Neuropathic pain is a type of chronic pain caused by injury or dysfunction of the nervous system, without effective therapeutic approaches. Mesenchymal stromal cells (MSCs), through their paracrine action, have great potential in the treatment of this syndrome. In the present study, the therapeutic potential of MSC-derived conditioned medium (CM) was investigated in a mouse model of neuropathic pain induced by partial sciatic nerve ligation (PSL). PSL mice were treated by endovenous route with bone marrow-derived MSCs (1 × 10⁶), CM, or vehicle. Gabapentin was the reference drug. Twelve hours after administration, neuropathic mice treated with CM exhibited an antinociceptive effect that was maintained throughout the evaluation period. MSCs also induced nonreversed antinociception, while gabapentin induced short-lasting antinociception. The levels of IL-1β, TNF-α, and IL-6 were reduced, while IL-10 was enhanced on sciatic nerve and spinal cord by treatment with CM and MSCs. Preliminary analysis of the CM secretome revealed the presence of growth factors and cytokines likely involved in the antinociception. In conclusion, the CM, similar to injection of live cells, produces a powerful and long-lasting antinociceptive effect on neuropathic pain, which is related with modulatory properties on peripheral and central levels of cytokines involved with the maintenance of this syndrome.

Chagas disease (CD) affects approximately 6–7 million people worldwide, from which 30% develop chronic Chagas cardiomyopathy (CCC), usually after being asymptomatic for years. Currently available diagnostic methods are capable of adequately identifying infected patients, but do not provide information regarding the individual risk of developing the most severe form of the disease. The identification of biomarkers that predict the progression from asymptomatic or indeterminate form to CCC, may guide early implementation of pharmacological therapy. Here, six circulating microRNAs (miR-19a-3p, miR-21-5p, miR-29b-3p, miR-30a-5p, miR-199b-5p and miR-208a-3p) were evaluated and compared among patients with CCC (n = 28), CD indeterminate form (n = 10) and healthy controls (n = 10). MiR-19a-3p, miR-21-5p, and miR-29b-3p were differentially expressed in CCC patients when compared to indeterminate form, showing a positive correlation with cardiac dysfunction, functional class, and fibrosis, and a negative correlation with ejection fraction and left ventricular strain. Cardiac tissue analysis confirmed increased expression of microRNAs in CCC patients. In vitro studies using human cells indicated the involvement of these microRNAs in the processes of cardiac hypertrophy and fibrosis. Our study suggests that miRNAs are involved in the process of cardiac fibrosis and remodeling presented in CD and indicate a group of miRNAs as potential biomarkers of disease progression in CCC.

Chagas disease, caused by Trypanosoma cruzi infection, is a leading cause of heart failure in Latin American countries. In a previous study, we showed beneficial effects of granulocyte colony‐stimulating factor (G‐CSF) administration in the heart function of mice with chronic T. cruzi infection. Presently, we investigated the mechanisms by which this cytokine exerts its beneficial effects. Mice chronically infected with T. cruzi were treated with human recombinant G‐CSF (3 courses of 200 μg/kg/d for 5 d). Inflammation and fibrosis were reduced in the hearts of G‐CSF‐treated mice, compared with the hearts of vehicle‐treated mice, which correlated with decreased syndecan‐4, intercellular adhesion molecule‐1, and galectin‐3 expressions. Marked reductions in interferon‐γ and tumor necrosis factor‐α and increased interleukin‐10 and transforming growth factor‐β were found after G‐CSF administration. Because the therapy did not induce a Th1 to Th2 immune response deviation, we investigated the role of regulatory T (T _reg ) cells. A significant increase in CD3 ⁺ Foxp3 ⁺ cells was observed in the hearts of G‐CSF‐treated mice. In addition, a reduction of parasitism was observed after G‐CSF treatment. Our results indicate a role of T _reg cells in the immunosuppression induced by G‐CSF treatment and reinforces its potential therapeutic use for patients with Chagas disease.—Vasconcelos, J. F., Souza, B. S. F., Lins, T. F. S., Garcia, L. M. S., Kaneto, C. M., Smapaio, G. P., de Alcântara, A. C., Meira, C. S., Macambira, S. G., Ribeiro‐dos‐Santos, R., Soares, M. B. P., Administration of granulocyte colony‐stimulating factor induces immunomodulation, recruitment of T regulatory cells, reduction of myocarditis and decrease of parasite load in a mouse model of chronic Chagas disease cardiomyopathy. FASEB J. 27, 4691–4702 (2013). www.fasebj.org