Poster Session : Transcription and Metabolic Disease ; Inner ear hair cell generation via stepwise differentiation of mesenchymal stem cell isolated from the human mastoid process bone marrow

( Sujeong Jang ),( Myung Joo Jang ),( Sung Jun Park ),( Song Hee Kim ),( Hyong Ho Cho ),( Yong Bum Cho ),( Jong Seong Park ),( Han Seong Jeong ) 한국생화학분자생물학회 (구 한국생화학회) 2007 생화학분자생물학회 춘계학술발표논문집 Vol.2007 No.-

Transplantation of human adipose tissue-derived stem cells for repair of injured spiral ganglion neurons in deaf guinea pigs

Jang, Sujeong,Cho, Hyong-Ho,Kim, Song-Hee,Lee, Kyung-Hwa,Cho, Yong-Bum,Park, Jong-Seong,Jeong, Han-Seong Medknow PublicationsMedia Pvt Ltd 2016 Neural regeneration research Vol.11 No.6

<P>Excessive noise, ototoxic drugs, infections, autoimmune diseases, and aging can cause loss of spiral ganglion neurons, leading to permanent sensorineural hearing loss in mammals. Stem cells have been confirmed to be able to differentiate into spiral ganglion neurons. Little has been reported on adipose tissue-derived stem cells (ADSCs) for repair of injured spiral ganglion neurons. In this study, we hypothesized that transplantation of neural induced-human ADSCs (NI-hADSCs) can repair the injured spiral ganglion neurons in guinea pigs with neomycin-induced sensorineural hearing loss. NI-hADSCs were induced with culture medium containing basic fibroblast growth factor and forskolin and then injected to the injured cochleae. Guinea pigs that received injection of Hanks’ balanced salt solution into the cochleae were used as controls. Hematoxylin-eosin staining showed that at 8 weeks after cell transplantation, the number of surviving spiral ganglion neurons in the cell transplantation group was significantly increased than that in the control group. Also at 8 weeks after cell transplantation, immunohistochemical staining showed that a greater number of NI-hADSCs in the spiral ganglions were detected in the cell transplantation group than in the control group, and these NI-hADSCs expressed neuronal markers neurofilament protein and microtubule-associated protein 2. Within 8 weeks after cell transplantation, the guinea pigs in the cell transplantation group had a gradually decreased auditory brainstem response threshold, while those in the control group had almost no response to 80 dB of clicks or pure tone burst. These findings suggest that a large amount of NI-hADSCs migrated to the spiral ganglions, survived for a period of time, repaired the injured spiral ganglion cells, and thereby contributed to the recovery of sensorineural hearing loss in guinea pigs.</P>

Neural Differentiation of Human Adipose Tissue-Derived Stem Cells Involves Activation of the Wnt5a/JNK Signalling

Jang, Sujeong,Park, Jong-Seong,Jeong, Han-Seong Hindawi Publishing Corporation 2015 Stem cells international Vol.2015 No.-

<P>Stem cells are a powerful resource for cell-based transplantation therapies, but understanding of stem cell differentiation at the molecular level is not clear yet. We hypothesized that the Wnt pathway controls stem cell maintenance and neural differentiation. We have characterized the transcriptional expression of Wnt during the neural differentiation of hADSCs. After neural induction, the expressions of Wnt2, Wnt4, and Wnt11 were decreased, but the expression of Wnt5a was increased compared with primary hADSCs in RT-PCR analysis. In addition, the expression levels of most Fzds and LRP5/6 ligand were decreased, but not Fzd3 and Fzd5. Furthermore, Dvl1 and RYK expression levels were downregulated in NI-hADSCs. There were no changes in the expression of ß-catenin and GSK3ß. Interestingly, Wnt5a expression was highly increased in NI-hADSCs by real time RT-PCR analysis and western blot. Wnt5a level was upregulated after neural differentiation and Wnt3, Dvl2, and Naked1 levels were downregulated. Finally, we found that the JNK expression was increased after neural induction and ERK level was decreased. Thus, this study shows for the first time how a single Wnt5a ligand can activate the neural differentiation pathway through the activation of Wnt5a/JNK pathway by binding Fzd3 and Fzd5 and directing Axin/GSK-3ß in hADSCs.</P>

Antidiabetic Drug Metformin Protects Neuronal Cells against Quinolinic Acid-Induced Excitotoxicity by Decreasing Intracellular Calcium

Jang, Sujeong,Park, Sah-Hoon Chonnam National University Medical School 2018 CMJ Vol.54 No.1

<P>The antidiabetic drug metformin has been found to have beneficial effects in various neurological disorders; however, the molecular mechanisms underlying these effects remain unclear. Here we report that metformin protects neuronal cells from quinolinic acid (QUIN)-induced excitotoxicity. For this, we pretreated N18D3 neuronal cells with metformin prior to QUIN for 24 h. We found that pretreating the cells with metformin significantly improved cell survival rate in a concentration-dependent manner and reduced apoptotic cell death, as revealed by a MTT assay and DAPI staining, respectively. Calcium imaging using fluo-4 showed that metformin (100 µM) inhibited the intracellular calcium increase that was induced by QUIN. In addition, mRNA expression of pro-apoptotic genes, p21 and Bax, was decreased and of anti-apoptotic genes, Bcl-2 and Bcl-xl, was increased with metformin treatment compared to QUIN-induced cells. The immunoreactivity of phosphorylated ERK1/2 was elevated in cells treated with metformin, indicating the ERK1/2 signaling pathway in the neuroprotective effects of metformin in QUIN-induced cell death. Collectively, our data demonstrates that metformin exerts its neuroprotective effects by inhibiting intracellular calcium increases, allowing it to regulate ERK1/2 signaling and modulate cell survival and death genes.</P>

Non-canonical Wnt mediated neurogenic differentiation of human bone marrow-derived mesenchymal stem cells

Jang, Sujeong,Cho, Hyong-Ho,Park, Jong-Seong,Jeong, Han-Seong Elsevier/North-Holland 2017 Neuroscience letters Vol.660 No.-

<P><B>Abstract</B></P> <P>Bone marrow-derived mesenchymal stem cells (BM-MSCs), which are characterized by multipotency and self-renewal, are responsible for tissue regeneration and repair. We have previously reported in adipose tissue-derived MSCs that only Wnt5a is enhanced at neurogenic differentiation, and the mechanism of differentiation is dependent on the Wnt5a/JNK pathway; however, the role of Wnt/MAPK pathway is yet to be investigated in neurogenic differentiation in BM-MSCs. We compared the transcriptional expression of Wnt in neurogenic induced-hBM-MSCs (NI-hBM-MSCs) with that in primary hBM-MSCs, using RT-PCR, qPCR, and western blotting. Although the expression of Wnt1 and Wnt2 was unchanged, the expression of Wnt4, Wnt5a, and Wnt11 increased after neurogenic differentiation. In addition, only the expression of frizzled class receptor (Fzd) 3 gene was increased, but not of most of the Fzds and Wnt ligands in NI-hBM-MSCs. Interestingly, Wnt4, Wnt5a, and Wnt11 gene expressions significantly increased in NI-hBM-MSCs by qPCR. In addition, the protein expression level of Wnt4 and Wnt5a, but not Wnt3, increased after neurogenic induction. Furthermore, the expressions of phosphorylated-GSK-3β, ERK1/2, and PKC decreased; however, JNK was activated after neurogenic differentiation. Thus, non-canonical Wnts, i.e., Wnt4, Wnt5a, and Wnt11, regulate neurogenic differentiation through Fzd3 activation and the increase in downstream targets of JNK, which is one of the non-canonical pathways, in hBM-MSCs.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Non-canonical Wnts are increased in neurogenic differentiation of stem cells. </LI> <LI> Wnt4, Wnt5a, and Wnt11 regulated Fzd3 activation. </LI> <LI> Non-canonical Wnts regulated in downstream targets of JNK. </LI> </UL> </P>

Histone deacetylase inhibition-mediated neuronal differentiation via the Wnt signaling pathway in human adipose tissue-derived mesenchymal stem cells

Jang, Sujeong,Jeong, Han-Seong Elsevier 2018 Neuroscience Letters Vol.668 No.-

<P><B>Abstract</B></P> <P>Histone deacetylase (HDAC) inhibitors, which have an effect on cell homeostasis, cell cycle progression, and terminal differentiation, can act to promote self-renewal and enhance directed differentiation of several lineages of stem cells. However, the roles of HDAC inhibitors on neurogenic differentiation and the mechanisms of Wnt signaling following treatment with HDAC inhibitors remain unclear in stem cells. We hypothesized that HDAC inhibitors regulate downstream Wnt signaling and neurogenic differentiation of mesenchymal stem cells. Following neural induction with supplementary factors, human adipose tissue-derived mesenchymal stem cells (hADSCs) were differentiated into neurogenic cells <I>in vitro</I>. We examined the neurogenic differentiation induced by the HDAC inhibitors, MS-275, sodium butyrate (NaB), trichostatin A (TSA), and valproic acid (VPA), by RT-PCR and western blot analysis. Based on RT-PCR analysis, the expressions of <I>NEUROG2</I> and <I>NEFL</I> were highly increased following HDAC inhibitor treatment compared with control medium. Most of the neuronal marker genes were expressed when neural-induced hADSCs (NI-hADSCs) were treated with the HDAC inhibitors individually. Interestingly, expression of most of the Wnt-related genes were highly increased following treatment with the HDAC inhibitors, especially with MS-275 treatment. Further, the protein level of Wnt5 was upregulated after neurogenic induction with MS-275 and VPA treatment, based on western blot analysis. Furthermore, we found that c-Jun expression was increased after treatment with the HDAC inhibitors, except with NaB. The protein levels of phosphor-JNK and phosphor-GSK-3β were upregulated considerably. In conclusion, the HDAC inhibitors could induce neurogenic differentiation of hADSCs by activating canonical Wnt or non-canonical Wnt signaling pathways.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Histone deacetylase inhibition promoted neurogenic differentiation of stem cells. </LI> <LI> Wnts were highly increased following treatment with the HDAC inhibitors. </LI> <LI> Non-canonical Wnts regulated in downstream targets of JNK. </LI> <LI> Canonical Wnts and GSK-3β expressed treatment with HDAC inhibitors. </LI> <LI> HDAC inhibitors enhanced canonical and non-canonical Wnt signaling. </LI> </UL> </P>

Effects of [D-Pen², D-Pen?]-enkephalin on the Neuronal Activity of Medial Vestibular Nuclear Neurons

Sujeong Jang,Han-Seong Jeong,Jong-Seong Park 대한의생명과학회 2009 Biomedical Science Letters Vol.15 No.3

This study was designed to investigate direct effects of [D-Pen², D-Pen?]-enkephalin, a δ-opioid receptor agonist on the neuronal activity of medial vestibular nuclear (MVN) neurons by whole-cell configuration patch clamp experiments. The spike frequency of MVN neuron was increased to 9.50±0.55 (P<0.05) and 10.56±0.66 (P<0.05) by 5 and 10 μM [D-Pen², D-Pen?]-enkephalin from the control level of 8.05±0.55 spikes/sec, respectively (n=18). The resting membrane potential of the neurons was increased to -37.86±0.92 and -36.97±0.97 (P<0.05) from -38.74±1.13 ㎷ by 5 and 10 μM [D-Pen², D-Pen?]-enkephalin, respectively. The amplitude of afterhyperpolarization was decreased to 23.78±0.65 and 21.67±0.89 (P<0.05) from 23.73±0.53 ㎷ by 5 and 10 μM [D-Pen², D-Pen?]-enkephalin, respectively. The spike width was changed to 2.22±0.08 and 2.24±0.07 from 2.20±0.08 ㎷ by 5 and 10 μM [D-Pen², D-Pen?]-enkephalin, respectively. After pretreatment of naltrindole, a highly selective δ-opioid receptor antagonist, [D-Pen², D-Pen?]-enkephalin did not change firing rate, resting membrane potential, afterhyperpolarization amplitude, and spike width of MVN neurons. The above experimental results suggest that [D-Pen², D-Pen?]-enkephalin increases the neuronal activity of MVN neurons via inhibition of calcium-dependent potassium currents underlying the afterhyperpolarization.

Protein Kinase C-mediated Neuroprotective Action of (-)-epigallocatechin-3-gallate against Aβ<SUB>1-42</SUB>-induced Apoptotic Cell Death in SH-SY5Y Neuroblastoma Cells

Sujeong Jang,Kyoung Wan You,Song-Hee Kim,Sung Jun Park,Han-Seong Jeong,Jong-Seong Park 대한생리학회-대한약리학회 2007 The Korean Journal of Physiology & Pharmacology Vol.21 No.1

The neurotoxicity of amyloid β (Aβ) is associated with an increased production of reactive oxygen species and apoptosis, and it has been implicated in the development of Alzheimer s disease. While (-)-epigallocatechin-3-gallate (EGCG) suppresses Aβ-induced apoptosis, the mechanisms underlying this process have yet to be completely clarified. This study was designed to investigate whether EGCG plays a neuroprotective role by activating cell survival system such as protein kinase C (PKC), extracellular-signal-related kinase (ERK), c-Jun N-terminal kinase (JNK), and anti-apoptotic and pro-apoptotic genes in SH-SY5Y human neuroblastoma cells. One μM Aβ<SUB>1-42</SUB> decreased cell viability, which was correlated with increased DNA fragmentation evidenced by DAPI staining. Pre-treatment of SH-SY5Y neuroblastoma cells with EGCG (1μM) significantly attenuated Aβ1-42-induced cytotoxicity. Potential cell signaling candidates involved in this neuroprotective effects were further examined. EGCG restored the reduced PKC, ERK, and JNK activities caused by Aβ<SUB>1-42 </SUB>toxicity. In addition, gene expression analysis revealed that EGCG prevented both the Aβ<SUB>1-42</SUB>-induced expression of a pro-apoptotic gene mRNA, Bad and Bax, and the decrease of an anti-apoptotic gene mRNA, Bcl-2 and Bcl-xl. These results suggest that the neuroprotective mechanism of EGCG against Aβ<SUB>1-42</SUB>-induced apoptotic cell death includes stimulation of PKC, ERK, and JNK, and modulation of cell survival and death genes.

Effects of Nitric Oxide on the Neuronal Activity of Rat Cerebellar Purkinje Neurons

Sujeong Jang,Han-Seong Jeong,Jong-Seong Park(박종성) 대한의생명과학회 2010 Biomedical Science Letters Vol.16 No.4

This study was designed to investigate the effects of nitric oxide on the neuronal activity of rat cerebellar Purkinje cells. Sprague-Dawley rats aged 14 to 16 days were decapitated under ether anesthesia. After treatment with pronase and thermolysin, the dissociated Purkinje cells were transferred into a chamber on an inverted microscope. Spontaneous action potentials and potassium currents were recorded by standard patch-clamp techniques under current and voltageclamp modes respectively. 15 Purkinje cells revealed excitatory responses to 20 μM of sodium nitroprusside (SNP) and 4 neurons (20%) did not respond to SNP. Whole potassium currents of Purkinje cells were decreased by SNP (n=10). Whole potassium currents of Purkinje cells were also decreased by L-arginine, substrate of nitric oxide (n=10). These experimental results suggest that nitric oxide increases the neuronal activity of Purkinje cells by altering the resting membrane potential and afterhyperpolarization.

Effect of Histone Deacetylase Inhibitors on Differentiation of Human Bone Marrow-derived Stem Cells Into Neuron-like Cells

Jang, Sujeong,Park, Seokho,Cho, Hyong-Ho,Yang, Ung,Kang, Maru,Park, Jong-Seong,Park, Sah-Hoon,Jeong, Han-Seong The Basic Science Institute Chosun University 2019 조선자연과학논문집 Vol.12 No.4

Mesenchymal stem cells (MSCs) are known to differentiate into multiple lineages, making neurogenic differentiation an important target in the clinical field. In the present study, we induced the neurogenic differentiation of cells using histone deacetylase (HDAC) inhibitors and studied their mechanisms for further differentiation in vitro. We treated cells with the HDAC inhibitors, MS-275 and NaB; and found that the cells had neuron-like features such as distinct bipolar or multipolar morphologies with branched processes. The mRNA expressions encoding for NEFL, MAP2, TUJ1, OLIG2, and SYT was significantly increased following HDAC inhibitors treatment compared to without HDAC inhibitors; high protein levels of MAP2 and Tuj1 were detected by immunofluorescence staining. We examined the mechanisms of differentiation and found that the Wnt signaling pathway and downstream mitogen-activate protein kinase were involved in neurogenic differentiation of MSCs. Importantly, Wnt4, Wnt5a/b, and Wnt11 protein levels were highly increased after treatment with NaB; signals were activated through the regulation of Dvl2 and Dvl3. Interestingly, NaB treatment increased the levels of JNK and upregulated JNK phosphorylation. After MS-275 treatment, Wnt protein levels were decreased and GSK-3β was phosphorylated. In this cell, HDAC inhibitors controlled the non-canonical Wnt expression by activating JNK phosphorylation and the canonical Wnt signaling by targeting GSK-3β.