IGFBP7 regulates cell proliferation and migration through JAK/STAT pathway in gastric cancer and is regulated by DNA and RNA methylation.

New biomarkers for early diagnosis of gastric cancer (GC), the second leading cause of cancer-related death, are urgently needed. IGFBP7, known to play various roles in multiple tumours, is complexly regulated across diverse cancer types, as evidenced by our pancancer analysis. Bioinformatics analysis revealed that IGFBP7 expression was related to patient prognosis, tumour clinicopathological characteristics, tumour stemness, microsatellite instability and immune cell infiltration, as well as the expression of oncogenes and immune checkpoints. GSEA links IGFBP7 to several cancer-related pathways. IGFBP7 deficiency inhibited GC cell proliferation and migration in vitro. Furthermore, an in vivo nude mouse model revealed that IGFBP7 downregulation suppressed the tumorigenesis of GC cells. Western blotting analysis showed that the JAK1/2-specific inhibitor ruxolitinib could rescue alterations induced by IGFBP7 overexpression in GC cells. Additionally, our bioinformatics analysis and in vitro assays suggested that IGFBP7 is regulated by DNA methylation at the genetic level and that the RNA m6A demethylase FTO modulates it at the posttranscriptional level. This study emphasizes the clinical relevance of IGFBP7 in GC and its influence on cell proliferation and migration via the JAK/STAT signalling pathway. This study also highlights the regulation of IGFBP7 in GC by DNA and m6A RNA methylation.

IGFBP7+ subpopulation and IGFBP7 risk score in astrocytoma: insights from scRNA-Seq and bulk RNA-Seq.

Background: Glioma is the predominant malignant brain tumor that lacks effective treatment options due to its shielding by the blood-brain barrier (BBB). Astrocytes play a role in the development of glioma, yet the diverse cellular composition of astrocytoma has not been thoroughly researched. Methods: We examined the internal diversity of seven distinct astrocytoma subgroups through single-cell RNA sequencing (scRNA-seq), pinpointed crucial subgroups using CytoTRACE, monocle2 pseudotime analysis, and slingshot pseudotime analysis, employed various techniques to identify critical subgroups, and delved into cellular communication analysis. Then, we combined the clinical information of GBM patients and used bulk RNA sequencing (bulk RNA-seq) to analyze the prognostic impact of the relevant molecules on GBM patients, and we performed in vitro experiments for validation. Results: The analysis of the current study revealed that C0 IGFBP7+ Glioma cells were a noteworthy subpopulation of astrocytoma, influencing the differentiation and progression of astrocytoma. A predictive model was developed to categorize patients into high- and low-scoring groups based on the IGFBP7 Risk Score (IGRS), with survival analysis revealing a poorer prognosis for the high-IGRS group. Analysis of immune cell infiltration, identification of genes with differential expression, various enrichment analyses, assessment of copy number variations, and evaluation of drug susceptibility were conducted, all of which highlighted their significant influence on the prognosis of astrocytoma. Conclusion: This research enhances comprehension of the diverse cell composition of astrocytoma, delves into the various factors impacting the prognosis of astrocytoma, and offers fresh perspectives on treating glioma.

Dynamic changes in insulin-like growth factor binding protein expression occur between embryonic and early post-hatch development in broiler chickens.

Somatotropic gene expression has been altered by genetic selection, and developmental changes in insulin-like growth factor (IGF) and IGF binding protein (IGFBP) expression may contribute to rapid growth and muscle accretion in commercial broilers. The objective of this study was to evaluate changes in somatotropic axis activity between embryonic day (e) 12 and post-hatch day (d) 21. Liver and breast muscle (pectoralis major) were collected to measure gene expression, and blood was collected post-hatch to measure circulating IGFs. Liver IGF1 rose rapidly post-hatch and, in muscle, IGF1 exhibited a dynamic expression pattern. Levels decreased from e14 to e20, returned to e14 levels at d3, decreased again at d10, and stayed low thereafter. In both tissues, mRNA levels of several IGFBPs changed between embryogenesis and post-hatch. Liver IGFBP2 increased between e12 and e20, returned to e12 levels on d1, and remained low. Conversely, liver IGFBP4 expression was greater post-hatch than during embryogenesis. Expression of select IGFBPs was depressed in liver during the peri-hatch period. Liver IGFBP1, IGFBP3, IGFBP5, and IGFBP7 mRNA levels all decreased around this time and returned to embryonic levels by d3. In breast muscle, expression of both IGFBP2 and IGFBP4 was reduced after hatch. Circulating insulin-like growth factor IGF1 and IGF2 levels did not change between hatch and d21. These data suggest that post-hatch IGF effects are likely modulated by target tissue IGFR1 and IGFBP expression rather than changes in circulating hormone levels, with promotion or restriction of IGF-receptor binding regulating growth. Downregulation of several IGFBPs synthesized in the liver may facilitate the metabolic transition from utilizing yolk lipids to dietary carbohydrates. Several IGFBPs produced in breast muscle appear to have growth-promotive effects during embryogenesis but restrict growth of this tissue after hatch, as their post-hatch downregulation could facilitate local IGF signaling. These developmental gene expression patterns suggest that somatotropic hormonal signaling regulating growth and muscle accretion might be controlled through differential actions of IGFBPs and provide a basis for future functional studies.

Vaccine Therapy for Heart Failure Targeting the Inflammatory Cytokine Igfbp7.

BACKGROUND: The heart comprises many types of cells such as cardiomyocytes, endothelial cells (ECs), fibroblasts, smooth muscle cells, pericytes, and blood cells. Every cell type responds to various stressors (eg, hemodynamic overload and ischemia) and changes its properties and interrelationships among cells. To date, heart failure research has focused mainly on cardiomyocytes; however, other types of cells and their cell-to-cell interactions might also be important in the pathogenesis of heart failure. METHODS: Pressure overload was imposed on mice by transverse aortic constriction and the vascular structure of the heart was examined using a tissue transparency technique. Functional and molecular analyses including single-cell RNA sequencing were performed on the hearts of wild-type mice and EC-specific gene knockout mice. Metabolites in heart tissue were measured by capillary electrophoresis-time of flight-mass spectrometry system. The vaccine was prepared by conjugating the synthesized epitope peptides with keyhole limpet hemocyanin and administered to mice with aluminum hydroxide as an adjuvant. Tissue samples from heart failure patients were used for single-nucleus RNA sequencing to examine gene expression in ECs and perform pathway analysis in cardiomyocytes. RESULTS: Pressure overload induced the development of intricately entwined blood vessels in murine hearts, leading to the accumulation of replication stress and DNA damage in cardiac ECs. Inhibition of cell proliferation by a cyclin-dependent kinase inhibitor reduced DNA damage in ECs and ameliorated transverse aortic constriction-induced cardiac dysfunction. Single-cell RNA sequencing analysis revealed upregulation of Igfbp7 (insulin-like growth factor-binding protein 7) expression in the senescent ECs and downregulation of insulin signaling and oxidative phosphorylation in cardiomyocytes of murine and human failing hearts. Overexpression of Igfbp7 in the murine heart using AAV9 (adeno-associated virus serotype 9) exacerbated cardiac dysfunction, while EC-specific deletion of Igfbp7 and the vaccine targeting Igfbp7 ameliorated cardiac dysfunction with increased oxidative phosphorylation in cardiomyocytes under pressure overload. CONCLUSIONS: Igfbp7 produced by senescent ECs causes cardiac dysfunction and vaccine therapy targeting Igfbp7 may be useful to prevent the development of heart failure.

IGFBP7 promotes endothelial cell repair in the recovery phase of acute lung injury.

IGFBP7 has been found to play an important role in inflammatory diseases, such as acute lung injury (ALI). However, the role of IGFBP7 in different stages of inflammation remains unclear. Transcriptome sequencing was used to identify the regulatory genes of IGFBP7, and endothelial IGFBP7 expression was knocked down using Aplnr-Dre mice to evaluate the endothelial proliferation capacity. The expression of proliferation-related genes was detected by Western blotting and RT-PCR assays. In the present study, we found that knockdown of IGFBP7 in endothelial cells significantly decreases the expression of endothelial cell proliferation-related genes and cell number in the recovery phase but not in the acute phase of ALI. Mechanistically, using bulk-RNA sequencing and CO-IP, we found that IGFBP7 promotes phosphorylation of FOS and subsequently up-regulates YAP1 molecules, thereby promoting endothelial cell proliferation. This study indicated that IGFBP7 has diverse roles in different stages of ALI, which extends the understanding of IGFBP7 in different stages of ALI and suggests that IGFBP7 as a potential therapeutic target in ALI needs to take into account the period specificity of ALI.

Role of the Insulin-like Growth Factor System in Neurodegenerative Disease.

The insulin-like growth factor (IGF) system has paracrine and endocrine roles in the central nervous system. There is evidence that IGF signalling pathways have roles in the pathophysiology of neurodegenerative disease. This review focusses on Alzheimer's disease and Parkinson's disease, the two most common neurodegenerative disorders that are increasing in prevalence globally in relation to the aging population and the increasing prevalence of obesity and type 2 diabetes. Rodent models used in the study of the molecular pathways involved in neurodegeneration are described. However, currently, no animal model fully replicates these diseases. Mice with triple mutations in APP, PSEN and MAPT show promise as models for the testing of novel Alzheimer's therapies. While a causal relationship is not proven, the fact that age, obesity and T2D are risk factors in both strengthens the case for the involvement of the IGF system in these disorders. The IGF system is an attractive target for new approaches to management; however, there are gaps in our understanding that first need to be addressed. These include a focus beyond IGF-I on other members of the IGF system, including IGF-II, IGF-binding proteins and the type 2 IGF receptor.

Activated Clec4nhi Neutrophils Aggravate Lung Injury in an Endothelial IGFBP7-Dependent Manner.

The role of endothelial cells in acute lung injury (ALI) has been widely elaborated, but little is known about the role of different subtypes of endothelial cells in ALI. ALI models were established by lipopolysaccharide. Single-cell RNA sequencing was used to identify differential molecules in endothelial subtypes and the heterogeneity of lung immune cells. Specific antibodies were used to block insulin-like growth factor binding protein 7 (IGFBP7), and AAVshIGP7 was used to specifically knock down IGFBP7. Here, we found that IGFBP7 was the most differentially expressed molecule in diverse subsets of endothelial cells and that IGFBP7 was strongly associated with inflammatory responses. Elevated IGFBP7 significantly exacerbated barrier dysfunction in ALI, whereas blockade of IGFBP7 partially reversed barrier damage. General capillary cells are the primary source of elevated serum IGFBP7 after ALI. Using single-cell RNA sequencing, we identified significantly increased Clec4nhi neutrophils in mice with ALI, whereas IGFBP7 knockdown significantly reduced infiltration of Clec4nhi cells and mitigated barrier dysfunction in ALI. In addition, we found that IGFBP7 activated the NF-κB signaling axis by promoting phosphorylation and ubiquitination degradation of F-box/WD repeat-containing protein 2 (FBXW2), thereby exacerbating barrier dysfunction in ALI. Taken together, our data indicate that blockade of serum IGFBP7 or IGFBP7 depletion in general capillary cells reversed barrier damage in ALI. Therefore, targeting IGFBP7 depletion could be a novel strategy for treating ALI.

Piwi expressed in Drosophila adipose tissues regulates systemic IGF signaling and growth via IGF-binding protein.

Piwi and its partner, Piwi-interacting RNA (piRNA), are pivotal in suppressing the harmful effects of transposable elements (TEs) linked to genomic insertional mutagenesis. While primarily active in Drosophila's adult gonadal tissues, causing sterility in its absence, Piwi's role in post-embryonic development remains unclear. Our study reveals Piwi's functional presence in the larval fat body, where it governs developmental growth through systemic insulin/insulin-like growth factor (IGF) signaling (IIS). Piwi knockdown in the fat body resulted in dysregulated TE expression, reduced developmental rate and body growth, and diminished systemic IIS activity. Notably, Piwi knockdown increased Imaginal Morphogenic Protein Late 2 (Imp-L2) expression, akin to insulin-like growth factor-binding protein 7 (IGFBP7), reducing systemic IIS and inhibiting body growth. This unveils a novel role for Piwi in larval adipose tissues, emphasizing its importance in regulating systemic IIS and overall organismal growth.

Antisense Oligonucleotide-Mediated Downregulation of IGFBPs Enhances IGF-1 Signaling.

Insulin-like growth factor-1 (IGF-1) has been considered as a therapeutic agent for muscle wasting conditions including Duchenne muscular dystrophy as it stimulates muscle regeneration, growth and function. Several preclinical and clinical studies have been conducted to show the therapeutic potential of IGF-1, however, delivery issues, short half-life and isoform complexity have impose challenges. Antisense oligonucleotides (AONs) are able to downregulate target proteins by interfering with their transcripts. Here, we investigated the feasibility of enhancing IGF-1 signaling by downregulation of IGF-binding proteins. We observed that out of frame exon skipping of Igfbp1 and Igfbp3 downregulated their protein expression, which increased Akt phosphorylation on the downstream IGF-1 signaling in vitro. 3'RNA sequencing analysis revealed the related transcriptome in C2C12 cells in response to IGFBP3 downregulation. The AONs did however not induce any exon skipping or protein knockdown in mdx mice after 6 weeks of systemic treatment. We conclude that IGFBP downregulation could be a good strategy to increase IGF-1 signaling but alternative tools are needed for efficient delivery and knockdown in vivo.

Food deprivation reduces sensitivity of liver Igf1 synthesis pathways to growth hormone in juvenile gopher rockfish (Sebastes carnatus).

Growth hormone (Gh) regulates growth in part by stimulating the liver to synthesize and release insulin-like growth factor-1 (Igf1), which then promotes somatic growth. However, for fish experiencing food limitation, elevated blood Gh can occur even with low circulating Igf1 and slow growth, suggesting that nutritional stress can alter the sensitivity of liver Igf1 synthesis pathways to Gh. Here, we examined how recent feeding experience affected Gh regulation of liver Igf1 synthesis pathways in juvenile gopher rockfish (Sebastes carnatus) to illuminate mechanisms underlying the nutritional modulation of Igf1 production. Juvenile gopher rockfish were maintained under conditions of feeding or complete food deprivation (fasting) for 14 d and then treated with recombinant sea bream (Sparus aurata) Gh or saline control. Gh upregulated hepatic igf1 mRNA levels in fed fish but not in fasted fish. The liver of fasted rockfish also showed a lower relative abundance of gene transcripts encoding teleost Gh receptors 1 (ghr1) and 2 (ghr2), as well as reduced protein levels of phosphorylated janus tyrosine kinase 2 (pJak2) and signal transducer and activator of transcription 5 (pStat5), which function to induce igf1 gene transcription following Gh binding to Gh receptors. Relative hepatic mRNA levels for suppressors of cytokine signaling (Socs) genes socs2, socs3a, and socs3b were also lower in fasted rockfish. Socs2 can suppress Gh activation of Jak2/Stat5, and fasting-related variation in socs expression may reflect modulated inhibitory control of igf1 gene transcription. Fasted rockfish also had elevated liver mRNA abundances for lipolytic hormone-sensitive lipase 1 (hsl1) and Igf binding proteins igfbp1a, -1b and -3a, reduced liver mRNAs encoding igfbp2b and an Igfbp acid labile subunit-like (igfals) gene, and higher transcript abundances for Igf1 receptors igf1ra and igf1rb in skeletal muscle. Together, these findings suggest that food deprivation impacts liver Igf1 responsiveness to Gh via multiple mechanisms that include a downregulation of hepatic Gh receptors, modulation of the intracellular Jak2/Stat5 transduction pathway, and possible shifts in Socs-inhibitory control of igf1 gene transcription, while also demonstrating that these changes occur in concert with shifts in liver Igfbp expression and muscle Gh/Igf1 signaling pathway components.

Depletion of Igfbp7 alleviates zebrafish NAFLD progression through inhibiting hepatic ferroptosis.

AIMS: The global increased expression of Insulin-like growth factor binding protein 7 (IGFBP7) has been detected in non-alcoholic fatty liver disease (NAFLD) patients, however, its roles in NAFLD and the mechanism remain largely unclear. The goal of this study is to investigate the effect and mechanism of Igfbp7 using a zebrafish NAFLD model. MAIN METHODS: The igfbp7-/- null zebrafish mutant and the Igfbp7 liver overexpressed (LOE) transgenic zebrafish based on Gal4/UAS system were generated by CRISPR/Cas9 and Tol2 transgenic technique, respectively. The zebrafish NAFLD models in wildtypes, igfbp7-/- mutants and Igfbp7 LOE fishes have been established by high-fat diet feeding. The Igfbp7 dynamic expression and its effects on NAFLD progression have been detected and analyzed in both human NAFLD patients and zebrafish models. And the potential mechanism has been investigated through transcriptome analysis and subsequent detection and verification. KEY FINDINGS: High Igfbp7 levels in NASH and fibrosis stages have been detected in liver tissues of both human NAFLD patients and zebrafish models. Depletion of Igfbp7 significantly alleviated liver steatosis, inflammation, and fibrosis, whereas liver specific Igfbp7 overexpression dramatically exacerbated liver fibrosis in zebrafish NAFLD model. The hepatic iron deposition, lipid peroxidation products, and ferroptosis-related index were also significantly reduced at the NASH stage in the absence of Igfbp7. Igfbp7 promotes NAFLD progression through regulating ferroptosis, and Ncoa4-mediated ferritinophagy may be the pathway of Igfbp7-regulated ferroptosis. SIGNIFICANCE: Igfbp7 is confirmed as an important regulator in NAFLD progression. Depleting Igfbp7 effectively alleviates zebrafish NAFLD progression by inhibiting hepatic ferroptosis, suggesting a novel potential target for NAFLD treatment.

The diagnostic value of serum insulin-like growth factor binding protein 7 in gastric cancer.

Backgrounds: Early detection might help in reducing the burden and promoting the survival rate of gastric cancers. Herein, we tried to explore the diagnostic value of insulin-like growth factor binding protein 7 (IGFBP7) in gastric cancers. Methods: In this study, we first analyzed the expression levels and prognostic value of IGFBP7 mRNA in gastric cancers from The Cancer Genome Atlas (TCGA) database. Then, we recruited 169 gastric cancer patients and 100 normal controls as training cohort, and 55 gastric cancer patients and 55 normal controls as independent validation cohort. Enzyme-linked immunosorbent assay was applied to test the serum levels of IGFBP7. The receiver operating characteristic curve (ROC) and the area under the curve (AUC) were applied to evaluation the diagnostic value. Results: TCGA showed that IGFBP7 mRNA was dysregulated and associated with prognosis in gastric cancer patients. Then, we examined the expression of serum IGFBP7 and found that serum IGFBP7 expressed lower in gastric cancer patients than normal controls both in training and independent validation cohorts (p < 0.0001). In training cohort, with the cutoff value of 1.515 ng/ml, the AUC for distinguishing gastric cancer patients was 0.774 (95% CI [0.713-0.836]) with sensitivity of 36.7% (95% CI [29.5-44.5]) and specificity of 90.0% (95% CI [82.0-94.8]). As for early-stage EJA, the AUC was 0.773 (95% CI [0.701-0.845]) with the sensitivity of 33.3% (95% CI [14.4-58.8]). In independent validation cohort, with the same cutoff value, the AUC reached to 0.758 (95% CI [0.664-0.852]). Similarly, for early-stage gastric cancer diagnosis in the independent validation cohort, the AUC value was 0.778 (95% CI [0.673-0.882]). Conclusions: This study indicated that serum IGFBP7 might act as a potential early diagnostic marker for gastric cancers.

Pan-cancer analysis of oncogenic role of insulin-like growth factor-binding proteins and validation in ovarian cancer.

BACKGROUND: Numerous studies have shown that the insulin-like growth factor (IGF) pathway is highly associated with tumor initial and progression in several tumors. However, compared with IGF1/1R and IGF2/2R, insufficient studies have focused on IGF-binding proteins (IGFBPs). METHODS: The GDC TCGA and GTEx data of 33 cancers, TCGA pan-cancer immune phenotypes, tumor mutation burdens, and the copy number alterations of IGFBPs were extracted. Next, the prognostic value of IGFBPs was analyzed based on a univariate Cox analysis. Additionally, the ESTIMATE algorithm was used to calculate stromal and immune scores and tumor purity, and the CIBERSORT algorithm was used to estimate tumor-infiltrating immunocyte levels. Ultimately, the correlation between IGFBP expression and cancer hallmark pathways was estimated with a Spearman analysis. RESULTS: The expression of IGFBPs was differentially expressed and correlated with prognosis in specific cancers. IGFBPs may operate as biological markers for carcinogenesis and progression and as prognostic biomarkers. Additionally, IGFBP5 has been proved that promotes the invasion and migration of ovarian cancer. CONCLUSIONS: In general, IGFBPs can serve as predictable biomarkers and potential therapeutic targets for specific tumors. Our results could provide underlying targets for the design of laboratory experiments to elucidate the mechanism of IGFBPs in cancers and identify IGFBP5 as a prognostic factor in ovarian cancers.

Expression characteristics and their functional role of IGFBP gene family in pan-cancer.

BACKGROUND: Insulin-like growth factor binding proteins (IGFBPs) are critical regulators of the biological activities of insulin-like growth factors. The IGFBP family plays diverse roles in different types of cancer, which we still lack comprehensive and pleiotropic understandings so far. METHODS: Multi-source and multi-dimensional data, extracted from The Cancer Genome Atlas (TCGA), Oncomine, Cancer Cell Line Encyclopedia (CCLE), and the Human Protein Atlas (HPA) was used for bioinformatics analysis by R language. Immunohistochemistry and qRT-PCR were performed to validate the results of the database analysis results. Bibliometrics and literature review were used for summarizing the research progress of IGFBPs in the field of tumor. RESULTS: The members of IGFBP gene family are differentially expressed in various cancer types. IGFBPs expression can affect prognosis of different cancers. The expression of IGFBPs expression is associated with multiple signal transduction pathways. The expression of IGFBPs is significantly correlated with tumor mutational burden, microsatellite instability, tumor stemness and tumor immune microenvironment. The qRT-PCR experiments verified the lower expression of IGFBP2 and IGFBP6 in gastric cancer and the lower expression of IGFBP6 in colorectal cancer. Immunohistochemistry validated a marked downregulation of IGFBP2 protein in gastric cancer tissues. The keywords co-occurrence analysis of IGFBP related publications in cancer showed relative research have been more concentrating on the potential of IGFBPs as tumor diagnostic and prognostic markers and developing cancer therapies. CONCLUSIONS: These findings provide frontier trend of IGFBPs related research and new clues for identifying novel therapeutic targets for various cancers.

Signaling Pathways of the Insulin-like Growth Factor Binding Proteins.

The 6 high-affinity insulin-like growth factor binding proteins (IGFBPs) are multifunctional proteins that modulate cell signaling through multiple pathways. Their canonical function at the cellular level is to impede access of insulin-like growth factor (IGF)-1 and IGF-2 to their principal receptor IGF1R, but IGFBPs can also inhibit, or sometimes enhance, IGF1R signaling either through their own post-translational modifications, such as phosphorylation or limited proteolysis, or by their interactions with other regulatory proteins. Beyond the regulation of IGF1R activity, IGFBPs have been shown to modulate cell survival, migration, metabolism, and other functions through mechanisms that do not appear to involve the IGF-IGF1R system. This is achieved by interacting directly or functionally with integrins, transforming growth factor ß family receptors, and other cell-surface proteins as well as intracellular ligands that are intermediates in a wide range of pathways. Within the nucleus, IGFBPs can regulate the diverse range of functions of class II nuclear hormone receptors and have roles in both cell senescence and DNA damage repair by the nonhomologous end-joining pathway, thus potentially modifying the efficacy of certain cancer therapeutics. They also modulate some immune functions and may have a role in autoimmune conditions such as rheumatoid arthritis. IGFBPs have been proposed as attractive therapeutic targets, but their ubiquity in the circulation and at the cellular level raises many challenges. By understanding the diversity of regulatory pathways with which IGFBPs interact, there may still be therapeutic opportunities based on modulation of IGFBP-dependent signaling.

Effects of the short-term fasting and refeeding on growth-related genes in Japanese eel (Anguilla japonica) larvae.

The Japanese eel (Anguilla japonica) spends a long period as the leptocephalus larval form under current rearing conditions. The duration of the larval stage until metamorphosis is influenced by body size and growth; however, little knowledge exists of the regulatory mechanism of growth in eel larvae. The present study focused on growth hormone (GH), insulin-like growth factors (IGFs), and IGF binding protein (IGFBP) as the central regulators of growth in teleost fishes and transforming growth factor-beta 3 (TGF-ß3) as a possible key modulator of muscle growth and body component synthesis. Japanese eel IGFBP-1a and TGF-ß3, comprising 264 and 411 amino acids, respectively, were cloned. Short-term (5-day) fasting and refeeding experiments were performed to understand changes in growth-related genes affected by nutritional status. The relative expression of gh increased with fasting and subsequently decreased with refeeding to the basal levels of the fed control. Relative igf-1 and igf-2 expression levels were high in the fasted group. Relative igf-1 was reduced after 2-day refeeding, whereas igf-2 decreased to the basal level after 1-day refeeding, suggesting that IGF-1 and IGF-2 might be regulated independently and contribute to postnatal growth in eel larvae. Relative igfbp-1a expression was sharply increased by fasting, whereas tgf-ß3 showed high and low values in the fed and fasted groups, respectively. Relative igfbp-1a and tgf-ß3 levels were negatively and positively correlated with body size, respectively. These results suggest that igfbp-1a and tgf-ß3 are potential indices of growth for exploring optimal rearing conditions to shorten the larval stage in Japanese eels.

Isolation of a novel missense mutation in insulin receptor as a spontaneous revertant in ImpL2 mutants in Drosophila.

Evolutionarily conserved insulin/insulin-like growth factor (IGF) signaling (IIS) correlates nutrient levels to metabolism and growth, thereby playing crucial roles in development and adult fitness. In the fruit fly Drosophila, ImpL2, an ortholog of IGFBP7, binds to and inhibits the function of Drosophila insulin-like peptides. In this study, we isolated a temperature-sensitive mutation in the insulin receptor (InR) gene as a spontaneous revertant in ImpL2 null mutants. The p.Y902C missense mutation is located at the functionally conserved amino acid residue of the first fibronectin type III domain of InR. The hypomorphic InR mutant animals showed a temperature-dependent reduction in IIS and body size. The mutant animals also exhibited metabolic defects, such as increased triglyceride and carbohydrate levels. Metabolomic analysis further revealed that defects in InR caused dysregulation of amino acid and ribonucleotide metabolism. We also observed that InR mutant females produced tiny irregular-shaped embryos with reduced fecundity. In summary, this novel allele of InR is a valuable tool for the Drosophila genetic model of insulin resistance and type 2 diabetes.

Co-amplified with PDGFRA, IGFBP7 is a prognostic biomarker correlated with the immune infiltrations of glioma.

BACKGROUND: A subgroup of glioma carry genetic 4q12 amplification including platelet derived growth factor receptor α (PDGFRA) and insulin like growth factor binding protein 7 (IGFBP7). However, the prognosis of PDGFRA and IGFBP7 in glioma is unclear. METHODS: The prognosis of PDGFRA and IGFBP7 was determined using cox regression and Kaplan-Meier survival analysis. Pathways associated with IGFBP7 were analyzed through gene set enrichment analysis (GSEA). Immune profiling of glioma was determined using "ESTIMATE" and "TIMER" database. RESULTS: PDGFRA amplification or expression was not correlated with the outcomes of glioblastoma (GBM). IGFBP7 but not PDGFRA was over-expressed in GBM. IGFBP7 over-expression was correlated with the unfavorable outcomes of GBM. In lower grade glioma (LGG), PDGFRA over-expression was not correlated with the unfavorable prognosis of LGG, while, IGFBP7 was a prognostic biomarker of LGG. LGG patients with IGFBP7 lower expressions had prolonged clinical overall survival. Combination of IDH mutation, LGG grade and IGFBP7 achieved even better prognostic effects in LGG. Moreover, IGFBP7 was over-expressed in glioma patients with wild type IDH or with high grades. IGFBP7 over-expression was correlated with the unfavorable outcomes of glioma. Furthermore, IGFBP7 was hypo-methylated in GBM or LGG patients without IDH mutations. IGFBP7 hyper-methylation was correlated with the lower overall survival of GBM or LGG. LGG patients with wild type IDH and with IGFBP7 hypo-methylation demonstrated even worse prognosis. IGFBP7 was associated with multiple immune-related signaling pathways in GBM or LGG. The stromal score, immune score and the infiltrations of immune cells were also correlated with IGFBP7 and the prognosis of LGG. CONCLUSIONS: IGFBP7 but not PDGFRA served an ideal prognostic marker and therapeutic target of glioma.

Comparative Genomic Characterization of Insulin-Like Growth Factor Binding Proteins in Cattle and Buffalo.

The somatotropic axis consists of genes associated with economic traits like muscle growth and carcass traits in livestock. Insulin-like growth factor binding proteins (IGFBPs) are the major proteins that play a vital role in the somatotropic axis. The present study performed a genome-wide characterization of IGFBP genes in cattle. Genomic sequences of the IGFBP gene family for different mammals (cattle, buffalo, goat, and sheep) were recovered from the NCBI database. Sequence analyses were performed to investigate cattle's genomic variations in the IGFBP gene family. Phylogenetic analysis, gene structure, motif patterns, and conserved domain analysis (CDA) of the IGFBP family revealed the evolutionarily conserved nature of the IGFBP genes in cattle and other studied species. Physicochemical properties of IGFBP proteins in cattle revealed that most of these proteins are unstable, hydrophilic, thermostable, and acidic. Comparative amino acid analysis revealed variations in all protein sequences with single indels in IGFBP3 and IGFBP6. Mutation analysis revealed only one nonsynonymous mutation D212 > E in the IGFBP6 protein of cattle. A total of 245 nuclear hormone receptor (NHRs) sites were detected, including 139 direct repeats (DR), 65 everted repeats (ER), and 41 inverted repeats (IR). Out of 133 transcription factors (TFs), 10 TFs (AHR, AHRARNT, AP4, CMYB, E47, EGR2, GATA, SP1, and SRF) had differential distribution (P value < 0.05) of putative transcriptional binding sites (TFBS) in cattle compared to buffalo. Synteny analysis revealed the conserved nature of genes between cattle and buffalo. Two gene pairs (IGFBP1/IGFBP3 and IGFBP2/IGFBP5) showed tandem duplication events in cattle and buffalo. This study highlights the functional importance of genomic variation in IGFBP genes and necessitates further investigations better to understand the role and mechanisms of IGFBPs in bovines.

IGFBPs were associated with stemness, inflammation, extracellular matrix remodeling and poor prognosis of low-grade glioma.

Background: The IGFBP family of insulin-like growth factor binding proteins has important biological functions in the organism. However, the role of the IGFBP family in low-grade glioma (LGG) has not been fully explored. Methods: We validated the clinical value of the IGFBP family using RNA-seq and clinical data of LGG in the TCGA and constructed an IGFBPScore using LASSO-regression analysis for prognosis prediction, subtype determination, and treatment sensitivity determination. Subsequently, we explored the role of the IGFBP family in the development of LGG using PanCanAtlas data. Results: Our results suggest that most IGFBP family members were aberrantly expressed and were strongly associated with poor prognosis in LGG. By constructing an IGFBPScore representing the IGFBP family, we found that tumor samples with a high IGFBPScore had a glioblastoma-like mutation pattern characterized by IDH1wt, EGFRmut, PTENmut, and NF1mut with hypo-methylation and glioma stem cell (GSC) diversity. In contrast, the low IGFBPScore group was characterized by IDH1mut accompanied by TP53mut, CICmut, and ATRXmut, and had hyper-methylation status as well as the GSC restriction. Additionally, the high-IGFBPScore group had a high inflammation phenotype with increased immune antigenicity and increased infiltration of immune molecules and cells, as well as a high extracellular matrix phenotype and enhanced multiple metabolic pathways compared with the immune-quiet phenotype of the low-IGFBPScore group, which was strongly associated with poor prognosis. Conclusion: Our study provides a summary analysis and a theoretical basis for the biological role and clinical value of the IGFBP family in LGG, providing an important therapeutic target for LGG.