Influence of bone morphogenetic proteins-2 and strontium chloride on the human umbilical cord mesenchymal stem cells proliferation and osteogenic differentiation

Objective To study the effects of combination of bone morphogenetic protein-2 (BMP-2) and strontium chloride on proliferation and osteogenic differentiation of human umbilical cord mesenchymal stem cells(hUCM-SCs)in vitro culture.

Effects of Aging on the Proliferation and Differentiation Capacity of Human Periodontal Ligament Stem Cells

periodontal ligament stem cells; aging; proliferation; osteogenic differentiation Objective The aim of this study is to investigate the proliferation, differentiation and apoptosis of periodontal ligament stem cells （PDLSC） derived from different aged donors, and to evaluate the effects of aging on the biological characteristics of PDLSC. Methods Periodontal ligament tissues were obtained from 24 surgically extracted human premolars during orthodontics therapy. The specimens were divided into three groups according to the donor’s age. Group A： 18-20 years, group B： 30-35 years, group C： 45-50 years. PDLSC were isolated and cultured using a tissue-block-based enzymolytic method by limiting dilution assay. The colony forming efficiency of PDLSC for three experimental groups was determined. Senescence-Associated β-Galactosidase （SA-β-G） expression in the three groups was examined using β-galactosidase staining working solution. Cell cycle and apoptosis of the PDLSC were examined by the flow cytometry. Alkaline phosphatase （ALP） activity was evaluated by ALP staining. The expression of osteoplastic differentiation related genes Runt-related transcription factor-2 （Runx-2）, Collagen Type 1 （col-1）, and ALP of PDLSC were examined by quantitative real-time RT-PCR. Results The colony forming efficiency of PDLSC in Group A, B and C was 36.67%, 22.67% and 9.33%, respectively, which decreased with donors’ age （P〈0.05）. SA-β-G expression of the senescent PDLSC in group A, B and C were 4.14%, 16.39%, 50.38%, respectively （P〈0.05）. Cells in G2/S phase was 38.73%, 29.88%, 18.25% （P〈0.05）, and the apoptosis rate was 1.57%, 4.56%, 5.84% （P〈0.05）, in group A, B and C respectively. The ALP staining in the three groups decreased with the increase of donors’ ages, and the expression of Runx-2, col-1 and ALP decreased gradually from group A to group C （all P〈0.05）, which indicated the osteogenic differentiation capacity of PDLSC decreased while donor aging. Conclusion Human PDLSC could be successfully isolated from periodontal ligament tissues of different aged donors. However, the proliferation and osteogenic differentiation capacity of PDLSC decreased while donor aging.

SPOC domain-containing protein 1 regulates the proliferation and apoptosis of human spermatogonial stem cells through adenylate kinase 4

BACKGROUND Spermatogonial stem cells(SSCs)are the origin of male spermatogenesis,which can reconstruct germ cell lineage in mice.However,the application of SSCs for male fertility restoration is hindered due to the unclear mechanisms of proliferation and self-renewal in humans.AIM To investigate the role and mechanism of SPOC domain-containing protein 1(SPOCD1)in human SSC proliferation.METHODS We analyzed publicly available human testis single-cell RNA sequencing(RNAseq)data and found that SPOCD1 is predominantly expressed in SSCs in the early developmental stages.Small interfering RNA was applied to suppress SPOCD1 expression to detect the impacts of SPOCD1 inhibition on SSC proliferation and apoptosis.Subsequently,we explored the target genes of SPOCD1 using RNA-seq and confirmed their role by restoring the expression of the target genes.In addition,we examined SPOCD1 expression in some non-obstructive azoospermia(NOA)patients to explore the correlation between SPOCD1 and NOA.RESULTS The uniform manifold approximation and projection clustering and pseudotime analysis showed that SPOCD1 was highly expressed in the early stages of SSC,and immunohistological results showed that SPOCD1 was mainly localized in glial cell line-derived neurotrophic factor family receptor alpha-1 positive SSCs.SPOCD1 knockdown significantly inhibited cell proliferation and promoted apoptosis.RNA-seq results showed that SPOCD1 knockdown significantly downregulated genes such as adenylate kinase 4(AK4).Overexpression of AK4 in SPOCD1 knockdown cells partially reversed the phenotypic changes,indicating that AK4 is a functional target gene of SPOCD1.In addition,we found a significant downregulation of SPOCD1 expression in some NOA patients,suggesting that the downregulation of SPOCD1 may be relevant for NOA.CONCLUSION Our study broadens the understanding of human SSC fate determination and may offer new theories on the etiology of male infertility.

Propofol and remifentanil at moderate and high concentrations affect proliferation and differentiation of neural stem/progenitor cells

Propofol and remifentanil alter intracellular Ca^2＋ concentration （[Ca^2＋]i） in neural stem/progen-itor cells by activating γ-aminobutyric acid type A receptors and by reducing testosterone levels. However, whether this process affects neural stem/progenitor cell proliferation and differenti-ation remains unknown. In the present study, we applied propofol and remifentanil, alone or in combination, at low, moderate or high concentrations （1, 2–2.5 and 4–5 times the clinically effective blood drug concentration）, to neural stem/progenitor cells from the hippocampi of newborn rat pups. Low concentrations of propofol, remifentanil or both had no noticeable effect on cell proliferation or differentiation; however, moderate and high concentrations of propofol and/or remifentanil markedly suppressed neural stem/progenitor cell proliferation and differen-tiation, and induced a decrease in [Ca^2＋]i during the initial stage of neural stem/progenitor cell differentiation. We therefore propose that propofol and remifentanil interfere with the prolifer-ation and differentiation of neural stem/progenitor cells by altering [Ca^2＋]i. Our ifndings suggest that propofol and/or remifentanil should be used with caution in pediatric anesthesia.

Decreased proliferation ability and differentiation potential of mesenchymal stem cells of osteoporosis rat

Objective:To explore decreased proliferation ability and differentiation potential of mesenchymal stem cells(MSCs) of osteoporosis rat.Methods:MSCs were obtained from osteoporosis rat,and proliferation potency and impaired osteogenic differentiation potential were determined.Results:The result showed a significant downregulation of MSCs pluripotency related gene(Oct4) and osteogenic genes(BSP,OCN) expression in OVX MSCs compared with Sham MSCs(P<0.05).Conclusions:These data suggest that MSCs are aging in osteoporosis body,and autologous OVX MSCs transplantation is not appropriate to treat osteoporosis if necessary.There will be a possibility in establishing a new clinical application of MSCs autologous transplantation to treat osteoporosis,if OVX MSCs have stronger proliferation and differentiation.

Dorsal root ganglion neurons promote proliferation and osteogenic differentiation of bone marrow mesenchymal stem cells

Preliminary animal experiments have confirmed that sensory nerve fibers promote osteoblast differentiation, but motor nerve fibers have no promotion effect. Whether sensory neurons pro- mote the proliferation and osteogenic differentiation of bone marrow mesenchymal stem cells remains unclear. No results at the cellular level have been reported. In this study, dorsal root ganglion neurons （sensory neurons） from Sprague-Dawley fetal rats were co-cultured with bone marrow mesenchymal stem cells transfected with green fluorescent protein 3 weeks after osteo- genic differentiation in vitro, while osteoblasts derived from bone marrow mesenchymal stem cells served as the control group. The rat dorsal root ganglion neurons promoted the prolifera- tion of bone marrow mesenchymal stem cell-derived osteoblasts at B and 5 days of co-culture, as observed by fluorescence microscopy. The levels of mRNAs for osteogenic differentiation-re- lated factors （including alkaline phosphatase, osteocalcin, osteopontin and bone morphogenetic protein 2） in the co-culture group were higher than those in the control group, as detected by real-time quantitative PCR. Our findings indicate that dorsal root ganglion neurons promote the proliferation and osteogenic differentiation of bone marrow mesenchymal stem cells, which pro- vides a theoretical basis for in vitro experiments aimed at constructing tissue-engineered bone.

Effect of Stathmin Decoy-oligodeoxynucleotides on the Proliferation and Differentiation of Precartilainous Stem Cells

By using decoy-oligodeoxynucleotides （decoy-ODNS） technique, the effects of Stathmin gene on the proliferation and differentiation of in vitro cultured precartilainous stem cells （PSCs） were investigated. The Stathmin decoy-ODNs were transfected into PSCs in rats by using gene transfection technique. Under the induction of cortisol （1 μmol/L）, electrophoretic mobility shift assay was used the inhibitory effects of decoy-ODNS on Stathmin gene. MTT and cytometry were used to test the cell proliferation. The expression of collagen Ⅱ and Ⅴ and Stathmin protein was detected by using Western blot. The results showed that Stathmin decoy-ODNs inhibited the Stathmin activity in a dose-dependent manner. When the concentration of decoy-ODNs was 10 times of standard con- centration, the proliferation of PSCs was obviously suppressed and the differentiation happened. Compared to the control group, the difference was significant （P〈0.05）. It was concluded that decoy-ODNs could inhibit the proliferation and promote the differentiation of PSCs by antagonizing Stathmin activity.

Cerebral dopamine neurotrophic factor promotes the proliferation and differentiation of neural stem cells in hypoxic environments

Previous research found that cerebral dopamine neurotrophic factor(CDNF)has a protective effect on brain dopaminergic neurons,and CDNF is regarded as a promising therapeutic agent for neurodegenerative diseases.However,the effects of CDNF on the proliferation,differentiation,and apoptosis of neural stem cells(NSCs),which are very sensitive to hypoxic environments,remain unknown.In this study,NSCs were extracted from the hippocampi of fetal rats and cultured with different concentrations of CDNF.The results showed that 200 nM CDNF was the optimal concentration for significantly increasing the viability of NSCs under non-hypoxic environmental conditions.Then,the cells were cultured with 200 nM CDNF under the hypoxic conditions of 90%N_2,5%CO_2,and 5%air for 6 hours.The results showed that CDNF significantly improved the viability of hypoxic NSCs and reduced apoptosis among hypoxic NSCs.The detection of markers showed that CDNF increased the differentiation of hypoxic NSCs into neurons and astrocytes.CDNF also reduced the expression level of Lin28 protein and increased the expression of Let-7 mRNA in NSCs,under hypoxic conditions.In conclusion,we determined that CDNF was able to reverse the adverse proliferation,differentiation,and apoptosis effects that normally affect NSCs in a hypoxic environment.Furthermore,the Lin28/Let-7 pathway may be involved in this regulated function of CDNF.The present study was approved by the Laboratory Animal Centre of Southeast University,China(approval No.20180924006)on September 24,2018.

Effects of olfactory ensheathing cells on the proliferation and differentiation of neural stem cells

BACKGROUND： Olfactory ensheathing cells can promote oriented differentiation and proliferation of neural stem cells by cell-secreted neural factors. OBJECTIVE： To observe the effect of olfactory ensheathing cells on the differentiation and proliferation of neural stem cells. DESIGN, TIME AND SETTING： Cytology was performed at the Department of Neurology, Tongji Medical College, Huazhong University of Science and Technology, China, from September 2007 to October 2008. MATERIALS： Mouse anti-nestin polyclonal antibody （Chemicon, USA）, mouse anti-glial fibrillary acidic protein （GFAP） IgG1, mouse anti-2＇, 3＇-cyclic nucleotide 3＇-phosphodiesterase （CNPase） IgG1, mouse anti-Tubulin Class-Ill IgG1 （Neo Markers, USA）, Avidin-labeled Cy3 （KPL, USA）, and goat anti-mouse IgGl： fluorescein isothiocyanate （FITC） （Serotec, UK） were used in this study. METHODS：Tissues were isolated from the embryonic olfactory bulb and subependymal region of Wistar rats. Serum-free DMEM/F12 culture media was used for co-culture experiments. Neural stem cells were incubated in serum-free or 5% fetal bovine serum-containing DMEM/F12 as controls. MAIN OUTCOME MEASURES： After 7 days of co-culture, neural stem cells and olfactory ensheathing cells underwent immunofluorescent staining for nestin, tubulin, glial fibrillary acidic protein, and CNPase. RESULTS： Olfactory ensheathing cells promoted proliferation and differentiation of neural stem cells into neuron-like cells, astrocytes and oligodendrocytes. The proportion of neuron-like cells was 78.2%, but the proportion of neurons in 5% fetal bovine serum DMEM/F12 was 48.3%. In the serum-free DMEM/F12, neural stem cells contracted, unevenly adhered to the glassware wall, or underwent apoptosis at 7 days. CONCLUSION： Olfactory ensheathing cells promote differentiation of neural stem cells mainly into neuron-like cells, and accelerate proliferation of neural stem cells. The outcome is better compared with serum-free medium or medium containing 5% fetal bovine serum.

Comprehensive regulation of traditional Chinese medicine on proliferation and differentiation of neural stem cells

Since the diccovery of neural stem cells(NSCs)in the embryonic and adult mammalian central nerous system,it provided novel ideas forneurogenesis as the potential of proliferation and differentiation of NSCs.One of the ways to promote the clinical application of neural stem cells(NSCs)is searching effective methods which regulate the proliferation and differentiation.This is also a problem urgently to be solved in medical field.Plenty of earlier studies have shown that traditional chinese medicine can promote the proliferation and differentiation of NSCs by regulating the related signaling pathway in vivo and in vitro.The reports of Chinese and foreign literatures on regulating the proliferation and differentiation of neural stem cells in recent ten years and their target and signaling pathways is analyzed in this review.The traditional chinese medicine regulate proliferation and differentiation of NSCs by the signaling pathways of Notch,PI3K/Akt,Wnt/β-catenin,and GFs.And,those signaling pathways have cross-talk in the regulation progress.Moreover,some traditional Chinese medicine,such as astragalus,has a variety of active ingredients to regulate proliferation and differentiation of NSCs through different signaling pathways.However,to accelerate the clinical application of neural stem cells,the studies aboutthe proliferation and differentiation of NSCs and Chinese medicine should be further deepened,the mechanism of multiple targets and the comprehensive regulation function of traditional Chinese medicine should be clarified.

Ipsilateral versus bilateral limb-training in promoting the proliferation and differentiation of endogenous neural stem cells following cerebral infarction in rats

We investigated the effects of ipsilateral versus bilateral limb-training on promotion of endogenous neural stem cells in the peripheral infarct zone and the corresponding cerebral region in the unaffected hemisphere of rats with cerebral infarction. Middle cerebral artery occlusion was induced in Wistar rats. The rat forelimb on the unaffected side was either wrapped up with tape to force the use of the paretic forelimb in rats or not braked to allow bilateral forelimbs to participate in training. Daily training consisted of mesh drum training, balance beam training, and stick rolling training for a total of 40 minutes, once per day. Control rats received no training. At 14 days after functional training, rats receiving bilateral limb-training exhibited milder neurological impairment than that in the ipsilateral limb-training group or the control group. The number of nestin/glial fibrillary acidic protein-positive and nestin/microtubule-associated protein 2-positive cells in the peripheral infarct zone and in the corresponding cerebral region in the unaffected hemisphere was significantly higher in rats receiving bilateral limb-training than in rats receiving ipsilateral limb-training. These data suggest that bilateral limb-training can promote the proliferation and differentiation of endogenous neural stem cells in the bilateral hemispheres after cerebral infarction and accelerate the recovery of neurologic function. In addition, bilateral limb-training produces better therapeutic effects than ipsilateral limb-training.

Fetal bovine serum versus Chinese herbal formula Naoluoxintong serum supplementation for proliferation and differentiation of rat embryonic neural stem cells

BACKGROUND： How to induce endogenous neural stem cells （NSCs） to differentiate into needed neural cell types is a hot spot of current researches. OBJECTIVE： To compare differences between fetal bovine serum and Chinese herbal formula Naoluoxintong serum supplementation for inducing proliferation and differentiation in rat embryonic NSCs. DESIGN, TIME AND SETTING： An in vitro, serum pharmacology, comparative, observation study was performed from March to September in 2008 at the Laboratory of Neurodegenerative Diseases, College of Life Science in University of Science and Technology of China, the Key Laboratory Breeding Base of Acupuncture Foundation and Technology in Anhui University of Traditional Chinese Medicine, the Anhui Province Key Laboratory of R ＆ D of Chinese Medicine, and at the Level 3 Laboratory of Molecular Biology of the State Administration of Traditional Chinese Medicine. MATERIALS： The Chinese herbal formula Naoluoxintong was produced by Radix Astragali, Radix Notoginseng, Rhizoma Chuanxiong, Scolopendra at Anhui University of Traditional Chinese Medicine. Mouse anti-rat nestin, gliat fibrillary acidic protein, and galactocerebroside monoclonal antibodies, as well as rabbit anti-neuron-specific enolase polyclonal antibody were produced by Chemicon, Billerica, MA, USA. METHODS： Wistar rats aged 3 months were intragastrically infused with Naoluoxintong. Wistar rat embryonic NSCs （passage 8） were induced to proliferate and differentiate using 10% fetal bovine serum, 10% Naoluoxintong serum, and 10% rat serum. MAIN OUTCOME MEASURES： Phenotypic changes in cultured cells were detected using phase contrast microscopy, and cell proliferation and differentiation were observed using immunofluorescence staining. RESULTS： Proliferation and differentiation of embryonic NSCs was induced by three different types of blood serum. Although the differentiation time course with Nao/uoxintongserum was later than with the other two methods, the differentiated cells were morphologically similar to mature neurons to a greater extent. CONCLUSION： Nao/uoxintong serum supplementation induced differentiation of NSCs into neuronal-like cells and stimulated neuronal maturation.

MKK7-mediated phosphorylation of JNKs regulates the proliferation and apoptosis of human spermatogonial stem cells

BACKGROUND Human spermatogonial stem cells(SSCs)are the basis of spermatogenesis.However,little is known about the developmental regulatory mechanisms of SSC due to sample origin and species differences.AIM To investigates the mechanisms involved in the proliferation of human SSC.METHODS The expression of mitogen-activated protein kinase kinase 7(MKK7)in human testis was identified using immunohistochemistry and western blotting(WB).MKK7 was knocked down using small interfering RNA,and cell proliferation and apoptosis were detected by WB,EdU,cell counting kit-8 and fluorescenceactivated cell sorting.After bioinformatic analysis,the interaction of MKK7 with c-Jun N-terminal kinases(JNKs)was verified by protein co-immunoprecipitation and WB.The phosphorylation of JNKs was inhibited by SP600125,and the phenotypic changes were detected by WB,cell counting kit-8 and fluorescenceactivated cell sorting.RESULTS MKK7 is mainly expressed in human SSCs,and MKK7 knockdown inhibits SSC proliferation and promotes their apoptosis.MKK7 mediated the phosphorylation of JNKs,and after inhibiting the phosphorylation of JNKs,the phenotypic changes of the cells were similar to those after MKK7 downregulation.The expression of MKK7 was significantly downregulated in patients with abnormal spermatogenesis,suggesting that abnormal MKK7 may be associated with spermatogenesis impairment.CONCLUSION MKK7 regulates the proliferation and apoptosis of human SSC by mediating the phosphorylation of JNKs.

miR-103-3p targets Ndel1 to regulate neural stem cell proliferation and differentiation

The regulation of adult neural stem cells(NSCs) is critical for lifelong neurogenesis. MicroRNAs(miRNAs) are a type of small, endogenous RNAs that regulate gene expression post-transcriptionally and influence signaling networks responsible for several cellular processes. In this study, mi R-103-3 p was transfected into neural stem cells derived from embryonic hippocampal neural stem cells. The results showed that mi R-103-3 p suppressed neural stem cell proliferation and differentiation, and promoted apoptosis. In addition, mi R-103-3 p negatively regulated Nud E neurodevelopment protein 1-like 1(Ndel1) expression by binding to the 3′ untranslated region of Ndel1. Transduction of neural stem cells with a lentiviral vector overexpressing Ndel1 significantly increased cell proliferation and differentiation, decreased neural stem cell apoptosis, and decreased protein expression levels of Wnt3 a, β-catenin, phosphor-GSK-3β, LEF1, c-myc, c-Jun, and cyclin D1, all members of the Wnt/β-catenin signaling pathway. These findings suggest that Ndel1 is a novel mi R-103-3 p target and that mi R-103-3 p acts by suppressing neural stem cell proliferation and promoting apoptosis and differentiation. This study was approved by the Animal Ethics Committee of Nantong University, China(approval No. 20200826-003) on August 26, 2020.

Effects of neurotrophin-3 intervention on on bone marrow mesenchymal stem cell osteoblast differentiation as well as cell proliferation and apoptosis

Objective:To study the effects of neurotrophin-3 (NT-3) intervention on bone marrow mesenchymal stem cell osteoblast differentiation as well as cell proliferation and apoptosis. Methods: Bone marrow mesenchymal stem cells were cultured and divided into control group, 25 ng/mL NT-3 group, 50 ng/mL NT-3 group and 100 ng/mL NT-3 group, they were treated with different doses of NT-3 for 24 h, and then osteoblast marker gene, cell proliferation gene and apoptosis gene expression were determined.Results: RUNX2, Osterix, ALP, OCN, BMP-2, Bcl-2, Nrf2, ERK1/2 and PCNA mRNA expression in 25 ng/mL NT-3 group, 50 ng/mL NT-3 group and 100 ng/mL NT-3 group were significantly higher than those in control group whereas Bim, Bax, Caspase-3, CHOP and Beclin1 mRNA expression were significantly lower than those in control group, and the larger the dose of NT-3, the higher the RUNX2, Osterix, ALP, OCN, BMP-2, Bcl-2, Nrf2, ERK1/2 and PCNA mRNA expression whereas the lower the Bim, Bax, Caspase-3, CHOP and Beclin1 mRNA expression.Conclusion: NT-3 intervention in bone marrow mesenchymal stem cells can promote osteoblast differentiation and cell proliferation and inhibit apoptosis.

Proliferation and tenogenic differentiation of bone marrow mesenchymal stem cells in a porous collagen sponge scaffold

BACKGROUND Collagen is one of the most commonly used natural biomaterials for tendon tissue engineering.One of the possible practical ways to further enhance tendon repair is to combine a porous collagen sponge scaffold with a suitable growth factor or cytokine that has an inherent ability to promote the recruitment,proliferation,and tenogenic differentiation of cells.However,there is an incomplete understanding of which growth factors are sufficient and optimal for the tenogenic differentiation of rat bone marrow mesenchymal stem cells(BMSCs)in a collagen sponge-based 3D culture system.AIM To identify one or more ideal growth factors that benefit the proliferation and tenogenic differentiation of rat BMSCs in a porous collagen sponge scaffold.METHODS We constructed a 3D culture system based on a type I collagen sponge scaffold.The surface topography of the collagen sponge scaffold was observed by scanning electron microscopy.Primary BMSCs were isolated from Sprague-Dawley rats.Cell survival on the surfaces of the scaffolds with different growth factors was assessed by live/dead assay and CCK-8 assay.The mRNA and protein expression levels were confirmed by quantitative real-time polymerase chain reaction and Western blot,respectively.The deposited collagen was assessed by Sirius Red staining.RESULTS Transforming growth factorβ1(TGF-β1)showed great promise in the tenogenic differentiation of BMSCs compared to growth differentiation factor 7(GDF-7)and insulin-like growth factor 1(IGF-1)in both the 2D and 3D cultures,and the 3D culture enhanced the differentiation of BMSCs into tenocytes well beyond the level of induction in the 2D culture after TGF-β1 treatment.In the 2D culture,the proliferation of the BMSCs showed no significant changes compared to the control group after TGF-β1,IGF-1,or GDF-7 treatment.However,TGF-β1 and GDF-7 could increase the cell proliferation in the 3D culture.Strangely,we also found more dead cells in the BMSC-collagen sponge constructs that were treated with TGF-β1.Moreover,TGF-β1 promoted more collagen deposition in both the 2D and 3D cultures.CONCLUSION Collagen sponge-based 3D culture with TGF-β1 enhances the responsiveness of the proliferation and tenogenic differentiation of rat BMSCs.

Effects of Buyang Huanwu decoction on cell proliferation and differentiation in the hippocampal dentate gyrus of aged rats following cerebral ischemia/reperfusion

BACKGROUND： The mobilization of endogenous stem cells is an effective way to promote repair following ischemic brain damage. Buyang Huanwu decoction （BHD） can effectively improve cerebral blood flow and protect against cerebral ischemia/reperfusion damage. OBJECTIVE： To study the effects of BHD on cell proliferation and differentiation in the hippocampal dentate gyrus of rats following cerebral infarction, to investigate the protective effects of BHD against cerebral infarction, and to analyze the dose-effect relationship. DESIGN, TIME AND SETTING： This randomized, controlled, animal study was performed at the Laboratory of Department of Physiology, Henan College of Traditional Chinese Medicine, China from June 2007 to February 2008. MATERIALS： A total of 36 male, Sprague Dawley rats, aged 20-21 months, were equally and randomly assigned to the following groups： sham operation, model control, and nimodipine, as well as high-dose, moderate-dose, and low-dose BHD. BHD was composed of milkvetch root, Chinese angelica, red peony root, earthworm, peach seed, safflower, and Szechwan Iovage rhizome, which were provided by the Outpatient Department, Henan College of Traditional Chinese Medicine, China. METHODS： The Chinese medicinal ingredients described above were decocted. The external carotid artery was ligated in rats from the sham operation group. Rat models of focal cerebral infarction were established by middle cerebral artery occlusion in the model control and nimodipine groups, as well as the high-dose, moderate-dose, and low-dose BHD groups. The drugs were administered by gavage 5 days, as well as 2 hours, prior to model induction. Rats in the nimodipine group were daily administered a 6 mg/kg nimodipine suspension by gavage. Rats in the high-dose, moderate-dose, and low-dose BHD groups were administered daily 26, 13, and 6.5 g/kg BHD, respectively. Rats in the sham operation and model control groups were treated with an equal volume of saline. MAIN OUTCOME MEASURES： The effects of BHD on neurological dysfunction score, brain water content, cell proliferation and differentiation in the hippocampal dentate gyrus, and pathological changes in the ischemic brain hemisphere were measured in cerebral infarction rats. RESULTS： Compared with the sham operation group, the neurological dysfunction score, brain water content, number of BrdU-positive cells, BrdU/NeuN-positive cells, and BrdU/GFAP-positive cells in the hippocampal dentate gyrus significantly increased in the model control group （P 〈 0.01 ）. Compared with the model control group, neurological dysfunction score and brain water content were significantly decreased （P 〈 0.01 or 0.05）, as were the number of BrdU-positive and BrdU/NeuN-positive cells （P 〈 0.01 or 0.05）. The number of BrdU/GFAP-positive cells was significantly reduced （P 〈 0.05） in the nimodipine group, high-dose, moderate-dose, and low-dose BHD groups. Compared with the nimodipine group, the neurological dysfunction score was significantly reduced in the moderate-dose BHD group （P 〈 0.05）. However, the number of BrdU-positive cells was significantly increased in the rat hippocampal dentate gyrus in the high-dose and moderate-dose BHD groups （P 〈 0.01 or 0.05）. The following was determined by microscopy： slightly disarranged neural cells, mild vascular dilatation, inflammatory cell infiltration, and light tissue edema were observed in the nimodipine group; inflammatory celt infiltration was reduced in the low-dose BHD group; cerebral edema and inflammatory cell infiltration were significantly reduced in the high-dose and in the moderate-dose BHD group. Electron microscopy revealed lipofuscin, slightly swollen mitochondria, and normal rough endoplasmic reticulum in the high-dose and moderate-dose BHD groups. Improvement was best in the moderate-dose BHD group. CONCLUSION： Cerebral ischemia activated proliferation of neural stem cells in the rat hippocampal dentate gyrus. The actions of BHD against cerebral ischemia/reperfusion damage correlated with proliferation and differentiation of neural stem cells in the hippocampal dentate gyrus. A moderate-dose of BHD resulted in the most effective outcome.

PROLIFERATION AND DIFFERENTIATION OF NEURAL STEMCELLS IN ADULT RATS AFTER CEREBRAL INFARCTION

Objective To investigate proliferation and differentiation of neural stem cells in adult rats after cerebral infarction. Methods Models of cerebral infarction in rats were made and the time-course expression of bromodeoxyuridine(BrdU), Musashi1, glial fibrillary acidic protein (GFAP), and neuronal nuclear antigen (NeuN) were determined by immunohistochemistry and immunofluorescence staining. BrdU and Musashi1 were used to mark dividing neural stem cells. GFAP and NeuN were used to mark differentiating neural stem cells. Results Compared with controls, the number of BrdU-labeled and BrdU-labeled with Musashi1-positive cells incre-ased strikingly 1 day after cerebral infarction; approximately 6 fold with a peak 7 days later; markedly decreased 14 days later, but was still elevated compared with that of controls; decling to the control level 28 days later. The number of BrdU-labeled with GFAP-positive cells nearly remained unchanged in the hippocampus after cerebral infarction. The nu-mber of BrdU-labeled with NeuN-positive cells increased strikingly 14 days after cerebral infarction, reached maximum peak in the hippocampus 28 days after cerebral infarction in rats. Conclusion Cerebral infarction stimulate proliferation of inherent neural stem cells and most proliferated neural stem cells differentiate into neurons.

Growth and differentiation of neural stem cells in a three-dimensional collagen gel scaffold

Collagen protein is an ideal scaffold material for the transplantation of neural stem cells. In this study rat neural stern cells were seeded into a three-dimensional collagen gel scaffold, with suspension cultured neural stem cells being used as a control group. Neural stem cells, which were cultured in medium containing epidermal growth factor and basic fibroblast growth factor, actively expanded and formed neurospheres in both culture groups. In serum-free medium conditions, the processes extended from neurospheres in the collagen gel group were much longer than those in the suspension culture group. Immunofluorescence staining showed that neurespheres cultured in collagen gels were stained positive for nestin and differentiated cells were stained positive for the neuronal marker βIII-tubulin, the astrocytic marker glial fibrillary acidic protein and the oligodendrocytic marker 2＇,3＇-cyclic nucleotide 3＇-phosphodiesterase. Compared with neurospheres cultured in suspension, the differentiation potential of neural stem cells cultured in collagen gels increased, with the formation of neurons at an early stage. Our results show that the three-dimensional collagen gel culture system is superior to suspension culture in the proliferation, differentiation and process outgrowth of neural stem cells.

Neuronal-like cell differentiation of non-adherent bone marrow cell-derived mesenchymal stem cells

Non-adherent bone marrow cell-derived mesenchymal stem cells from C57BL/6J mice were sepa- rated and cultured using the ＂pour-off＂ method. Non-adherent bone marrow cell-derived mesen- chymal stem ceils developed colony-forming unit-fibroblasts, and could be expanded by supple- mentation with epidermal growth factor. Immunocytochemistry showed that the non-adherent bone marrow cell-derived mesenchymal stem cells exposed to basic fibroblast growth factor/epidermal growth factor/nerve growth factor expressed the neuron specific markers, neurofilament-200 and NeuN, in vitro. Non-adherent bone marrow cell-derived mesenchymal stem cells from 13-galactosidase transgenic mice were also transplanted into focal ischemic brain （right corpus striatum） of C57BL/6J mice. At 8 weeks, cells positive for LacZ and 13-galactosidase staining were observed in the ischemic tissues, and cells co-labeled with both 13-galactosidase and NeuN were seen by double immunohistochemical staining. These findings suggest that the non-adherent bone marrow cell-derived mesenchymal stem cells could differentiate into neuronal-like cells in vitro and in vivo.