Involvement of GPR43 Receptor in Effect of Lacticaseibacillus rhamnosus on Murine Steroid Resistant Chronic Obstructive Pulmonary Disease: Relevance to Pro-Inflammatory Mediators and Oxidative Stress in Human Macrophages.

BACKGROUND: Cytokine storm and oxidative stress are present in chronic obstructive pulmonary disease (COPD). Individuals with COPD present high levels of NF-κB-associated cytokines and pro-oxidant agents as well as low levels of Nrf2-associated antioxidants. This condition creates a steroid-resistant inflammatory microenvironment. Lacticaseibacillus rhamnosus (Lr) is a known anti-cytokine in lung diseases; however, the effect of Lr on lung inflammation and oxidative stress in steroid-resistant COPD mice remains unknown. OBJECTIVE: Thus, we investigated the Lr effect on lung inflammation and oxidative stress in mice and macrophages exposed to cigarette smoke extract (CSE) and unresponsive to steroids. METHODS: Mice and macrophages received dexamethasone or GLPG-094 (a GPR43 inhibitor), and only the macrophages received butyrate (but), all treatments being given before CSE. Lung inflammation was evaluated from the leukocyte population, airway remodeling, cytokines, and NF-κB. Oxidative stress disturbance was measured from ROS, 8-isoprostane, NADPH oxidase, TBARS, SOD, catalase, HO-1, and Nrf2. RESULTS: Lr attenuated cellularity, mucus, collagen, cytokines, ROS, 8-isoprostane, NADPH oxidase, and TBARS. Otherwise, SOD, catalase, HO-1, and Nrf2 were upregulated in Lr-treated COPD mice. Anti-cytokine and antioxidant effects of butyrate also occurred in CSE-exposed macrophages. GLPG-094 rendered Lr and butyrate less effective. CONCLUSIONS: Lr attenuates lung inflammation and oxidative stress in COPD mice, suggesting the presence of a GPR43 receptor-dependent mechanism also found in macrophages.

Steroid Resistance Associated with High MIF and P-gp Serum Levels in SLE Patients.

Approximately 30% of patients with systemic lupus erythematosus (SLE) present steroid resistance (SR). Macrophage migration inhibition factor (MIF) and P-glycoprotein (P-gp) could be related to SR. This work aims to evaluate the relationship between MIF and P-pg serum levels in SR in SLE. Methods: Case−control study including 188 SLE patients who were divided into two groups (90 in the steroid-resistant group and 98 in the steroid-sensitive (SS) group) and 35 healthy controls. MIF and P-gp serum levels were determined by ELISA. Multivariable logistic regression and chi-squared automatic interaction detection (CHAID) were used to explore risk factors for SR. Results: The steroid-resistant group presented higher MIF and P-gp serum levels in comparison with the SS (p < 0.001) and reference (p < 0.001) groups. MIF correlated positively with P-gp (rho = 0.41, p < 0.001). MIF (≥15.75 ng/mL) and P-gp (≥15.22 ng/mL) were a risk factor for SR (OR = 2.29, OR = 5.27). CHAID identified high P-gp as the main risk factor for SR and high MIF as the second risk factor in those patients with low P-gp. Conclusions: An association between MIF and P-gp serum levels was observed in SR. CHAID identified P-gp ≥ 15.22 ng/mL as the main risk factor for SR. More studies are needed to validate these results.

THE METABOLOMICS SIGNATURE ASSOCIATED WITH RESPONSIVENESS TO STEROID THERAPY IN FOCAL SEGMENTAL GLOMERULOSCLEROSIS: A PILOT STUDY.

BACKGROUND: Focal segmental glomerulosclerosis (FSGS) is considered one of the most severe glomerular diseases and around 80% of cases are resistant to steroid treatment. Since a large proportion of steroid-resistant (SR) FSGS patients progress to end-stage renal disease, other therapeutic strategies may benefit this population. However, identification of non-invasive biomarkers to predict this high-risk population is needed. OBJECTIVE: We aimed to identify the biomarker candidates to distinguish SR from steroid-sensitive (SS) patients using metabolomics approach and to identify the possible molecular mechanism of resistance. METHODS: Urine was collected from biopsy-proven FSGS patients eligible for monotherapy with prednisolone. Patients were followed for 6-8 weeks and categorized as SS or SR. Metabolite profile of urine samples was analyzed by one-dimensional 1H-nuclear magnetic resonance (1H-NMR). Predictive biomarker candidates and their diagnostic importance impaired molecular pathways in SR patients, and the common target molecules between biomarker candidates and drug were predicted. RESULTS: Homovanillic acid, 4-methylcatechol, and tyrosine were suggested as the significant predictive biomarker candidates, while L-3,4-dihydroxyphenylalanine, norepinephrine, and gentisic acid had high accuracy as well. Tyrosine metabolism was the most important pathway that is perturbed in SR patients. Common targets of the action of biomarker candidates and prednisolone were molecules that contributed in apoptosis. CONCLUSION: Urine metabolites including homovanillic acid, 4-methylcatechol, and tyrosine may serve as potential non-invasive predictive biomarkers for evaluating the responsiveness of FSGS patients.

The metabolomics signature associated with responsiveness to steroid therapy in focal segmental glomerulosclerosis: a pilot study

Abstract Background Focal segmental glomerulosclerosis (FSGS) is considered one of the most severe glomerular diseases and around 80% of cases are resistant to steroid treatment. Since a large proportion of steroid-resistant (SR) FSGS patients progress to end-stage renal disease, other therapeutic strategies may benefit this population. However, identification of non-invasive biomarkers to predict this high-risk population is needed. Objective We aimed to identify the biomarker candidates to distinguish SR from steroid-sensitive (SS) patients using metabolomics approach and to identify the possible molecular mechanism of resistance. Methods Urine was collected from biopsy-proven FSGS patients eligible for monotherapy with prednisolone. Patients were followed for 6-8 weeks and categorized as SS or SR. Metabolite profile of urine samples was analyzed by one-dimensional 1H-nuclear magnetic resonance (1H-NMR). Predictive biomarker candidates and their diagnostic importance impaired molecular pathways in SR patients, and the common target molecules between biomarker candidates and drug were predicted. Results Homovanillic acid, 4-methylcatechol, and tyrosine were suggested as the significant predictive biomarker candidates, while L-3,4-dihydroxyphenylalanine, norepinephrine, and gentisic acid had high accuracy as well. Tyrosine metabolism was the most important pathway that is perturbed in SR patients. Common targets of the action of biomarker candidates and prednisolone were molecules that contributed in apoptosis. Conclusion Urine metabolites including homovanillic acid, 4-methylcatechol, and tyrosine may serve as potential non-invasive predictive biomarkers for evaluating the responsiveness of FSGS patients.

Multidrug resistance gene (MDR-1) expression in the colonic mucosa of patients with refractory ulcerative colitis / Expresión del gen de multirresistencia a drogas (MDR-1) en la mucosa colónica de pacientes con colitis ulcerosa refractaria

BACKGROUND: P-Glycoprotein (P-gp), a product of the MDR-1 gene, is a transmembrane efflux pump involved in drug transport, first described in cancer refractoriness. In the normal bowel P-gp is detectable on superficial epithelial cells, but has not been described in crypt epithelium. The role of P-gp and its intestinal expression in steroid-refractory ulcerative colitis (UC) are controversial. AIM: to compare P-gp immunostaining pattern in colonic epithelial cells of steroid-refractory versus steroid-responder UC patients. METHODS: P-gp was assessed by immunohistochemistry in rectal biopsies obtained from 19 patients with active UC, including pre-surgical samples from 11 refractory patients who underwent colectomy, and 8 responders. We devised a 5-point (0-4) score, according to the percentage of epithelial surface with positive immunostaining in the superficial and crypt epithelium (apical, lateral and cytoplasmic areas). RESULTS: Compared with responders, steroid-refractory patients had significantly higher immunostaining scores in the superficial epithelium, both in apical (2.8+/-0.5 versus 1.1+/-0.5, p=0.023) and cytoplasmic cellular areas (2.7+/-0.5 versus 1.2+/-0.5, p=0.032). Positive immunostaining of the superficial epithelium was frequently detected in refractory patients (apical: 9/11 cases, cytoplasmic: 10/11 cases) but was only observed in 4/8 responders. P-gp was also detected in similar areas of the crypt epithelium in 6/11 refractory patients, while it was infrequent in the group of 8 responders (1 apical 1 case, cytoplasmic 2 cases). Samples from the mucosa of normal ileal pouch-anal anastomoses obtained several years after the surgical procedure had a P-gp immunostaining pattern which was similar to that of rectal samples from patients with refractory UC. CONCLUSIONS: These results suggest a critical role of P-gp overexpression in steroid-refractory UC.

Antecedentes. La glicoproteína P (P-gp), un producto del gen MDR-1, es una bomba de eflujo transmembranainvolucrada en el transporte de drogas, descripta por primera vez en el cáncer refractario. En el intestino normal, P-gp se detecta sobre las célulasepiteliales superficiales, pero no se la ha descripto en el epitelio de las criptas. El papel de P-gp y su expresiónintestinal en la colitis ulcerosa (CU) refractaria a esteroides es controvertido. Objetivo. Comparar elpatrón de inmunotinción de P-gp en células epiteliales colónicas de pacientes con CU refractaria vs.respondedora a esteroides. Métodos. Se estudió P-gp por inmunohistoquímica en biopsias rectales obtenidasde 19 pacientes con CU activa, incluyendo muestras prequirúrgicas de 11 pacientes refractarios que fueronsometidos a una colectomía y muestras de 8 respondedores. Ideamos un score de 5 puntos (0-4), según elporcentaje de superficie epitelial con inmunotinción positiva en el epitelio superficial y críptico (áreas apical,lateral y citoplásmica). Resultados. Comparados con los respondedores, los pacientes refractarios a esteroides tenían scores de inmunotinción significativamente mayores en el epitelio superficial, tanto en lasáreas celulares apical (2.8+0.5 vs. 1.1+0.5, p=0.023) como citoplásmica (2.7+0.5 vs. 1.2+0.5, p=0.032). Se detectó frecuentemente inmunotinción positiva en el epitelio superficial en los pacientes refractarios (apical: 9/11 casos, citoplásmica: 10/11 casos), pero la misma se observó sólo en 4/8 respondedores. P-gp también sedetectó en áreas similares del epitelio de las criptas en 6/11 pacientes refractarios, en tanto que fue infrecuenteen el grupo de los 8 respondedores (1 caso en el área apical y 2 en la citoplásmica). Fuerón estudiadasbiopsias de la mucosa de la anastomosis pouch ileal - anal, obtenidas varios años después del procedimeinto quirúrgico, observándose un patrón de...