Conophylline Promotes the Proliferation of Immortalized Mesenchymal Stem Cells Derived from Fetal Porcine Pancreas (iPMSCs)

Conophylline, is a bis （indole） alkaloid consisting of two pentacyclic aspidosperma skeletons, isolated from Tabernaemontana divaricata, which has been found to induce β-cell differentiation in rat pancreatic acinar carcinoma cells and in cultured rat pancreatic tissue. However, the precise role of conophylline in the growth and survival of immortalized pancreatic mesenchymal stem cells （iPMSCs） derived from fetal porcine pancreas were not understood at present. To determine whether this molecule is involved in controlling the proliferation of iPMSCs, we examined the effects of conophylline on iPMSCs. We found that conophylline can robustly stimulate iPMSCs proliferation, even promote their potential differentiation into islet-like clusters analyzed by cell counting, morphology, RT-PCR and real-time PCR, Western blotting, glucose-stimulated insulin release and insulin content analysis. The effects of conophylline were inhibited by LY294002, which is the inhibitor of the PI3K pathway. These results suggest that conophylline plays a key role in the regulation of cell mass proliferation, maintenance of the undifferentiated state of iPMSCs and also promotes iPMSCs differentiated into insulin-producing cells.

Effects of 13 T Static Magnetic Fields (SMF) in the Cell Cycle Distribution and Cell Viability in Immortalized Hamster Cells and Human Primary Fibroblasts Cells

Magnetic resonance image （MRI） systems with a much higher magnetic flux density were developed and applied for potential use in medical diagnostic. Recently, much attention has been paid to the biological effects of static, strong magnetic fields （SMF）. With the 13 T SMF facility in the Institute of Plasma Physics, Chinese Academy of Sciences, the present study focused on the cellular effects of the SMF with 13 T on the cell viability and the cell cycle distribution in immortalized hamster cells, such as human-hamster hybrid （AL） cells, Chinese hamster ovary （CHO） cells, DNA double-strand break repair deficient mutant （XRS-5） cells, and human primary skin fibroblasts （AG1522） cells. It was found that the exposure of 13 T SMF had less effect on the colony formation in either nonsynchronized or synchronized AL cells. Moreover, as compared to non-exposed groups, there were slight differences in the cell cycle distribution no matter in either synchronized or nonsynchronized immortalized hamster ceils after exposure to 13 T SMF. However, it should be noted that the percentage of exposed AG1522 cells at G0/G1 phase was decreased by 10% as compared to the controls. Our data indicated that although 13 T SMF had minimal effects in immortalized hamster cells, the cell cycle distribution was slightly modified by SMF in human primary fibroblasts.

Efficient generation of functional hepatocytelike cells from mouse liver progenitor cells via indirect co-culture with immortalized human hepatic stellate cells

BACKGROUND： Differentiation of liver progenitor cells（LPCs） to functional hepatocytes holds great potential to develop new strategies for hepatocyte transplantation and the screening of drug-induced cytotoxicity. However, reports on the efficient and convenient hepatic differentiation of LPCs to hepatocytes are few. The present study aims to investigate the possibility of generating functional hepatocytes from LPCs in an indirect co-culture system.METHODS： Mouse LPCs were co-cultured in Transwell plates with an immortalized human hepatic stellate cell line（HSCLi） we previously established. The morphology, expression of hepatic markers, and functions of mouse LPC-derived cells were monitored and compared with those of conventionally cultured LPCs. RESULTS： Co-culturing with HSC-Li cells induced differentiation of mouse LPCs into functional hepatocyte-like cells. The differentiated cells were morphologically transformed into hepatocyte-like cells 3 days after co-culture initiation. In addition, the differentiated cells expressed liver-specific genes and possessed hepatic functions, including glycogen storage, lowdensity lipoprotein uptake, albumin secretion, urea synthesis, and cytochrome P450 1A2 enzymatic activity.CONCLUSIONS： Our method, which employs indirect co-culture with HSC-Li cells, can efficiently induce the differentiation of LPCs into functional hepatocytes. This finding suggests that this co-culture system can be a useful method for the efficient generation of functional hepatocytes from LPCs.

Expression of hepatitis B virus 1.3-fold genome plasmid in an SV40 T-antigen-immortalized mouse hepatic cell line

AIM:To investigate the expression of the hepatitis B virus(HBV)1.3-fold genome plasmid(pHBV1.3)in an immortalized mouse hepatic cell line induced by SV40T-antigen(SV40T)expression.METHODS:Mouse hepatic cells were isolated from mouse liver tissue fragments from 3-5 d old Kunming mice by the direct collagenase digestion method and cultured in vitro.The pRSV-T plasmid was transfected into mouse hepatic cells to establish an SV40LT-immortalized mouse hepatic cell line.The SV40LT-immortalized mouse hepatic cells were identified and transfected with the pHBV1.3 plasmid.The levels of hepatitis B surface antigen(HBsAg)and hepatitis B e antigen(HBeAg)in the supernatant were determined by an electrochemiluminescence immunoassay at 24,48,72 and 96 h after transfection.The expressions of HBsAg and hepatitis B c antigen(HBcAg)in the cells were investigated by indirect immunofluorescence analysis.The presence of HBV DNA replication intermediates in the transfected cells and viral particles in the supernatant of the transfected cell cultures was monitored using the Southern hybridization assay and transmission electronic microscopy,respectively.RESULTS:The pRSV-T plasmid was used to immortalize mouse hepatocytes and an SV40LT-immortalized mouse hepatic cell line was successfully established.SV40LT-immortalized mouse hepatic cells have the same morphology and growth characteristics as primary mouse hepatic cells can be subcultured and produce albumin and cytokeratin-18 in vitro.Immortalized mouse hepatic cells did not show the characteristics of tumor cells,as alpha-fetoprotein levels were comparable(0.58±0.37 vs 0.61±0.31,P=0.37).SV40LTimmortalized mouse hepatic cells were then transfected with the pHBV1.3 plasmid,and it was found that the HBV genome replicated in SV40LT-immortalized mouse hepatic cells.The levels of HBsAg and HBeAg continuously increased in the supernatant after the transfection of pHBV1.3,and began to decrease 72 h after transfection.The expressions of HBsAg and HBcAg were observed in the pHBV1.3-transfected cells.HBV DNA replication intermediates were also observed at72 h after transfection,including relaxed circular DNA,double-stranded DNA and single-stranded DNA.Furthermore,a few 42 nm Dane particles,as well as many22 nm subviral particles with a spherical or filamentous shape,were detected in the supernatant.CONCLUSION:SV40T expression can immortalize mouse hepatic cells,and the pHBV1.3-transfected SV40T-immortalized mouse hepatic cell line can be a new in vitro cell model.

Immortalized Rat Astrocyte Strain Genetically Modified by Rat Preprogalanin Gene

Summary: To construct an immortalized rat astrocyte strain genetically modified by rat preprogalanin gene (IAST/GAL) and detect its galanin (GAL) expression and secretion, a cDNA fragment of rat GAL in plasmid of pBS KS(+)-GAL was inserted into eukaryotic expression vector pcDNA3.1(+) by DNA recombinant technology, then the restriction enzyme digestion and DNA sequencing were carried out to evaluate the recombinant. The pcDNA3.1(+)-GAL and pcDNA3.1(+) construct were transfected into immortalized rat astrocyte strain (IAST) by lipofectamine and the population of cells which stably integrated the construct was selected with 600 μg/mL G418. Individual clones were screened and expanded into clonal cell strains. Detection of Neo gene was used to validate the success of the transfection. Immunocytochemical staining, RT-PCR and radioimmunoassay were used to detect the expression and secretion level of GAL. The recombinant had been successfully constructed by restriction enzyme digestion and DNA sequencing. Detection of Neo gene showed that the pcDNA3.1(+)-GAL and pcDNA3.1(+) have been successfully transfected into IAST. After selection by using G418, IAST/GAL and IAST/Neo cell strains were obtained. IAST/GAL, IAST/Neo and IAST were immunostained positively for GAL, but the GAL average optical density of IAST/GAL was significantly higher than that of IAST/Neo and IAST (P< 0.01). The level of GAL mRNA expression and the supernatant concentration of GAL in cultured IAST/GAL were significantly higher than those of IAST and IAST/Neo (P<0.01), but no significant differences were found between the IAST and IAST/Neo (P>0.05). It was concluded that IAST/GAL strain was constructed successfully and it might provide a basis for the further study of pain therapy.

Immortalized Sertoli cell lines sk11 and sk9 and binding of spermatids in vitro

Aim： To determine the effectiveness of the ski 1, sk9 and ski 1 TNUA5 Sertoli cell lines in binding germ cells in vitro. Methods： The immortalized Sertoli cell lines sk9, ski 1 and ski 1 TNUA5 were used in co-culture experiments with germ cells in media with or without reproductive hormones and incubated for 44 h at 32℃. The number of germ cells bound to Sertoli cells was then determined and statistically analyzed. Western blot analysis and reverse transcriptasepolymerase chain reaction （RT-PCR） studies were employed to investigate the presence of cell adhesion proteins and follicle stimulating hormone （FSH） receptor, respectively. Results： No statistical difference between the number of bound step-8 spermatids and bound pre-step 8 spermatids on Sertoli cells from any of the cell lines existed. After the addition of germ cells, Sertoli ceils showed more lipid accumulation in their cytoplasm, indicating active phagocytosis. Western blot analysis in the ski I TNUA5 line indicated the expression of N-cadherin. FSH-only and testosterone-only treatments increased N-cadherin expression, regardless of germ cell addition. The addition of germ cells to the ski l TNUA5 Sertoli cells increased the expression of espin, as did the addition of FSH with germ cells. RT-PCR studies of the ski I TNUA5 cells indicated that the mRNA for FSH receptor decreased with successive passages. Conclusion： In vitro binding between isolated germ cells and sk9, skll or skll TNUA5 Sertoli cells is not feasible, and therefore these cell lines are not useful for the in vitro investigation of Sertoli-germ cell interactions and primary Sertoli cell isolates must still be used.

Genetic dissection of ear-related traits using immortalized F2 population in maize

Ear-related traits are often selection targets for maize improvement. This study used an immortalized F(IF) population to elucidate the genetic basis of ear-related traits. Twelve ear-related traits(namely, row number(RN), kernel number per row(KNPR), ear length(EL), ear diameter(ED), ten-kernel thickness(TKT), ear weight(EW), cob diameter(CD),kernel length(KL), kernel width(KW), grain weight per ear(GW), 100-kernel weight(HKW), and grain yield per plot(GY)),were collected from the IFpopulation. The ear-related traits were comprised of 265 crosses derived from 516 individuals of the recombinant inbred lines(RILs) under two separated environments in 2017 and 2018, respectively. Quantitative trait loci(QTLs) analyses identified 165 ear traits related QTLs, which explained phenotypic variation ranging from 0.1 to 12.66%. Among the 165 QTLs, 19 underlying nine ear-related traits(CD, ED, GY, RN, TKT, HKW, KL, GW, and KNPR)were identified across multiple environments and recognized as reliable QTLs. Furthermore, 44.85% of the total QTLs showed an overdominance effect, and 12.72% showed a dominance effect. Additionally, we found 35 genomic regions exhibiting pleiotropic effects across the whole maize genome, and 17 heterotic loci(HLs) for RN, EL, ED and EW were identified. The results provide insights into genetic components of ear-related traits and enhance the understanding of the genetic basis of heterosis in maize.

Effects of plasma from patients with acute on chronic liver failure on function of cytochrome P450 in immortalized human hepatocytes

BACKGROUND: The bioartificial liver is anticipated to be a promising alternative choice for patients with liver failure. Toxic substances which accumulate in the patients' plasma exert deleterious effects on hepatocytes in the bioreactor, and potentially reduce the efficacy of bioartificial liver devices. This study was designed to investigate the effects of plasma from patients with acute on chronic liver failure (AoCLF) on immortalized human hepatocytes in terms of cytochrome P450 gene expression, drug metabolism activity and detoxification capability. METHODS: Immortalized human hepatocytes (HepLi-2 cells) were cultured in medium containing fetal calf serum or human plasma from three patients with AoCLF. The cytochrome P450 (CYP3A5, CYP2E1, CYP3A4) expression, drug metabolism activity and detoxification capability of HepLi-2 cells were assessed by RT-PCR, lidocaine clearance and ammonia elimination assay. RESULTS: After incubation in medium containing AoCLF plasma for 24 hours, the cytochrome P450 mRNA expression of HepLi-2 cells was not significantly decreased compared with control culture. Ammonia elimination and lidocaine clearance assay showed that the ability of ammonia removal and drug metabolism remained stable. CONCLUSIONS: Immortalized human hepatocytes can be exposed to AoCLF plasma for at least 24 hours with no significant reduction in the function of cytochrome P450. HepLi-2 cells appear to be effective in metabolism and detoxification and can be potentially used in the development of bioartificial liver. (Hepatobiliary Pancreat Dis Int 2010; 9:611-614)

Establishment and characterization of immortalized bovine male germline stem cell line

Male germline stem cells （mGSCs） are unique adult germ cells with self-renewal potential and spermatogenesis function in the testis. However, further studies are needed to establish a long-term cultural system of mGSCs in vitro, especially for large animals such as bovine mGSCs. In this study, we first established a stable immortalized bovine male germline stem cell line by transducing Simian virus 40 （SV40） large T antigen. The proliferation of these cells was improved significantly. These cells could express spermatogonial stem cell （SSC）-specific markers, such as PLZF, PGP9.5, VASA, LIN28A, and CD49F, both in the mRNA and protein levels. Additionally, these cells could be differentiated into three germ layer cells to enter meiosis, form colonies, and proliferate in the seminiferous tubules of busulfan-induced infertile mice. The immortalized bovine mGSCs maintain the criteria of mGSCs.

Immortalized hippocampal astrocytes from 3xTg-AD mice,a new model to study disease-related astrocytic dysfunction:a comparative review

Alzheimer's disease(AD)is characterized by complex etiology,long-lasting pathogenesis,and celltype-specific alterations.Currently,there is no cure for AD,emphasizing the urgent need for a comprehensive understanding of cell-specific pathology.Astrocytes,principal homeostatic cells of the central nervous system,are key players in the pathogenesis of neurodegenerative diseases,including AD.Cellular models greatly facilitate the investigation of cell-specific pathological alterations and the dissection of molecular mechanisms and pathways.Tumor-derived and immortalized astrocytic cell lines,alongside the emerging technology of adult induced pluripotent stem cells,are widely used to study cellular dysfunction in AD.Surprisingly,no stable cell lines were available from genetic mouse AD models.Recently,we established immortalized hippocampal astroglial cell lines from amyloid-βprecursor protein/presenilin-1/Tau triple-transgenic(3xTg)-AD mice(denominated as wild type(WT)-and 3Tg-iAstro cells)using retrovirus-mediated transduction of simian virus 40 large T-antigen and propagation without clonal selection,thereby maintaining natural heterogeneity of primary cultures.Several groups have successfully used 3Tg-iAstro cells for single-cell and omics approaches to study astrocytic AD-related alterations of calcium signaling,mitochondrial dysfunctions,disproteostasis,altered homeostatic and signaling support to neurons,and blood-brain barrier models.Here we provide a comparative overview of the most used models to study astrocytes in vitro,such as primary culture,tumor-derived cell lines,immortalized astroglial cell lines,and induced pluripotent stem cell-derived astrocytes.We conclude that immortalized WT-and 3Tg-iAstro cells provide a noncompetitive but complementary,low-cost,easy-to-handle,and versatile cellular model for dissection of astrocyte-specific AD-related alterations and preclinical drug discovery.

Establishment of Immortalized Cow Mammary Epithelial Cells Expressing Both h TERT and SV40 T

Vectors of pcDNA3.1-hTERT and pcDNA 3. 1-SV40 T were established. After linearization, they were cotransfected to mammary epithelial cells of Holstein cow, in order to research on the role of hTERT and SV40 T in immortalized mammary epithelial cells in vitro. Both PT-PCR and immunohistochemical as- says of cells were carried out. Results showed that the expression of hTERT and SV40 T could effectively prolong the culture time in vitro of mammary epithelial cells, and enhance the cell passage number. The obtained cell line could be expressed normally, indicating that the in vitro cultured mammary epithelial cells expressing both hTERT and SV40 T could effectively prolong cell llfe without affecting the characteristics of mammary cells.

EXPERIMENTAL STUDY OF THE DIFFERENTIATION HPV16 SUBGENES-IMMORTALIZED HUMAN ENDOCERVICAL CELLS INDUCED BY ALL-TRANS-RETINOIC ACID

Objective： To investigate the differentiation-inducing effects of all-trans-retinoic （ATRA） to HPV16 subgenesimmortalized human l：ndocervical cells （H8 cell） in vitro. Methods： HPV16 subgenes-immortalized human endocervical cells （H8 cells） were cultured in vitro. After treated with ATRA, the proliferation of immortalized human endocervical cells was measured by MTT assay; morphological changes were observed using M and TEM; cell cycle was analyzed by FCM; expression of Ki67 was tested using immunocytochemistry and the activity of telomerase was tested using PCR-ELISA. Results： ATRA could inhibit proliferation of H8 cells significantly and induce their morphodifferentiation. According to FCM, H8 cells accumulated in G1 phase and expression of Ki67 and activity of telomerase reduced significantly after treatment with ATRA. Conclusion： ATRA could induce the differentiation of H8 cell line obviously, which might be achieved by inhibiting proliferation, blocking cell cycle, and reducing activity of telomerase.

Cilia containing 9+2 structures grown from immortalized cells

Cilia depend on their highly differentiated structure, a 9 ＋ 2 arrangement, to remove particles from the lung and to transport reproductive cells. Immortalized cells could potentially be of great use in cilia research. Immortalization of cells with cilia structure containing the 9 ＋ 2 arrangement might be able to generate cell lines with such cilia structure. How- ever, whether immortalized cells can retain such a highly differentiated structure remains unclear. Here we demonstrate that （1） using Ela gene transfection, tracheal cells are immortalized; （2） interestingly, in a gel culture the immortalized cells form spherical aggregations within which a lumen is developed; and （3） surprisingly, inside the aggregation, cilia containing a 9 ＋ 2 arrangement grow from the cell＇s apical pole and protrude into the lumen. These results may influence future research in many areas such as understanding the mechanisms of cilia differentiation, cilia generation in other existing cell lines, cilia disorders, generation of other highly differentiated structures besides cilia using the gel culture, immortalization of other ciliated cells with the Ela gene, development of cilia motile function, and establishment of a research model to provide uniform ciliated cells.

Inhibitory Effect of Nordy on HPV16 E6 Gene in Human Immortalized Endocervical Cells

Objective： To study the inhibitory effect of Nordy on HPV16 E6 gene in human immortalized endocervical cells （H8）. Methods： The expressions of E6 and p53 proteins of H8 cells were detected by immunocytochemistry, and the expression of HPV16E6 mRNA of H8 cells was detected by RT-PCR. Results： According to immunocytochemistry, expressions of E6 and p53 proteins of H8 cells after treatment with 100 μtmol/L Nordy for 72 h were weaker than control group obviously. After treatment with 50, 100, 200 μmol/L Nordy for 72 h. HPV16E6 mRNA expressions of H8 cells were lower than the control group significantly （P〈0.05）. Conclusion： Nordy could inhibit the expression of HPV16 E6 mRNA in H8 cells, influence transcription of E6 gene and result in decreased expressions of E6 and p53 proteins.

Generation of functionally mature neurons from a telomerase-immortalized human glial progenitor cell line

BACKGROUND： It has long been thought that neurons and glial cells are produced from distinct progenitor pools, but recent studies suggest that the glial progenitor cell in the subventricular zone can generate neurons in the adult rodent brain. OBJECTIVE： To investigate the ability of a telomerase-immortalized human glial progenitor cell line to differentiate into functionally mature neurons. DESIGN, TIME AND SETTING： The cellular and molecular biology experiment was performed at the Cell Biology Laboratory in the School of Basic Medical Sciences, Peking University Health Science Center, between July 2007 and May 2008. MATERIALS： A telomerase reverse transcriptase immortalized human glial progenitor cell line, was established in our laboratory. Dibutyryl cyclic AMP was purchased from Sigma （USA）. Specific antibodies against glial fibrillary acidic protein, ~ -tubulin-Ⅲand A2B5 were purchased from Chemicon, USA. Polyclonal antibodies against nestin and MAP2ab were obtained from Neomarker, USA. METHODS： The telomerase immortalized human glial progenitor cell line was passaged and maintained in growth medium consisting of DMEM/F12 （1：1） with N2 supplement （1%, v/v）, L-Glutamine （2 mmol/L）, epidermal growth factor （20 ng/mL）, basic fibroblast growth factor （20 ng/mL） and 3% fetal bovine serum. Neuronal differentiation was induced by the addition of 1 mmol/L dibutyryl cyclic AMP and 10% fetal bovine serum. MAIN OUTCOME MEASURES： Neuronal differentiation was evaluated by RT-PCR, quantitative PCR, immunofluorescence staining, Western blot analysis and electrophysiology. RESULTS： After dibutyryl cyclic AMP induction in the telomerase immortalized human glial progenitor cells, the expression of neuronal-specific marker mRNAs and proteins increased significantly. Concurrently, an apparent fast inward Na^＋ current was evoked in the cells after induction. CONCLUSION： This study suggests that some human glial progenitor ceils are indeed capable of generating functionally mature neurons, and such cells may be useful for treating human neurological disorders.

Effects of Nordy on the proliferation, differentiation,and apoptosis of HPV16 subgene-immortalized human endocervical cells

Objective The aim of this study was to investigate the effects of Nordy on the proliferation, differentiation, and apoptosis of HPV16 subgene-immortalized human endocervical cells(H8 cells).Methods After treatment with Nordy, H8 cell proliferation was evaluated using the MTT assay. The effects of Nordy on the cell cycle and apoptosis of H8 cells were analyzed by flow cytometry(FCM) and the Annexin V-FITC method. H8 cell MCM5 expression was detected by immunocytochemistry. Morphological changes were observed by light and electron microscopy. Telomerase activity was evaluated by TRAP-ELISA.Results We found that 10 μmol/L–100 μmol/L Nordy significantly inhibited H8 cell proliferation. After treatment with Nordy, H8 cells were blocked in the G0/G1 phase, and the rate of cell apoptosis increased significantly. Cells differentiated toward innocuousness, and MCM5 expression and telomerase activity notably decreased.Conclusion Nordy was observed to inhibit proliferation and promote apoptosis in H8 cells. Nordy also induced H8 cell differentiation; this effect may have been achieved by blocking the cell cycle and decreasing telomerase activity.

Advancing Environmental Toxicology In Vitro:From Immortalized Cancer Cell Lines to 3D Models Derived from Stem Cells

In recent years,rapid industrial development has resulted in the production and exposure of a substantial number of compounds to the human body.This has created an urgent need in environmental toxicology for models that are efficient,accurate,and cost-effective in evaluating the health impacts of these compounds on humans.Over the past seven decades,various cancer cell lines and immortalized cell lines have made significant contributions to the advancement of research on organ toxicity.Pluripotent stem cell technology,especially toxicological models derived from pluripotent stem cells,presents modern environmental toxicologists with high-throughput,species-relevant,and predictive options.In this comprehensive review,we assess the characteristics of representative human cancer cell lines and immortalized cell lines in environmental toxicology,as well as introduce two distinct human pluripotent stem cell types and their innovative toxicological models.We explore their applications and prospects in the field of environmental toxicology,while also addressing the readiness of in vitro models to confront the emerging challenges of the future.

Photobiomodulation:a novel approach to promote trans-differentiation of adipose-derived stem cells into neuronal-like cells

Photobiomodulation,originally used red and near-infrared lasers,can alter cellular metabolism.It has been demonstrated that the visible spectrum at 451-540 nm does not necessarily increase cell proliferation,near-infrared light promotes adipose stem cell proliferation and affects adipose stem cell migration,which is necessary for the cells homing to the site of injury.In this in vitro study,we explored the potential of adipose-derived stem cells to differentiate into neurons for future translational regenerative treatments in neurodegenerative disorders and brain injuries.We investigated the effects of various biological and chemical inducers on trans-differentiation and evaluated the impact of photobiomodulation using 825 nm near-infrared and 525 nm green laser light at 5 J/cm2.As adipose-derived stem cells can be used in autologous grafting and photobiomodulation has been shown to have biostimulatory effects.Our findings reveal that adipose-derived stem cells can indeed trans-differentiate into neuronal cells when exposed to inducers,with pre-induced cells exhibiting higher rates of proliferation and trans-differentiation compared with the control group.Interestingly,green laser light stimulation led to notable morphological changes indicative of enhanced trans-differentiation,while near-infrared photobiomodulation notably increased the expression of neuronal markers.Through biochemical analysis and enzyme-linked immunosorbent assays,we observed marked improvements in viability,proliferation,membrane permeability,and mitochondrial membrane potential,as well as increased protein levels of neuron-specific enolase and ciliary neurotrophic factor.Overall,our results demonstrate the efficacy of photobiomodulation in enhancing the trans-differentiation ability of adipose-derived stem cells,offering promising prospects for their use in regenerative medicine for neurodegenerative disorders and brain injuries.

Genetic Components of Heterosis for Seedling Traits in an Elite Rice Hybrid Analyzed Using an Immortalized F2 Population

Utilization of heterosis has greatly contributed to rice productivity in China and many Asian countries. Superior hybrids usually show heterosis at two stages： canopy development at vegetative stage and panicle development at reproductive stage resulting in heterosis in yield. Although the genetic basis of heterosis in rice has been extensively investigated, all the previous studies focused on yield traits at maturity stage. In this study, we analyzed the genetic basis of heterosis at seedling stage making use of an ＂immortalized F2＂ population composed of 105 hybrids produced by intercrossing recombinant inbred lines （RILs） from a cross between Zhenshan 97 and Minghui 63, the parents of Shanyou 63, which is an elite hybrid widely grown in China. Eight seedling traits, seedling height, tiller number, leaf number, root number, maximum root length, root dry weight, shoot dry weight and total dry weight, were investigated using hydroponic culture. We analyzed single-locus and digenic genetic effects at the whole genome level using an ultrahigh-density SNP bin map obtained by population re-sequencing. The analysis revealed large numbers of heterotic effects for seedling traits including dominance, over- dominance and digenic dominance （epistasis） in both positive and negative directions. Overdominance effects were prevalent for all the traits, and digenic dominance effects also accounted for a large portion of the genetic effects. The results suggested that cumulative small advantages of the single-locus effects and two-locus interactions, most of which could not be detected statistically, could explain the genetic basis of seedling heterosis of the F1 hybrid.