Antioxidant mechanisms of mesenchymal stem cells and their therapeutic potential in vitiligo.

Vitiligo is a skin pigmentation disorder caused by melanocyte damage or abnormal function. Reac-tive oxygen species Reactive oxygen species can cause oxidative stress damage to melanocytes, which in turn induces vitiligo. Traditional treatments such as phototherapy, drugs, and other methods of treatment are long and result in frequent recurrences. Currently, mesenchymal stem cells (MSCs) are widely used in the research of various disease treatments due to their excellent paracrine effects, making them a promising immunoregulatory and tissue repair strategy. Furthermore, an increasing body of evi-dence suggests that utilizing the paracrine functions of MSCs can downregulate oxidative stress in the testes, liver, kidneys, and other affected organs in animal models of certain diseases. Addition-ally, MSCs can help create a microenvironment that promotes tissue repair and regeneration in are-as with oxidative stress damage, improving the disordered state of the injured site. In this article, we review the pathogenesis of oxidative stress in vitiligo and promising strategies for its treatment.

Advances in the research of the role of macrophage/microglia polarization-mediated inflammatory response in spinal cord injury.

It is often difficult to regain neurological function following spinal cord injury (SCI). Neuroinflammation is thought to be responsible for this failure. Regulating the inflammatory response post-SCI may contribute to the recovery of neurological function. Over the past few decades, studies have found that macrophages/microglia are one of the primary effector cells in the inflammatory response following SCI. Growing evidence has documented that macrophages/microglia are plastic cells that can polarize in response to microenvironmental signals into M1 and M2 macrophages/microglia. M1 produces pro-inflammatory cytokines to induce inflammation and worsen tissue damage, while M2 has anti-inflammatory activities in wound healing and tissue regeneration. Recent studies have indicated that the transition from the M1 to the M2 phenotype of macrophage/microglia supports the regression of inflammation and tissue repair. Here, we will review the role of the inflammatory response and macrophages/microglia in SCI and repair. In addition, we will discuss potential molecular mechanisms that induce macrophage/microglia polarization, with emphasis on neuroprotective therapies that modulate macrophage/microglia polarization, which will provide new insights into therapeutic strategies for SCI.

Neuroinflammation and Scarring After Spinal Cord Injury: Therapeutic Roles of MSCs on Inflammation and Glial Scar.

Transected axons are unable to regenerate after spinal cord injury (SCI). Glial scar is thought to be responsible for this failure. Regulating the formation of glial scar post-SCI may contribute to axonal regrow. Over the past few decades, studies have found that the interaction between immune cells at the damaged site results in a robust and persistent inflammatory response. Current therapy strategies focus primarily on the inhibition of subacute and chronic neuroinflammation after the acute inflammatory response was executed. Growing evidences have documented that mesenchymal stem cells (MSCs) engraftment can be served as a promising cell therapy for SCI. Numerous studies have shown that MSCs transplantation can inhibit the excessive glial scar formation as well as inflammatory response, thereby facilitating the anatomical and functional recovery. Here, we will review the effects of inflammatory response and glial scar formation in spinal cord injury and repair. The role of MSCs in regulating neuroinflammation and glial scar formation after SCI will be reviewed as well.

[CD133(+) cells derived from human placenta identified as initiating cells for LTC-IC colony formation].

The aim of this study was to evaluate whether human placenta CD133(+) cells have an ability to reconstitute long-term hematopoiesis. Magnetic-activated cell sorting (MACS) was applied to enrich human placental CD133(+) cells. The isolated human placental CD133(+)cells of four different densities were established by limiting-dilution assay and primary fetal bone marrow stromal cells separated from bone marrow as feeder layer cells were co-cultured in long-term culture system so as to observe the incidence of long-term culture initiating-cells (LTC-IC) and their ability of proliferation and differentiation.The results showed that human placenta derived CD133(+) cells contained LTC-IC with frequency of 1/645 which have an ability to proliferate and differentiate into granulocyte/macrophage colony-forming units (CFU-GM) and mixed colony-forming units (CFU-Mix). In all LTC-IC positive wells, 71.43% form only CFU-GM and 28.57% display both CFU-GM and CFU-Mix formation. It is concluded that human placental CD133(+) cells possess LTC-IC with colony-forming capacity of hematopoietic early progenitor cells.

[Effects of ANP upon ion pump activity and gene expression in aortic smooth muscle cells from spontaneously hypertensive rats].

OBJECTIVE: To explore the effects of atrial natriuretic peptide (ANP) upon the activities of Na(+), K(+)-ATPase, Ca(2+)-ATPase and mRNA expression levels of Na(+), K(+)-ATPase alpha(1)-subunit and plasma membrane Ca(2+)-ATPase isoform 1 (PMCA1) in cultured thoracic aortic vascular smooth muscle cells (ASMCs) isolated from spontaneously hypertensive rats (SHR). METHODS: ASMCs isolated from 14-week-old male SHR and Wistar-Kyoto (WKY) rats were interference-cultured in different doses of ANP and Angiotensin II (AngII). The contents of ANP and AngII in supernatant from ASMCs were measured by radioimmunoassay. The activities of the above two ATPases were measured by biochemistry and enzymology. RT-PCR assay was employed to determine the relative levels of Na(+), K(+)-ATPase alpha(1)-subunit and PMCA1 mRNA in ASMCs. RESULTS: The ANP level of supernatant in SHR ASMCs was significantly lower than those from WKY control [(7.3 +/- 2.4) pg x 10(-6) cells vs (19.3 +/- 3.3) pg x 10(-6) cells, P < 0.01] while the content of AngII in SHR ASMCs was significantly higher than those from WKY control [(57 +/- 4) pg x 10(-6) cells vs (44 +/- 4) pg x 10(-6) cells, P < 0.01]. The activity of Na(+), K(+)-ATPase [(4.3 +/- 0.8) micromol x h(-1) x mg(-1) vs (5.3 +/- 1.0) micromol x h(-1) x mg(-1)], Ca(2+)-ATPase [(3.2 +/- 0.7) micromol x h(-1) x mg(-1) vs (4.5 +/- 0.7) micromol x h(-1) x mg(-1)] in ASMCs from SHR were significantly lower than those from WKY control (both P < 0.01). The mRNA expression of Na(+), K(+)-ATPase alpha(1)-subunit (0.524 +/- 0.025 vs 0.704 +/- 0.116), PMCA1 (0.193 +/- 0.030 vs 0.547 +/- 0.045) significantly decreased in ASMCs from SHR versus the WKY control (both P < 0.01). As compared with SHR control, exogenous ANP improved obviously the activities of Na(+), K(+)-ATPase, Ca(2+)-ATPase and expression of alpha(1)-subunit, PMCA1 mRNA in a does-dependent manner (P < 0.05-P < 0.01). Exogenous AngII (1 x 10(-9), 1 x 10(-8), 1 x 10(-7) mol/L) significantly repressed activities of Ca(2+)-ATPase and attenuated the expression of PMCA1 mRNA (P < 0.05-P < 0.01). Only AngII (1 x 10(-7) mol/L) significantly inhibited the activity of Na(+), K(+)-ATPase and attenuated the expression of Na(+), K(+)-ATPase alpha(1)-subunit mRNA (both P < 0.05). ANP antagonized the effects of AngII (1 x 10(-7) mol/L) upon the activities of two ATPases and the expression of Na(+), K(+)-ATPase alpha(1)-subunit PMCA1 mRNA (P < 0.05-P < 0.01). AngII (1 x 10(-7) mol/L) increased the Na(+), K(+)-ATPase activity and the expression of Na(+), K(+)-ATPase alpha(1)-subunit mRNA, repressed the Ca(2+)-ATPase activity and the expression of PMCA1 mRNA in ASMCs from WKY rat (P < 0.05-P < 0.01). ANP antagonized the effects of AngII (1 x 10(-7) mol/L) upon the activity of Ca(2+)-ATPase and the expression of PMCA1 mRNA (P < 0.05-P < 0.01), but did not antagonize the effects of AngII (1 x 10(-7) mol/L) upon the activity of Na(+), K(+)-ATPase and the expression of alpha(1)-subunit mRNA in ASMCs from WKY rats (P > 0.05). CONCLUSION: The decreased activities of Na(+), K(+)-ATPase and Ca(2+)-ATPase may be related to the abnormal autocrine of ANP and AngII in ASMC of SHR. ANP can antagonize the effects of AngII upon the activities of two ATPases and the expression of Na(+), K(+)-ATPase alpha(1)-subunit PMCA1 mRNA.

[Ex vivo expansion of megakaryocyte progenitor cells for CD133(+) cells derived from human umbilical cord blood].

To study the expansion potentiality of megakaryocyte progenitor cells (MPCs) derived from human umbilical cord blood CD133(+) (UCB-CD133(+)) cells and determine the optimal harvest time. UCB-CD133(+) cells were purified from mononuclear cells (MNCs) by magnetic activated cell sorting (MACS) and seeded in serum-free liquid culture medium supplemented with thrombopoietin (TPO), interleukin-3 (IL-3), and stem cell factor (SCF) to expand MPCs. At day 0, 6, 10 and 14 of culture, the total cell number was counted and the dynamic changes of CD133, CD34, and CD41 antigen expression during ex vivo expansion were analyzed by flow cytometry (FCM). At different expansion times, the CD133(+) cells were collected and cultured in collagen semisolid medium to carry out CFU-MK colony culture. The incidence of CFU-MK was calculated and the morphology of MPCs and CFU-MK were detected by immunohistochemistry and Wright-Giemsa staining. The results showed that UCB-CD133(+) cells optimally expanded at day 7 with expansion multiple of 8.2 +/- 2.2 in serum-free liquid culture systems and the total cell number was expanded by 116-fold at day 14. At 10 days, each UCB-CD133(+) cell can form 2.5 +/- 1.0, 2.6 +/- 0.5 and 20.3 +/- 5.9 cells of CD133(+)CD41(+), CD34(+)CD41(+) and CD41(+) respectively, from which the number of CD133(+)CD41(+) and CD34(+)CD41(+) cells reach the highest. UCB-CD133(+) cells both before and after expansion could form CFU-MK, the total number of CFU-MK reached the peak from cells of 10 days expansion of UCB-CD133(+) cells and the expansion multiple of CFU-MK was 59.5 +/- 11.8. Immunohistochemical results indicated that the expanded megakaryocytic cells were immature and no sign of platelet formation. It is concluded that the human UCB-CD133(+) cells have a high ability of MPC expansion, 10 days of culture can be result in optimal expansion effect.

[In vitro expansion of megakaryocyte progenitor cells from human placenta CD133+ cells].

OBJECTIVE: To study the expansion potential of megakaryocyte progenitor cells (MPC) from human placenta tissue CD133+ (PT-CD133+) cells. METHODS: PT-CD133+ cells were purified from mononuclear cells (MNC) by magnetic activated cell sorting (MACS) and seeded in serum-free liquid culture medium supplemented with thrombopoietin (TPO), interleukin-3 (IL-3), and stem cell factor (SCF) to expand MPC. At day 7, 10 and 14, the total cell number was counted and the dynamic changes of CD133, CD34, and CD41 antigens expression during ex-vivo expansion were analyzed by flow cytometry (FCM). PT-CD133+ cells at different expansion time were collected and cultured in collagen semisolid medium for colony forming units-megakaryocyte (CFU-MK) assay. RESULTS: PT-CD133+ cells could be optimally expanded at day 7 by 13 +/- 2 fold increase in serum-free liquid culture systems and the total cell number was expanded by 160 fold at day 14. With the expansion time going on, the expression of CD133, CD34 decreased and that of CD41 increased. The expanded megakaryocytes were immature and no sign of platelet formation. Both PT-CD133+ cells before and after expansion could form CFU-MK, the total number of CFU-MK peaked at day 10 of expansion by 54 +/- 10 fold increase. CONCLUSION: Human PT-CD133+ cells have a high capacity of MPC expansion, 10 days culture could give rise to the maximum number of CFU-MK.

[Hematopoietic stem/progenitor cells and phenotypes of lymphocyte subpopulations in human placenta].

OBJECTIVE: To study whether human placenta contains hematopoietic stem/progenitor cells (HSPCs), and analyze phenotypes of lymphocyte subpopulations in the placenta. METHODS: Nucleated cells from fresh human placenta were analyzed for phenotypes of HSPCs and lymphocyte subpopulations by flow cytometry (FCM). And CD(34)(+) cells were sorted from human placenta nucleated cells by FCM or MiniMACS. RESULTS: (1) CD(34)(+) cells, CD(34)(+)/CD(38)(+) cells, and CD(34)(+)/CD(38)(-) cells from a human placenta were 8.8, 4.6 and 11.9 times higher than those from umbilical cord blood (UCB), respectively. (2) The yields and purity of CD(34)(+) cells isolated from human placenta by FCM sorting system were (63.05 +/- 10.14)% and (86.39 +/- 11.27)%, respectively. (3) Lymphocytes, T cells (CD(3)(+)/CD(2)(+)), B cells (CD(19)(+)), Th cells (CD(3)(+), CD(4)(+)), and Th/Ts ratio in the placenta tissue were apparently lower than those in the UCB, while the CD(8)(+)/CD(28)(-) T suppressor cells were higher in the placenta than in the UCB. CONCLUSIONS: Human placenta is rich in HSPCs, and has important hematopoietic function in ontogeny. It is probable that human placenta would be graft resource for HSPCs transplantation. CD(8)(+)/CD(28)(-) T suppressor cells might play an important role in feto-maternal immunologic tolerance.