Human Mesenchymal Stem Cell Delivery System Modulates Ischemic Cardiac Remodeling With an Increase of Coronary Artery Blood Flow.

Ways for extending the longevity of stem cells are imperative to attain diverse expected therapeutic effects. Here, we constructed a three-dimentional (3D) scaffold system for human mesenchymal stem cell (hMSC) delivery. Intramyocardial injections of porous PEI1.8k blended with poly(lactic-co-glycolic acid) (PLGA) (PLGA/PEI1.8k) (PPP) microparticles by physical electrostatic conjugation and structural entrapment of hMSCs demonstrated enhanced functional and geometric improvements on post-infarct cardiac remodeling in rats. In the hMSC-loaded PPP delivery, increases of coronary artery blood flow rate and in vivo engraftment rate as well as time-dependent functional, geometric, and pathologic findings reversing post-infarct cardiac remodeling account for improved left ventricular (LV) systolic function up to the level of sham thoracotomy group. This study expands our understanding by proving that increase of coronary artery blood flow augmented functional recovery of hMSC-loaded PPP delivery system after myocardial infarction (MI).

VEGF therapeutic gene delivery using dendrimer type bio-reducible polymer into human mesenchymal stem cells (hMSCs).

The therapeutic potential of mesenchymal stem cells (MSCs) has garnered great attention in the expansive diversity of biomedical research. Despite this broad interest in stem cells, limited incorporation and poor viability are major disadvantages for accomplishing therapeutic success in the field of hMSC-based cell therapy, and an optimal approach for hMSC-based cell therapy using non-viral vectors has not been established. Hence, we examined the possibility of performing gene therapy using the biodegradable polymeric non-viral vector Arginine-grafted poly (cystaminebisacrylamide-diaminohexane) (ABP)-conjugated poly (amidoamine) (PAMAM) dendrimer (PAM-ABP) in hMSCs. PAM-ABP formed compact nanosized polyplexes and showed low cytotoxicity compared to bPEI 25k and Lipofectamine® 2000 in hMSCs. Although the cellular uptake was similar, the transfection efficiency and VEGF expression of PAM-ABP using gWiz-Luc and pß-VEGF were higher than those of the control groups. Although hMSCs were transfected, their stem cell characteristics were retained. Our results suggest that PAM-ABP has the ability to deliver a therapeutic gene in hMSCs.

Development of porous PLGA/PEI1.8k biodegradable microspheres for the delivery of mesenchymal stem cells (MSCs).

Multipotent mesenchymal stem cells (MSCs) promise a therapeutic alternative for many debilitating and incurable diseases. However, one of the major limitations for the therapeutic application of human MSC (hMSC) is the lengthy ex vivo expansion time for preparing a sufficient amount of cells due to the low engraftment rate after transplantation. To solve this conundrum, a porous biodegradable polymeric microsphere was investigated as a potential scaffold for the delivery of MSCs. The modified water/oil/water (W1/O/W2) double emulsion solvent evaporation method was used for the construction of porous microspheres. PEI1.8k was blended with poly(lactic-co-glycolic acid) (PLGA) to enhance electrostatic cellular attachment to the microspheres. The porous PLGA/PEI1.8k (PPP) particles demonstrated an average particle size of 290µm and an average pore size of 14.3µm, providing a micro-carrier for the MSC delivery. PPP particles allowed for better attachment of rMSCs than non-porous PLGA/PEI1.8k (NPP) particles and non-porous (NP) and porous PLGA (PP) microspheres. rMSC successfully grew on the PPP particles for 2weeks in vitro. Next, PPP particles loaded with 3 different amounts of hMSC showed increased in vivo engraftment rates and maintained the stemness characteristics of hMSC compared with hMSCs-alone group in rats 2weeks after intramyocardial administration. These customized PPP particles for MSC delivery are a biodegradable and injectable scaffold that can be used for clinical applications.

Polymeric delivery of therapeutic RAE-1 plasmid to the pancreatic islets for the prevention of type 1 diabetes.

The activating receptor NKG2D plays an important role in the development of type-1 diabetes. Exploiting a natural phenomenon observed in tumors, plasmid DNA encoding for a soluble ligand to NKG2D (sRAE-1γ) was isolated and engineered into a plasmid expression system. A polymeric gene delivery system was developed to deliver the soluble RAE-1 plasmid to the pancreatic islets. The bioreducible cationic polymer poly(cystamine bisacrylamide-diamino hexane) (p(CBA-DAH)) was modified with poly(ethylene glycol) (PEG) and the targeting peptide CHVLWSTRC, known to target the EphA2 and EphA4 receptors. We observed a higher uptake of the targeting polymer Eph-PEG-p(CBA-DAH) in the pancreas of NOD mice compared to non-targeting controls. To evaluate the efficacy of preventing diabetes, the Eph-PEG-p(CBA-DAH)/RAE-1 complex (polyplex) was intravenously injected into 6-week-old female NOD mice. Within 17 weeks blood glucose levels were stabilized in animals injected with polyplex, while those treated without therapeutic plasmid developed progressive hyperglycemia. Additionally, the degree of insulitis and the infiltration of CD8⁺ T-cells in the polyplex treated group were improved over the targeting polymer only treated group. The current study suggests that the therapy of the Eph-PEG-p (CBA-DAH) delivering therapeutic sRAE-1 gene may be used to protect ß-cells from autoimmune destruction and prevent type-1 diabetes.

The activation of ERK1/2 via a tyrosine kinase pathway attenuates trail-induced apoptosis in HeLa cells.

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) serves as an extracellular signal that triggers apoptosis in tumor cells. To characterize the molecular events involved in TRAIL-induced apoptotic signaling, we investigated the role of extracellular signal-regulated kinase 1/2 (ERK1/2) in HeLa cell death. Here we show that TRAIL-activated ERK1/2 through a tyrosine kinase-dependent pathway, subsequently elevated anti-apoptotic Bcl-2 protein levels. ERK1/2 inhibition with PD98059 promoted apoptotic cell death through the downregulation of ERK1/2 activity and Bcl-2 protein levels. Moreover, tyrosine kinase inhibition with Genistein in TRAIL-induced apoptosis effectively attenuated ERK1/2 activity and enhanced apoptotic cell death. Taken together, our results indicate that ERK1/2 activation via tyrosine kinase pathway plays a protective role as the cellular defense mechanism through the upregulation of Bcl-2 protein levels in TRAIL-induced apoptosis.

Baicalein prevents 6-hydroxydopamine-induced dopaminergic dysfunction and lipid peroxidation in mice.

The effects of baicalein on 6-hydroxydopamine (6-OHDA)-induced neurotoxicity were evaluated. Intracerebroventricularly (i.c.v.) injection of 6-OHDA was done to young mice. Baicalein was administered intraperitoneally 30 min before and 90 min after i.c.v. injection. Animals received further injection of bacalein daily for 3 consecutive days. Rotarod performance was assessed, tyrosine hydroxylase (TH) Western blotting was performed, and dopamine (DA) levels and peroxidation were determined. High dose of baicalein effectively improved rotarod performance and prevented the reduction of striatal DA levels and TH contents in the striatum and subtantia nigra (SN). In addition, lipid peroxidation level was decreased by baicalein at 3 and 7 days after 6-OHDA injection. These results showed that baicalein effectively prevents the 6-OHDA-induced dopaminergic dysfunction through an antioxidative action.

Melatonin protects against neuronal damage induced by 3-nitropropionic acid in rat striatum.

In this study, the protective effects of melatonin were evaluated against 3-nitropropionic acid (3-NP)-induced striatal neuronal damage in rats. Lesions were induced in the right striatum of Sprague-Dawley rats by stereotaxic injection with 3-NP and melatonin was intraperitoneally administered both 30 min before and 60 min after 3-NP injection. And rats continuously received melatonin daily for 3 days. As indicators of oxidative damage, lipid peroxidation and protein oxidation in the lesioned striatum were measured at 1 day after 3-NP injection. Levels of malondialdehyde (MDA) and protein carbonyl were significantly increased by 3-NP injection, but reduced in the melatonin-treated rats. Four days post-lesion, large lesions and extensive neuronal damage were produced in the 3-NP-injected striata, as revealed by 2,3,5-triphenyltetrazolium chloride (TTC) staining. In addition, marked ipsilateral rotational behavior following apomorphine challenge and a decrease of dopamine content in the lesioned striatum were observed in the 3-NP-injected rats. However, melatonin treatment significantly attenuated the 3-NP-induced neuronal damage, reduced the degree of asymmetric rotational behavior, and restored the dopamine level in the lesioned striatum. The present results indicate that melatonin effectively protects against the neuronal damage caused by 3-NP in vivo and that the neuroprotective effects of melatonin may be related to antioxidant action.

Mitogen-activated protein kinase/extracellular signal-regulated kinase attenuates 3-hydroxykynurenine-induced neuronal cell death.

3-Hydroxykynurenine (3-HK), an endogenous tryptophan metabolite, is known to have toxic effects in brain. However, the molecular mechanism of the toxicity has not been well identified. In this study, we investigated the involvement of MAPK/extracellular signal-regulated kinase (ERK) in the 3-HK-induced neuronal cell damage. Our results showed that 3-HK induced apoptotic neuronal cell death and ERK phosphorylation occurred during cell death. Inhibition of ERK activation using PD98059 considerably increased cell death. Furthermore, cell death was preceded by mitochondrial malfunction including collapse of mitochondrial membrane potential (DeltaPsi(m)) and cytochrome c release from mitochondria to the cytosol. Interestingly, inhibition of ERK dramatically increased mitochondrial malfunction, and enhanced caspase activation, resulting in enhanced neuronal cell death. Thus, our results show that ERK plays a protective role by maintaining mitochondrial function and regulating caspase activity under conditions of cellular stress.

Genetically modified human embryonic stem cells relieve symptomatic motor behavior in a rat model of Parkinson's disease.

Embryonic stem (ES) cells have great potential as a cell source for cell replacement therapy. To investigate the possibility of using ES cells as a carrier of therapeutic gene(s), human ES cells (MB03) were co-transfected with cDNAs coding for tyrosine hydroxylase (TH) and GTP cyclohydrolase I (GTPCH I), then bulk-selected in the presence of neomycin and hygromycin-B. Successful transfection was confirmed by Western immunoblotting and RT-PCR. The genetically modified ES cells (bk-THGC) were found to produce a significant amount of L-dopa spontaneously and relieved apomorphine-induced asymmetric motor behavior by approximately 54% when grafted into striatum of 6-OHDA-denervated rat brain. The number of rotations, however, increased up to 176+/-18% in 6 weeks when PBS was used instead (sham-graft). Immunohistochemical stainings revealed that the grafted human ES cells survived and expressed TH for at least 6 weeks while the experiment was continued.

General pharmacology of indole [2',3':3,4]pyrido[2,1-b]quinazolinium- 5,7,8,13-tetrahydro-14-methyl-5-oxo-chloride, a new anti-dementia agent.

The general pharmacological properties of indolo[2',3':3,4]pyrido[2,1-b]quinazolinium-5,7,8,13-tetrahydro-14- methyl-5-oxo-chloride (dehydroevodiamine-HCl, DHED, CAS 67909-49-3), a new potential anti-dementia agent, were studied to investigate side effects using various experimental animals. Both oral and intraperitoneal administration of DHED had no effects on the central nervous system except that they showed an analgesic activity. DHED had no significant effect on heart rate, blood pressure and coronary flow in isolated rat hearts. DHED had negligible effects on the autonomic nervous system and smooth muscle in isolated rat ileum, rat vas deferens and rat aorta. DHED did not influence the gastrointestinal system except that it inhibited the intestinal travel of a charcoal meal in mice. Neither blood coagulation mechanism nor liver function was affected by DHED. Therefore, it is concluded from these general pharmacological studies that DHED does not induce any serious side effects at the dose levels showing anticholinesterase and memory enhancing activities in the experimental animals.

Acupuncture prevents 6-hydroxydopamine-induced neuronal death in the nigrostriatal dopaminergic system in the rat Parkinson's disease model.

Parkinson's disease (PD) is a chronic neurodegenerative disorder, and it has been suggested that treatments promoting survival and functional recovery of affected dopaminergic neurons could have a significant and long-term therapeutic value. In the present study, we investigated the neuroprotective effects of acupuncture on the nigrostriatal system in rat unilaterally lesioned with 6-hydroxydopamine (6-OHDA, 4 microg/microl, intrastriatal injection) using tyrosine hydroxylase (TH) and receptor for brain-derived neurotrophic factor, trkB, immunohistochemistries. Two weeks after the lesions were made, rats presented with asymmetry in rotational behavior (118.3 +/- 17.5 turns/h) following injection with apomorphine, a dopamine receptor agonist (0.5 mg/kg, sc). In contrast, acupunctural treatment at acupoints GB34 and LI3 was shown to significantly reduce this motor deficit (14.6 +/- 13.4 turns/h). Analysis via TH immunohistochemistry revealed a substantial loss of cell bodies in the substantia nigra (SN) (45.7% loss) and their terminals in the dorsolateral striatum ipsilateral to the 6-OHDA-induced lesion. However, acupunctural treatment resulted in the enhanced survival of dopaminergic neurons in the SN (21.4% loss) and their terminals in the dorsolateral striatum. Acupuncture also increased the expression of trkB significantly (35.6% increase) in the ipsilateral SN. In conclusion, we observed that only acupuncturing without the use of any drug has the neuroprotective effects against neuronal death in the rat PD model and these protective properties of acupuncture could be mediated by trkB.