Mesenchymal stem cells attenuate acute liver failure by promoting expansion of regulatory T cells in an indoleamine 2,3-dioxygenase-dependent manner

© 2020, University of Kragujevac, Faculty of Science. All rights reserved. The influence of mesenchymal stem cells (MSCs) on the phenotype and function of CD4+CD49b+FoxP3-regulatory cells has not been elucidated. We used Concanavalin A (ConA)-and α-galactosylceramide (α-GalCer)-induced acute liver injury to estimate the effects of MSCs on liver-infiltrating CD4+CD49b+FoxP3-regulatory cells. MSCs significantly reduced ConA-and α-GalCer-mediated liver injury in C57BL/6 mice, as demonstrated by biochemical tests, reduced influx of inflammatory CD4+ T cells, and increased presence of CD4+CD49b+FoxP3-regulatory cells in the injured livers. The number of CD4+CD49b+FoxP3-regulatory cells was also significantly increased in α-GalCer-treated mice that received MSC-derived condi-tioned medium (MSC-CM). The presence of 1-methyltryp-tophan, a specific inhibitor of indoleamine 2,3-dioxygenase (IDO), in MSC-CM completely abrogated the hepatopro-tective effect of MSCs and significantly decreased the total number of liver-infiltrated CD4+CD49b+FoxP3-regulatory cells, indicating the crucial importance of MSC-derived IDO for the expansion of CD4+CD49b+FoxP3-regulatory cells and the consequent MSC-dependent attenuation of acute liver injury

pH-Responsive Hydrogel Beads Based on Alginate, k-Carrageenan and Poloxamer for enhanced curcumin, natural bioactive compound, encapsulation and controlled release efficiency

Polyphenolic compounds are used for treating various diseases due to their antioxidant and anticancer properties. However, utilization of hydrophobic compounds is limited due to their low bioavailability. In order to achieve a greater application of hydrophobic bioactive compounds, hydrogel beads based on biopolymers can be used as carriers for their enhanced incorporation and controlled delivery. In this study, beads based on the biopolymers-k-carrageenan, sodium alginate and poloxamer 407 were prepared for encapsulation of curcumin. The prepared beads were characterized using IR, SEM, TGA and DSC. The curcumin encapsulation efficiency in the developed beads was 95.74 +/- 2.24%. The release kinetics of the curcumin was monitored in systems that simulate the oral delivery (pH 1.2 and 7.4) of curcumin. The drug release profiles of the prepared beads with curcumin indicated that the curcumin release was significantly increased compared with the dissolution of curcumin itself. The cumulative release of curcumin from the beads was achieved within 24 h, with a final release rate of 12.07% (gastric fluid) as well as 81.93% (intestinal fluid). Both the in vitro and in vivo studies showed that new hydrogel beads based on carbohydrates and poloxamer improved curcumin’s bioavailability, and they can be used as powerful carriers for the oral delivery of different hydrophobic nutraceuticals

Therapeutic efficacy of mesenchymal stem cells for cardiovascular diseases

Despite the improvements in pharmacological and surgical treatments, cardiovascular diseases (CVDs) are the number one cause of death worldwide. During the last two decades, the search for new therapies has been revolutionized with the growing knowledge of stem cell biology. Due to their huge differentiation capacity and paracrine effects, mesenchymal stem cells (MSCs) are a promising tool for the treatment of CVDs. The encouraging outcomes of preclinical studies using MSCs as a treatment for diseased myocardium have set the scene for worldwide clinical trials. In this review, we overview either complete or ongoing clinical trials using MSCs for the therapy of CVDs. In particular, we analyze the biological properties of MSCs, elucidate recent clinical findings and clinical trial phases of investigation, highlight clinical therapeutic effects of MSCs, and discuss challenges towards the clinical use of these cells in the therapy of CVDs

Gal-3 plays an important pro-inflammatory role in the induction phase of acute colitis by promoting activation of NLRP3 inflammasome and production of IL-β in macrophages

BACKGROUND AND AIMS: Galectin-3 [Gal-3] is an endogenous lectin with a broad spectrum of immunoregulatory effects: it plays an important role in autoimmune/inflammatory and malignant diseases, but the precise role of Gal-3 in pathogenesis of ulcerative colitis is still unknown. METHODS: We used a model of dextran sulphate sodium [DSS]-induced acute colitis. The role of Gal-3 in pathogenesis of this disease was tested by evaluating disease development in Gal-3 deficient mice and administration of Gal-3 inhibitor. Disease was monitored by clinical, histological, histochemical, and immunophenotypic investigations. Adoptive transfer was used to detect cellular events in pathogenesis. RESULTS: Genetic deletion or pharmacological inhibition of Gal-3 significantly attenuate DSS-induced colitis. Gal-3 deletion suppresses production of pro-inflammatory cytokines in colonic macrophages and favours their alternative activation, as well as significantly reducing activation of NOD-like receptor family, pyrin domain containing 3 [NLRP3] inflammasome in macrophages. Peritoneal macrophages isolated from untreated Gal-3(-/-) mice and treated in vitro with bacterial lipopolysaccharide or DSS produce lower amounts of tumour necrosis factor alpha [TNF-α] and interleukin beta [IL-1β] when compared with wild type [WT] cells. Genetic deletion of Gal-3 did not directly affect total neutrophils, inflammatory dendritic cells [DCs] or natural killer [NK] T cells. However, the total number of CD11c+ CD80+ DCs which produce pro-inflammatory cytokines, as well as TNF-α and IL-1β producing CD45+ CD11c- Ly6G+ neutrophils were significantly lower in colons of Gal-3(-/-) DSS-treated mice. Adoptive transfer of WT macrophages significantly enhanced the severity of disease in Gal-3(-/-) mice. CONCLUSIONS: Gal-3 expression promotes acute DSS-induced colitis and plays an important pro-inflammatory role in the induction phase of colitis by promoting the activation of NLRP3 inflammasome and production of IL-1β in macrophages

Stem Cells: New Hope For Spinal Cord Injury

Stem cell therapy offers several attractive strategies for spinal cord repair. The regenerative potential of pluripotent stem cells was confirmed in an animal model of Spinal Cord Injury (SCI); nevertheless, optimized growth and differentiation protocols along with reliable safety assays should be established prior to the clinical application of hESCs and iPSCs. Th e therapeutic effects of mesenchymal stem cells (MSCs) in SCI result from neurotrophin secretion, angiogenesis, and antiinflammatory actions. Several preclinical SCI studies have reported that the occurrence of axonal extension, remyelination and neuroprotection occur after the transplantation of olfactory ensheathing cells (OECs). The transplantation of neural stem cells NSCs (NSCs) promotes partial functional improvement after SCI because of their potential to differentiate into neurons, oligodendrocytes, and astrocytes. The ideal source of stem cells for safe and efficient cell-based therapy for SCI remains a challenging issue that requires further investigation

Bacterial flora play important roles in acute dextran sulphate sodium-induced colitis but are not involved in Gal-3 dependent modulation of colon inflammation

© 2017, University of Kragujevac, Faculty of Science. All rights reserved. An altered immune response to normal gut microflora is important for the pathogenesis of ulcerative colitis (UC). Galectin- 3 (Gal-3) is an endogenous lectin that plays an important pro-inflammatory role in the induction phase of acute colitis by promoting activation of the NLRP3 inflammasome and production of IL-1β in macrophages. By using dextran sulphate sodium (DSS) induced colitis, a well-established animal model of UC, we determined whether Gal-3 affects the function of colon infiltrating macrophages by interfering with intestinal microflora. Our results showed that genetic deletion of Gal-3 significantly attenuates DSS-induced colitis by down-regulating infiltration of phagocytic cells (neutrophils, macrophages and dendritic cells) in colon tissue of DSS-treated mice, and this correlated with differences in bacterial flora of the gut. Antibiotic treatment attenuates DSS-induced colitis in WT and Gal-3-/- mice without affecting differences between the groups. In conclusion, Gram negative bacterial flora play an important role in DSS-induced acute colitis of mice but are not involved in Gal-3 dependent modulation of colon inflammation

Mesenchymal Stem Cell-Based Therapy of Inflammatory Lung Diseases: Current Understanding and Future Perspectives.

During acute or chronic lung injury, inappropriate immune response and/or aberrant repair process causes irreversible damage in lung tissue and most usually results in the development of fibrosis followed by decline in lung function. Inhaled corticosteroids and other anti-inflammatory drugs are very effective in patients with inflammatory lung disorders, but their long-term use is associated with severe side effects. Accordingly, new therapeutic agents that will attenuate ongoing inflammation and, at the same time, promote regeneration of injured alveolar epithelial cells are urgently needed. Mesenchymal stem cells (MSCs) are able to modulate proliferation, activation, and effector function of all immune cells that play an important role in the pathogenesis of acute and chronic inflammatory lung diseases. In addition to the suppression of lung-infiltrated immune cells, MSCs have potential to differentiate into alveolar epithelial cells in vitro and, accordingly, represent new players in cell-based therapy of inflammatory lung disorders. In this review article, we described molecular mechanisms involved in MSC-based therapy of acute and chronic pulmonary diseases and emphasized current knowledge and future perspectives related to the therapeutic application of MSCs in patients suffering from acute respiratory distress syndrome, pneumonia, asthma, chronic obstructive pulmonary diseases, and idiopathic pulmonary fibrosis

Bacterial Flora Play Important Roles in Acute Dextran Sulphate Sodium-Induced Colitis But Are Not Involved in Gal-3 Dependent Modulation of Colon Inflammation

An altered immune response to normal gut microflora is important for the pathogenesis of ulcerative colitis (UC). Galectin- 3 (Gal-3) is an endogenous lectin that plays an important pro-inflammatory role in the induction phase of acute colitis by promoting activation of the NLRP3 infl ammasome and production of IL-1β in macrophages. By using dextran sulphate sodium (DSS) induced colitis, a well-established animal model of UC, we determined whether Gal-3 affects the function of colon infiltrating macrophages by interfering with intestinal microfl ora. Our results showed that genetic deletion of Gal-3 significantly attenuates DSS-induced colitis by down-regulating infiltration of phagocytic cells (neutrophils, macrophages and dendritic cells) in colon tissue of DSS-treated mice, and this correlated with differences in bacterial flora of the gut. Antibiotic treatment attenuates DSS-induced colitis in WT and Gal-3-/- mice without affecting differences between the groups. In conclusion, Gram negative bacterial flora play an important role in DSS-induced acute colitis of mice but are not involved in Gal-3 dependent modulation of colon inflammation

Galectin 3 protects from cisplatin-induced acute kidney injury by promoting TLR-2-dependent activation of IDO1/Kynurenine pathway in renal DCs.

Strategies targeting cross-talk between immunosuppressive renal dendritic cells (DCs) and T regulatory cells (Tregs) may be effective in treating cisplatin (CDDP)-induced acute kidney injury (AKI). Galectin 3 (Gal-3), expressed on renal DCs, is known as a crucial regulator of immune response in the kidneys. In this study, we investigated the role of Gal-3 for DCs-mediated expansion of Tregs in the attenuation of CDDP-induced AKI. Methods: AKI was induced in CDDP-treated wild type (WT) C57BL/6 and Gal-3 deficient (Gal-3-/-) mice. Biochemical, histological analysis, enzyme-linked immunosorbent assay (ELISA), immunohistochemistry, real-time PCR, magnetic cell sorting, flow cytometry and intracellular staining of renal-infiltrated immune cells were used to determine the differences between CDDP-treated WT and Gal-3-/- mice. Newly synthesized selective inhibitor of Gal-3 (Davanat) was used for pharmacological inhibition of Gal-3. Recombinant Gal-3 was used to demonstrate the effects of exogenously administered soluble Gal-3 on AKI progression. Pam3CSK4 was used for activation of Toll-like receptor (TLR)-2 in DCs. Cyclophosphamide or anti-CD25 antibody were used for the depletion of Tregs. 1-Methyl Tryptophan (1-MT) was used for pharmacological inhibition of Indoleamine 2,3-dioxygenase-1 (IDO1) in TLR-2-primed DCs which were afterwards used in passive transfer experiments. Results: CDDP-induced nephrotoxicity was significantly more aggravated in Gal-3-/- mice. Significantly reduced number of immunosuppressive TLR-2 and IDO1-expressing renal DCs, lower serum levels of KYN, decreased presence of IL-10-producing Tregs and significantly higher number of inflammatory IFN-γ and IL-17-producing neutrophils, Th1 and Th17 cells were observed in the CDDP-injured kidneys of Gal-3-/- mice. Pharmacological inhibitor of Gal-3 aggravated CDDP-induced AKI in WT animals while recombinant Gal-3 attenuated renal injury and inflammation in CDDP-treated Gal-3-/- mice. CDDP-induced apoptosis, driven by Bax and caspase-3, was aggravated in Gal-3-/- animals and in WT mice that received Gal-3 inhibitor (CDDP+Davanat-treated mice). Recombinant Gal-3 managed to completely attenuate CDDP-induced apoptosis in CDDP-injured kidneys of Gal-3-/- mice. Genetic deletion as well as pharmacological inhibition of Gal-3 in renal DCs remarkably reduced TLR-2-dependent activation of IDO1/KYN pathway in these cells diminishing their capacity to prevent transdifferentiation of Tregs in inflammatory Th1 and Th17 cells. Additionally, Tregs generated by Gal-3 deficient DCs were not able to suppress production of IFN-γ and IL-17 in activated neutrophils. TLR-2-primed DCs significantly enhanced capacity of Tregs for attenuation of CDDP-induced AKI and inflammation and expression of Gal-3 on TLR-2-primed DCs was crucially important for their capacity to enhance nephroprotective and immunosuppressive properties of Tregs. Adoptive transfer of TLR-2-primed WTDCs significantly expanded Tregs in the kidneys of CDDP-treated WT and Gal-3-/- recipients resulting in the suppression of IFN-γ and IL-17-driven inflammation and alleviation of AKI. Importantly, this phenomenon was not observed in CDDP-treated WT and Gal-3-/- recipients of TLR-2-primed Gal-3-/-DCs. Gal-3-dependent nephroprotective and immunosuppressive effects of renal DCs was due to the IDO1-induced expansion of renal Tregs since either inhibition of IDO1 activity in TLR-2-primed DCs or depletion of Tregs completely diminished DCs-mediated attenuation of CDDP-induced AKI. Conclusions: Gal-3 protects from CDDP-induced AKI by promoting TLR-2-dependent activation of IDO1/KYN pathway in renal DCs resulting in increased expansion of immunosuppressive Tregs in injured kidneys. Activation of Gal-3:TLR-2:IDO1 pathway in renal DCs should be further explored as new therapeutic approach for DC-based immunosuppression of inflammatory renal diseases

Stem cells and labeling for spinal cord injury

© 2016 by the authors; licensee MDPI, Basel, Switzerland. Spinal cord injury (SCI) is a devastating condition that usually results in sudden and long-lasting locomotor and sensory neuron degeneration below the lesion site. During the last two decades, the search for new therapies has been revolutionized with the improved knowledge of stem cell (SC) biology. SCs therapy offers several attractive strategies for spinal cord repair. The transplantation of SCs promotes remyelination, neurite outgrowth and axonal elongation, and activates resident or transplanted progenitor cells across the lesion cavity. However, optimized growth and differentiation protocols along with reliable safety assays should be established prior to the clinical application of SCs. Additionally, the ideal method of SCs labeling for efficient cell tracking after SCI remains a challenging issue that requires further investigation. This review summarizes the current findings on the SCs-based therapeutic strategies, and compares different SCs labeling approaches for SCI