Advances in treatment of neurodegenerative diseases: Perspectives for combination of stem cells with neurotrophic factors

Neurodegenerative diseases,including Alzheimer’s disease,Parkinson’s disease,Huntington’s disease and amyotrophic lateral sclerosis,are a group of incurable neurological disorders,characterized by the chronic progressive loss of different neuronal subtypes.However,despite its increasing prevalence among the everincreasing aging population,little progress has been made in the coincident immense efforts towards development of therapeutic agents.Research interest has recently turned towards stem cells including stem cells-derived exosomes,neurotrophic factors,and their combination as potential therapeutic agents in neurodegenerative diseases.In this review,we summarize the progress in therapeutic strategies based on stem cells combined with neurotrophic factors and mesenchymal stem cells-derived exosomes for neurodegenerative diseases,with an emphasis on the combination therapy.

Retinal ganglion cell neuroprotection by growth factors and exosomes:lessons from mesenchymal stem cells

Retinal ganglions cells （RGCs） are responsible for propagating electrochemical information from the eye to the brain along their axons which make up the optic nerve. The loss of RGCs is characteristic in several conditions such as glaucoma and trau- matic optic neuropathy and leads to visual loss and blindness. While no therapy exists to directly treat RGCs, the use of bone marrow-derived mesenchymal stem cells （BMSCs） has shown promise in eliciting significant RGC neuroprotection.

Intrastriatal glial cell line-derived neurotrophic factors for protecting dopaminergic neurons in the substantia nigra of mice with Parkinson disease

BACKGROUND： Substantia nigra is deep in position and limited in range, the glial cell line-derived neurotrophic factor （GDNF） injection directly into substantia nigra has relatively greater damages with higher difficulty. GDNF injection into striatum, the target area of dopaminergic neuron, may protect the dopaminergic neurons in the compact part of substantia nigra through retrograde transport. OBJECTIVE： To investigate the protective effect of intrastriatal GDNF on dopaminergic neurons in the substantia nigra of mice with Parkinson disease （PD）, and analyze the action pathway. DESIGN： A controlled observation. SETTING： Neurobiological Laboratory of Xuzhou Medical College. MATERIALS： Twenty-four male Kunming mice of 7 - 8 weeks old were used. GDNF, 1-methy1-4-pheny1-1,2,3,6-tetrahydropyridine （MPTP） were purchased from Sigma Company （USA）; LEICAQWin image processing and analytical system. METHODS： The experiments were carded out in the Neurobiological Laboratory of Xuzhou Medical College from September 2005 to October 2006. The PD models were established in adult KunMing mice by intraperitoneal injection of MPTP. The model mice were were randomly divided into four groups with 6 mice in each group： GDNF 4-day group, phosphate buffer solution （PSB） 4-day group, GDNF 6-day group and PSB 6-day group. Mice in the GDNF 4 and 6-day groups were administrated with 1 μ L GDNF solution （20 μ g/L, dispensed with 0.01 mol/L PBS） injected into right striatum at 4 and 6 days after model establishment. Mice in the PSB 4 and 6-day groups were administrated with 0.01 mol/L PBS of the same volume to the same injection at corresponding time points. ② On the 12^th day after model establishment, the midbrain tissue section of each mice was divided into 3 areas from rostral to caudal sides. The positive neurons of tyroxine hydroxylase （TH） and calcium binding protein （CB） with obvious nucleolus and clear outline were randomly selected for the measurement, and the number of positive neurons in unit area was counted. MAIN OUTCOME MEASURES： Number of positive neurons of TH and CB in midbrain substantia nigra of mice in each group. RESULTS： All the 24 mice were involved in the analysis of results. The numbers of TH^＋ and CB^＋ neurons in the GDNF 4-day group （54.33±6.92, 46.33±5.54） were obviously more than those in the PBS 4-day group （27.67±5.01, 21.50±5.96, P 〈 0.01）. The numbers of TH^＋ and CB^＋ neurons in the GDNF 6-day group （75.67±5.39, 69.67±8.69） were obviously more than those in the PBS 6-day group （27.17±4.50, 21.33 ±5.72, P 〈 0.01） and those in the GDNF 4-day group （P 〈 0.01 ）. CONCLUSION： Intrastriatal GDNF can protect dopaminergic neurons in substantia nigra of PD mice, and it may be related to the increase of CB expression.

Molecular and cellular changes in the post-traumatic spinal cord remodeling after autoinfusion of a genetically-enriched leucoconcentrate in a mini-pig model

Post-traumatic spinal cord remodeling includes both degenerating and regenerating processes,which affect the potency of the functional recovery after spinal cord injury(SCI).Gene therapy for spinal cord injury is proposed as a promising therapeutic strategy to induce positive changes in remodeling of the affected neural tissue.In our previous studies for delivering the therapeutic genes at the site of spinal cord injury,we developed a new approach using an autologous leucoconcentrate transduced ex vivo with chimeric adenoviruses(Ad5/35)carrying recombinant cDNA.In the present study,the efficacy of the intravenous infusion of an autologous genetically-enriched leucoconcentrate simultaneously producing recombinant vascular endothelial growth factor(VEGF),glial cell line-derived neurotrophic factor(GDNF),and neural cell adhesion molecule(NCAM)was evaluated with regard to the molecular and cellular changes in remodeling of the spinal cord tissue at the site of damage in a model of mini-pigs with moderate spinal cord injury.Experimental animals were randomly divided into two groups of 4 pigs each:the therapeutic(infused with the leucoconcentrate simultaneously transduced with a combination of the three chimeric adenoviral vectors Ad5/35‐VEGF165,Ad5/35‐GDNF,and Ad5/35‐NCAM1)and control groups(infused with intact leucoconcentrate).The morphometric and immunofluorescence analysis of the spinal cord regeneration in the rostral and caudal segments according to the epicenter of the injury in the treated animals compared to the control mini-pigs showed:(1)higher sparing of the grey matter and increased survivability of the spinal cord cells(lower number of Caspase-3-positive cells and decreased expression of Hsp27);(2)recovery of synaptophysin expression;(3)prevention of astrogliosis(lower area of glial fibrillary acidic protein-positive astrocytes and ionized calcium binding adaptor molecule 1-positive microglial cells);(4)higher growth rates of regeneratingβIII-tubulin-positive axons accompanied by a higher number of oligodendrocyte transcription factor 2-positive oligodendroglial cells in the lateral corticospinal tract region.These results revealed the efficacy of intravenous infusion of the autologous genetically-enriched leucoconcentrate producing recombinant VEGF,GDNF,and NCAM in the acute phase of spinal cord injury on the positive changes in the post-traumatic remodeling nervous tissue at the site of direct injury.Our data provide a solid platform for a new ex vivo gene therapy for spinal cord injury and will facilitate further translation of regenerative therapies in clinical neurology.

The Impact Heme Oxygenase -1 on the Regulating Factors of Hepatoma Cells＇ Cell Cycle

It aims to analyze the impact heme oxygenase -1 （heme oxygenase 1, HO-1） on regulating factors of human hepatoma cell HepG2＇s cell cycle, through constructing recombinant vector of pcDNA3.1 containing wild-type and mutant HO-1 gene （＋）-wtHO-1 and pcDNA3.1 （＋）-mHO-1G143H. By using the method of liposome-mediated, the recombinant vector was transfected hepatoma cell line HepG2. And the transfected one with empty vector was treated as a control group. By the selection of G418, stable expression of wild-type and mutant HO-1 in HepG2 liver cancer cell lines were established. Use the blot of semi-quantitative RT-PCR and Western to test transfected cell lines expressing levels of riO-1 mRNA and protein. As HO-1 expression in stably transfected cell lines altered, we use Western blot to test transfected cell lines P21, P27 protein expression levels. As result shows, we got 1 HO-over-expression of wild-type and mutant in HepG2 cells; wild- type and mutant＇s over expression of HO-1 can induce the expression of tumor suppressor genes p21 and p27.we got the conclusion that HO-l＇s over-expression of tumor suppressor genes p21 and p27 is unrelated to the expression of heme decomposition products. HO-1 may regulate the expression of p21 and p27 through other mechanisms.

Glial cell line-derived neurotrophic factor and brain-derived neurotrophic factor regulate the interaction between astrocytes and Schwann cells at the trigeminal root entry zone

The trigeminal root entry zone is the zone at which the myelination switches from peripheral Schwann cells to central oligodendrocytes.Its special anatomical and physiological structure renders it susceptible to nerve injury.The etiology of most primary trigeminal neuralgia is closely related to microvascular compression of the trigeminal root entry zone.This study aimed to develop an efficient in vitro model mimicking the glial environment of trigeminal root entry zone as a tool to investigate the effects of glial cell line-derived neurotrophic factor and brain-derived neurotrophic factor on the structural and functional integrity of trigeminal root entry zone and modulation of cellular interactions.Primary astrocytes and Schwann cells isolated from trigeminal root entry zone of postnatal rats were inoculated into a two-well silicon culture insert to mimic the trigeminal root entry zone microenvironment and treated with glial cell line-derived neurotrophic factor and brain-derived neurotrophic factor.In monoculture,glial cell line-derived neurotrophic factor promoted the migration of Schwann cells,but it did not have effects on the migration of astrocytes.In the co-culture system,glial cell line-derived neurotrophic factor promoted the bidirectional migration of astrocytes and Schwann cells.Brain-derived neurotrophic factor markedly promoted the activation and migration of astrocytes.However,in the co-culture system,brain-derived neurotrophic factor inhibited the migration of astrocytes and Schwann cells to a certain degree.These findings suggest that glial cell line-derived neurotrophic factor and brain-derived neurotrophic factor are involved in the regulation of the astrocyte-Schwann cell interaction in the co-culture system derived from the trigeminal root entry zone.This system can be used as a cell model to study the mechanism of glial dysregulation associated with trigeminal nerve injury and possible therapeutic interventions.

Therapeutic effect of Cistanche deserticola on defecation in senile constipation rat model through stem cell factor/C-kit signaling pathway

BACKGROUND Constipation is one of the chronic gastrointestinal functional diseases.It seriously affects the quality of life.Cistanche deserticola(C.deserticola)can treat constipation obviously,but its mechanism has not been clarified.We supposed that mechanism of it improved the intestinal motility by stimulating interstitial Cajal cells(ICC).Activation of the C-kit receptor on the surface of ICC is closely related to ICC function,and the stem cell factor(SCF)/C-kit signaling pathways plays an important role on it.To investigate the mechanism of how C.deserticola treats constipation,this study aimed to establish a constipation model in rats and explore the role of SCF/C-kit signaling pathway in the treatment.AIM To explore the SCF/C-kit signaling pathways in the role of C.deserticola for treatment of constipation by a constipation rat model.METHODS Forty-eight 8-mo-old Sprague–Dawley rats were divided into 4 groups by random weight method:Normal group(n=12),model group(n=12),C.deserticola group(n=12)and blocker group(n=12).The normal group received normal saline by gavage;the model group received loperamide by gavage;the blocker group received loperamide and C.deserticola by gavage,and STI571 was injected by intraperitoneally.During treatment,the weight,fecal granules and fecal quality were recorded every 10 d.On day 20 after model induction,the colon tissues of each group were removed.Hematoxylin and eosin staining was used to observe pathological changes.Expression levels of SCF,C-kit and Aquaporin genes were detected by immunohistochemistry,western blotting,and real-time-quantitative polymerase chain reaction.The colonic epithelial mitochondria and goblet cells were observed by transmission electron microscopy.RESULTS Compared with the normal group,as treatment progressed,the weight of rats in the model and blocker groups decreased significantly,the stool weight decreased,and the stool quality was dry(P<0.05).C.deserticola reversed the decrease in body weight and stool weight and improved stool quality.Histopathological analysis indicated that the colonic mucosal epithelium in the model group was incomplete,and the arrangement of the glands was irregular or damaged.Treatment with C.deserticola improved the integrity and continuity of the epithelial cells and regular arrangement of the glands.The blocking agents inhibited the effects of C.deserticola Immunohistochemistry and real-timequantitative polymerase chain reaction showed that expression of SCF and C-kit protein or genes in the colonic tissue of the model group was decreased(P<0.05),while treatment with C.deserticola increased protein or gene expression(P<0.05).Western blotting showed that expression of aquaporin APQ3 was increased,while the expression of Cx43 decreased in the model group.Treatment with C.deserticola inhibited expression of APQ3 and promoted expression of Cx43.Transmission electron microscopy showed that the mitochondria of the colonic epithelium in the model group were swollen and arranged disorderly,and microvilli were sparse.The condition was better in the C.deserticola group.Mice treated with STI571 blocker confirmed that blocking the SCF/C-kit pathway inhibited the improvement of constipation by C.deserticola.CONCLUSION C.deserticola improved defecation in rats with constipation,and the SCF/C-kit signaling pathway,which is a key link of ICC function,played an important role of the treatment.

Type-B monoamine oxidase inhibitors in neurological diseases:clinical applications based on preclinical findings

Type-B monoamine oxidase inhibitors,encompassing selegiline,rasagiline,and safinamide,are available to treat Parkinson's disease.These drugs ameliorate motor symptoms and improve motor fluctuation in the advanced stages of the disease.There is also evidence suppo rting the benefit of type-B monoamine oxidase inhibitors on non-motor symptoms of Parkinson's disease,such as mood deflection,cognitive impairment,sleep disturbances,and fatigue.Preclinical studies indicate that type-B monoamine oxidase inhibitors hold a strong neuroprotective potential in Parkinson's disease and other neurodegenerative diseases for reducing oxidative stress and stimulating the production and release of neurotrophic factors,particularly glial cell line-derived neurotrophic factor,which suppo rt dopaminergic neurons.Besides,safinamide may interfere with neurodegenerative mechanisms,countera cting excessive glutamate overdrive in basal ganglia motor circuit and reducing death from excitotoxicity.Due to the dual mechanism of action,the new generation of type-B monoamine oxidase inhibitors,including safinamide,is gaining interest in other neurological pathologies,and many supporting preclinical studies are now available.The potential fields of application concern epilepsy,Duchenne muscular dystrophy,multiple scle rosis,and above all,ischemic brain injury.The purpose of this review is to investigate the preclinical and clinical pharmacology of selegiline,rasagiline,and safinamide in Parkinson's disease and beyond,focusing on possible future therapeutic applications.

Overexpression of lentivirus-mediated glial cell line-derived neurotrophic factor in bone marrow stromal cells and its neuroprotection for the PC12 cells damaged by lactacystin

Objective To construct recombinant lentiviral vectors for gene delivery of the glial cell line-derived neurotropnic factor （GDNF）, and evaluate the neuroprotective effect of GDNF on lactacystin-damaged PC12 cells by transfecting it into bone marrow stromal cells （BMSCs）. Methods pLenti6/V5-GDNF plasmid was set up by double restriction enzyme digestion and ligation, and then the plasmid was transformed into Top10 cells. Purified pLenti6/V5-GDNF plasmids from the positive clones and the packaging mixture were cotransfected to the 293FT packaging cell line by Lipofectamine2000 to produce lentivirus, then the concentrated virus was transduced to BMSCs. Overexpression of GDNF in BMSCs was tested by RT-PCR, ELISA and immunocytochemistry, and its neuroprotection for lactacystin-damaged PC12 cells was evaluated by MTT assay. Results Virus stock of GDNF was harvested with the titer of 5.6×10^5 TU/mL. After tmnsduction, GDNF-BMSCs successfully secreted GDNF to supematant with nigher concentration （800 pg/mL） than BMSCs did （less than 100 pg/mL）. The supematant of GDNF-BMSCs could significantly alleviate the damage of PC12 cells induced by lactacystin （10 μmol/L）. Conclusion Overexpression of lentivirus-mediated GDNF in the BMSCs cells can effectively protect PC12 cells from the injury by the proteasome inhibitor.

Cav3.2 channel regulates cerebral ischemia/reperfusion injury:a promising target for intervention

Calcium influx into neurons triggers neuronal death during cerebral ischemia/reperfusion injury.Various calcium channels are involved in cerebral ischemia/reperfusion injury.Cav3.2 channel is a main subtype of T-type calcium channels.T-type calcium channel blockers,such as pimozide and mibefradil,have been shown to prevent cerebral ischemia/reperfusion injury-induced brain injury.However,the role of Cav3.2 channels in cerebral ischemia/reperfusion injury remains unclear.Here,in vitro and in vivo models of cerebral ischemia/reperfusion injury were established using middle cerebral artery occlusion in mice and high glucose hypoxia/reoxygenation exposure in primary hippocampal neurons.The results showed that Cav3.2 expression was significantly upregulated in injured hippocampal tissue and primary hippocampal neurons.We further established a Cav3.2 gene-knockout mouse model of cerebral ischemia/reperfusion injury.Cav3.2 knockout markedly reduced infarct volume and brain water content,and alleviated neurological dysfunction after cerebral ischemia/reperfusion injury.Additionally,Cav3.2 knockout attenuated cerebral ischemia/reperfusion injury-induced oxidative stress,inflammatory response,and neuronal apoptosis.In the hippocampus of Cav3.2-knockout mice,calcineurin overexpression offset the beneficial effect of Cav3.2 knockout after cerebral ischemia/reperfusion injury.These findings suggest that the neuroprotective function of Cav3.2 knockout is mediated by calcineurin/nuclear factor of activated T cells 3 signaling.Findings from this study suggest that Cav3.2 could be a promising target for treatment of cerebral ischemia/reperfusion injury.

Uptake of bacterial lipopolysaccharide and expression of tumor necrosis factor α mRNA in isolated rat intrahepatic bile duct epithelial cells *

AIM To study the uptake of bacterial lipopolysaccharides (LPS) and expression of tumor necrosis factor α mRNA (TNF α mRNA) with cultured rat intrahepatic bile duct epithelial cells.

Effects of P2Y_1 receptor on glial fibrillary acidic protein and glial cell line-derived neurotrophic factor production of astrocytes under ischemic condition and the related signaling pathways

Objective The present study aimed to explore the role of P2Y1 receptor in glial fibrillary acidic protein （GFAP） production and glial cell line-derived neurotrophic factor （GDNF） secretion of astrocytes under ischemic insult and the related signaling pathways. Methods Using transient right middle cerebral artery occlusion （tMCAO） and oxygen-glucose-serum deprivation for 2 h as the model of ischemic injury in vivo and in vitro, immunofluorescence, quantitative real-time reverse transcription-polymerase chain reaction （RT-PCR）, Western blotting, enzyme linked immunosorbent assay （ELISA） were used to investigate location of P2Y1 receptor and GDNF, the expression of GFAP and GDNF, and the changes of signaling molecules. Results Blockage of P2Y1 receptor with the selective antagonist N^6-methyl-2′-deoxyadenosine 3′,5′-bisphosphate diammonium （MRS2179） reduced GFAP production and increased GDNF production in the antagonist group as compared with simple ischemic group both in vivo and in vitro. Oxygen-glucose-serum deprivation and blockage of P2Y1 receptor caused elevation of phosphorylated Akt and cAMP response element binding protein （CREB）, and reduction of phosphorylated Janus kinase2 （JAK2） and signal transducer and activator of transcription3 （STAT3, Ser727）. After blockage of P2Y1 receptor and deprivation of oxygen-glucose-serum, AG490 （inhibitor of JAK2） reduced phosphorylation of STAT3 （Ser727） as well as expression of GFAP; LY294002, an inhibitor of phosphatidylinositol 3-kinase （PI3-K）, decreased phosphorylation of Akt and CREB; the inhibitor of mitogen-activated protein kinase kinase 1/2 （MEK 1/2） U0126, an important molecule of Ras/extracellular signal- regulated kinase （ERK） signaling pathway, decreased the phosphorylation of JAK2, STAT3 （Ser727）, Akt and CREB. Conclusion These results suggest that P2Y1 receptor plays a role in the production of GFAP and GDNF in astrocytes under transient ischemic condition and the related signaling pathways may be JAK2/STAT3 and PI3-K/Akt/CREB, respectively, and that crosstalk probably exists between them.

Loss of interstitial cells of Cajal network in severe idiopathic gastroparesis

AIM: To report a case of severe idiopathic gastroparesis in complete absence of Kit-positive gastric interstitial cells of Cajal (ICC). METHODS: Gastric tissue from a patient with severe idiopathic gastroparesis unresponsive to medical treatment and requiring surgery was analyzed by conventional histology and immunohistochemistry. RESULTS: Gastric pacemaker cells expressing Kit receptor had completely disappeared while the local level of stem cell factor, the essential ligand for its development and maintenance, was increased. No signs of cell death were observed in the pacemaker region. CONCLUSION: These results are consistent with the hypothesis that a lack of Kit expression may lead to impaired functioning of ICC. Total gastrectomy proves to be curative.

Expression of germ cell nuclear factor in mouse germ cells and sperm during postnatal period

Aim: To assess the spatial and temporal expression of germ cell nuclear factor (GCNF) in male mouse germ cells during postnatal development and in sperm before and after capacitation. Methods: The indirect immun-ofluorescence method with anti-GCNF antiserum was used to investigate the GCNF expression in mice at day 8, 10, 14, 17, 20, 28, 35, 70, and 420 after birth and in sperm before and after capacitation. Results: With the proceeding of spermatogenesis, GCNF was first detected in the nuclei of spermatogonia and a few early stage primary sperma-tocytes at day 8, which was increased gradually at day 10 to 14 inclusive. From day 17 to day 20, the GCNF was concentrated in round spermatids, while both spermatogonia and early stage primary spermatocytes became GCNF negative. From day 28 until day 420, strong GCNF expression was shown in round spermatids and pachytene spermatocytes, while spermatogonia, early primary spermatocytes and elongating spermatids were all GCNF negative. In addition, it was also found that GCNF was localized on the acrosomal cap region of spermatozoa and there was a big change in GCNF expression during capacitation, from 98 % GCNF positive before capacitation to about 20 % positive following capacitation. The localization of GCNF in caput and cauda spermatozoa was similar. Conclusion: GCNF may play important roles in spermatogenesis, capacitation and fertilization.

Expression change of stem cell-derived neural stem/progenitor cell sup-porting factor gene in injured spinal cord of rats

Objective To explore the expression change of stem cell-derived neural stem/progenitor cell supporting factor （SDNSF） gene in the injuried spinal cord tissues of rats, and the relation between the expressions of SDNSF and nestin. Methods The spinal cord contusion model of rat was established according to Allen＇s falling strike method. The expression of SDNSF was studied by RT-PCR and in situ hybridization （ISH）, and the expression of nestin was detected by immunochemistry. Results RT-PCR revealed that SDNSF mRNA was upregulated on day 4 after injury, peaked on day 8-12, and decreased to the sham operation level on day 16. ISH revealed that SDNSF mRNA was mainly expressed in the gray matter cells, probably neurons, of spinal cord. The immunohistochemistry showed that accompanied with SDNSF mRNA upregulation, the nestin-positive cells showed erupted roots, migrated peripherad and proliferation on the 8-day slice. However, the distribution pattern of these new cells was different from that of SDNSF-positive cells. Conclusion （1） SDNSF is expressed in the gray matter of spinal cord. The expression of SDNSF mRNA in the spinal cord varies with injured time. （2） The nestin-positive cells proliferate accompanied with spinal cord injury repair, but do not secrete SDNSF.

Spatial and temporal expression of germ cell nuclear factorin murine epididymis

Aim: To investigate the spatial and temporal expression of germ cell nuclear factor (GCNF) in mouse and rat epididymis during postnatal period. Methods: The epididymal sections from different postnatal days were stained for GCNF by the indirect immunofluorescence technique and digital photographs were taken by a Carl Zeiss confocal microscope. Results: GCNF was first detected on day 12 in mouse epididymis and day 14 in rat epididymis. The highest expression of GCNF was observed on day 35 in both mouse and rat epididymis. In adults, GCNF exhibited a region-specific expression pattern, i.e., it was expressed predominantly in the initial segment, caput and proximal corpus of rat epididymis and was abundant in the proximal corpus of mouse epididymis. GCNF could be found in the nuclei of the principal, apical, narrow, clear and halo cells. Conclusion: GCNF may play an important role in epididymal differentiation and development and in sperm maturation.

Antenatal taurine reduces cerebral cell apoptosis in fetal rats with intrauterine growth restriction

From pregnancy to parturition, Sprague-Dawley rats were daily administered a low protein diet to establish a model of intrauterine growth restriction. From the 12th day of pregnancy, 300 mg/kg taurine was daily added to food until spontaneous delivery occurred. Brain tissues from normal neonatal rats at 6 hours after delivery, neonatal rats with intrauterine growth restriction, and neo- natal rats with intrauterine growth restriction undergoing taurine supplement were obtained for fur- ther experiments. The terminal deoxyribonucleotidyl transferase （TdT）-mediated biotin-16-dUTP nick-end labeling assay revealed that the number of apoptotic cells in the brain tissue of neonatal rats with intrauterine growth restriction significantly increased. Taurine supplement in pregnant rats reduced cell apoptosis in brain tissue from neonatal rats with intrauterine growth restriction. Immu- nohistochemical staining revealed that taurine supplement increased glial cell line-derived neuro- trophic factor expression and decreased caspase-3 expression in the cerebral cortex of intrauterine growth-restricted fetal rats. These results indicate that taurine supplement reduces cell apoptosis through the glial cell line-derived neurotrophic factor-caspase-3 signaling pathway, resulting in a protective effect on the intrauterine growth-restricted fetal rat brain.

Effects of bone marrow-derived mesenchymal stemcells engraftment on vascular endothelial cell growthfactor in lung tissue and plasma at early stage of smoke inhalation injury

BACKGROUND： This study was undertaken to determine the effect of mesenchymal stem cells （MSCs） engraftment on vascular endothelial cell growth factor （VEGF） in lung tissue, plasma and extravascular lung water at early stage of smoke inhalation injury.METHODS： A rabbit smoke inhalation injury model was established using a home-made smoke inhalation injury generator, and rabbits were divided into two groups randomly： a control group （S group, n=32） and a MSCs treatment group （M group, n=32）. 10 ml PBS was injected via the ear marginal vein immediately at injury into the S group. Third generation MSCs with a concentration of 1×107/10 ml PBS were injected via the ear marginal vein immediately at injury into the M group. VEGF in peripheral blood and lung tissue were measured at 0 （baseline）, 2, 4 and 6 hours after injection respectively and analyzed. The right lungs of rabbits were taken to measure lung water mass fraction.RESULTS： In the lung tissue, VEGF decreased gradually in the S group （P〈0.05） and signi？ cantly decreased in the M group （P〈0.05）, but it increased more signi？ cantly than the values at the corresponding time points （P〈0.05）. In peripheral blood, VEGF increased gradually in the S group （P〈0.05） and markedly increased in the M group （P〈0.05）, but it decreased more signi？ cantly than the values at corresponding time points （P〈0.05）.CONCLUSION： MSCs engraftment to smoke inhalation injury could increase VEGF in lung tissue, decrease VEGF in plasma and reduce extravascular lung water, indicating its protective effect on smoke inhalation injury.

Neuroprotective effects of BDNF and GDNF in intravitreally transplanted mesenchymal stem cells after optic nerve crush in mice

AIM： To assess the neuro-protective effect of bone marrow mesenchymal stem cells （BMSCs） on retinal ganglion cells （RGCs） following optic nerve crush in mice. METHODS： C56BL/6J mice were treated with intravitreal injection of PBS, BMSCs, BDNF-interference BMSCs （BIM）, and GDNF-interference BMSCs （GIM） following optic nerve crush, respectively. The number of surviving RGCs was determined by whole-mount retinas and frozen sections, while certain mRNA or protein was detected by q-PCR or ELISA, respectively.RESULTS： The density （cell number/mm^2） of RGCs was 410.77±56.70 in the retina 21d after optic nerve crush without any treatment, compared to 1351.39±195.97 in the normal control （P〈0.05）. RGCs in BMSCs treated eyes was 625.07±89.64/mm^2, significantly higher than that of no or PBS treatment （P〈0.05）. While RGCs was even less in the retina with intravitreal injection of BIM （354.07±39.77） and GIM （326.67±33.37） than that without treatment （P〈0.05）. BMSCs injection improved the internal BDNF expression in retinas.CONCLUSION： Optic nerve crush caused rust loss of RGCs and intravitreally transplanted BMSCs at some extent protected RGCs from death. The effect of BMSCs and level of BDNF in retinas are both related to BDNF and GDNF expression in BMSCs.

Role of Stem Cell Factor and Its Receptor in the Pathogenesis of Pediatric Aplastic Anemia

In order to investigate the levels of stem cell factor (SCF) and its receptor c-kit protein and mRNA in pediatric aplastic anemia (AA) and their relevance to the pathogenesis, immunocytochemical and in situ hybridization were utilized to detect the expression of SCF and its receptor c-kit gene protein and mRNA, respectively in 59 children with AA and 51 normal controls. The relationship between SCF and c-kit and the pathogenesis of AA was analyzed subsequently. The results showed that the positive rate of SCF protein and mRNA expression in children with AA was significantly lower than that in healthy controls (P<0.05). However, there was no significant difference in the positive rate of c-kit protein and mRNA expression between children with AA and control group (P>0.05). It was concluded that the expression of SCF is significantly decreased in children with AA, which may be closely associated with the pathogenesis of the AA. c-kit may be unrelated to the development of pediatric AA. Therefore, AA in children may have abnormalities at SCF/c-kit signal transduction levels.