Combined application of neural stem/progenitor cells and scaffolds on locomotion recovery following spinal cord injury in rodents: a systematic review and meta-analysis.

BACKGROUND: This present study evaluates the pre-clinical evidence on the efficacy of NS/PC and scaffold (NS/PC + scaffold) transplantation on locomotor recovery after traumatic spinal cord injury (SCI). METHOD: Two independent reviewers screened the records gathered through a systematic search in MEDLINE, Embase, Scopus, and Web of Sciences databases. Studies on rats/mice evaluating the efficacy of simultaneous transplantation of NS/PCs and scaffold in the treatment of SCI were included. The results were reported as standardized mean difference (SMD) and 95% confidence interval (95% CI). RESULTS: Forty-seven articles were retrieved. Analyses showed that NS/PC + scaffold transplantation significantly improved locomotion in animals with SCI compared to that of the non-treatment group (SMD = 2.71, 95% CI: 1.89 to 3.54; I2 = 95.15%, p < 0.0001), scaffold alone (SMD = 2.28; 95% CI: 1.56 to 3.00; I2 = 94.38%; p < 0.0001), and NS/PCs alone (SMD = 1.74, 95% CI: 0.64 to 2.83; I2 = 92.02%, p < 0.0001). Moreover, the effectiveness of the treatment significantly increases when PLGA-based scaffolds and antibiotics are used. In addition, the NS/PC + scaffold transplantation during the first week after injury led to a significant improvement in locomotion, while concomitant transplantation of NS/PC + scaffold did not improve locomotion in cervical lesions. CONCLUSION: The findings showed that using NS/PCs with scaffold not only improves locomotion recovery, but also is superior to NS/PCs alone and scaffold alone. Future experiments and translational clinical studies are recommended to focus on the assessment of the safety and efficacy of the application of NS/PC + scaffold on SCI recovery.

TLR4 /NF-ĸB and JAK2/STAT3 signaling pathways: Cellular signaling pathways targeted by cell-conditioned medium therapy in protection against ischemic stroke.

Human amniotic membrane-derived mesenchymal stem cell-conditioned medium (hAMSC-CM) has been known to improve neuronal survival following ischemic stroke. The present study was designed to examine whether protective effects of hAMSC-CM against stroke can be linked to reducing neuroinflamation by targeting TLR4 /NF-ĸB and Jak2/Stat3 signaling pathways. Immunohistochemistry of hippocampus and western blot assay were performed to evaluate the expression of TLR4 /NF-ĸB and Jak2/Stat3, respectively. Real-time PCR assay was applied to investigate the mRNA levels of Jak2/Stat3. Hematoxylin and eosin (H&E) staining was used to investigate tissue damage and morphological changes in the CA1 region of hippocampus. Increased brain edema was seen in middle cerebral artery occlusion (MCAO) rats compared to sham. Post-treatment with hAMSC-CM markedly reduced brain edema in comparison with MCAO group (P < 0.05). Compared to sham, significantly increased levels of TLR4 /NF-ĸB and Jak2/Stat3 were seen in MCAO rats. Intravenous injection of hAMSC-CM after reperfusion markedly reduced levels of TLR4 /NF-ĸB and Jak2/Stat3 in hippocampus region (P < 0.05). Tissue damage and neuronal cell increased in the CA1 region of hippocampus that reversed by post-treatment by hAMSC-CM. Interestingly, our finding showed that hAMSC-CM can be considered as good candidate to reduce injury following ischemic stroke by decreasing activity of TLR4 /NF-ĸB and Jak2/Stat3 signaling pathways.

FoxO1 and Wnt/ß-catenin signaling pathway: Molecular targets of human amniotic mesenchymal stem cells-derived conditioned medium (hAMSC-CM) in protection against cerebral ischemia/reperfusion injury.

Ischemia-reperfusion (I/R) injury has weakened the effects of available treatment options for ischemic stroke. Although conditioned medium obtained from human amniotic mesenchymal stem cells (hAMSC-CM) has been reported to exert protective effect against stroke, detailed knowledge about its possible molecular mechanisms is not still completely available. The present study was designed to investigate whether hAMSC-CM can modulate FoxO1 and Wnt/ß-catenin signaling pathway after ischemic stroke to create neuroprotective effects. Middle cerebral artery occlusion (MCAO) model with male Wistar rats was used to evaluate the effects of hAMSC-CM on activities of FoxO1, Wnt/ß-catenin signaling pathway, and endogenous antioxidant system and apoptotic cell death. The results demonstrated that induction of MCAO significantly reduced activities of FoxO1, Wnt/ß-catenin signaling pathway, and endogenous antioxidant system and enhanced apoptotic cell death (P < 0.05). In addition, treatment by hAMSC-CM immediately after cerebral reperfusion resulted in significantly reduced infarct size and increased activities of FoxO1, Wnt/ß-catenin signaling pathway, and restoring endogenous antioxidant system and suppressing apoptotic cell death (P < 0.05). Likewise, increased activity of Wnt/ß-catenin signaling pathway resulted in suppressing the neuroinflammation by inhibiting the expression of TNF-α and increasing the expression of IL-10. These findings demonstrate that hAMSC-CM can be considered as an excellent candidate in the treatment of acute ischemic stroke in clinical routine.

Donepezil attenuates injury following ischaemic stroke by stimulation of neurogenesis, angiogenesis, and inhibition of inflammation and apoptosis.

Donepezil has proven to be an effective drug to reduce neuronal death and subsequently injury in neurodegenerative diseases. The current study evaluated the neuroprotective effects of donepezil in a rat model of ischaemic stroke and explored possible mechanisms which by this drug may reduce cell death. Temporary middle cerebral artery occlusion (tMCAO) was exerted for 45 min to induce ischaemic stroke. The animals were assigned into five groups: sham, control, and three groups treated with different doses of donepezil. Donepezil was intraperitoneally (IP) injected 4 h after reperfusion for 10 consecutive days. Infarct size was determined using TTC staining. The expression of proteins was evaluated using immunohistochemistry assays. Compared with the control group, infarct size was significantly reduced in tMCAO rats treated with different doses of donepezil. Moreover, our results showed significant decreased expression levels of apoptotic markers and pro-inflammatory mediators after treatment with different doses of donepezil for 10 days (P < 0.05). Likewise, significant increase of brain-derived neurotrophic factor (BDNF) and peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) proteins were found in tMCAO rats treated with donepezil compared with the control group (P < 0.05). Collectively, our findings show the validity of donepezil as a new therapeutic agent for attenuation of injury following ischaemic stroke through attenuation of inflammation and improvement of mitochondrial function, neurogenesis, and angiogenesis.

Conditioned medium obtained from human amniotic mesenchymal stem cells attenuates focal cerebral ischemia/reperfusion injury in rats by targeting mTOR pathway.

Conditioned medium obtained from human amniotic mesenchymal stem cells (hAMSC-CM) was recently shown to have many antioxidant, antiapoptotic and proangiogenic growth factors. The present study was performed to investigate whether protective effects of hAMSC-CM against focal cerebral ischemia/ reperfusion (I/R) injury is associated with modulation of the mammalian target of rapamycin (mTOR) pathway. A rat model of middle cerebral artery occlusion (MCAO) was created and the animals were divided into three groups including sham, MCAO and MCAO + hAMSC-CM. Drug was administrated immediately after cerebral reperfusion (i.v). The expressions of mTOR, p-mTOR and LC3 were measured using Western blotting and real time-PCR, respectively. Apoptosis and neuronal loss were determined using TUNEL and Nissl staining, respectively. Infarct volume and the blood-brain barrier (BBB) damage were evaluated using 2,3,5-triphenyltetrazolium chloride (TTC) staining and Evans Blue (EB) uptake, respectively. Compared with sham, significant infarct volume, apoptotic cell death, and neuronal loss were found in MCAO rats that reversed by hAMSC-CM (P < 0.05). Likewise, MCAO rats exhibited increased mRNA level of light-chain 3 (LC3) and the LC3II/LC3I ratio as well as decreased expression level of p-mTOR that reversed by hAMSC-CM (P < 0.05). There were no significant differences in the expression of total mTOR among the experimental groups. In summary, our results demonstrate that hAMSC-CM gives rise to neuroprotection following ischemic stroke by restoring mTOR activity and inhibiting autophagy.

A combination of mesenchymal stem cells and scaffolds promotes motor functional recovery in spinal cord injury: a systematic review and meta-analysis.

OBJECTIVE: There is controversy about the role of scaffolds as an adjunctive therapy to mesenchymal stem cell (MSC) transplantation in spinal cord injury (SCI). Thus, the authors aimed to design a meta-analysis on preclinical evidence to evaluate the effectiveness of combination therapy of scaffold + MSC transplantation in comparison with scaffolds alone and MSCs alone in improving motor dysfunction in SCI. METHODS: Electronic databases including Medline, Embase, Scopus, and Web of Science were searched from inception until the end of August 2018. Two independent reviewers screened related experimental studies. Animal studies that evaluated the effectiveness of scaffolds and/or MSCs on motor function recovery following experimental SCI were included. The findings were reported as standardized mean difference (SMD) and 95% confidence interval (CI). RESULTS: A total of 34 articles were included in the meta-analysis. Analyses show that combination therapy in comparison with the scaffold group alone (SMD 2.00, 95% CI 1.53-2.46, p < 0.0001), the MSCs alone (SMD 1.58, 95% CI 0.84-2.31, p < 0.0001), and the nontreated group (SMD 3.52, 95% CI 2.84-4.20, p < 0.0001) significantly improved motor function recovery. Co-administration of MSCs + scaffolds only in the acute phase of injury (during the first 3 days after injury) leads to a significant recovery compared to scaffold alone (SMD 2.18, p < 0.0001). In addition, the cotransplantation of scaffolds with bone marrow-derived MSCs (SMD 1.99, p < 0.0001) and umbilical cord-derived MSCs (SMD 1.50, p = 0.001) also improved motor function following SCI. CONCLUSIONS: The findings showed that scaffolds + MSCs is more effective than scaffolds and MSCs alone in improving motor function following SCI in animal models, when used in the acute phase of injury.

Conditioned medium obtained from mesenchymal stem cells attenuates focal cerebral ischemia reperfusion injury through activation of ERK1/ERK2-BDNF signaling pathway.

Previous studies have shown that conditioned medium (CM) obtained from mesenchymal stem cells (MSCs) might exert neuroprotective effects against focal cerebral ischemia reperfusion (I/R) injury. This study was conducted to investigate if CM obtained from MSCs gives rise to neuroprotection by targeting neurogenesis. To induce focal cerebral ischemia in rats, middle cerebral artery (MCA) was occluded for 1 h and the amniotic mesenchymal stem cells-conditioned medium (AMSC-CM) at the dose of 0.5 µl was administered 30 min after reperfusion by stereotactic intracerebral infusion. The animals were randomly divided into three groups: sham operated animals received all procedures except occlusion of MCA (sham, n = 12), I/R group only received occlusion of MCA (MCAO, n = 17), treatment group received MCAO + 0.5 µl of AMSC-CM (MCAO + AMSC-CM, n = 17). The expression of Phospho-ERK1/ERK2, BDNF, VEGF and NGF were determined using immunohistochemical assay. Neuronal loss and DNA fragmentation were evaluated by Nissl and TUNEL assay, respectively. Our results demonstrated that the expression of Phospho-ERK1/ERK2 and BDNF, VEGF and NGF significantly decreased in MCAO rats and was reversed by AMSC-CM. Likewise, AMSC-CM markedly reduced neuronal loss and DNA fragmentation at 24 h after reperfusion. In sum, our study showed that AMSC-CM administration at the onset of reperfusion led to neuroprotection by activating neuronal ERK1/ERK2-BDNF signaling pathway, neurogenesis, angiogenesis as well as suppression of apoptosis.

Conditioned medium obtained from human amniotic membrane-derived mesenchymal stem cell attenuates heart failure injury in rats.

OBJECTIVES: Heart failure (HF) is one of the leading causes of death worldwide. Due to beneficial effects of stem cells, paracrine secretion of them has recently been used by researchers. The purpose of this study was to investigate the effects of intravenous injection (IV) of conditioned medium (CM) of human amniotic membrane-derived mesenchymal stem cell (MSC-CM) on HF. MATERIALS AND METHODS: Male Wistar rats (n=35, 180 g) were randomly divided into five groups: sham, HF, HF+MSC-CM, HF+culture medium and HF+phosphate-buffered saline (PBS). To induce HF, isoproterenol (170 mg/kg/d) was injected subcutaneously for 4 consecutive days. After 28 days, induction of HF was evaluated by echocardiography. A day after echocardiography, 50 µg culture medium/5 ml PBS in HF+culture medium group, 50 µg MSC-CM/5 ml PBS in HF+MSC-CM group and 5 ml PBS in HF+PBS group were injected two times for 4 successive days. The echocardiography was performed 4 weeks after the last injection of isoproterenol. To evaluate the fibrosis, morphology, and cardiac function, Trichrome Masson's staining, Hematoxylin and Eosin staining and echocardiography were performed, respectively. RESULTS: CM significantly increased fractional shortening and ejection fraction, and also significantly decreased apoptotic nuclear condensation. Moreover, significant decreased level of fibrosis and increased level of angiogenesis was observed in the treatment group (P<0.05). CONCLUSION: Our results indicated that IV injection of CM has therapeutic effects on HF by reducing fibrosis and preventing the progression of failure due to its paracrine effects.

Natural lavender oil (Lavandula angustifolia) exerts cardioprotective effects against myocardial infarction by targeting inflammation and oxidative stress.

BACKGROUND: The study was conducted to examine therapeutic effects of lavender oil (LO) against myocardial infarction (MI) and its potential mechanisms. METHODS: A rat model of MI was established and LO (100, 200 and 300 mg/kg) was intraperitoneally administrated immediately after ischemia. Anti-inflammatory and antioxidant activity of LO were evaluated by immunohistochemical assay and measurement of SOD, GSH, and MDA. The myocardial injury markers, apoptotic activity and infarct volume were examined by ELISA, TUNEL and TTC staining, respectively. RESULTS: Compared with the control I/R-Vehicle, the expression of tumor necrosis factor-α (TNF-α) and interleukin-1ß (IL-1ß) significantly reduced 8 h after reperfusion and expression of interleukin-10 (IL-10) elevated 48 h after reperfusion in LO-treated rats (P < 0.05). Likewise, significant decreases in apoptotic activity, infarct volume and significant restoration of antioxidant endogenous defenses were observed in LO-treated rats (P < 0.05). CONCLUSION: Collectively, these findings confirm that LO can be a good candidate to reduce injury after MI.

The membrane mesenchymal stem cell derived conditioned medium exerts neuroprotection against focal cerebral ischemia by targeting apoptosis.

OBJECTIVE: The mesenchymal stem cells derived from human amniotic membrane have the ability to secrete and release some factors that can promote the repair of damaged tissues. This secretome contains proteins and factors that reduce apoptosis and increase angiogenesis in the ischemia/reperfusion models. The present study was conducted to determine whether this secretome provides protection against transient focal cerebral ischemia. MATERIALS AND METHODS: A rat model of focal cerebral ischemia was established through middle cerebral artery occlusion (MCAO) for 60 min and 24 h reperfusion. The amniotic mesenchymal stem cells-conditioned medium (AMSC-CM) at the dose of 0.5 µl was injected intracerebroventriculary (ICV) 30 min after reperfusion. Infarct volume, brain edema, neurobehavioral functions, and blood brain barrier (BBB) integrity were assessed 24 h after reperfusion. Neuronal loss and expression of caspase-3, Bax and Bcl-2 in motor cortex were evaluated by nissl staining and immunohistochemistry assay respectively. RESULTS: ICV administration of AMSC-CM markedly reduced infarct volume, brain edema and the evans blue penetration rate compared with MCAO group (P < 0.05). Additionally, post-treatment with AMSC-CM significantly reduced neuronal loss, neurological motor disorders and expression of caspase-3, Bax and Bcl-2 in motor cortex compared with MCAO group (P < 0.05). CONCLUSION: The results of this study indicate that treatment with AMSC-CM improves the pathological effects in the acute phase of cerebral ischemia. These findings establish a substantial foundation for stroke therapy and future research.

Targeting signal transducers and activators of transcription (STAT) in human cancer by dietary polyphenolic antioxidants.

Over the course of the last three decades, a large body of evidence has shown that polyphenols, the secondary metabolites occurring in plant foods and beverages, exert protective effects due to their antioxidant activity mediated through different mechanisms ranging from direct radical scavenging and metal chelating activities, to the capacity to inhibit pro-oxidant enzymes and to target specific cell-signalling pathways. In the last decade, dietary components, and polyphenols in particular have gained considerable attention as chemopreventive agents against different types of cancer. The signal transducers and activators of transcription (STAT) family is a group of cytoplasmic transcription factors which interact with specific sequences of DNA, inducing the expression of specific genes which in turn give rise to adaptive and highly specific biological responses. Growing evidence suggests that, of the seven STAT members identified, STAT3 is over-expressed in many human tumors (i.e. solid tumors and hematological malignancies) promoting the onset and development of cancer in humans by inhibiting apoptosis or by inducing cell proliferation, angiogenesis, invasion, and metastasis. This review article aims to assess the most recent studies on the role of STATs, with focus on STAT3, in oncogenesis, and the promising effects of some polyphenols on STAT expression. Moreover, the mechanisms behind the anti-inflammatory and antioxidant activities of polyphenols which have an influence on STAT expression are discussed, with a focus on their ability to target specific cell-signalling pathways.