The present study was performed to investigate the effects of NH3-N and nitrifying microorganisms on the increased BOD of downstream of the Yeongsan river in Gwangju. Water samples were collected periodically from the 13 sampling sites of rivers from April to October 2021 to monitor water qualities. In addition, the trends of nitrogenous biochemical oxygen demand (NBOD) and microbial clusters were analyzed by adding different NH3-N concentrations to the water samples. The monitoring results showed that NH3-N concentration in the Yeongsan river was 22 times increased after the inflow of discharged water from the Gwangju 1st public sewage treatment plant (G-1-PSTP). Increased NH3-N elevated NBOD levels through the nitrification process in the river, consequently, it would attribute to the increase of BOD in the Yeongsan river. Meanwhile, there was no proportional relation between NBOD and NH3-N concentrations. However, there was a significant difference in NBOD occurrence by sampling sites. Specifically, when 5 mg/L NH3-N was added, NBOD of the river sample showed 2-4 times higher values after the inflow of discharged water from G-1-PSTP. Therefore, it could be thought other factors such as microorganisms influence the elevated NBOD levels. Through next-generation sequencing analysis, nitrifying microorganisms such as Nitrosomonas, Nitroga, and Nitrospira (Genus) were detected in rivers samples, especially, the proportion of them was the highest in river samples after the inflow of discharged water from G-1-PSTP. These results indicated the effects of nitrifying microorganisms and NH3-N concentrations as important limiting factors on the increased NBOD levels in the rivers. Taken together, comprehensive strategies are needed not only to reduce the NH3-N concentration of discharged water but also to control discharged nitrifying microorganisms to effectively reduce the NBOD levels in the downstream of the Yeongsan river where discharged water from G-1-PSTP flows.

Mammalian oocytes are sensitive to psychological stress at each period of follicular development. Especially, thermal stress interfere with reproductive condition by inducing formation of reactive oxygen species (ROS) and oxidative stress (OS). ROS lead to oocyte apoptosis, weakening oocyte quality and lowering the fertilization rate. As a result, the pregnancy rate is lowered, leading to infertility. Thermal stress also seems to influence zygotes through physiological changes in the maternal environment surrounding them. Loss of developmental competence suggests hyperthermia-induced oxidative stress in embryos. Interest in organic Lonicera caerulea berries has increased in recent years. They are abundant in various health-improving materials. Berries that found from natural products can be as free as possible from the bioactive toxicity of the active ingredient without side effects, and it can be a big advantage because it can work. Mammalian oocytes are arrested at the first meiotic prophase stage and get their meiotic competence to produce offspring during the development of follicle. A series of nuclear and cytoplasmic maturations are involved in this process and these vary in temperature sensitivity. Our study demonstrated that L. caerulea can relieve the negative effects of maternal hyperthermia by reducing ROS level at the developmental stage.

Previous studies have shown that Lonicera caerulea has a chemical protective effect. Phenolic and vitamin C contained in Lonicera caerulea prevent cancer, diabetes and cardiovascular disease, lower blood pressure and delay the aging process. However, the antioxidant mechanism of male reproductive system to heat stress is still unknown. Male reproductive system is very sensitive to heat. When scrotum temperature increase, oxidative stress can occur. Oxidative stress affects sperm motility and spermatogenesis, resulting in infertility. Therefore, we investigated the antioxidant effect of L. Caerulea in male genitalia by inducing oxidative stress by artificially exposing the testicles to heat at 42 ° C. The experiment was performed by dividing the ICR mouse into four groups. Each group is n = 5. Control group (C) and heat stress group (HS) were oral gavage administered D.W. Honey berry group (HB) and Honeyberry / heat stress group (HB + HS) were oral gavage administered honey berry (250mg / kg / day). HS groups (n=5, per n=5) received heat stress by exposing their lower bodies in the water bath at 42℃ for 30 minutes. We confirmed that there was a significant difference in the motility, morphology and the number of sperms using CASA(computer-assisted semen analysis). Lipid peroxidation assay results showed heat causes oxidative stress in serum. This study is conducting to investigate the antioxidant effect of L. Caerulea. Histologically analyzed the testicular form of each group, the activity level of heat shock protein and the level of reactive oxygen species were measured by Western blot and the level of catalase and HSP-90 was examined by RT-PCR analysis. Thus, studies of testicular morphology, sperm kinetics, hormone levels, heat shock protein expression and antioxidant enzymes under heat stress have shown that L. Caerulea ingestion has Anti-oxidant and thermal protective activity on the testis by heat damage.

Cyanobacteria have been used as pollution indicator species in freshwater ecosystems, and identifying their fluctuations can be an important part about management of surface waters globally. Cyanotoxins produced by cyanobacteria are directly or indirectly a threat to human and environmental health. In order to confirm the potential risk of these cyanotoxins, the fluctuations of phytoplankton and phylogenetic analysis of cyanotoxin synthetase genes were conducted at each point in the Yeongsan River water system in Gwangju from November 2021 to October 2022. Diatoms which grow well in winter were dominant at 99.4 ~ 99.5%, and diatoms and green algae were dominant from the spring to autumn when the water temperature rises. Stephanodiscus spp. were dominant at 92.7 to 97.5 % at all sites in the winter, and Aulacoseira spp., which grow in warm water temperatures, were dominant in summer and autumn. Microcystis aeruginosa was dominant at 25.2% in summer only at site 5. mcyB and anaC have been detected as cyanotoxin synthetase genes. The phylogenetic tree of anaC could be divided into two groups (Group 1 & Group 2). Group 1 contained Aphanizomenon sp. and Cuspidothrix issatschenkoi. It is combined with Aphanizomenon sp. and Cuspidothrix issatschenkoi, which are known to produce cyanotoxins.

This study identified concentrations, toxicities, and sources of polycylic aromatic hydrocarbons (PAHs) and heavy metals in roadside sediment from different areas of Gwangju City. Samples were collected from 13 sites of heavy traffic area (TA), downtown area (DA) and park area (PA) during February and June in 2014. The results showed a wide distribution range of PAHs concentrations between 0.139 mg/kg and 1.740 mg/kg. The highest concentration of PAHs appeared in heavy traffic area (TA). The toxic equivalent quotients (TEQs) of PAHs in the roadside sediment ranged from 27 ng/g to 159 ng/g. The TEQs and PAHs ratio of heavy traffic area and downtown area was 9.1 to 11.0%, respectively. The contributions from potential sources to PAHs in roadside sediment were estimated by the principal component analysis (PCA) and diagnostic ratios between PAHs. Vehicular (gasoline and diesel engine) emissions were found to the predominant contributor of PAHs. The concentrations of heavy metals were highest in the heavy traffic areas. The correlation analysis among traffic intensity and heavy metals, showed that AADT correlates very strongly with Cr, Cu and Pb concentrations. From the results of pollution index (PI) calculation for roadside sediment, heavy traffic area was severly polluted by heavy metals such as Cr, Cu, Pb and Zn. Contaminants in roadside sediment were found to be much affected by the vehicles. Therefore, roadside deposited sediments would be expected to be managedon a regular basis.

Neural precursor cells (NPCs) with abilities to self-renew and differentiate into neurons are born in the subventricular zone of the hippocampus and the subgranular zone in the adult mammalian brain. NPCs maintain their population by symmetric cell division and neuronal cell differentiation started by asymmetric cell division. Asymmetric cell division produces two daughter cells with different cellular fates. It has been shown that multiple transcription factors, like homeodomain transcription factors and basic helix loop helix (bHLH) transcription factors, play cruel role in cell fate determination (Bertrand et al., 2002). Multipotent cortical progenitors are maintained in a proliferative state by bHLH factors including Id and Hes families. The transition from proliferation to neurogenesis involves a coordinate increase in the activity of proneural bHLH factors (Mash1, Neurogenin1, and Neurogenin2). As development proceeds, inhibition of proneural bHLH factors in cortical progenitors promotes the formation of astrocytes. Finally, the formation of oligodendrocytes is triggered by an increase in the activity of bHLH factors Olig1 and Olig2 that may be coupled with a decrease in Id activity. Thus, bHLH factors have key roles in corticogenesis, affecting the timing of differentiation and the specification of cell fate. Hes1 is a vertebrate homologue of the Drosophila bHLH protein Hairy, originally known as a transcriptional repressor that negatively regulates neuronal differentiation. Hes1 expression in neuronal precursors precedes and represses the expression of the neuronal commitment gene Mash1, a bHLH activator homologus to the proneuronal Achaete-Scute genes in Drosophila (Campuzano and Modolell, 1992). Down regulation of Hes1 expression in developing neuroblasts may be necessary for the induction of a regulatory cascade of bHLH activator proteins that controls the commitment and progression of neural differentiation. Expression of Hes1 inhibited neurite outgrowth, whereas Mash1 expression increased neurite outgrowth. Mash1 can induce bipolar neuron differentiation (Tomita et al., 1996) and NSCs culture obtained from Mash1-/- mice cannot differentiate into GBAergic neurons (Oishi et al., 2009) Hes1 is an essential effector for Notch signaling, which regulates the maintenance of undifferentiated cells (Artavanis-Tsakonas et al., 1999). In contrast, it is previously reported that platelet-derived growth factor induces the expression of Mash1 mRNA by regulating the phosphorylation of Hes1 and TLE1 (Ju et al., 2004). Hes1 is required for neuronal differentiation in PDGF treated NSC cultures. The major cell types in the cerebral cortex and hippocampus are the glutamatergic neurons and the GABAergic neurons. Cholinergic neurons are important in spatial learning and memory formation and depleted in patient’s brain of early Alzheimer’s disease. It has not been clear, however, whether new born adult NPCs could generate different cell types of neurons with distinct cellular and physiological properties. During the development, glutamatergic neurons consisting of radially migrating neurons are originated from the ventricular zone of the dorsal telenchephalon (pallium) and give rise to pyramidal neurons. Glutamate and glutamate receptors are involved in cognitive functions by forming major excitatory network. GABAergic neurons in the neocortex and hippocampus are in part migrated from the ventral telenchephalon or from the dorsal NPCs and function as local interneurons by forming inhibitory networks which regulate large populations of glutamatergic pyramidal neurons. During the development, spatiotemporal gene expression regulated by extracellular signaling factors is believed to determine the formation of neuronal phenotypes. Platelet derived growth factor B is known to induce the differentiation into neurons rather than glial cells in the rat NPCs. We found that platelet derived growth factor B is expressed in dorsal cortex and hippocampus more than in ventral cortex in the period of pyramidal cell differentiation of the embryonic rat brain. It indeed induces cell type specific differentiation into glutamatergic cells that produce the glutamate transpoter, vGluT1 and glutamate at the late stage of differentiation although it promotes neuronal differentiation at the early stage in NPCs primarily cultured from the rat embryonic hippocampus. Brain-derived neurotrophic factor, however, facilitated GABAergic differentiation in the hippocampal NPCs that generate glutamatergic pyramidal cells in a similar manner. We also found many transcriptional factors such as homeobox genes (Dlx1, Nkx2.1, Pax6) and bHLH genes (NeuroD, Ngn1, Hes1) are involved in cell type specific differentiation into glutamatergic, GABAergic, and cholinergic cells. We observed the expression of Pax6, homeodomain transcription factor, and Hes1, bHLH transcription factor, increased during PDGF-induced early differentiation in neural stem cells. These transcription factors, however, are also expressed in differentiated neurons with specific phenotype at late differentiation stage. We found pax6 is expressed in cholinergic neurons in the adult brains and in cultures. Phosphorylation of neurogenic transcription factors by protein kinases has been reported as predominant strategy in gene regulation during neuronal development and these regulated activities of different transcription factors are known to be involved in cell fate determination. Homeodomaininteracting protein kinases2 (HIPK2) which belongs to HIPK family has been identified as a nuclear serine-threonine kinase and is known to interact with several transcription factors to regulate gene transcriptions. Among several transcription factors, HIPK2 is mainly reported to target the homeodomain transcription factors such as Nkx and Pax6. Considering the importance of homeodomain transcription factors in neurogenesis and differentiation, HIPK2 also seem to play critical roles in those transcriptional regulations during embryogenesis. To define the roles of HIPK2 in neuronal differentiation during embryonic development, we investigated the expression patterns of neurogenic transcription factors such as Pax6, Hes1 and Mash1 in HIPK2 overexpressing NSCs. Hes1 showed different expression patterns between the wild type and mutant HIPK2 overexpressed cells and Mash1, which is reported to be repressed by Hes1, also showed altered expression patterns. We detected the mRNA expression of Hes1 is upregulated by HIPK2 during neuronal differentiation. The overexpressed Pax6 induced differentiation of neural stem cells into cholinergic neurons and suppressed differentiation into GABAnergic neuron both in vitro and in vivo transplantation study. To evaluate the effect of Pax6 on the transcriptional activation of Hes1 promoter, we performed luciferase reporter assay in NIH3T3 cells. Reporter expression of Hes1 promoter was enhanced upon stimulation with wild type Pax6 and wild type HIPK2. Furthermore, the HDAC inhibition mediated by TSA(Trichostatin A) has been shown to repress the reporter expression. The treatment of TSA increased neurofilaments and GAD expression in E14.5 cortical neuronal cell. These findings suggest that Pax6 promotes neuronal subtype differentiation via regulation of Hes1 bHLH transcription factor, which is mediated by HDAC. To examine the effect of Pax6 and HIPK2 on the transcriptional activation of Hes1, efficiency of hes1 promoter was measured by a luciferase reporter assay. When DNA constructs encoding Pax6 and HIPK2 were transfected along with Hes1 promoter, the expression of the reporter was highly increased. Furthermore, the HDAC inhibition mediated by TSA(Trichostatin A) repressed the reporter expression. Interaction of Pax6 and HIPK2 was shown by co-immunoprecipitation and binding of Pax6 to hes1 promoter was detected by chromatin immunoprecipitation. I also found overexpression of HIPK2 and Pax6 facilitated neural stem cells to differentiate into cholinergic cell fate in NSCs primarily cultured from the rat hippocampus. This is also supported by analysis of the brains of sey/neu Pax6 mutant mice and HIPK2 knock out mice. These findings suggest that Pax6 activation by HIPK2 promotes neuronal subtype differentiation via up regulation of Hes1 and down regulation of Mash1 and it is mediated by HDAC.