLE-LN), 2) patients with SLE with renal activity (SLE+LN), 3) patients with other types of glomerulopathy (glomerulonephritis, GMN), 4) and healthy patients (controls). RESULTS: In all, 44 patients, with an average age of 35.9±11.5 years, were evaluated. uTWEAK levels were higher in patients with SLE+LN compared with patients in the other groups: SLE+LN 12.88±8.33, SLE-LN 3.12±2.31, GMN 4.36±2.31 and controls 2.41±1.94pg/mg Cr (p=0.007). A total of 72.7% of the cases had renal activity index scores above 12, and 90.9% of the cases had scores of chronicity below 6 points. Receiver Operating Characteristic (ROC) curve analysis revealed that uTWEAK levels above 4.91pg/mg Cr had a sensitivity of 81% and a specificity of 75% for the diagnosis of renal activity due to lupus, with an area under the curve of 0.876 (95% CI: 0.75-0.99). However, no significant correlation was observed between the levels of uTWEAK and the histological findings specific to the activity and chronicity associated with SLE. CONCLUSIONS: Our study revealed that uTWEAK can adequately distinguish renal activity due to lupus, but cannot predict the degree of histological activity in Mexican patients with active lupus nephropathy.

Behavior of Oxidative Stress Markers in Alcoholic Liver Cirrhosis Patients.

Alcohol is the most socially accepted addictive substance worldwide, and its metabolism is related with oxidative stress generation. The aim of this work was to evaluate the role of oxidative stress in alcoholic liver cirrhosis (ALC). This study included 187 patients divided into two groups: ALC, classified according to Child-Pugh score, and a control group. We determined the levels of reduced and oxidized glutathione (GSH and GSSG) and the GSH/GSSG ratio by an enzymatic method in blood. Also, protein carbonyl and malondialdehyde (MDA) content were estimated in serum. MDA levels increased in proportion to the severity of damage, whereas the GSH and GSSG levels decreased and increased, respectively, at different stages of cirrhosis. There were no differences in the GSH/GSSG ratio and carbonylated protein content between groups. We also evaluated whether the active consumption of or abstinence from alcoholic beverages affected the behavior of these oxidative markers and only found differences in the MDA, GSH, and GSSG determination and the GSH/GSSG ratio. Our results suggest that alcoholic cirrhotic subjects have an increase in oxidative stress in the early stages of disease severity and that abstinence from alcohol consumption favors the major antioxidant endogen: GSH in patients with advanced disease severity.

Treatment with metadoxine and its impact on early mortality in patients with severe alcoholic hepatitis.

BACKGROUND & AIM: Despite treatment with glucocorticoids, mortality remains high in patients with severe alcoholic hepatitis. Oxidative stress and depletion of mitochondrial glutathione are implicated factors in liver injury. The aim of this study was to evaluate the impact of the addition of metadoxine, a drug which possesses a multifactorial mechanism of action, including antioxidant properties, to standard treatment with glucocorticoids in patients with severe alcoholic hepatitis. MATERIAL AND METHODS: This randomized open label clinical trial was performed in Mexico's General Hospital (Registry Key DIC/10/107/03/043). We randomized 70 patients with severe alcoholic hepatitis. The first group received prednisone (40 mg/day), and the second group received prednisone (40 mg/day) plus metadoxine tablets (500 mg three times daily). The duration of treatment in both groups was 30 days. Survival at 30 and 90 days, development of complications, adverse events and response to treatment (Lille model) were assessed. RESULTS: In the group receiving metadoxine, significant improvements were observed, as follows: survival at 30 days (74.3 vs. 45.7%, P = 0.02); survival at 90 days (68.6 vs. 20.0%, P = 0.0001). There was less development or progression of encephalopathy (28.6 vs. 60.0%, P = 0.008) and hepatorenal syndrome (31.4 vs. 54.3%, P = 0.05), and the response to treatment (Lille model) was higher in the metadoxine group (0.38 vs. 0.63, P = 0.001; 95% CI 0.11 to 0.40). There were no differences between groups regarding the development or progression of variceal hemorrhage or infection. The incidence of adverse events, mainly gastrointestinal, was similar in both groups. CONCLUSIONS: Addition of metadoxine to glucocorticoid treatment improves the short-term survival of patients with severe alcoholic hepatitis and diminishes the development or progression of encephalopathy and hepatorenal syndrome.

IL-10 and TNF-alpha polymorphisms in subjects with irritable bowel syndrome in Mexico.

BACKGROUND: there has been recent evidence of an alteration in irritable bowel syndrome (IBS) immune regulation, as well as variations in cytokine polymorphisms. AIMS: to determine the frequency of the IL-10 (-1082G/A) and TNF-alpha (-308G/A) polymorphisms in subjects with IBS in Mexico. METHODS: volunteers answered the Rome II Questionnaire and were classified as IBS (n = 45) and controls (n = 92). The IBS subjects were then categorized as IBS-D: 22.2%, IBS-C: 28.9%, and IBS-A/M: 48.9%. The polymorphism frequency among groups was compared. RESULTS: there were no differences between IBS vs. controls in the frequency of the high (8.9 vs. 18.5%), intermediate (60.0 vs. 57.6%), or low (23.9 vs. 38.9%) producer IL-10 genotypes, p = 0.315. Neither were there differences in the high (0 vs. 1.1%), intermediate (55.4 vs. 43.2%), or low (43.5 vs. 56.8%) producer TNF-alpha genotypes, p = 0.296. However the low producer of IL-10 was more frequent in IBS-D vs. IBS-C vs. IBS-A/M (63.6 vs. 7.1 vs. 33,3%) p = 0.023. CONCLUSIONS: in this group of volunteers in Mexico, the frequency of the IL-10 (-1082G/A) and TNF-alpha (-308G/A) genotypes was similar in IBS and controls. However, there was a greater frequency of the low producer of IL-10 in those subjects with IBS-D, suggesting a genetic predisposition to abnormal immune regulation due to a lower anti-inflammatory component in this subgroup.

Polimorfismos de IL-10 y TNF-alfa en sujetos con síndrome de intestino irritable en México / IL-10 and TNF-alpha polymorphisms in subjects with irritable bowel syndrome in Mexico

Antecedentes: evidencias recientes han mostrado una alteración en la regulación inmune en el síndrome de intestino irritable (SII) así como variaciones en los polimorfismos de citocinas. Objetivos: determinar la frecuencia de polimorfismos IL-10 (-1082G/A) y TNF-alpha (-308G/A) en sujetos con SII en México. Métodos: sujetos voluntarios contestaron el Cuestionario de Roma II y fueron clasificados como SII (n = 45) y controles (n = 92). Aquellos con SII fueron a su vez clasificados en SII-D: 22,2 %, SII-E: 28,9 % y SII-A/M: 48,9 %. Se comparó la frecuencia de los polimorfismos entre los grupos. Resultados: no hubo diferencias entre SII vs. controles en la frecuencia del genotipo alto (8,9 vs. 18,5 %), intermedio (60,0 vs. 57,6 %) y bajo productor (23,9 vs. 38,9 %) de IL-10, p = 0,315. Tampoco en alto (0 vs. 1,1 %), intermedio (55,4 vs. 43,2 %) o bajo productor (43,5 vs. 56,8 %) de TNF-alpha, p = 0,296. Sin embargo, el bajo productor de IL-10 fue más frecuente en SII-D vs. SII-E vs. SII-A/M (63,6 vs. 7,1 vs. 33,3 %) p = 0,023. Conclusiones: en este grupo de voluntarios en México la frecuencia de genotipos de IL-10 (-1082G/A) y TNF-alpha (-308G/A) fue similar en SII y controles, pero aquellos con SII-D presentaron mayor frecuencia del bajo productor de IL-10 sugiriendo una predisposición genética a una regulación inmune anormal dada por un menor componente antiinflamatorio en este subgrupo (AU)

Background: there has been recent evidence of an alteration in irritable bowel syndrome (IBS) immune regulation, as well as variations in cytokine polymorphisms. Aims: to determine the frequency of the IL-10 (-1082G/A) and TNF-áalpha(-308G/A) polymorphisms in subjects with IBS in Mexico. Methods: volunteers answered the Rome II Questionnaire and were classified as IBS (n = 45) and controls (n = 92). The IBS subjects were then categorized as IBS-D: 22.2 %, IBS-C: 28.9 %, and IBS-A/M: 48.9 %. The polymorphism frequency among groups was compared. Results: there were no differences between IBS vs. controls in the frequency of the high (8.9 vs. 18.5 %), intermediate (60.0 vs. 57.6 %), or low (23.9 vs. 38.9 %) producer IL-10 genotypes, p = 0.315. Neither were there differences in the high (0 vs. 1.1 %), intermediate (55.4 vs. 43.2 %), or low (43.5 vs. 56.8 %) producer TNF-alpha genotypes, p = 0.296. However the low producer of IL-10 was more frequent in IBS-D vs. IBS-C vs. IBS-A/M (63.6 vs. 7.1 vs. 33,3 %) p = 0.023. Conclusions: in this group of volunteers in Mexico, the frequency of the IL-10 (-1082G/A) and TNF-alpha (-308G/A) genotypes was similar in IBS and controls. However, there was a greater frequency of the low producer of IL-10 in those subjects with IBS-D, suggesting a genetic predisposition to abnormal immune regulation due to a lower anti-inflammatory component in this subgroup (AU)

Liver exhibits thermal variations according to the stage of fibrosis progression: A novel use of modulated-differential scanning calorimetry for research in hepatology.

AIM: Liver fibrosis results in a disproportion of the hepatic composition and architecture, characterized by a progressive accumulation of fibrillar proteins at the liver parenchyma. Modulated-differential scanning calorimetry (mDSC) is an experimental methodology able to determine the specific thermal signature from any biological substance, based on the variation in heat flow and heat capacity. As these physicochemical properties are directly influenced by compositional and structural changes, we decided to study the thermal behavior of the liver during fibrosis using mDSC. METHODS: Liver fibrosis was induced in rats by bile duct ligation or carbon tetrachloride administration. Degree of liver fibrosis was determined by histological examination using the Masson-trichrome stain, accompanied by hepatic expression of α-smooth muscle actin. The thermal analysis was performed in a modulated-differential scanning calorimeter using 20 mg of fresh liver mass. RESULTS: The liver showed a characteristic thermal signature in control animals, which progressively differed among mild (F1), moderate (F2) and advanced (F3-F4) liver fibrosis. For heat flow, the hepatic thermal signature from F3-F4 rats exhibited significant differences when compared with F1, F2 and controls. In terms of heat capacity, liver specimens provided a specific thermal signature for each stage of disease, characterized by a transition temperature onset at 95°C for controls, whereas in F1, F2 and F3-F4 animals this temperature significantly decreased to 93°C, 84°C and 75°C, respectively. CONCLUSION: Because the liver shows a differential thermal signature according to the degree of fibrosis, mDSC could be a novel tool in the study of liver fibrosis progression.

Metabolic syndrome induces changes in KATP-channels and calcium currents in pancreatic ß-cells.

Metabolic syndrome (MS) can be defined as a group of signs that increases the risk of developing type 2 diabetes mellitus (DM2). These signs include obesity, hyperinsulinemia and insulin resistance. We are interested in the mechanisms that trigger hyperinsulinemia as a step to understand how ß cells fail in DM2. Pancreatic ß cells secrete insulin in response to glucose variations in the extracellular medium. When they are chronically over-stimulated, hyperinsulinemia is observed; but then, with time, they become incapable of maintaining normal glucose levels, giving rise to DM2. A chronic high sucrose diet for two months induces MS in adult male Wistar rats. In the present article, we analyzed the effect of the internal environment of rats with MS, on the activity of ATP-sensitive potassium channels (KATP) and calcium currents of pancreatic ß cells. After 24 weeks of treatment with 20% sucrose in their drinking water, rats showed central obesity, hyperinsulinemia and insulin resistance, and their systolic blood pressure and triglycerides plasma levels increased. These signs indicate the onset of MS. KATP channels in isolated patches of ß cells from MS rats, had an increased sensitivity to ATP with respect to controls. Moreover, the macroscopic calcium currents, show increased variability compared with cells from control individuals. These results demonstrate that regardless of genetic background, a high sucrose diet leads to the development of MS. The observed changes in ionic channels can partially explain the increase in insulin secretion in MS rats. However, some ß cells showed smaller calcium currents. These cells may represent a ß cell subpopulation as it becomes exhausted by the long-term high sucrose diet.

Lower serum IL-10 is an independent predictor of IBS among volunteers in Mexico.

OBJECTIVES: Studies suggest that altered immune activation, manifested by an imbalance in anti- and pro-inflammatory cytokine levels, exists in a subgroup of irritable bowel syndrome (IBS) patients. However, similar studies have not been conducted in Latin populations. The objective of this study was to measure serum levels of interleukin (IL)-10 and tumor necrosis factor (TNF)-α in subjects fulfilling symptom criteria for IBS and controls. METHODS: Volunteers (n=178) from a university population in Mexico City, participated in the study. Of the sample, 34.8% met Rome II criteria for IBS and 65.2% were designated as controls. Serum cytokines were measured by enzyme-linked immunoabsorbent assay. Analysis of covariance models were used to test main effects between gender, IBS symptoms, and bowel habit subtype to explain the cytokine serum levels. Statistical models were tested using body mass index as a covariate. RESULTS: IL-10 levels were significantly lower in IBS vs. controls (mean (95% confidence interval): 15.6 (14.8, 16.3) vs. 18.6 (17.9, 19.4) pg/ml, P<0.001), while TNF-α levels were higher in IBS (20.9 (19.1, 23.0) vs. 17.9 (16.7, 19.3) pg/ml, P=0.010). IBS and female gender were independent predictors for IL-10 (P<0.05). In contrast, female gender was an independent predictor for TNF-α. In addition, women with IBS-D had the lowest IL-10 (P<0.001) and highest TNF-α (P=0.021) vs. other subtypes. CONCLUSIONS: The lower serum IL-10 in our subjects fulfilling IBS Rome II symptom criteria suggests an altered immune regulation. Further studies are needed to elucidate if a lower serum IL-10 may be useful as a biomarker for IBS in the Mexican population, especially for women with IBS-D.

Th2-associated alternative Kupffer cell activation promotes liver fibrosis without inducing local inflammation.

Cirrhosis is the final outcome of liver fibrosis. Kupffer cell-mediated hepatic inflammation is considered to aggravate liver injury and fibrosis. Alternatively-activated macrophages are able to control chronic inflammatory events and trigger wound healing processes. Nevertheless, the role of alternative Kupffer cell activation in liver harm is largely unclear. Thus, we evaluated the participation of alternatively-activated Kupffer cells during liver inflammation and fibrosis in the murine model of carbon tetrachloride-induced hepatic damage. To stimulate alternative activation in Kupffer cells, 20 Taenia crassiceps (Tc) larvae were inoculated into BALBc/AnN female mice. Six weeks post-inoculation, carbon tetrachloride or olive oil were orally administered to Tc-inoculated and non-inoculated mice twice per week during other six weeks. The initial exposure of animals to T. crassiceps resulted in high serum concentrations of IL-4 accompanied by a significant increase in the hepatic mRNA levels of Ym-1, with no alteration in iNOS expression. In response to carbon tetrachloride, recruitment of inflammatory cell populations into the hepatic parenchyma was 5-fold higher in non-inoculated animals than Tc-inoculated mice. In contrast, carbon tetrachloride-induced liver fibrosis was significantly less in non-inoculated animals than in the Tc-inoculated group. The latter showed elevated IL-4 serum levels and low IFN-γ concentrations during the whole experiment, associated with hepatic expression of IL-4, TGF-ß, desmin and α-sma, as well as increased mRNA levels of Arg-1, Ym-1, FIZZ-1 and MMR in Kupffer cells. These results suggest that alternative Kupffer cell activation is favored in a Th2 microenvironment, whereby such liver resident macrophages could exhibit a dichotomic role during chronic hepatic damage, being involved in attenuation of the inflammatory response but at the same time exacerbation of liver fibrosis.

Early endocrine and molecular changes in metabolic syndrome models.

The twenty-first century arrived in the middle of a global epidemic of metabolic syndrome (MS) and type 2 diabetes mellitus (DM2). It is generally accepted that an excess of nutrients linked to a low physical activity triggers the problem. However, the molecular features that interact to develop the MS are not clear. In an effort to understand and control them, they have been extensively studied, but this goal has not been achieved yet. Nonhuman animal models have been used to explore diet and genetic factors in which experimental conditions are controlled. For example, only one factor in the diet, such as fats or carbohydrates can be modified to better understand a single change that would be impossible in humans. Most of the studies have been done in rodents. However, it is difficult to directly compare them, because experiments are different in more than one variable; genetic strains, amount, and the type of fat used in the diet and sex. Thus, the only possible criteria of comparison are the relevance of the observed changes. We review different animal models and add some original observations on short-term changes in metabolism and beta cells in our own model of adult Wistar rats that are not especially prone to get fat or develop DM2, treated with 20% sucrose in drinking water. One early change observed in pancreatic beta cells is the increase in GLUT2 expression that is located to the membrane of the cells. This change could partially explain the presence of insulin hypersecretion and hyperinsulinemia in these rats. Understanding early changes that lead to MS and in time to pancreatic islet exhaustion is an important biomedical problem that may contribute to learn how to prevent or even reverse MS, before developing DM2.