Cytokine profiling in 128 patients with transient abnormal myelopoiesis: a report from the JPLSG TAM-10 trial.

Transient abnormal myelopoiesis (TAM) occurs in 10% of neonates with Down syndrome (DS). Although most patients show spontaneous resolution of TAM, early death occurs in approximately 20% of cases. Therefore, new biomarkers are needed to predict early death and determine therapeutic interventions. This study aimed to determine the association between clinical characteristics and cytokine levels in patients with TAM. A total of 128 patients with DS with TAM enrolled in the TAM-10 study conducted by the Japanese Pediatric Leukemia/Lymphoma Study Group were included in this study. Five cytokine levels [interleukin (IL)-1b, IL-1 receptor agonist, IL-6, IL-8, and IL-13] were significantly higher in patients with early death than in those with non-early death. Cumulative incidence rates (CIR) of early death were significantly associated with high levels of the five cytokines. Based on unsupervised consensus clustering, patients were classified into three cytokine groups: hot-1 (n = 37), hot-2 (n = 42), and cold (n = 49). The CIR of early death was significantly different between the cytokine groups [hot-1/2 (n = 79); cold (n = 49); CIR (95% confidence interval [CI]) = 16.5% (7.9%-24.2%); 2.0% (0.0%-5.9%), P = 0.013]. Furthermore, cytokine groups (hot-1/2 vs. cold) were independent poor prognostic factors in the multivariable analysis for early death [hazard ratio (95% CI) = 19.25 (2.056-180.3), P = 0.010]. These results provide valuable information that cytokine level measurement was useful in predicting early death in patients with TAM and might help to determine the need for therapeutic interventions.

Gene-specific somatic epigenetic mosaicism of FDFT1 underlies a non-hereditary localized form of porokeratosis.

Porokeratosis is a clonal keratinization disorder characterized by solitary, linearly arranged, or generally distributed multiple skin lesions. Previous studies showed that genetic alterations in MVK, PMVK, MVD, or FDPS-genes in the mevalonate pathway-cause hereditary porokeratosis, with skin lesions harboring germline and lesion-specific somatic variants on opposite alleles. Here, we identified non-hereditary porokeratosis associated with epigenetic silencing of FDFT1, another gene in the mevalonate pathway. Skin lesions of the generalized form had germline and lesion-specific somatic variants on opposite alleles in FDFT1, representing FDFT1-associated hereditary porokeratosis identified in this study. Conversely, lesions of the solitary or linearly arranged localized form had somatic bi-allelic promoter hypermethylation or mono-allelic promoter hypermethylation with somatic genetic alterations on opposite alleles in FDFT1, indicating non-hereditary porokeratosis. FDFT1 localization was uniformly diminished within the lesions, and lesion-derived keratinocytes showed cholesterol dependence for cell growth and altered expression of genes related to cell-cycle and epidermal development, confirming that lesions form by clonal expansion of FDFT1-deficient keratinocytes. In some individuals with the localized form, gene-specific promoter hypermethylation of FDFT1 was detected in morphologically normal epidermis adjacent to methylation-related lesions but not distal to these lesions, suggesting that asymptomatic somatic epigenetic mosaicism of FDFT1 predisposes certain skin areas to the disease. Finally, consistent with its genetic etiology, topical statin treatment ameliorated lesions in FDFT1-deficient porokeratosis. In conclusion, we identified bi-allelic genetic and/or epigenetic alterations of FDFT1 as a cause of porokeratosis and shed light on the pathogenesis of skin mosaicism involving clonal expansion of epigenetically altered cells.

Systematic molecular analyses for 115 karyotypically normal men with isolated non-obstructive azoospermia.

STUDY QUESTION: Do copy-number variations (CNVs) in the azoospermia factor (AZF) regions and monogenic mutations play a major role in the development of isolated (non-syndromic) non-obstructive azoospermia (NOA) in Japanese men with a normal 46, XY karyotype? SUMMARY ANSWER: Deleterious CNVs in the AZF regions and damaging sequence variants in eight genes likely constitute at least 8% and approximately 8% of the genetic causes, respectively, while variants in other genes play only a minor role. WHAT IS KNOWN ALREADY: Sex chromosomal abnormalities, AZF-linked microdeletions, and monogenic mutations have been implicated in isolated NOA. More than 160 genes have been reported as causative/susceptibility/candidate genes for NOA. STUDY DESIGN, SIZE, DURATION: Systematic molecular analyses were conducted for 115 patients with isolated NOA and a normal 46, XY karyotype, who visited our hospital between 2017 and 2021. PARTICIPANTS/MATERIALS, SETTING, METHODS: We studied 115 unrelated Japanese patients. AZF-linked CNVs were examined using sequence-tagged PCR and multiplex ligation-dependent probe amplification, and nucleotide variants were screened using whole exome sequencing (WES). An optimized sequence kernel association test (SKAT-O), a gene-based association study using WES data, was performed to identify novel disease-associated genes in the genome. The results were compared to those of previous studies and our in-house control data. MAIN RESULTS AND THE ROLE OF CHANCE: Thirteen types of AZF-linked CNVs, including the hitherto unreported gr/gr triplication and partial AZFb deletion, were identified in 63 (54.8%) cases. When the gr/gr deletion, a common polymorphism in Japan, was excluded from data analyses, the total frequency of CNVs was 23/75 (30.7%). This frequency is higher than that of the reference data in Japan and China (11.1% and 14.7%, respectively). Known NOA-causative AZF-linked CNVs were found in nine (7.8%) cases. Rare damaging variants in known causative genes (DMRT1, PLK4, SYCP2, TEX11, and USP26) and hemizygous/multiple-heterozygous damaging variants in known spermatogenesis-associated genes (TAF7L, DNAH2, and DNAH17) were identified in nine cases (7.8% in total). Some patients carried rare damaging variants in multiple genes. SKAT-O detected no genes whose rare damaging variants were significantly accumulated in the patient group. LIMITATIONS, REASONS FOR CAUTION: The number of participants was relatively small, and the clinical information of each patient was fragmentary. Moreover, the pathogenicity of identified variants was assessed only by in silico analyses. WIDER IMPLICATIONS OF THE FINDINGS: This study showed that various AZF-linked CNVs are present in more than half of Japanese NOA patients. These results broadened the structural variations of AZF-linked CNVs, which should be considered for the molecular diagnosis of spermatogenic failure. Furthermore, the results of this study highlight the etiological heterogeneity and possible oligogenicity of isolated NOA. STUDY FUNDING/COMPETING INTEREST(S): This study was supported by Grants from the Japan Society for the Promotion of Science (21K19283 and 21H0246), the Japan Agency for Medical Research and Development (22ek0109464h0003), the National Center for Child Health and Development, the Canon Foundation, the Japan Endocrine Society, and the Takeda Science Foundation. The results of this study were based on samples and patient data obtained from the International Center for Reproductive Medicine, Dokkyo Medical University Saitama Medical Center, Koshigaya, Japan. The authors have no conflicts of interest to disclose. TRIAL REGISTRATION NUMBER: N/A.

Loss of NSD2 causes dysregulation of synaptic genes and altered H3K36 dimethylation in mice.

Background: Epigenetic disruptions have been implicated in neurodevelopmental disorders. NSD2 is associated with developmental delay/intellectual disability; however, its role in brain development and function remains unclear. Methods: We performed transcriptomic and epigenetic analyses using Nsd2 knockout mice to better understand the role of NSD2 in the brain. Results and discussion: Transcriptomic analysis revealed that the loss of NSD2 caused dysregulation of genes related to synaptic transmission and formation. By analyzing changes in H3 lysine 36 dimethylation (H3K36me2), NSD2-mediated H3K36me2 mainly marked quiescent state regions and the redistribution of H3K36me2 occurred at transcribed genes and enhancers. By integrating transcriptomic and epigenetic data, we observed that H3K36me2 changes in a subset of dysregulated genes related to synaptic transmission and formation. These results suggest that NSD2 is involved in the regulation of genes important for neural function through H3K36me2. Our findings provide insights into the role of NSD2 and improve our understanding of epigenetic regulation in the brain.

Identification of a KDM6A somatic mutation responsible for Kabuki syndrome by excluding a conflicting KMT2D germline variant through episignature analysis.

Kabuki syndrome (KS) is a congenital disorder caused by mutations in either KMT2D on chromosome 12 or KDM6A on chromosome X, encoding a lysine methyltransferase and a lysine demethylase, respectively. A 9-year-4-month-old male patient with a normal karyotype presented with KS and autism spectrum disorder. Genetic testing for KS was conducted by Sanger sequencing and episignature analysis using DNA methylation array data. The patient had a mosaic stop-gain variant in KDM6A and a heterozygous missense variant (rs201078160) in KMT2D. The KDM6A variant is expected to be deleterious. The KMT2D variant pathogenicity has been inconsistently reported in the ClinVar database. Using biobanking resources, we identified two heterozygous individuals possessing the rs201078160 variant. In a subsequent episignature analysis, the KS patient showed the KS episignature, but two control individuals with the rs201078160 variant did not. Our results indicate that the mosaic stop-gained variant in KDM6A, but not the rs201078160 variant in KMT2D, is responsible for the KS phenotype in the patient. This study further demonstrated the utility of DNA methylation information in diagnosing rare genetic diseases and emphasized the importance of a reference dataset containing both genotype and DNA methylation information.

Prevalence of pathogenic variants in cancer-predisposing genes in second cancer after childhood solid cancers.

BACKGROUND: Second malignant neoplasms (SMNs) are one of the most severe late complications after pediatric cancer treatment. However, the effect of genetic variation on SMNs remains unclear. In this study, we revealed germline genetic factors that contribute to the development of SMNs after treatment of pediatric solid tumors. METHODS: We performed whole-exome sequencing in 14 pediatric patients with SMNs, including three brain tumors. RESULTS: Our analysis revealed that five of 14 (35.7%) patients had pathogenic germline variants in cancer-predisposing genes (CPGs), which was significantly higher than in the control cohort (p < 0.01). The identified genes with variants were TP53 (n = 2), DICER1 (n = 1), PMS2 (n = 1), and PTCH1 (n = 1). In terms of the type of subsequent cancer, leukemia and multiple episodes of SMN had an exceptionally high rate of CPG pathogenic variants. None of the patients with germline variants had a family history of SMN development. Mutational signature analysis showed that platinum drugs contributed to the development of SMN in three cases, which suggests the role of platinum agents in SMN development. CONCLUSIONS: We highlight that overlapping effects of genetic background and primary cancer treatment contribute to the development of second cancers after treatment of pediatric solid tumors. A comprehensive analysis of germline and tumor samples may be useful to predict the risk of secondary cancers.

Identification of the ultrahigh-risk subgroup in neuroblastoma cases through DNA methylation analysis and its treatment exploiting cancer metabolism.

Neuroblastomas require novel therapies that are based on the exploitation of their biological mechanism. To address this need, we analyzed the DNA methylation and expression datasets of neuroblastomas, extracted a candidate gene characterizing the aggressive features, and conducted functional studies. Based on the DNA methylation data, we identified a subgroup of neuroblastoma cases with 11q loss of heterozygosity with extremely poor prognosis. PHGDH, a serine metabolism-related gene, was extracted as a candidate with strong expression and characteristic methylation in this subgroup as well as in cases with MYCN amplification. PHGDH inhibition suppressed neuroblastoma cell proliferation in vitro and in vivo, indicating that the inhibition of serine metabolism by PHGDH inhibitors is a therapeutic alternative for neuroblastoma. Inhibiting the arginine metabolism, which is closely related to serine metabolism using arginine deiminase, had a combination effect both in vitro and in vivo, especially on extracellular arginine-dependent neuroblastoma cells with ASS1 deficiency. Expression and metabolome analyses of post-dose cells confirmed the synergistic effects of treatments targeting serine and arginine indicated that xCT inhibitors that inhibit cystine uptake could be candidates for further combinatorial treatment. Our results highlight the rational therapeutic strategy of targeting serine/arginine metabolism for intractable neuroblastoma.

Identification of unique DNA methylation sites in Kabuki syndrome using whole genome bisulfite sequencing and targeted hybridization capture followed by enzymatic methylation sequencing.

BACKGROUND: Kabuki syndrome (KS) is a congenital malformation syndrome caused by mutations in the KMT2D and KDM6A genes that encode histone modification enzymes. Although KS is considered a single gene disorder, its symptoms vary widely. Recently, disease-specific DNA methylation patterns, or episignatures, have been recognized and used as a diagnostic tool for KS. Because of various crosstalk mechanisms between histone modifications and DNA methylation, DNA methylation analysis may have high potential for investigations into the pathogenesis of KS. RESULTS: In this study, we investigated altered CpG-methylation sites that were specific to KS to find important genes associated with the various phenotypes or pathogenesis of KS. Whole genome bisulfite sequencing (WGBS) was performed to select target CpG islands, and enzymatic conversion technology was applied after hybridization capture to confirm KS-specific episignatures of 130 selected differently methylated target regions (DMTRs) in DNA samples from the 65 participants, 31 patients with KS and 34 unaffected individuals, in this study. We identified 26 candidate genes in 22 DMTRs that may be associated with KS. Our results indicate that disease-specific methylation sites can be identified from a small number of WGBS samples, and hybridization capture followed by enzymatic methylation sequencing can simultaneously test the sites. CONCLUSIONS: Although DNA methylation can be tissue-specific, our results suggest that methylation profiling of DNA extracted from peripheral blood may be a powerful approach to study the pathogenesis of diseases.

A familial case of periodontal Ehlers-Danlos syndrome lacking skin extensibility and joint hypermobility with a missense mutation in C1R.

Periodontal Ehlers-Danlos syndrome (pEDS) is an autosomal-dominant disorder first described by Stewart in 1977 that is characterized by severe gingival recession and periodontitis that triggers premature loss of permanent teeth and alveolar bone absorption. It was recently shown that pEDS is caused by a heterozygous missense mutation in C1R or C1S, which encode complement 1 proteases. Here, we report a familial case of pEDS with a novel heterozygous missense mutation, c.674G>C (p.R225P), in C1R (NM_001733.4). The case exhibited pretibial hyperpigmentation and extended periodontitis but neither skin extensibility nor joint hypermobility, suggesting that this mutation will expand the definition of pEDS.

DNA methylation analysis of cord blood samples in neonates born to gestational diabetes mothers diagnosed before 24 gestational weeks.

INTRODUCTION: Genome-wide methylation analyses of gestational diabetes mellitus (GDM) diagnosed after 24 gestational weeks (late GDM (L-GDM)) using cord blood have been reported. However, epigenetic changes in neonates born to mothers with GDM diagnosed before 24 gestational weeks (early GDM (E-GDM)) have not been reported. We investigated DNA methylation in neonates born to mothers with E-GDM using cord blood samples. RESEARCH DESIGN AND METHODS: Genome-wide DNA methylation analysis was performed using an Illumina EPIC array to compare methylation rates of 754 255 autosomal sites in cord blood samples from term neonates born to 162 mothers with GDM (E-GDM: n=84, L-GDM: n=78) and 60 normal glucose tolerance (normal OGTT) pregnancies. GDM was diagnosed based on Japan Society of Obstetrics and Gynecology criteria modified with International Association of Diabetes in Pregnancy Study Group criteria. In this study, all GDM mothers underwent dietary management, while self-monitoring of blood glucose and insulin administration was initiated when dietary modification did not achieve glycemic control. RESULTS: There were no significant differences in genome-wide DNA methylation of cord blood samples between the GDM (E-GDM and L-GDM) groups and normal OGTT group or between the E-GDM and normal OGTT groups, L-GDM and normal OGTT groups, and E-GDM and L-GDM groups. CONCLUSIONS: This is the first report to determine the DNA methylation patterns in neonates born to mothers with E-GDM. Neonates born to mothers with GDM, who were diagnosed based on Japan Society of Obstetrics and Gynecology criteria, may not differ in DNA methylation compared with those born to normal OGTT mothers.

Genome-wide DNA methylation analysis in pediatric acute myeloid leukemia.

We investigated genome-wide DNA methylation patterns in 64 pediatric patients with acute myeloid leukemia (AML). Based on unsupervised clustering with the 567 most variably methylated cytosine guanine dinucleotide (CpG) sites, patients were categorized into 4 clusters associated with genetic alterations. Clusters 1 and 3 were characterized by the presence of known favorable prognostic factors, such as RUNX1-RUNX1T1 fusion and KMT2A rearrangement with low MECOM expression, and biallelic CEBPA mutations (all 8 patients), respectively. Clusters 2 and 4 comprised patients exhibiting molecular features associated with adverse outcomes, namely internal tandem duplication of FLT3 (FLT3-ITD), partial tandem duplication of KMT2A, and high PRDM16 expression. Depending on the methylation values of the 1243 CpG sites that were significantly different between FLT3-ITD+ and FLT3-ITD- AML, patients were categorized into 3 clusters: A, B, and C. The STAT5-binding motif was most frequently found close to the 1243 CpG sites. All 8 patients with FLT3-ITD in cluster A harbored high PRDM16 expression and experienced adverse events, whereas only 1 of 7 patients with FLT3-ITD in the other clusters experienced adverse events. PRDM16 expression levels were also related to DNA methylation patterns, which were drastically changed at the cutoff value of PRDM16/ABL1 = 0.10. The assay for transposase-accessible chromatin sequencing of AMLs supported enhanced chromatin accessibility around genomic regions, such as HOXB cluster genes, SCHIP1, and PRDM16, which were associated with DNA methylation changes in AMLs with FLT3-ITD and high PRDM16 expression. Our results suggest that DNA methylation levels at specific CpG sites are useful to support genetic alterations and gene expression patterns of patients with pediatric AML.

Association of allele-specific methylation of the ASNS gene with asparaginase sensitivity and prognosis in T-ALL.

Asparaginase therapy is a key component of chemotherapy for patients with T-cell acute lymphoblastic leukemia (T-ALL). Asparaginase depletes serum asparagine by deamination into aspartic acid. Normal hematopoietic cells can survive due to asparagine synthetase (ASNS) activity, whereas leukemia cells are supposed to undergo apoptosis due to silencing of the ASNS gene. Because the ASNS gene has a typical CpG island in its promoter, its methylation status in T-ALL cells may be associated with asparaginase sensitivity. Thus, we investigated the significance of ASNS methylation status in asparaginase sensitivity of T-ALL cell lines and prognosis of childhood T-ALL. Sequencing of bisulfite polymerase chain reaction products using next-generation sequencing technology in 22 T-ALL cell lines revealed a stepwise allele-specific methylation of the ASNS gene, in association with an aberrant methylation of a 7q21 imprinted gene cluster. T-ALL cell lines with ASNS hypermethylation status showed significantly higher in vitro l-asparaginase sensitivity in association with insufficient asparaginase-induced upregulation of ASNS gene expression and lower basal ASNS protein expression. A comprehensive analysis of diagnostic samples from pediatric patients with T-ALL in Japanese cohorts (N = 77) revealed that methylation of the ASNS gene was associated with an aberrant methylation of the 7q21 imprinted gene cluster. In pediatric T-ALL patients in Japanese cohorts (n = 75), ASNS hypomethylation status was significantly associated with poor therapeutic outcome, and all cases with poor prognostic SPI1 fusion exclusively exhibited ASNS hypomethylation status. These observations show that ASNS hypomethylation status is associated with asparaginase resistance and is a poor prognostic biomarker in childhood T-ALL.

Large-scale DNA demethylation occurs in proliferating ovarian granulosa cells during mouse follicular development.

During ovarian follicular development, granulosa cells proliferate and progressively differentiate to support oocyte maturation and ovulation. To determine the underlying links between proliferation and differentiation in granulosa cells, we determined changes in 1) the expression of genes regulating DNA methylation and 2) DNA methylation patterns, histone acetylation levels and genomic DNA structure. In response to equine chorionic gonadotropin (eCG), granulosa cell proliferation increased, DNA methyltransferase (DNMT1) significantly decreased and Tet methylcytosine dioxygenase 2 (TET2) significantly increased in S-phase granulosa cells. Comprehensive MeDIP-seq analyses documented that eCG treatment decreased methylation of promoter regions in approximately 40% of the genes in granulosa cells. The expression of specific demethylated genes was significantly increased in association with specific histone modifications and changes in DNA structure. These epigenetic processes were suppressed by a cell cycle inhibitor. Based on these results, we propose that the timing of sequential epigenetic events is essential for progressive, stepwise changes in granulosa cell differentiation.

NUDT15 variants confer high incidence of second malignancies in children with acute lymphoblastic leukemia.

The effect of genetic variation on second malignant neoplasms (SMNs) remains unclear. First, we identified the pathogenic germline variants in cancer-predisposing genes among 15 children with SMNs after childhood leukemia/lymphoma using whole-exome sequencing. Because the prevalence was low, we focused on the association between SMNs and NUDT15 in primary acute lymphoblastic leukemia (ALL) cases. NUDT15 is one of the 6-mercaptopurine (6-MP) metabolic genes, and its variants are common in East Asian individuals. The prevalence of NUDT15 hypomorphic variants was higher in patients with SMNs (n = 14; 42.9%) than in the general population in the gnomAD database (19.7%; P = .042). In the validation study with a cohort of 438 unselected patients with ALL, the cumulative incidence of SMNs was significantly higher among those with (3.0%; 95% confidence interval [CI], 0.6% to 9.4%) than among those without NUDT15 variants (0.3%; 95% CI, 0.0% to 1.5%; P = .045). The 6-MP dose administered to patients with ALL with a NUDT15 variant was higher than that given to those without SMNs (P = .045). The 6-MP-related mutational signature was observed in SMN specimens after 6-MP exposure. In cells exposed to 6-MP, a higher level of 6-MP induced DNA damage in NUDT15-knockdown induced pluripotent stem cells. Our study indicates that NUDT15 variants may confer a risk of SMNs after treatment with 6-MP in patients with ALL.

LH Induces De Novo Cholesterol Biosynthesis via SREBP Activation in Granulosa Cells During Ovulation in Female Mice.

In the liver, the sterol response element binding protein (SREBP) and the SREBP cleavage-activated protein (SCAP) complex upregulate cholesterol biosynthesis by gene induction of de novo cholesterol synthetic enzymes (Hmgcr, Cyp51, and Dhcr7). Insulin induced gene 1 (INSIG1) negatively regulates cholesterol biosynthesis by the inhibition of de novo cholesterol biosynthetic gene expression. In the ovary, cholesterol is de novo synthesized; however, the roles of SREBP and its regulators (SCAP and INSIG1) are not well understood. In this study, when immature mice were treated with gonadotropins (eCG followed by hCG), eCG induced and hCG maintained the expression of SREBP-1a, -2, and SCAP granulosa cells, whereas INSIG1 expression was dramatically downregulated after hCG injection. Downregulation of INSIG1 led to generate the SREBPs active form and translocate the SREBPs active form to nuclei. Inhibition of generation of the SREBPs active form by fatostatin or Scap siRNA in both in vivo and in vitro significantly decreased the expressions of de novo cholesterol biosynthetic enzymes, cholesterol accumulation, and progesterone (P4) production compared with the control group. Fatostatin treatment inhibited the ovulation and increased the formation of abnormal corpus luteum which trapped the matured oocyte in the corpus luteum; however, the phenomenon was abolished by P4 administration. The results showed that decreasing INSIG1 level after hCG stimulation activated SREBP-induced de novo cholesterol biosynthesis in granulosa cells of preovulatory follicles, which is essential for P4 production and the rupture of matured oocyte during ovulation process.

Epigenetic Changes in Neonates Born to Mothers With Gestational Diabetes Mellitus May Be Associated With Neonatal Hypoglycaemia.

The detection of epigenetic changes associated with neonatal hypoglycaemia may reveal the pathophysiology and predict the onset of future diseases in offspring. We hypothesized that neonatal hypoglycaemia reflects the in utero environment associated with maternal gestational diabetes mellitus. The aim of this study was to identify epigenetic changes associated with neonatal hypoglycaemia. The association between DNA methylation using Infinium HumanMethylation EPIC BeadChip and neonatal plasma glucose (PG) level at 1 h after birth in 128 offspring born at term to mothers with well-controlled gestational diabetes mellitus was investigated by robust linear regression analysis. Cord blood DNA methylation at 12 CpG sites was significantly associated with PG at 1 h after birth after adding infant sex, delivery method, gestational day, and blood cell compositions as covariates to the regression model. DNA methylation at two CpG sites near an alternative transcription start site of ZNF696 was significantly associated with the PG level at 1 h following birth (false discovery rate-adjusted P < 0.05). Methylation levels at these sites increased as neonatal PG levels at 1 h after birth decreased. In conclusion, gestational diabetes mellitus is associated with DNA methylation changes at the alternative transcription start site of ZNF696 in cord blood cells. This is the first report of DNA methylation changes associated with neonatal PG at 1 h after birth.

Identification of epigenetic memory candidates associated with gestational age at birth through analysis of methylome and transcriptional data.

Preterm birth is known to be associated with chronic disease risk in adulthood whereby epigenetic memory may play a mechanistic role in disease susceptibility. Gestational age (GA) is the most important prognostic factor for preterm infants, and numerous DNA methylation alterations associated with GA have been revealed by epigenome-wide association studies. However, in human preterm infants, whether the methylation changes relate to transcription in the fetal state and persist after birth remains to be elucidated. Here, we identified 461 transcripts associated with GA (range 23-41 weeks) and 2093 candidate CpG sites for GA-involved epigenetic memory through analysis of methylome (110 cord blood and 47 postnatal blood) and transcriptional data (55 cord blood). Moreover, we discovered the trends of chromatin state, such as polycomb-binding, among these candidate sites. Fifty-four memory candidate sites showed correlation between methylation and transcription, and the representative corresponding gene was UCN, which encodes urocortin.

Adverse effect of superoxide-induced mitochondrial damage in granulosa cells on follicular development in mouse ovaries.

High mitochondrial oxidative phosphorylation (mt-OXPHOS) levels are required to supply the ATP necessary for follicle-stimulating hormone (FSH)-induced granulosa cell proliferation during the follicular development process. Consequently, excessive reactive oxygen species (ROS) might be generated and have an adverse effect on follicular health. This study aimed to elucidate the negative effects of ROS on mitochondrial functions in FSH-stimulated granulosa cells during the follicular development process and to investigate whether pyrroloquinoline quinone (PQQ) treatment could accelerate this process by ameliorating the adverse effects. To do this, both in vitro and in vivo experiments were performed with granulosa cells from superovulated immature (3-week-old) mice that were pretreated with or without PQQ, and a natural mating study was also performed. The ROS level in FSH-/eCG-stimulated granulosa cells was significantly increased. Moreover, high oxidative stress and mtDNA damage levels were evident in the granulosa cells. PQQ treatment not only reduced the ROS and oxidative stress levels but also ameliorated mtDNA damage, accelerated FSH-/eCG-induced ATP production, and increased the mitochondrial membrane potential and the expression levels of mitochondrial genes (Nd1, Cytb, Cox1, ATPase6) and the mt-ND1 protein. Accordingly, the proliferation and viability of granulosa cells, numbers of healthy preovulatory follicles and ovulated oocytes and serum estrogen level were significantly improved, while the apoptosis of granulosa cells was reduced. However, PQQ treatment did not change the fertility parameters in mature mice with natural cycles but did significantly increased the number of offspring born per delivery. These results revealed that ROS-associated damage in FSH-stimulated granulosa cells adversely affects their physiology and follicular health during the follicular development process. Treatment with PQQ is a beneficial tool to increase both the number of ovulated oocytes and pups per delivery.