Human Umbilical Cord-Derived Mesenchymal Stem Cells Improve Learning and Memory Function in Hypoxic-Ischemic Brain-Damaged Rats via an IL-8-Mediated Secretion Mechanism Rather than Differentiation Pattern Induction

Background/Aims: Stem cell-based therapy is attractive in many clinical studies, but current data on the safety of stem cell applications remains inadequate. This study observed the safety, immunological effect of cynomolgus monkey umbilical cord mesenchymal stem cells (mUC-MSCs) injected into cynomolgus monkeys, in order to evaluate the safety of human umbilical cord mesenchymal stem cells (hUC-MSCs) prepared for human clinical application. Methods: Eighteen cynomolgus monkeys were divided into three groups. Group 1 is control group, Group 2 is low-dose group, Group 3 is high-dose group. After repeated administrations of mUC-MSCs, cynomolgus monkeys were observed for possible toxic reactions. Results: During the experiment, no animal died. There were no toxicological abnormalities in body weight, body temperature, electrocardiogram, coagulation and pathology. In the groups 2 and 3, AST and CK transiently increased, and serum inorganic P slightly decreased. All animals were able to recover at 28 days after the infusion was stopped. In the groups 2 and 3, CD3⁺ and IL-6 levels significantly increased, and recovery was after 28 days of infusion. There were no obvious pathological changes associated with the infusion of cells in the general and microscopic examinations. Conclusions: The safe dosage of repeated intravenous infusion of mUC-MSCs in cynomolgus monkeys is 1.0 × 10⁷/kg, which is 10 times of that in clinical human use.

Section: Discussionmentioning

confidence: 99%

Chronic Toxicity Test in Cynomolgus Monkeys For 98 Days with Repeated Intravenous Infusion of Cynomolgus Umbilical Cord Mesenchymal Stem Cells

Ruan

Xiang

et al. 2017

“…Ischemic stroke, accounts for 80% of stroke, which is mainly caused by an insufficient supply of glucose and oxygen to central nervous system (CNS) tissue and thus resulting in a significant amount of cell damages [2]. A series of complex cellular and biochemical molecular mechanisms are involved in the pathology, such as the excitotoxicity, mitochondrial dysfunction, ionic imbalance, oxidative stress, and inflammation, eventually leading to a loss of neurological functions and even cell death [3, 4]. Hypoxia is a critical factor for cell death or survival in ischemic stroke [5].…”

Section: Introductionmentioning

confidence: 99%

Maternally Expressed Gene 3 (MEG3) Enhances PC12 Cell Hypoxia Injury by Targeting MiR-147

Han

Dong

Liu

et al. 2017

Background/Aims: Cerebral ischemia often leads to breakdown of blood–brain barrier (BBB) and vasogenic edema. It remains to be established whether MEG3 is responsible for the hypoxic damage in neural cells. This study aimed to investigate the role of MEG3 in the hypoxia-induced injuries of PC12 cells. Methods: The PC12 cells were seeded and cultured under hypoxia and normoxia culture conditions. The cell viability determined by trypan blue exclusion, apoptosis using propidium iodide (PI) and fluorescein isothiocynate (FITC)-conjugated Annexin V staining, cell-migration using a modified two-chamber migration assay with a pore size of 8 µM and invasion using 24-well Millicell Hanging Cell Culture inserts with 8 µM PET membranes. Results: Cell viability, relative migration and relative invasion decreased significantly in PC12 cells injured due to hypoxia as compared to control cells. An increase in apoptosis was also observed. The expression of MEG3 was up-regulated in hypoxia-injured PC12 cells. MEG3 overexpression enhanced hypoxia injuries, while MEG3 suppression attenuated the injuries. Meanwhile, MEG3 negatively regulated miR-147 expression. In addition, we found that the expression of Sox2 was increased in PC12 cells after hypoxia and miR-147 negatively regulated Sox2 expression through targets its 3’-UTR. Interesting, Sox2 activated NF-κB pathway and Wnt/β-catenin pathway in PC12 cells. Conclusion: Considering the observations in our study, we can conclude that MEG3 aggravated the hypoxial injury in PC12 cells by down-regulating miR-147 gene and miR-147 further negatively regulated Sox2 expression.

“…Hypoxia inducible factor-1 (HIF-1) as an important endogenous signaling protein contributes to pathophysiologic changes of homeostasis under conditions of oxygen deprivation [5][6][7][8][9][10]. Accumulated subunit HIF-1α in the cellular nucleus and cytoplasm modulates the expression of several target genes that involve in neuroprotection, erythropoiesis, and apoptosis modulation [11,12].…”

Section: Introductionmentioning

confidence: 99%

HIF-1α Activation Attenuates IL-6 and TNF-α Pathways in Hippocampus of Rats Following Transient Global Ischemia

Xing

2016

Background/Aims: This study was to examine the role played by hypoxia inducible factor-1 (HIF-1α) in regulating pro-inflammatory cytokines (PICs) pathway in the rat hippocampus after cardiac arrest (CA) induced-transient global ischemia followed by cardiopulmonary resuscitation (CPR). Those PICs include interleukin-1β (IL-1β), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α). Methods: A rat model of CA induced by asphyxia was used in the current study. Following CPR, the hippocampus CA1 region was obtained for ELISA to determine the levels of HIF-1α and PICs; and Western Blot analysis to determine the protein levels of PIC receptors. Results: Our data show that IL-1β, IL-6 and TNF-α were significant elevated in the hippocampus after CPR as compared with control group. This was companied with increasing of HIF-1α and the time courses for HIF-1α and PICs were similar. In addition, PIC receptors, namely IL-1R, IL-6R and TNFR1 were upregulated in CA rats. Also, stimulation of HIF-1α by systemic administration of ML228, HIF-1α activator, significantly attenuated the amplified IL-6/IL-6R and TNF-α /TNFR1 pathway in the hippocampus of CA rats, but did not modify IL-1β and its receptor. Moreover, ML228 attenuated upregulated expression of Caspase-3 indicating cell apoptosis evoked by CA. Conclusion: Transient global ischemia induced by CA increases the levels of IL-1β, IL-6 and TNF-α and thereby leads to enhancement in their respective receptor in the rat hippocampus. Stabilization of HIF-1α plays a role in attenuating amplified expression IL-6R, TNFR1 and Caspase-3 in the processing of transient global ischemia. Results of our study suggest that PICs contribute to cerebral injuries evoked by transient global ischemia and in this pathophysiological process activation of HIF-1α improves tissues against ischemic injuries. Our data revealed specific signaling pathways in alleviating CA-evoked global cerebral ischemia by elucidating that HIF-1α plays an important role in regulating PIC signal pathways and Caspase-3. The subsequent induction of HIF-1α and its target signals is likely a part of the intrinsic neuroprotective effects aimed at attenuating damage as a result of global cerebral ischemia. Thus, targeting one or more of these signaling molecules has clinical implications for treatment and improvement of CA-evoked global cerebral ischemia often observed in clinics.