Dopaminergic neurons derived from porcine induced pluripotent stem cell like cells function in the Lanyu pig model of Parkinson's disease.

The induced pluripotent stem cells (iPSCs) are able to differentiate into dopaminergic neurons and execute the therapeutic effects for Parkinson's disease (PD). Here, we established a animal model of PD in Lanyu pigs by injecting 5 mg/kg of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine hydrochloride (MPTP). Next, the porcine iPSC-like cells (piPSC-like cells) were differentiated into D18 neuronal progenitors (D18 NPs) that were transplanted into the striatum to evaluate their therapeutic effects of PD. We showed that after 8 weeks of cell transplantation, the behavior score was significantly ameliorated and fully recovered at the 14th week of cell transplantation. The number of dopaminergic neurons was also significantly improved at the end of the experiment although the number was still about 50% lower than that in the control group. Our findings suggest that piPSC-like cell-derived D18 NPs exhibit a potential for the treatment of PD in the Lanyu pig model.

G-CSF enhances the therapeutic potency of stem cells transplantation in spinal cord-injured rats.

Aim: The therapeutic effects of human wisdom teeth-derived neuronal stem cell (tNSC) cotreatment with granulocyte-colony-stimulating factor (G-CSF) were evaluated for contusion-induced spinal cord injury in rats. Materials & methods: 7 days after contusion, tNSCs were transplanted to the injury site and followed by G-CSF cotreatment for 5 days. Behavioral deficits were evaluated by the Basso, Beattie and Bresnahan test. The injury site was collected for immunohistochemistry analysis. Results: The Basso, Beattie and Bresnahan test significantly improved in the cotreated group compared with the tNSCs or G-CSF single treatment groups. However, inflammation indices did not differ among the three groups. In vitro experiment demonstrated that tNSCs express both G-CSF and its relevant receptor. G-CSF enhanced tNSC proliferation and neurotrophins secretion in vitro. Conclusion: This study demonstrated that G-CSF enhances neurotrophins secretion of tNSCs, and might help improving functional recovery from spinal cord injury in rats if they were given together.

Derivation of porcine pluripotent stem cells for biomedical research.

Pluripotent stem cells including embryonic stem cells (ESCs), embryonic germ cells (EGCs), and induced pluripotent stem cells (iPSCs) are capable of self-renew and limitlessly proliferating in vitro with undifferentiated characteristics. They are able to differentiate in vitro, spontaneously or responding to suitable signals, into cells of all three primary germ layers. Consequently, these pluripotent stem cells will be valuable sources for cell replacement therapy in numerous disorders. However, the promise of human ESCs and EGCs is cramped by the ethical argument about destroying embryos and fetuses for cell line creation. Moreover, there are still carcinogenic risks existing toward the goal of clinical application for human ESCs, EGCs, and iPSCs. Therefore, a suitable animal model for stem cell research will benefit the further development of human stem cell technology. The pigs, on the basis of their similarity in anatomy, immunology, physiology, and biochemical properties, have been wide used as model animals in the study of various human diseases. The development of porcine pluripotent stem cell lines will hold the opportunity to provide an excellent material for human counterpart to the transplantation in biomedical research and further development of cell-based therapeutic strategy.

Antioxidants cause rapid expansion of human adipose-derived mesenchymal stem cells via CDK and CDK inhibitor regulation.

BACKGROUND: Antioxidants have been shown to enhance the proliferation of adipose-derived mesenchymal stem cells (ADMSCs) in vitro, although the detailed mechanism(s) and potential side effects are not fully understood. RESULTS: During log-phase growth, exposure to ImF-A resulted in a higher percentage of ADMSCs in the S phase of the cell cycle and a smaller percentage in G0/G1 phase. This resulted in a significantly reduced cell-doubling time and increased number of cells in the antioxidant-supplemented cultures compared with those supplemented with FGF-2 alone, an approximately 225% higher cell density after 7 days. Western blotting showed that the levels of the CDK inhibitors p21 and p27 decreased after ImF-A treatment, whereas CDK2, CDK4, and CDC2 levels clearly increased. In addition, ImF-A resulted in significant reduction in the expression of CD29, CD90, and CD105, whereas relative telomere length, osteogenesis, adipogenesis, and chondrogenesis were enhanced. The results were similar for ADMSCs treated with antioxidants and those under hypoxic conditions. CONCLUSION: Antioxidant treatment promotes entry of ADMSCs into the S phase by suppressing cyclin-dependent kinase inhibitors and results in rapid cell proliferation similar to that observed under hypoxic conditions.

Reduction of motor disorder in 6-OHDA-induced severe parkinsonism rats by post treatment with granulocyte-colony stimulating factor.

Granulocyte-colony stimulating factor (G-CSF) induced regeneration of dopaminergic neurons and improved behavior deficit in moderate Parkinson's disease (PD) model mice. Post treatment of G-CSF in severe PD model has not been addressed. A very severe PD model in rats was induced by a high dose 6-hydroxydopamine (6-OHDA) injected into the right medial forebrain bundle to evaluate therapeutic effects of G-CSF. G-CSF (50 microg/kg/day for five days) was given on the 9th day after the 6-OHDA injection. Rotational behavior was examined on the 9th and 28th days. Rats were killed on the 28th day and survival dopaminergic neurons in the substantia nigra, dopaminergic axons and dopaminergic receptor 2 in the striatum were examined. We, for the first time, demonstrated that post treatment with G-CSF reduced abnormal rotational behavior and increased the lesion to non-lesion ratio of dopaminergic fibers in the striatum, but the treatment promoted neither the increase in survival dopaminergic neurons nor the increase in dopaminergic receptor 2 expression. We conclude that post treatment with G-CSF can reduce the abnormal rotational behavior of severe PD rats primarily through relative increases in dopaminergic fibers of the lesion side in the striatum. Results of our study suggest therapeutic potentials of G-CSF for treating severe PD patients.

Transplantation of porcine embryonic stem cells and their derived neuronal progenitors in a spinal cord injury rat model.

BACKGROUND AIMS: The purpose of this study was to investigate therapeutic potential of green fluorescent protein expressing porcine embryonic stem (pES/GFP(+)) cells in A rat model of spinal cord injury (SCI). METHODS: Undifferentiated pES/GFP(+) cells and their neuronal differentiation derivatives were transplanted into the contused spinal cord of the Long Evans rat, and in situ development of the cells was determined by using a live animal fluorescence optical imaging system every 15 days. After pES/GFP(+) cell transplantation, the behavior functional recovery of the SCI rats was assessed with the Basso, Beattie, and Bresnahan Locomotor Rating Scale (BBB scale), and the growth and differentiation of the grafted pES/GFP(+) cells in the SCI rats were analyzed by immunohistochemical staining. RESULTS: The relative green fluorescent protein expression level was decreased for 3 months after transplantation. The pES/GFP(+)-derived cells positively stained with neural specific antibodies of anti-NFL, anti-MBP, anti-SYP and anti-Tuj 1 were detected at the transplanted position. The SCI rats grafted with the D18 neuronal progenitors showed a significant functional recovery of hindlimbs and exhibited the highest BBB scale score of 15.20 ± 1.43 at week 24. The SCI rats treated with pES/GFP(+)-derived neural progenitors demonstrated a better functional recovery. CONCLUSIONS: Transplantation of porcine embryonic stem (pES)-derived D18 neuronal progenitors has treatment potential for SCI, and functional behavior improvement of grafted pES-derived cells in SCI model rats suggests the potential for further application of pES cells in the study of replacement medicine and functionally degenerative pathologies.

Directed differentiation into neural lineages and therapeutic potential of porcine embryonic stem cells in rat Parkinson's disease model.

This study was conducted to direct porcine embryonic stem (pES) cells differentiating into neural lineages and to investigate therapeutic potential of GFP-expressing pES (pES/GFP(+)) in the rat model of Parkinson's disease (PD). Directed differentiation of pES into neural lineages was induced by suspension culture in medium containing RA, SHH, and FGF combinations without going through embryoid body formation. A high yield of nestin-expressing neural precursors was found in all treatments on day 2 after the 12-day induction. On day 6 after replating, more than 86.2 and 83.4% of the differentiated cells stained positively for NFL and MAP2, respectively. The expression of TH, ChAT, and GABA specific markers were also observed in these NFL-positive neural cells. The undifferentiated pES/GFP(+) cells and their neuronal differentiation derivatives were transplanted into the Sprague-Dawley (SD) rat's brain, and their survival and development was determined by using live animal fluorescence optical imaging system every 15 days. The results showed that fluorescent signals from the injection site of SD rats' brain could be detected through the experimental period of 3 months. The level of fluorescent signal detected in the treatment group was twofold that of the control group. The results of behavior analysis showed that PD rats exhibited stably decreased asymmetric rotations after transplantation with pES/GFP(+)-derived D18 neuronal progenitors. The dopaminergic differentiation of grafted cells in the brain was further confirmed by immunohistochemical staining with anti-TH, anti-DA, and anti-DAT antibodies. These results suggested that the differentiation approach we developed would direct pES cells to differentiate into neural lineages and benefit the development of novel therapeutics involving stem cell transplantation.

A simple and efficient method for generating Nurr1-positive neuronal stem cells from human wisdom teeth (tNSC) and the potential of tNSC for stroke therapy.

BACKGROUND AIMS: We have isolated human neuronal stem cells from exfoliated third molars (wisdom teeth) using a simple and efficient method. The cultured neuronal stem cells (designated tNSC) expressed embryonic and adult stem cell markers, markers for chemotatic factor and its corresponding ligand, as well as neuron proteins. The tNSC expressed genes of Nurr1, NF-M and nestin. They were used to treat middle cerebral artery occlusion (MCAO) surgery-inflicted Sprague-Dawley (SD) rats to assess their therapeutic potential for stroke therapy. METHODS: For each tNSC cell line, a normal human impacted wisdom tooth was collected from a donor with consent. The tooth was cleaned thoroughly with normal saline. The molar was vigorously shaken or vortexed for 30 min in a 50-mL conical tube with 15-20mL normal saline. The mixture of dental pulp was collected by centrifugation and cultured in a 25-cm(2) tissue culture flask with 4-5mL Medium 199 supplemented with 5-10% fetal calf serum. The tNSC harvested from tissue culture, at a concentration of 1-2x10(5), were suspended in 3 microL saline solution and injected into the right dorsolateral striatum of experimental animals inflicted with MCAO. RESULTS: Behavioral measurements of the tNSC-treated SD rats showed a significant recovery from neurologic dysfunction after MCAO treatment. In contrast, a sham group of SD rats failed to recover from the surgery. Immunohistochemistry analysis of brain sections of the tNSC-treated SD rats showed survival of the transplanted cells. CONCLUSIONS: These results suggest that adult neuronal stem cells may be procured from third molars, and tNSC thus cultivated have potential for treatment of stroke-inflicted rats.

Establishment and characterization of novel porcine embryonic stem cell lines expressing hrGFP.

The purpose of this study was to establish transgenic porcine embryonic stem (pES) cell lines that can stably express report gene. Established pES cell line at passage 44 was transfected with pAAV-hrGFP Control Plasmid by electroporation-mediated, viral vector-mediated, and liposome-mediated strategies. Although there were several pES colonies expressing green fluorescent protein (GFP) obtained from the retrovirus-mediated and liposome-mediated transfection methods, no stable GFP-expressing pES cell line was then derived. A total of 28 GFP-expressing pES cell colonies were obtained following electroporation with two DC pulses of 150 V/cm for 10 msec and three GFP-expressing pES (pES/GFP(+)) cell lines were established. These pES/GFP(+) cell lines stably expressed exogenous GFP and continuously proliferated in vitro for more than 90 passages in 20 months. They maintained normal karyotype of 36 + XX and typical characteristics of pluripotent stem cells, including expression of pluripotent markers Oct-4, AP, SSEA-4, TRA-1-60, and TRA-1-81, formation of embryoid bodies under suspension culture. They were able to differentiate in vitro into neural and cardiomyocytic lineage, respectively, under suitable induction. To our knowledge, there has been no report of establishing GFP-expressing pES cell lines. These novel pES/GFP(+) cell lines established in this study might serve as a nonrodent model and would benefit to the studies involving ES cell transplantation, cell replacement therapy, and tissue regeneration due to their traceable capacity.

Design and fabrication of a polyimide-based microelectrode array: application in neural recording and repeatable electrolytic lesion in rat brain.

The design and testing of a new microelectrode array, the NCTU (National Chiao Tung University) probe, was presented. Evaluation results showed it has good biocompatibility, high signal-to-noise ratio (SNR: the root mean square of background noise to the average peak-to-peak amplitude of spikes) during chronic neural recordings, and high reusability for electrolytic lesions. The probe was a flexible, polyimide-based microelectrode array with a long shaft (14.9 mm in length) and 16 electrodes (5 microm-thick and 16 microm in radius); its performance in chronic in vivo recordings was examined in rodents. To improve the precision of implantation, a metallic, impact-resistant layer was sandwiched between the polyimide layers to strengthen the probe. The three-dimensional (3D) structure of electrodes fabricated by electroplating produced rough textures that increased the effective surface area. The in vitro impedance of electrodes on the NCTU probe was 2.4+/-0.52 MOmega at 1 kHz. In addition, post-surgical neural recordings of implanted NCTU probes were conducted for up to 40 days in awake, normally behaving rats. The electrodes on the NCTU probe functioned well and had a high SNR (range: 4-5) with reliable in vivo impedance (<0.7 MOmega). The electrodes were also robust enough to functionally record events, even after the anodal current (30 microA, 10s) was repeatedly applied for 60 times. With good biocompatibility, high and stable SNR for chronic recording, and high tolerance for electrolytic lesion, the NCTU probe would serve as a useful device in future neuroscience research.

[18F]FBAU 3',5'-dibenzoate, a lipophilic prodrug, enhances brain uptake of the cell proliferation tracer [18F]FBAU.

INTRODUCTION: 1-(2-deoxy-2-[(18)F]fluoro-beta-D-arabinofuranosyl)-5-bromouracil ([(18)F]FBAU) is a cell proliferation tracer. However, it does not pass readily through the blood-brain barrier. We synthesized a lipophilic prodrug of [(18)F]FBAU that was intended to enhance brain uptake of [(18)F]FBAU to improve the imaging of brain cell proliferation. METHODS: [(18)F]FBAU was synthesized according to the methods described by Alauddin [J Med Chem 39 (1996) 2835-2843]. The prodrug, 1-(2-deoxy-3,5-O-dibenzoyl-2-[(18)F]fluoro-beta-D-arabinofuranosyl)-5-bromouracil ([(18)F]FBAU 3',5'-dibenzoate), was purified from an intermediate of [(18)F]FBAU. Their lipophilicity was determined by performing octanol/water partition coefficient (log P) measurements. In vitro metabolic fates of the prodrug were examined in rat and mouse plasma and brain homogenates. Brain uptake was determined following iv injection of the radiotracers by killing animals at various time points and dissecting and counting the radioactivity accumulation in the various tissues. RESULTS: Values of log P for [(18)F]FBAU 3',5'-dibenzoate and [(18)F]FBAU were 3.95 and -0.35, respectively. In rat plasma, the prodrug was gradually hydrolyzed to [(18)F]FBAU. Thirty minutes after mixing [(18)F]FBAU 3',5'-dibenzoate in the plasma, 25% of the prodrug had been hydrolyzed. The hydrolysis went more slowly in brain homogenates. At 15 min post injection, relative to animals injected with [(18)F]FBAU, brain uptake of radioactivity in animals injected with [(18)F]FBAU 3',5'-dibenzoate was increased by 150% (P=.005) and 78% (P=.037) in rats and mice, respectively. At 60 min post injection, the radioactive contents extracted from the brain were mostly [(18)F]FBAU. CONCLUSION: The synthesized novel prodrug [(18)F]FBAU 3',5'-dibenzoate has enhanced brain uptake in rodents, suggesting it may be useful as an imaging agent for tracing brain cell proliferation.

Urocortin modulates inflammatory response and neurotoxicity induced by microglial activation.

Microglia are the major inflammatory cells in the brain. Recent studies have highlighted the reciprocal roles of other brain cells in modulating the microglial inflammatory responses. Urocortin (UCN) is a member of the corticotropin-releasing hormone (CRH) family of neuropeptides that function to regulate stress responses. In the present study, we demonstrated that expression of UCN in rat substantia nigra was found to be localized principally to dopaminergic neurons. In cell culture models, the CRH receptors were expressed in microglia, and CRHR expression was up-regulated by treatment with LPS. Thus, it might be proposed that UCN regulates cellular communication between dopaminergic neurons and microglia. We show that femtomolar concentrations of UCN could inhibit LPS-induced TNF-alpha production in cultured microglia. Investigation of the underlying signaling pathway that mediated the anti-inflammatory effect of UCN the involved PI3K/Akt and glycogen synthase kinase-3beta pathway, but not cAMP pathway. Furthermore, UCN protected dopaminergic neurons against LPS-induced neurotoxicity by inhibiting microglial activation in LPS-treated mesencephalic neuron-glia cultures. These results suggest that endogenous UCN and its receptors might be involved in a complex network of paracrine interaction between dopaminergic neurons and glia.