miR-124 coordinates metabolic regulators acting at early stages of human neurogenesis.

Metabolic dysregulation of neurons is associated with diverse human brain disorders. Metabolic reprogramming occurs during neuronal differentiation, but it is not fully understood which molecules regulate metabolic changes at the early stages of neurogenesis. In this study, we report that miR-124 is a driver of metabolic change at the initiating stage of human neurogenesis. Proteome analysis has shown the oxidative phosphorylation pathway to be the most significantly altered among the differentially expressed proteins (DEPs) in the immature neurons after the knockdown of miR-124. In agreement with these proteomics results, miR-124-depleted neurons display mitochondrial dysfunctions, such as decreased mitochondrial membrane potential and cellular respiration. Moreover, morphological analyses of mitochondria in early differentiated neurons after miR-124 knockdown result in smaller and less mature shapes. Lastly, we show the potential of identified DEPs as novel metabolic regulators in early neuronal development by validating the effects of GSTK1 on cellular respiration. GSTK1, which is upregulated most significantly in miR-124 knockdown neurons, reduces the oxygen consumption rate of neural cells. Collectively, our data highlight the roles of miR-124 in coordinating metabolic maturation at the early stages of neurogenesis and provide insights into potential metabolic regulators associated with human brain disorders characterized by metabolic dysfunctions.

Aberrant Cortical Layer Development of Brain Organoids Derived from Noonan Syndrome-iPSCs.

Noonan syndrome (NS) is a genetic disorder mainly caused by gain-of-function mutations in Src homology region 2-containing protein tyrosine phosphatase 2 (SHP2). Although diverse neurological manifestations are commonly diagnosed in NS patients, the mechanisms as to how SHP2 mutations induce the neurodevelopmental defects associated with NS remain elusive. Here, we report that cortical organoids (NS-COs) derived from NS-induced pluripotent stem cells (iPSCs) exhibit developmental abnormalities, especially in excitatory neurons (ENs). Although NS-COs develop normally in their appearance, single-cell transcriptomic analysis revealed an increase in the EN population and overexpression of cortical layer markers in NS-COs. Surprisingly, the EN subpopulation co-expressing the upper layer marker SATB2 and the deep layer maker CTIP2 was enriched in NS-COs during cortical development. In parallel with the developmental disruptions, NS-COs also exhibited reduced synaptic connectivity. Collectively, our findings suggest that perturbed cortical layer identity and impeded neuronal connectivity contribute to the neurological manifestations of NS.

Dysregulated ECM remodeling proteins lead to aberrant osteogenesis of Costello syndrome iPSCs.

Costello syndrome (CS) is an autosomal dominant disorder caused by mutations in HRAS. Although CS patients have skeletal abnormalities, the role of mutated HRAS in bone development remains unclear. Here, we use CS induced pluripotent stem cells (iPSCs) undergoing osteogenic differentiation to investigate how dysregulation of extracellular matrix (ECM) remodeling proteins contributes to impaired osteogenesis. Although CS patient-derived iPSCs develop normally to produce mesenchymal stem cells (MSCs), the resulting CS MSCs show defective osteogenesis with reduced alkaline phosphatase activity and lower levels of bone mineralization. We found that hyperactivation of SMAD3 signaling during the osteogenic differentiation of CS MSCs leads to aberrant expression of ECM remodeling proteins such as MMP13, TIMP1, and TIMP2. CS MSCs undergoing osteogenic differentiation also show reduced ß-catenin signaling. Knockdown of TIMPs permits normal differentiation of CS MSCs into osteoblasts and enhances ß-catenin signaling in a RUNX2-independent manner. Thus, this study demonstrates that enhanced TIMP expression induced by hyperactivated SMAD3 signaling impairs the osteogenic development of CS MSCs via an inactivation of ß-catenin signaling.

Association between ARID2 and RAS-MAPK pathway in intellectual disability and short stature.

BACKGROUND: ARID2 belongs to the Switch/sucrose non-fermenting complex, in which the genetic defects have been found in patients with dysmorphism, short stature and intellectual disability (ID). As the phenotypes of patients with ARID2 mutations partially overlap with those of RASopathy, this study evaluated the biochemical association between ARID2 and RAS-MAPK pathway. METHODS: The phenotypes of 22 patients with either an ARID2 heterozygous mutation or haploinsufficiency were reviewed. Comprehensive molecular analyses were performed using somatic and induced pluripotent stem cells (iPSCs) of a patient with ARID2 haploinsufficiency as well as using the mouse model of Arid2 haploinsufficiency by CRISPR/Cas9 gene editing. RESULTS: The phenotypic characteristics of ARID2 deficiency include RASopathy, Coffin-Lowy syndrome or Coffin-Siris syndrome or undefined syndromic ID. Transient ARID2 knockout HeLa cells using an shRNA increased ERK1 and ERK2 phosphorylation. Impaired neuronal differentiation with enhanced RAS-MAPK activity was observed in patient-iPSCs. In addition, Arid2 haploinsufficient mice exhibited reduced body size and learning/memory deficit. ARID2 haploinsufficiency was associated with reduced IFITM1 expression, which interacts with caveolin-1 (CAV-1) and inhibits ERK activation. DISCUSSION: ARID2 haploinsufficiency is associated with enhanced RAS-MAPK activity, leading to reduced IFITM1 and CAV-1 expression, thereby increasing ERK activity. This altered interaction might lead to abnormal neuronal development and a short stature.

Correction to: SHP2 mutations induce precocious gliogenesis of Noonan syndrome-derived iPSCs during neural development in vitro.

An amendment to this paper has been published and can be accessed via the original article.

SHP2 mutations induce precocious gliogenesis of Noonan syndrome-derived iPSCs during neural development in vitro.

BACKGROUND: Noonan syndrome (NS) is a developmental disorder caused by mutations of Src homology 2 domain-containing protein tyrosine phosphatase 2 (SHP2). Although NS patients have diverse neurological manifestations, the mechanisms underlying the involvement of SHP2 mutations in neurological dysfunction remain elusive. METHODS: Induced pluripotent stem cells generated from dermal fibroblasts of three NS-patients (NS-iPSCs) differentiated to the neural cells by using two different culture systems, 2D- and 3D-cultured systems in vitro. RESULTS: Here we represent that SHP2 mutations cause aberrant neural development. The NS-iPSCs exhibited impaired development of EBs in which BMP and TGF-ß signalings were activated. Defective early neuroectodermal development of NS-iPSCs recovered by inhibition of both signalings and further differentiated into NPCs. Intriguingly, neural cells developed from NS-NPCs exhibited abundancy of the glial cells, neurites of neuronal cells, and low electrophysiological property. Those aberrant phenotypes were also detected in NS-cerebral organoids. SHP2 inhibition in the NS-NPCs and NS-cerebral organoids ameliorated those anomalies such as biased glial differentiation and low neural activity. CONCLUSION: Our findings demonstrate that SHP2 mutations contribute to precocious gliogenesis in NS-iPSCs during neural development in vitro.

A study on the intent to leave and stay among hospital nurses in Korea: A cross-sectional survey.

AIMS: To investigate the intent to leave or stay among Korean hospital nurses, and to identify what factors influence their intent to leave or stay. BACKGROUND: Previous studies have simply measured nurses' intent to leave or stay; however, this study examines the associations of intent to leave and intent to stay with influential factors among Korean hospital nurses. METHODS: A cross-sectional study was conducted with 267 nurses working at four general hospitals in South Korea. RESULT: The influencing factors on intent to leave were organisational commitment, practice environment and burnout, while intent to stay was influenced by organisational commitment. CONCLUSION: The study demonstrates that, for Korean hospital nurses, intent to leave and intent to stay are not simply contrary concepts, but are different concepts influenced by varying factors. IMPLICATIONS FOR NURSING MANAGEMENT: This study clarifies the difference between the concepts of intent to stay and intent to leave, and demonstrates that the variables affecting Korean nurses' intent to stay and intent to leave differ from each other. Therefore, focusing on improving nurses' intent to either leave or stay would be effective when developing personnel management policies for nurses, thereby contributing to enhancing nursing practice.

Sexual activity and hepatitis B and C virus infection among young adults after introduction of a vaccination program in an area of high endemicity.

BACKGROUND: In areas where hepatitis is endemic, little is known about the sexual transmission of HBV after introduction of an HBV vaccination program. METHODS: We used a self-administered questionnaire and serological tests for HBsAg, anti-HBs, anti-HBc, and anti-HCV to examine the role of sexual activity, as well as sociodemographic status, lifestyle habits, and a history of vaccinations, transfusions, and surgery, in the transmission of HBV and HCV in Korea. The subjects were 865 female and 541 male university students (median age, 19 years; age range, 16-25). RESULTS: Overall seropositivity was 8.1% for HBsAg, 69.3% for anti-HBs, 21.3% for anti-HBc, and 0.4% for anti-HCV. Regarding HBV, 8% of the subjects were chronic carriers or had recently been infected, 22.8% were never exposed and nonvaccinated, 16.6% were exposed noncarriers, and 52.7% had most likely been vaccinated. We found a significant association between HBsAg seropositivity and history of sexual intercourse (Odds Ratio, 1.8; 95% CI, 1.1-2.8). Students without serologic evidence of immunization against HBV were more likely to have become HBsAg-positive after becoming sexually active. CONCLUSIONS: Our findings suggest that sexual transmission does occur among adolescents and young adults who have not been vaccinated, whereas vaccination protects individuals from becoming an HBV carrier after becoming sexually active.

Prevalence of human papillomavirus and Chlamydia trachomatis infection among women attending cervical cancer screening in the Republic of Korea.

Cervical cancer screening with the conventional Papanicolaou test is recommended for the women aged 30 years and more in Korea. Cervical infection with human papillomavirus (HPV) is the most important cause of cervical cancer and Chlamydia trachomatis (CT) is the most common bacterial sexually transmitted infection and may also be associated with risk of cervical cancer. A cross-sectional study of women attending the National Cervical Cancer Screening Program in Busan and Suwon was carried out. Exfoliated cervical cells were collected, and questionnaires were administered to 4595 women. High-risk HPV types and CT were tested by Hybrid Capture 2 (HC2). HPV genotyping of 355 high-risk HPV-positive women at HC2 was performed using linear array. Age-standardized prevalence of high-risk HPV types and CT was 10.4% (95% confidence interval: 9.5-11.3) and 4.3% (95% confidence interval: 3.7-4.8). That 68.5% of women were high-risk HPV-positive at HC2 was confirmed by Linear Array whereas 17.5% seemed to be infected with only low-risk HPV types, not normally detected by HC2. Korean women showed a relatively high prevalence of high-risk HPV and a rather low prevalence of CT. As in cancer-free women in other Asian populations, HPV 52, 58, and 39 were detected more frequently than HPV 16. Cross-reaction of HC2 with low-risk HPV types is of some concern, were the test to be used in primary screening.

Acquisition of new infection and clearance of type-specific human papillomavirus infections in female students in Busan, South Korea: a follow-up study.

BACKGROUND: Little is known about the natural history of human papillomavirus (HPV) infection in Asian women. METHODS: A follow-up study was conducted, with exfoliated cervicovaginal cells self-collected from, and questionnaires administered to 197 female students, aged 17-26 years, who had been already examined one and half years before. The presence of 25 HPV types was evaluated by a polymerase chain reaction-based assay. RESULTS: The acquisition of new infection for any HPV type among 171 female students at risk who were negative at baseline, 60% of whom had remained as virgins, was 17.5% (95% confidence interval [CI]: 11.8-23.2). Among individual types, HPV16, 18 and 35 showed the highest rate of new infection. Women who had had first sexual intercourse (OR = 2.9; 95% CI: 1.0-8.8), or had changed sexual partners (OR = 2.9; 95% CI: 0.9-9.3) during the follow-up period showed a higher risk of new HPV infection than women who had remained virgins since baseline. The rate of new infection also tended to be higher in those who started, or continued smoking during the follow-up period, than in nonsmokers. Clearance of HPV infections since baseline examination was 80.6% (95% CI: 67.6-93.5), and did not differ between high-risk and low-risk HPV types or between single- and multiple-type infections. CONCLUSION: This study shows that the acquisition of new HPV infection among young women in the Republic of Korea is high and also the clearance is frequent. Self-collection of cervicovaginal cells is applicable to follow-up studies that include virgins.

Serologic response to oncogenic human papillomavirus types in male and female university students in Busan, South Korea.

In the absence of genital samples, human papillomavirus (HPV) serology may be useful to assess HPV infection in young men and women. HPV seroprevalence and determinants of seropositivity were assessed in 817 female and 518 male university students in Busan, South Korea, of whom 74% and 44%, respectively, reported never having had penetrative sexual intercourse. Type-specific HPV DNA status, assessed by a short PCR fragment primer set, was available from genital samples. Seropositivity to L1 proteins of HPV types 16, 18, 31, 33, 45, 52, and 58 were assessed using multiplex HPV serology. Among women, HPV seroprevalence was significantly higher among sexually active (26.1%) than nonsexually active students [11.1%, odds ratio (OR) = 2.9; 95% confidence interval (95% CI), 1.8-4.7], although the association was weaker than that for HPV DNA prevalence (OR, 14; 95% CI, 4.7-42). Furthermore, HPV seroprevalence was higher among HPV DNA-positive (24%) than HPV DNA-negative women (13%), and there was a positive correlation of type-specific seroprevalence with the presence of HPV DNA of the same type. In contrast, HPV seropositivity among men was not associated with sexual behavior or the presence of HPV DNA. Seroprevalence correlates with genital HPV exposure in young women, but its meaning in young men is unclear.

Clonorchis sinensis infection and increasing risk of cholangiocarcinoma in the Republic of Korea.

To evaluate the prevalence and risk factors of Clonorchis sinensis infection, an epidemiologic survey was performed (3,169 residents; age range: 30-87 years; mean age = 59; 1,973 women) in three areas with different mortality rates of cholangiocarcinoma. C. sinensis prevalence was 2.1% in Chuncheon, 7.8% in Chungju, and 31.3% in Haman, where cholangiocarcinoma incidence rate was 0.3, 1.8, and 5.5 per 100,000 persons, respectively. Of the four major risk factors for C. sinensis (male sex, alcohol consumption, raw freshwater fish intake, and area of residence), area was the strongest. Efforts to discourage raw freshwater fish intake, treat egg carriers, and protect water sources from C. sinensis contamination should be strengthened in the Republic of Korea.

[Epidemiologic study of Clonorchis sinensis infestation in a rural area of Kyongsangnam-do, South Korea].

OBJECTIVES: To investigate the prevalence of Clonorchis sinensis infestation and to determine the associated risk factors among a population in a part of the rural area of Gyeongsangnam-do, Korea, which is an area known to have a high mortality from liver cancer and a high infection of C. sinensis. METHODS: The study population consisted of those people who have lived in rural areas and who were over 40 years old. This study was performed in 5 areas during the period from 1999 to 2003. Informed consents were obtained from the 2,381 study participants, and these people were interviewed about their life style habits with using the structured questionnaire that was administered by trained staff members. The subjects underwent blood sampling and their stool specimens were examined by using the Formalin-ether sedimentation technique. RESULTS: Among the study subjects (N=2,381), the positivity for C. sinensis in the stool was 34.4% (95% CI= 36.3-42.5); it was 39.4% (95% CI=36.3-42.5) in the males and 30.9% (95% CI=28.5-33.3) in the females. The positivity for C. sinensis was associated with current alcohol drinking (odds ratio=1.8, 95% CI: 1.5-2.1) and raw fish consumption (odds ratio 1.2, 95% CI: 0.9-1.6). CONCLUSION: The present study confirmed the high prevalence of C. sinensis in the study subjects. It is necessary to establish consistent medical management and education programs for the treatment and prevention of C. sinensis infestation in the rural inhabitants of Korea.

Prevalence and determinants of genital infection with papillomavirus, in female and male university students in Busan, South Korea.

BACKGROUND: Little is known about the prevalence of human papillomavirus (HPV) infection in young adults in Asia. METHODS: We invited female and male students in Busan, South Korea, to participate in a survey that included, for females, self-collection of vaginal cells and, for males, physician-performed collection of exfoliated genital cells. The prevalences of 25 HPV types were evaluated, by a polymerase chain reaction-based assay, in 672 female students (median age, 19 years) and in 381 male students (median age, 22 years). RESULTS: HPV DNA was detected more frequently in female students (15.2%) than in male students (8.7%); in both sexes, high-risk HPV types were predominant. Among sexually active students, HPV prevalence was 38.8% in females and 10.6% in males. In female students, currently smoking cigarettes and having multiple lifetime sex partners were the strongest risk factors for HPV infection; in male students, associations between HPV prevalence and sexual habits were similar to those in female students but never attained statistical significance. CONCLUSIONS: Young women in South Korea start having penetrative sexual intercourse relatively late (median age, 18 years), but, once they begin, HPV prevalence quickly rises to levels comparable with those found in university students in the United States and in northern Europe. The high rate of participation in our study suggests that trials of new vaccines against HPV may be feasible among university students in South Korea.