Association of IGF-1 and IGF-2 genotypes with respiratory muscle strength in individuals with COPD: a cross-sectional study / Asociación de los genotipos de IGF-1 e IGF-2 con la fuerza muscular respiratoria en individuos con EPOC: estudio transversal

INTRODUCTION: Chronic obstructive pulmonary disease is a systemic disease characterized not only by respiratory symptoms but also by physical deconditioning and muscle weakness. One prominent manifestation of this disease is the decline in respiratory muscle strength. Previous studies have linked the genotypes of insulin-like growth factor 1 and 2 (IGF-1 and IGF-2) to muscle weakness in other populations without this disease. However, there is a notable knowledge gap regarding the biological mechanisms underlying respiratory muscle weakness, particularly the role of IGF-1 and IGF-2 genotypes in this pulmonary disease. Therefore, this study aimed to investigate, for the first time, the association between IGF-1 and IGF-2 genotypes with respiratory muscle strength in individuals with chronic obstructive pulmonary disease. In addition, we analyzed the relationship between oxidative stress, chronic inflammation, and vitamin D with respiratory muscle strength. METHODS: A cross sectional study with 61 individuals with chronic obstructive pulmonary disease. Polymerase chain reaction of gene polymorphisms IGF-1 (rs35767) and IGF-2 (rs3213221) was analyzed. Other variables, related to oxidative stress, inflammation and Vitamin D were dosed from peripheral blood. Maximal inspiratory and expiratory pressure were measured. RESULTS: The genetic polymorphisms were associated with respiratory muscle strength ( 3.0 and 3.5; = 0.57). Specific genotypes of IGF-1 and IGF-2 presented lower maximal inspiratory and expiratory pressure (<0.05 for all). Oxidative stress, inflammatory biomarkers, and vitamin D were not associated with respiratory muscle strength. CONCLUSION: The polymorphisms of IGF-1 and IGF-2 displayed stronger correlations with respiratory muscle strength compared to blood biomarkers in patients with chronic obstructive pulmonary disease. Specific genotypes of IGF-1 and IGF-2 were associated with reduced respiratory muscle strength in this population.

INTRODUCCIÓN: La enfermedad pulmonar obstructiva crónica es una enfermedad sistémica caracterizada no solo por síntomas respiratorios, sino también por el deterioro físico y la debilidad muscular. Una manifestación destacada de esta enfermedad es el declive en la fuerza de los músculos respiratorios. Estudios previos han vinculado los genotipos de factor de crecimiento insulínico 1 y 2 (IGF-1 e IGF-2) con la debilidad muscular en poblaciones sin esta enfermedad. Sin embargo, existe un vacío de conocimiento con respecto a los mecanismos biológicos subyacentes a la debilidad de los músculos respiratorios, en particular el papel de los genotipos IGF-1 e IGF-2 en esta enfermedad pulmonar. Por lo tanto, este estudio tuvo como objetivo investigar, por primera vez, la asociación de los genotipos IGF-1 e IGF-2 con la fuerza de los músculos respiratorios en individuos con enfermedad pulmonar obstructiva crónica. Además, analizamos la relación entre el estrés oxidativo, la inflamación crónica y la vitamina D con la fuerza de los músculos respiratorios. MÉTODOS: Un estudio transversal con 61 individuos con enfermedad pulmonar obstructiva crónica. Se analizó la reacción en cadena de la polimerasa de los polimorfismos genéticos IGF-1 (rs35767) e IGF-2 (rs3213221). Otras variables relacionadas con el estrés oxidativo, la inflamación y la vitamina D se dosificaron a partir de muestras de sangre periférica. Se midieron las presiones inspiratorias y espiratorias máximas. RESULTADOS: Los polimorfismos genéticos están asociados con la fuerza de los músculos respiratorios (F: 3.0 y 3.5; R2= 0.57). Genotipos específicos de IGF-1 e IGF-2 presentaron bajos valores en las presiones inspiratorias y espiratorias (p<0.05 en todos los casos). El estrés oxidativo, los biomarcadores inflamatorios y la vitamina D no se asociaron con la fuerza de los músculos respiratorios. CONCLUSIÓN: Los polimorfismos de IGF-1 e IGF-2 mostraron correlaciones más sólidas con la fuerza de los músculos respiratorios en pacientes con enfermedad pulmonar obstructiva crónica en comparación con los biomarcadores sanguíneos. Genotipos específicos de IGF-1 e IGF-2 se asociaron con una disminución de la fuerza de los músculos respiratorios en esta población.

Plasma insulin-like growth factor-II (IGF-II) and IGF-II/IGF-I ratio in a chilean case of Doege-Potter Syndrome / Factor de crecimiento similar a la insulina-II (IGF-II) y razón IGF-II/ IGF-I en un caso chileno de síndrome de Doege-Potter

INTRODUCTION: Doege-Potter syndrome is a rare clinical entity characterized by recurrent hypoglycemic events caused by non-pancreatic tumors secreting an incompletely processed high-molecular-weight form of Insulin-like Growth factor-II (IGF-II). AIM: To report IGF-II and IGF-I circulating levels in a Chilean case of Doege-Potter syndrome and control individuals, and to identify the high-molecular-weight form of IGF-II. METHODS: We measured IGF-II and IGF-I plasma levels using enzyme-linked immunoassays (ELISA) in the patient and ten controls. We identified the high-molecular-weight form of IGF-II performed by Western blot. RESULTS: The plasma concentration of IGF-II in the patient was 868.9 ng/mL, which is only slightly > 80th percentile of controls (681,4 ± 212,8 ng/mL; mean ± standard deviation). In contrast, IGF-I plasma concentration in the patient was 17.6 ng/mL, which is notoriously lower than the corresponding levels in controls (109.1 ± 19.1 ng/mL). The IGF-II/IGF-I ratio in the patient was 49.4 (normal value < 10), which is 7.8 times higher compared to the average ratio of controls (6.3 ± 1.5). The high-molecular form of IGF-II presence in samples was confirmed through Western blot. CONCLUSIONS: The plasma IGF-II/IGF-I ratio better indicates the Doege-Potter syndrome's metabolic impairment than isolated measurements of circulating IGF-II or IGF-I levels.

INTRODUCCIÓN: El síndrome de Doege-Potter es una rara entidad clínica caracterizada por eventos hipoglicémicos recurrentes causados por tumores no-pancreáticos que secretan una forma incompletamente procesada con alto peso molecular del factor de crecimiento similar a la insulina-II (IGF-II). OBJETIVO: Reportar los niveles circulantes de IGF-II e IGF-I en un caso chileno de síndrome de Doege-Potter y en controles, así como identificar la forma de alto peso molecular de IGF-II. MÉTODOS: Los niveles plasmáticos de IGF-II e IGF-I se determinaron mediante inmunoensayos de tipo ELISA en el caso índice y en 10 controles. La forma de alto peso molecular de IGF-II se identificó mediante western-blot. RESULTADOS: La concentración plasmática de IGF-II en el paciente fue de 868,9 ng/mL, que es sólo ligeramente superior al percentil 80 del grupo control (681,4 ± 212,8 ng/mL; media ± desviación estándar). Sin embargo, la concentración plasmática de IGF-I en el paciente fue de 17,6 ng/ mL, que es notoriamente inferior a la de los controles (109,1 ± 19,1 ng/mL). La razón IGF-II/IGF-I en el paciente fue de 49,4 (valor normal < 10), que es 7,8 veces superior a la media de los controles (6,3 ± 1,5). La presencia de la forma de alto peso molecular de IGF-II se confirmó mediante western-blot. CONCLUSIONES: La razón IGF-II/IGF-I en plasma es un mejor indicador de las alteraciones metabólicas del síndrome de Doege-Potter que las mediciones aisladas de IGF-II o IGF-I circulantes.

The mechanism of enriched environment repairing the learning and memory impairment in offspring of prenatal stress by regulating the expression of activity-regulated cytoskeletal-associated and insulin-like growth factor-2 in hippocampus

BACKGROUND@#Prenatal stress can cause neurobiological and behavioral defects in offspring; environmental factors play a crucial role in regulating the development of brain and behavioral; this study was designed to test and verify whether an enriched environment can repair learning and memory impairment in offspring rats induced by prenatal stress and to explore its mechanism involving the expression of insulin-like growth factor-2 (IGF-2) and activity-regulated cytoskeletal-associated protein (Arc) in the hippocampus of the offspring.@*METHODS@#Rats were selected to establish a chronic unpredictable mild stress (CUMS) model during pregnancy. Offspring were weaned on 21st day and housed under either standard or an enriched environment. The learning and memory ability were tested using Morris water maze and Y-maze. The expression of IGF-2 and Arc mRNA and protein were respectively measured by using RT-PCR and Western blotting.@*RESULTS@#There was an elevation in the plasma corticosterone level of rat model of maternal chronic stress during pregnancy. Maternal stress's offspring exposed to an enriched environment could decrease their plasma corticosterone level and improve their weight. The offspring of maternal stress during pregnancy exhibited abnormalities in Morris water maze and Y-maze, which were improved in an enriched environment. The expression of IGF-2, Arc mRNA, and protein in offspring of maternal stress during pregnancy was boosted and some relationships existed between these parameters after being exposed enriched environment.@*CONCLUSIONS@#The learning and memory impairment in offspring of prenatal stress can be rectified by the enriched environment, the mechanism of which is related to the decreasing plasma corticosterone and increasing hippocampal IGF-2 and Arc of offspring rats following maternal chronic stress during pregnancy.

Recurrent Severe Hypoglycemia Secondary to Benign Phyllodes Tumor of the Breast: A rare case of Non-Islet Cell Tumor-induced Hypoglycemia (NICTH) / Journal of the ASEAN Federation of Endocrine Societies

@#Non-islet cell tumor-induced hypoglycemia (NICTH) secondary to phyllodes tumor is extremely rare but potentially life threatening if not treated promptly. We report a case of a 46-year-old Indian female without underlying diabetes mellitus who presented with a large breast tumor and recurrent severe symptomatic hypoglycemia. Investigations supported the diagnosis of NICTH. The hypoglycemia only resolved after corticosteroids and mastectomy. This case highlights the importance of considering NICTH in the evaluation of patients with voluminous tumor and hypoglycemia.

Epigenetic characterization of the H19/IGF2 locus in calf clones placenta / Caracterização epigenética do locus H19/IGF2 na placenta de bezerros clones

Somatic Cell Nuclear Transfer (SCNT-Cloning) is a promising technique in many areas and is based on genetically identical individuals. However, its efficiency is low. Studies suggest that the leading cause is inadequate epigenetic reprogramming. This study aimed to characterize the methylation pattern of the exon 10 regions of the IGF2 gene and the Imprinting Control Region (ICR) of the H19 gene in the placenta of cloned calves. For this study, female and male cloned calves presenting different phenotypes were used. Genomic DNA from these animals' placenta was isolated, then treated with sodium bisulfite and amplified to the ICR/H19 and IGF2 loci. PCR products were cloned into competent bacteria and finally sequenced. A significant difference was found between controls and clones with healthy phenotypes for the ICR/H19 region. In this region, controls showed a hemimethylated pattern, as predicted in the literature due to this region has an imprinted control, while clones were showed less methylated. For the IGF2, no significant differences were found between controls and clones. These results suggest that different genomic regions in the genome may be independently reprogrammed and that failures in reprogramming the DNA methylation patterns of imprinted genes may be one of the causes of the low efficiency of SCNT.(AU)

A Transferência Nuclear de Células Somáticas (TNCS-Clonagem) é uma técnica promissora em várias áreas, e se baseia na produção de indivíduos geneticamente idênticos. No entanto, sua eficiência é baixa. Estudos sugerem que a principal causa seja uma reprogramação epigenética inadequada. O objetivo desse trabalho é caracterizar o padrão de metilação da região éxon 10 do gene IGF2 e da Região Controladora de Imprinting (ICR) do gene H19 na placenta de bezerros clonados. Para a execução do trabalho foram selecionados clones bovinos fêmeas e machos, apresentando diferentes fenótipos. O DNA da placenta desses animais foi extraído, e em seguida foi tratado com bissulfito de sódio e amplificado para os loci ICR/H19 e IGF2. Os produtos da PCR foram clonados em bactérias competentes e, por fim, sequenciados. Foi encontrada uma diferença significativa entre os controles e os clones com fenótipos saudáveis para a região da ICR/H19. Nesta região, os controles tiveram um padrão hemimetilado, como previsto pela literatura, devido essa região ser imprinted. Enquanto os clones encontravam-se menos metilados. Para a região do éxon 10 do IGF2, não foi encontrada diferença significativa entre controles e clones. Estes resultados sugerem que as diferentes regiões do genoma podem se reprogramar independente umas das outras e que falhas na reprogramação do padrão de metilação do DNA de genes imprinted podem ser uma das causas da baixa eficiência da TNCS.(AU)

Expressão do mRNA para IGF-2 em oócitos e células do cumulus extraídos de folículos antrais e pré-antrais de ovelhas nativas do Estado de Pernambuco / IGF-2 mRNA expression in oocytes and cumulus cells of antral and preantral native sheep follicles in Pernambuco State, Brazil

Objetivou-se avaliar a expressão do mRNA para o gene do fator de crescimento IGF-2 em oócitos e células do cumulus de ovelhas em diferentes estágios do desenvolvimento folicular. Os folículos classificados morfologicamente como antrais (terciários e pré-ovulatórios) foram aspirados manualmente para obtenção dos oócitos e células do cumulus. Os folículos pré-antrais (secundários) foram extraídos do córtex ovariano, por microdissecção, e os oócitos retirados. Nos dois grupos, os oócitos foram desnudados e agrupados em "pools" de dez células cada (Grupo A, n=10; Grupo B, n=10) e dez amostras com grupos de células do cumulus (Grupo A1, n=10, B1, n=10). O mRNA foi extraído e convertido em cDNA utilizando a técnica da RT-PCR, utilizando Oligo DT randômico para o mRNA. A análise da expressão confirmou a expressão gênica para IGF-2 nos grupos de oócitos e células do cumulus. Houve um aumento da expressão relativa do mRNA para IGF-2 nos grupos de oócitos durante a fase mais tardia do desenvolvimento folicular e as diferenças foram consideradas significantes (p<0,05). Não houve variação significante da expressão de IGF2 entre os grupos de células do cumulus. Conclui-se que o fator de crescimento IGF-2 tem níveis mais elevados de expressão em oócitos ovinos, na segunda fase do desenvolvimento folicular, mas expressão semelhante em células do cumulus durante as fases estudadas do desenvolvimento folicular.(AU)

The aim of this study was to analyze the mRNA expression of IGF-2 growth factor in oocytes and cumulus cells from native sheep follicles at different stages of follicular development. The classified morphologically as antral follicles (tertiary preovulatory) were aspirated manually to obtain the oocyte and the cumulus cells. The preantral follicles (secondary) were extracted from the ovarian cortex by microdissection, and oocytes were removed. In both groups, oocytes were denuded and grouped into "pools" of ten cells each (Group A, n=10, Group B, n=10) and ten samples with groups of cumulus cells (Group A1, n=10; B1, n=10). The mRNA was extracted and converted to cDNA using the RT-PCR technique. The expression analysis confirmed the expression of IGF-2 gene for groups of oocyte and the cumulus cells. There was an increase in the relative expression of mRNA for IGF-2 for groups of oocytes during the later stage of follicular development and differences were considered significant (p<0.05). There was no significant variation in the expression of IGF2 between groups of cumulus cells. It is concluded that the growth factor IGF-2 has higher levels of expression in sheep oocytes in the second stage of follicular development in the conditions adopted and similar expression in cumulus cells during various stages of follicular development.(AU)

Effects of obesity on global genome DNA methylation and gene imprinting in mouse spermatozoa / 中华男科学杂志

Objective@#To investigate the influence of high fat diet-induced obesity (HFDIO) on the differentially methylated region (DMR) of the imprinted gene and global genome methylation of sperm DNA.@*METHODS@#We performed bisulfite sequencing on the DMR of the imprinted gene and global genome methylation of sperm DNA in the mouse model of HFDIO.@*RESULTS@#No statistically significant differences were found between the HFDIO model and normal control mice in MEG3-IG (93.73 vs 97.26%, P = 0.252), H19 (98.00 vs 97.83%, P = 0.920), IGF2 (97.34 vs 96.25%, P =0.166), IGF2R (1.43 vs 1.11%, P = 0.695), PEG3 (0.19 vs 0.38%, P = 0.537), MEST (0.23 vs 0.68%, P = 0.315), NNAT (0.31 vs 0.00%, P = 0.134), or SNRPN (1.88 vs 3.13%, P = 0.628). A total of 8 942 DMRs were detected across the sperm genome (P <0.05). Gene functional enrichment analysis indicated that the enriched terms with the largest numbers of genes were the metabolic process (n = 1 482), RNA synthesis (n = 779), and transcription (n = 767).@*CONCLUSIONS@#The methylation level underwent no significant change in the DMRs of the imprinted genes from the mice with HFDIO, but the CG methylation of the genes involved in the metabolic process, RNA synthesis and transcription were significantly altered.

Expression of intronic miRNAs and their host gene Igf2 in a murine unilateral ureteral obstruction model

The objective of this study was to determine the expression of miR-483 and miR-483* and the relationship among them, their host gene (Igf2), and other cytokines in a murine model of renal fibrosis. The extent of renal fibrosis was visualized using Masson staining, and fibrosis was scored 3 days and 1 and 2 weeks after unilateral ureteral obstruction (UUO). Expression of miR-483, miR-483* and various cytokine mRNAs was detected by real-time polymerase chain reaction (PCR). Expression of miR-483 and miR-483* was significantly upregulated in the UUO model, particularly miR-483 expression was the greatest 2 weeks after surgery. Additionally, miR-483 and miR-483* expression negatively correlated with Bmp7 expression and positively correlated with Igf2, Tgfβ, Hgf, and Ctgf expression, as determined by Pearson's correlation analysis. Hgf expression significantly increased at 1 and 2 weeks after the surgery compared to the control group. This study showed that miR-483 and miR-483* expression was upregulated in a murine UUO model. These data suggest that miR-483 and miR-483* play a role in renal fibrosis and that miR-483* may interact with miR-483 in renal fibrosis. Thus, these miRNAs may play a role in the pathogenesis of renal fibrosis and coexpression of their host gene Igf2.

Stability of XIST repression in relation to genomic imprinting following global genome demethylation in a human cell line

DNA methylation is essential in X chromosome inactivation and genomic imprinting, maintaining repression of XIST in the active X chromosome and monoallelic repression of imprinted genes. Disruption of the DNA methyltransferase genes DNMT1 and DNMT3B in the HCT116 cell line (DKO cells) leads to global DNA hypomethylation and biallelic expression of the imprinted gene IGF2 but does not lead to reactivation of XIST expression, suggesting that XIST repression is due to a more stable epigenetic mark than imprinting. To test this hypothesis, we induced acute hypomethylation in HCT116 cells by 5-aza-2′-deoxycytidine (5-aza-CdR) treatment (HCT116-5-aza-CdR) and compared that to DKO cells, evaluating DNA methylation by microarray and monitoring the expression of XIST and imprinted genes IGF2, H19, and PEG10. Whereas imprinted genes showed biallelic expression in HCT116-5-aza-CdR and DKO cells, the XIST locus was hypomethylated and weakly expressed only under acute hypomethylation conditions, indicating the importance of XIST repression in the active X to cell survival. Given that DNMT3A is the only active DNMT in DKO cells, it may be responsible for ensuring the repression of XIST in those cells. Taken together, our data suggest that XIST repression is more tightly controlled than genomic imprinting and, at least in part, is due to DNMT3A.

Epigenetic reprogramming, gene expression and in vitro development of porcine SCNT embryos are significantly improved by a histone deacetylase inhibitor--m-carboxycinnamic acid bishydroxamide (CBHA)

Insufficient epigenetic reprogramming of donor nuclei is believed to be one of the most important causes of low development efficiency of mammalian somatic cell nuclear transfer (SCNT). Previous studies have shown that both the in vitro and in vivo development of mouse SCNT embryos could be increased significantly by treatment with various histone deacetylase inhibitors (HDACi), including Trichostatin A, Scriptaid, and m-carboxycinnamic acid bishydroxamide (CBHA), in which only the effect of CBHA has not yet been tested in other species. In this paper we examine the effect of CBHA treatment on the development of porcine SCNT embryos. We have discovered the optimum dosage and time for CBHA treatment: incubating SCNT embryos with 2 μmol/L CBHA for 24 h after activation could increase the blastocyst rate from 12.7% to 26.5%. Immunofluorescence results showed that the level of acetylation at histone 3 lysine 9 (AcH3K9), acetylation at histone 3 lysine 18 (AcH3K18), and acetylation at histone 4 lysine 16 (AcH4K16) was raised after CBHA treatment. Meanwhile, CBHA treatment improved the expression of development relating genes such as pou5f1, cdx2, and the imprinted genes like igf2. Despite these promising in vitro results and histone reprogramming, the full term development was not significantly increased after treatment. In conclusion, CBHA improves the in vitro development of pig SCNT embryos, increases the global histone acetylation and corrects the expression of some developmentally important genes at early stages. As in mouse SCNT, we have shown that nuclear epigenetic reprogramming in pig early SCNT embryos can be modified by CBHA treatment.