Publications by authors named "Yong Pil Cheon"
Prion protein (PrP) is highly conserved and is expressed in most tissues in a developmental stage-specific manner. Glycosylated cellular prion protein (PrP) is found in most cells and subcellular areas as a physiological regulating molecule. On the other hand, the amyloid form of PrP, scrapie PrP (PrP), causes transmissible pathogenesis in the central nervous system and induces degeneration of the nervous system.
View Article and Find Full Text PDFCellular prion protein (PrP) encoded at gene is well-known to form a misfolded isoform, termed scrapie PrP (PrP) that cause transmissible degenerative diseases in central nervous system. The physiological role of PrP has been proposed by many studies, showing that PrP interacts with various intracellular, membrane, and extracellular molecules including mitochondrial inner membrane as a scaffold. PrP is expressed in most cell types including reproductive organs.
View Article and Find Full Text PDFPreviously, we showed that a chronic-low-dose nonylphenol (NP) exposure resulted in histological changes with sexually dimorphic pattern in rat adrenal glands. We hypothesized that such structural changes are closely related to the hormonal secretory patterns. To test this hypothesis, we developed the short-term adrenal incubation method, and measured the levels of catecholamines and cortical steroids using the high-performance liquid chromatography with electrochemical detection (HPLC-ECD) and specific enzyme-linked immunosorbent assay, respectively.
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- Gestational exposure to Bisphenol A (BPA) significantly impacts the uterine tissues of adult female offspring rats, revealing important epigenetic changes.* -
- DNA methylation analysis showed that this exposure leads to hypomethylation in the uterus, possibly explaining the increased expression of progesterone receptors (PR) in BPA-exposed groups.* -
- The results suggest a connection between BPA exposure, altered DNA methylation, and heightened PR levels, indicating that environmental chemicals can induce long-term effects on reproductive health.*
Article Synopsis
- Acetaminophen, a common pain reliever, can cause testicular damage and impair liver and kidney functions with high doses or long-term use.
- A study on male golden hamsters divided them into groups receiving different acetaminophen doses and control conditions over 4 weeks, revealing that high doses led to small testicles without sperm.
- The findings suggest that acetaminophen negatively impacts testicular health, causing regression in sperm production, especially when comparing treated animals to those in short photoperiod conditions.
Article Synopsis
- The study focuses on synthesizing non-toxic zinc oxide nanoparticles (ZnO NPs) from marine algae (Sargassum polycystum) due to concerns about their environmental impact and lack of regulation.* -
- Characterization methods showed that these nanoparticles are rod-shaped with an average diameter of about 100 nm and exhibit specific crystal properties.* -
- Toxicity tests using zebra fish larvae indicated that ZnO NPs caused developmental delays, increased deformities, oxidative stress, and changes in cellular activity, highlighting potential risks even with green synthesis methods.*
Synthesis and anti-prion aggregation activity of acylthiosemicarbazide analogues.
J Enzyme Inhib Med Chem
December 2023
Article Synopsis
- Prions are misfolded proteins that cause prion diseases by forming amyloids, which disrupt brain function and convert normal proteins into their harmful forms.
- Recent research identified acylthiosemicarbazides as effective inhibitors of prion aggregation, achieving nearly complete inhibition in lab tests.
- These compounds not only reduce the formation of new prions but also disassemble existing aggregates, showing promise as potential treatments for prion infections.
Article Synopsis
- Kisspeptins, derived from the KISS1 gene, are crucial regulators of GnRH neurons through their interaction with the GPR54 receptor, playing a key role in reproductive hormone signaling.
- The study investigates the presence of kisspeptin in Syrian hamster testes using RT-PCR and immunohistochemistry techniques, revealing detectable levels of kisspeptin in Leydig cells and some germ cells.
- These findings contribute to understanding the function of kisspeptin in hamster testes and its potential implications for reproductive physiology, particularly regarding the impact of photoperiod on gonadal regression.
Article Synopsis
- Uterine endometrial differentiation is crucial for female health, and there is a need for an effective in vitro model to study implantation and uterine responses.
- The new FSS (FHS mimic-stimulated synchronized) model uses primary mouse uterine stromal cells from eCG-primed mice and shows effective differentiation into cells similar to those in a natural pregnancy.
- Results indicate that the FSS model outperforms traditional models in specific markers and provides a flexible platform for studying endometrial diseases and embryo implantation, contributing to advancements in 3D uterine culture techniques.
Article Synopsis
- Phthalates, specifically di-(2-ethylhexyl) phthalate (DEHP), are recognized as endocrine disruptors, commonly found in industrial products, leading to significant exposure risks for adults.* -
- In a study with mature female mice, DEHP in drinking water was linked to an increase in adrenal gland wet weight and changes in the morphology of the zona fasciculata, indicating effects on the adrenal cortex.* -
- While some steroidogenic gene expressions were altered due to DEHP exposure, such as decreased levels of DAX1, there were no significant differences in the overall morphology or extracellular matrix arrangement in the adrenal gland compared to control groups.*
Article Synopsis
- SIRT1 is a protein involved in deacetylating histones and non-histone proteins, and is found to be upregulated in the uterus of infertile women with endometriosis.
- Research on mouse models showed that SIRT1 is most active during specific gestational days, and mice lacking SIRT1 (Sirt1d/d) displayed significant fertility issues, with fewer implantation sites.
- The study indicates that SIRT1 plays a critical role in the process of decidualization, which is essential for creating a suitable environment in the uterus for embryo implantation.
Article Synopsis
- * During this inactive phase, the blood-testis barrier (BTB) loses its integrity, causing developing germ cells to either be engulfed by Sertoli cells or slough off, leading to the absence of sperm in most epididymis regions.
- * Key genes responsible for tight junctions in the BTB (like claudin-11 and occludin) are present in active testes but not in inactive ones, indicating that structural disorganization of the BTB is linked to testicular regression and the removal of germ
Article Synopsis
- The study investigates the impact of the lack of functional estrogen receptor α (Esr1) on epididymal fat growth in ERαKO mice, focusing on changes in adipocyte-related gene expression over time.
- Results show that most gene expression peaked at 12 months old, while leptin levels increased early at 5 months and remained stable.
- Abnormal patterns of various regulatory genes associated with fat cell development were observed, indicating that disrupted ERα function affects adipocyte differentiation and maturation.
Article Synopsis
- Melatonin has been shown to cause testicular regression in seasonal breeding animals, particularly in male Syrian hamsters when injected in the afternoon.
- A study examined the effects of different dosages of melatonin given daily via gavage on hamsters kept in long and short photoperiods over 8 weeks.
- Results indicated that higher doses of melatonin led to significant testicular shrinkage compared to controls, with low doses having no adverse effect, similar to the large testes seen in the long photoperiod control group.
Article Synopsis
- Spermatogonial stem cells (SSCs) have unique characteristics that allow them to develop into gametes, undergoing significant changes in gene expression during spermatogenesis.
- The process includes phases like gene repression and chromatin modifications, ultimately leading to the formation of fertilization-ready spermatozoa.
- Recent research highlights the roles of transcription factors YY1 and CP2c in regulating spermatogenesis and stemness, providing insights into their interactions during specific stages of sperm development.
Article Synopsis
- - Ovarian reserve and fertility decline with age and poor energy balance, but the impact of obesity on aging ovarian reserve has not been well-studied until now.
- - In a study using a leptin-deficient mouse model, researchers found altered estrous cycles and differences in ovarian follicle development, indicating that obesity affects ovarian health as mice age.
- - Despite some hormonal similarities between lean and obese mice, the obese mice had more atretic follicles (non-viable) and fewer corpora lutea (mature follicles), suggesting that leptin deficiency may lead to prolonged ovarian reserves but reduced fertility.
Article Synopsis
- - The study built on previous findings indicating that low-dose nonylphenol (NP) exposure negatively impacts the reproductive health of female mice, specifically looking at its effects on their reproductive organs.
- - Mice were exposed to NP from before mating until their offspring were 33 days old, with significant findings such as early vaginal opening and differences in tissue weights related to NP exposure.
- - Pathohistological analysis revealed changes in ovarian follicle numbers and uterine structure, suggesting that NP exposure leads to early puberty and reproductive abnormalities, prompting the need for further research to clarify NP's effects and mitigate risks.
Article Synopsis
- This study introduces a novel electrochemical aptasensor (MEA) that utilizes a hybrid of MoS and TiCT MXene for the sensitive and rapid detection of the hormone Thyroxine (T4), which is essential for various bodily functions.
- The aptasensor is constructed using a nano-hybrid on a carbon electrode, with gold nanostructures enhancing the surface, allowing for improved signal amplification and a limit of detection of 0.39 pg/mL within 10 minutes.
- The aptasensor demonstrates effective T4 detection in human serum samples, yielding results that align well with the traditional ELISA method, indicating its reliability.
Article Synopsis
- The study investigates the expression and role of aquaporins (AQP7, AQP8, and AQP9) in granulosa cells during different stages of follicle development and their impact on fluid movement.
- AQP9 was found to be highly expressed during the rapid growth phase of follicles, particularly in the theca cells of tertiary and preovulatory follicles, suggesting its importance in folliculogenesis.
- Knockdown of AQP9 led to reduced follicle growth and fewer ovulated oocytes, indicating that AQP9 is crucial for antral growth and ovulation in a specific and regulated manner.
Article Synopsis
- Phthalates, commonly used in industrial applications, have been linked to negative effects on reproduction and development, particularly through their anti-androgenic properties.
- Studies have shown that phthalates, especially di-(2-ethylhexyl) phthalate (DEHP), can disrupt endocrine functions and harm male reproductive health, but the impacts on female reproduction are less understood.
- Chronic low-dose exposure to DEHP can lead to changes in uterine structure and function, potentially causing conditions like endometriosis and affecting fertility, with varied responses depending on species and developmental stages.
Article Synopsis
- * Researchers used reverse transcription polymerase chain reaction (RT-PCR) to analyze the expression of the SEMG gene in the seminal vesicles of mature versus regressed hamsters.
- * Results show that the SEMG gene is present in sexually mature hamsters but absent in regressed ones, indicating its link to reproductive capability in these animals.
Article Synopsis
- - Medical disorders from second-hand smoke are a significant public health issue, and using saliva to measure cotinine levels (a marker for this exposure) is a simpler, non-invasive alternative to traditional tests involving blood or urine.
- - The study presents an innovative all-in-one platform that uses a cotton swab collector, 3D-printed housing, and a microfluidic channel with an electrochemical immunosensor to analyze salivary cotinine directly, eliminating cumbersome procedures.
- - This platform was successfully tested on real human saliva samples from non-smokers, providing accurate cotinine levels comparable to advanced testing methods (like LC-MS/MS), showcasing its reliability and practicality.
Article Synopsis
- The study investigates how low-dose chronic exposure to endocrine disrupting chemicals (EDCs), specifically di(2-ethylhexyl) phthalate (DEHP) and nonylphenol (NP), affects the growth of uterine endometrial tissue and the positioning of steroid hormone receptors.* -
- Using specific methodologies, the researchers observed increased MKI67 protein levels in certain cell types due to chemical exposure, indicating enhanced cell proliferation, with variations based on the dose of the chemicals used.* -
- The chemical exposures altered the typical locations of estrogen and progesterone receptors in the cells, particularly shifting some from the nucleus to the cytoplasm, and these changes were found to be specific to the type and dose of EDCs
Article Synopsis
- * Mice were divided into control and NP-treated groups, with treatment continuing from the pre-mating period until postnatal day 55; no significant differences in overall weight were noted, except for changes in epididymal weight.
- * Pathological examinations revealed that NP-exposed F2 males had reduced seminiferous tubule diameters, fewer mature sperm, and other reproductive tissue abnormalities, suggesting epigenetic modifications and indicating potential multi-generational effects of NP on reproductive health.
Article Synopsis
- Nonylphenols (NPs) are chemicals used in industry that disrupt endocrine functions, prompting this study on their effects on male mice.
- Mice were divided into control and NP-exposed groups, with findings showing that NP exposure led to lower body weights and altered organ weights (higher testes weight but reduced epididymis, prostate, and seminal vesicle weights).
- Histological analysis revealed negative changes in reproductive structures, including decreased seminiferous tubule sizes and fewer mature sperm, indicating that even low doses of NP can cause harmful reproductive effects that might relate to human health concerns.