Overexpression Of Insulin-like Growth Factor Research Articles

Insulin-Like Growth Factor-1 Promotes Human Uterine Leiomyoma Cell Proliferation via PI3K/AKT/mTOR Pathway

The present research aimed to evaluate the expression of insulin-like growth factor-1 (IGF-1) in uterine leiomyoma, and explore its relationship with the occurrence and development of uterine leiomyoma and potential signal pathways. qRT-PCR and enzyme-linked immunosorbent assay were used for estimating the levels of IGF-1 in human uterine leiomyoma compared to myometrium. The expression of cell proliferation and PI3K/AKT/mTOR signaling pathway-related proteins in uterine leiomyoma cells was evaluated by western blot. Cell viability analysis was performed by CCK-8 assay. Lentivirus infection was used for IGF-1 overexpression and knockdown in uterine leiomyoma cells. The IGF-1 expression level was elevated in human uterine leiomyomas compared to myometrium. IGF-1 promoted the cell viability of human uterine leiomyoma cells. Overexpression of IGF-1 induced the expression of pro-proliferation markers including c-Myc, PCNA, and cyclin D1 in uterine leiomyoma cells. IGF-1 elevated the phosphorylation levels of PI3K, AKT, and mTOR, thus modifying PI3K/AKT/mTOR signaling in uterine leiomyoma cells. IGF-1 promotes proliferation of human uterine leiomyoma cells via PI3K/AKT/mTOR pathway.

The Overexpression of Insulin-Like Growth Factor-1 and Neurotrophin-3 Promote Functional Recovery and Alleviate Spasticity After Spinal Cord Injury.

ObjectiveThis study was conducted to investigate the effects of the exogenous overexpression of nerve growth factors NT-3 and IGF-1 on the recovery of nerve function after spinal cord injury (SCI) and identify the potential mechanism involved.MethodsSixty-four female SD rats were randomly divided into four groups: an SCI group, an adeno-associated viral (AAV)-RFP and AAV-GFP injection group, an AAV-IGF-1 and AAV-NT-3 injection group, and a Sham group. After grouping, the rats were subjected to a 10-week electrophysiological and behavioral evaluation to comprehensively evaluate the effects of the intervention on motor function, spasticity, mechanical pain, and thermal pain. Ten weeks later, samples were taken for immunofluorescence (IF) staining and Western blot (WB) detection, focusing on the expression of KCC2, 5-HT2A, and 5-HT2C receptors in motor neurons and the spinal cord.ResultsElectrophysiological and behavioral data indicated that the AAV-IGF-1 and AAV-NT-3 groups showed better recovery of motor function (P < 0.05 from D14 compared with the AAV-RFP + AAV-GFP group; P < 0.05 from D42 compared with SCI group) and less spasticity (4–10 weeks, at 5 Hz all P < 0.05 compared with SCI group and AAV- RFP + AAV-GFP group) but with a trend for more pain sensitivity. Compared with the SCI group, the von Frey value result of the AAV-IGF-1 and AAV-NT-3 groups showed a lower pain threshold (P < 0.05 at 4–8 weeks), and shorter thermal pain threshold (P < 0.05 at 8–10 weeks). IF staining further suggested that compared with the SCI group, the overexpression of NT-3 and IGF-1 in the SCI-R + G group led to increased levels of KCC2 (p < 0.05), 5-HT2A (p < 0.05), and 5-HT2C (p < 0.001) in motor neurons. WB results showed that compared with the SCI group, the SCI-R + G group exhibited higher expression levels of CHAT (p < 0.01), 5-HT2A (p < 0.05), and 5-HT2C (p < 0.05) proteins in the L2-L6 lumbar enlargement.ConclusionData analysis showed that the overexpression of NT-3 and IGF-1 may improve motor function after SCI and alleviate spasms in a rat model; however, these animals were more sensitive to mechanical pain and thermal pain. These behavioral changes may be related to increased numbers of KCC2, 5-HT2A, and 5-HT2C receptors in the spinal cord tissue. The results of this study may provide a new theoretical basis for the clinical treatment of SCI.

Exosomal miR-543 Inhibits the Proliferation of Ovarian Cancer by Targeting IGF2.

Objective Ovarian cancer (OvCa) is the most lethal gynaecological malignancy worldwide. We aimed to illustrate the potential function and molecular mechanism of exosomal microRNA-543 (miR-543) in the oncogenesis and development of OvCa. Methods Differentially expressed microRNAs in exosomes derived from OvCa cell lines were identified by bioinformatic analysis and verified by RT-PCR. Cell proliferation ability was estimated by clonogenic and 5-ethynyl-2′-deoxyuridine assays in vitro and in vivo. Potential involved pathways and targets of exosomal miRNAs were analysed using DIANA and verified by pyrosequencing, glucose quantification, dual-luciferase reporter experiments, and functional rescue assays. Results Bioinformatic analysis identified miR-543 and its potential target genes involved in the cancer-associated proteoglycan pathway. The expression of miR-543 was significantly decreased in exosomes derived from OvCa cell lines, patient serum, and OvCa tissues, while the mRNA levels of insulin-like growth factor 2 (IGF2) were increased. Furthermore, the overexpression of miR-543 resulted in the suppression of OvCa cell proliferation in vitro and in vivo. Moreover, miR-543 was significantly negatively correlated with IGF2 in OvCa tissues in comparison with paracarcinoma tissues. Notably, upregulation of miR-543 led to increased cell supernatant glucose levels and suppressed cell growth, which was rescued by overexpression of IGF2. Conclusions Exosomal miR-543 participates in the proteoglycan pathway to suppress cell proliferation by targeting IGF2 in OvCa.

Anti-inflammatory and neuroprotective effects of insulin-like growth factor-1 overexpression in pentylenetetrazole (PTZ)-induced mouse model of chronic epilepsy

Epileptogenesis is a dynamic process accompanied by the hippocampal neuroinflammation, aberrant neurogenesis and cognitive decline. Accordingly, anti-neuroinflammation and neuroprotective therapy may be considered in effective prophylaxis and therapeutics for epilepsy. Insulin-like growth factor-1 (IGF-1) is well acknowledged as a neuroprotective factor to promote neurogenesis and neuronal survival and synaptogenesis, wherein there has been controversy as to its implication in epilepsy. In our prior experiments, we established transgenic mice with overexpressed IGF-1 specifically in neural stem cells (NSCs). This experiment sought to investigate the implications of overexpressed IGF-1 in a PTZ-induced mouse model of chronic epilepsy. Herein we demonstrated that increasing hippocampal levels of IGF-1 sufficed to exhibit long-term anti-epileptogenesis effect on epileptic mouse model. The severity of epilepsy was assessed with onset latency, Racine score, percentage of mice with stage IV-V seizures, duration of seizures. Strikingly, IGF-1 transgenic mice showed more lessened severity than the wild-type (W-T) mice. Moreover, IGF-1 transgenic mice exhibited a lesser population of IBA-1-positive cells in CA1 of hippocampus than did W-T mice in the chronic phase, with a significant downregulation of IL-1β, IL-6, and TNF-α in hippocampus, indicating that IGF-1 overexpression significantly mitigated inflammation in the hippocampus. In addition, Nissl staining revealed a greater population of viable neurons in CA1 of IGF-1 transgenic mice versus the W-T mice. TUNEL staining and western blotting indicated fewer apoptotic cells in transgenic mice. Moreover, we identified the evident increase in BrdU-positive and DCX-positive cell populations in dentate gyrus (DG) in IGF-1 transgenic mice, versus the W-T mice, indicative of the role of IGF-1 overexpression in promoting long-term hippocampal neurogenesis in the chronic phase of epilepsy. Collectively, our data authenticated the neuroprotective and antiinflammatory effects of IGF-1 in the chronic phase of epilepsy, which may benefit the long-term anti-epileptogenesis regimens.

Circ_0026579 alleviates LPS-induced WI-38 cells inflammation injury in infantile pneumonia.

Circular RNA (circRNA) represents an important regulator in infantile pneumonia progression. To clarify the role of circ_0026579 in this disease, LPS was used to treat WI-38 cells to mimic inflammation injury. The levels of inflammatory factors were determined by ELISA assay. Cell proliferation and apoptosis were measured by MTT assay, EdU staining and flow cytometry. The protein levels of cyclinD1, cleaved-caspase-3 and insulin-like growth factor 2 (IGF2) were examined using Western blot analysis. Cell oxidative stress was assessed by detecting MDA level and SOD activity. The expression of circ_0026579, miR-24-3p and IGF2 were analyzed using quantitative real-time PCR, and the interaction between miR-24-3p and circ_0026579 or IGF2 was confirmed by dual-luciferase reporter assay and RIP assay. LPS induced inflammation in WI-38 cells. Circ_0026579 expression was promoted in LPS-induced WI-38 cells, and its knockdown alleviated LPS-induced WI-38 cells inflammation. MiR-24-3p was sponged by circ_0026579, and its expression was reduced by LPS. MiR-24-3p inhibitor reversed the regulation of circ_0026579 knockdown on LPS-induced WI-38 cells inflammation. IGF2 was targeted by miR-24-3p, and its expression could be enhanced by LPS. MiR-24-3p relieved the inflammation of WI-38 cells which could be abolished by IGF2 overexpression. Circ_0026579 positively regulated IGF2 expression through sponging miR-24-3p. Circ_0026579 knockdown alleviated LPS-induced WI-38 cells inflammation by miR-24-3p/IGF2 axis, suggesting that circ_0026579 might contribute to infantile pneumonia progression.

IGF-1 Promotes Epithelial-Mesenchymal Transition of Lens Epithelial Cells That Is Conferred by miR-3666 Loss.

The abnormal proliferation, migration, and epithelial-mesenchymal transformation (EMT) of lens epithelial cells (LECs) are the main reasons for vision loss caused by posterior capsular opacification (PCO) after cataract surgery. Insulin-like growth factor-1 (IGF-1) was found to be associated with the pathogenesis of cataracts, but its biological role in PCO is poorly understood. In the present study, IGF-1 overexpression facilitated the proliferation, migration, and EMT, whereas knockdown of IGF-1 markedly suppressed the proliferation, migration, and TGF-β2-induced EMT of LECs. Additionally, to evaluate valuable microRNAs (miRNAs) which target IGF-1 to modulate LEC-EMT, we predicted miR-3666 might regulate IGF-1 by binding its 3'UTR according to the bioinformatics database. Furthermore, we verified that miR-3666 directly targeted IGF-1 by luciferase reporter assay. By using miR-3666 mimics, cell proliferation, migration, and invasion were suppressed, while being enhanced by the reduction of miR-3666. Knockout of IGF1 reverses the effect of the miR-3666 inhibitor on the malignant behavior of LECs. These results indicate the role of miR-3666/IGF-1 in LEC-EMT that offers new strategies for the therapy and prevention of PCO.

Macrophage-Specific IGF-1 Overexpression Reduces CXCL12 Chemokine Levels and Suppresses Atherosclerotic Burden in Apoe-Deficient Mice.

IGF-1 (insulin-like growth factor 1) exerts pleiotropic effects including promotion of cellular growth, differentiation, survival, and anabolism. We have shown that systemic IGF-1 administration reduced atherosclerosis in Apoe-/- (apolipoprotein E deficient) mice, and this effect was associated with a reduction in lesional macrophages and a decreased number of foam cells in the plaque. Almost all cell types secrete IGF-1, but the effect of macrophage-derived IGF-1 on the pathogenesis of atherosclerosis is poorly understood. We hypothesized that macrophage-derived IGF-1 will reduce atherosclerosis. Approach and Results: We created macrophage-specific IGF-1 overexpressing mice on an Apoe-/- background. Macrophage-specific IGF-1 overexpression reduced plaque macrophages, foam cells, and atherosclerotic burden and promoted features of stable atherosclerotic plaque. Macrophage-specific IGF1 mice had a reduction in monocyte infiltration into plaque, decreased expression of CXCL12 (CXC chemokine ligand 12), and upregulation of ABCA1 (ATP-binding cassette transporter 1), a cholesterol efflux regulator, in atherosclerotic plaque and in peritoneal macrophages. IGF-1 prevented oxidized lipid-induced CXCL12 upregulation and foam cell formation in cultured THP-1 macrophages and increased lipid efflux. We also found an increase in cholesterol efflux in macrophage-specific IGF1-derived peritoneal macrophages. Macrophage IGF-1 overexpression reduced atherosclerotic burden and increased features of plaque stability, likely via a reduction in CXCL12-mediated monocyte recruitment and an increase in ABCA1-dependent macrophage lipid efflux.

Clinicopathologic features of thyroid neoplasm with THADA-IGF2BP3 fusion

Abstract Introduction/Objective Thyroid adenoma-associated (THADA)-IGF2BP3 fusions is related to strong overexpression of insulin-like growth factor 2 mRNA-binding protein 3 (IGF2BP3) mRNA and protein, increased IGF2 translation and IGF1 receptor signaling via PI3K and MAPK pathways. THADA-IGF2BP3 have been identified as an oncogenic event in thyroid neoplasms, but the clinicopathologic features have not been greatly evaluated. The purpose of this cases review is to describe the clinical and pathologic findings of thyroid nodules with THADA-IGF2BP3 fusion on molecular testing. Methods/Case Report Surgical Pathology 220 cases of total and hemithyroidectomy from January 2018 to December 2019 were reviewed for cytology fine needle aspiration (FNA), molecular testing results and surgical resection pathology. Results (if a Case Study enter NA) Three cases of THADA-IGF2BP3 fusion identified by Thyroseq testing from FNA of thyroid nodules with all diagnosed as atypia of undetermined significance, Bethesda category 3. No other mutations or gene fusions are identified. Successive surgical interventions are performed. Case 1 is a 49-year-old female right hemithyroidectomy with pathologic diagnosis of papillary thyroid carcinoma (PTC) follicular variant with tumor capsular invasion and no lymphvascular invasion. The tumor is 2cm, two lymph nodes evaluated are not involved by tumor and pathological stage is pT1b pN0. Case 2 is a 71-year-old female total thyroidectomy and the pathologic diagnosis is PTC follicular variant with tumor capsular invasion and no lymphvascular invasion. The tumor is 2cm, one lymph node evaluated is not involved by tumor and pathologic stage is pT1b pN0. Case 3 is a 76-year-old male left hemithyroidectomy and pathologic diagnosis is PTC follicular variant with tumor capsular invasion and no lymphvascular invasion. The tumor is 2cm, two lymph nodes evaluated are not involved by tumor and pathologic stage is pT1b pN0. Conclusion THADA-GF2BP3 fusion is uncommon in thyroid neoplasms and only three cases are detected in 220 cases evaluated. The three cases of thyroid nodules are all diagnosed as AUS by FNA, and all are diagnosed as PTC follicular variant with capsular invasion upon resection without lymphvascular invasion or lymph node involvement. THADA-F2BP3 fusion is associated with thyroid carcinoma, with low-risk non-aggressive behavior, conservative surgery appears necessary and lobectomy is likely adequate.

MiRNA‑7515 suppresses pancreatic cancer cell proliferation, migration and invasion via downregulating IGF‑1 expression.

Pancreatic cancer (PC) is a lethal malignancy of the gastrointestinal tract. Previous studies have reported that microRNAs (miRNAs/miRs) are involved in the tumorigenesis of PC. Therefore, the present study aimed to determine the effects of miR-7515 on PC cell proliferation, invasion and migration in vitro and in vivo, and investigate its underlying molecular mechanism using bioinformatics, double luciferase assay and western blotting. The results revealed that the expression levels of miR-7515 were downregulated in PC, which predicted a poor clinical outcome. The overexpression of miR-7515 significantly decreased the proliferation, invasive and migratory abilities of PC cells in vitro and in vivo, while the knockdown of miR-7515 exerted the opposite effects. miR-7515 was identified to directly bind to insulin-like growth factor 1 (IGF-1) and downregulate its expression, which subsequently downregulated the Ras/Raf/MEK/ERK signalling pathway. The overexpression of IGF-1 reversed the inhibitory effects of miR-7515 overexpression on PC cells. In conclusion, the findings of the present study indicated that miR-7515 may act as a tumor suppressor in PC, as it repressed PC cell proliferation invasion and migration via downregulating the expression of IGF-1 and the activity of the Ras/Raf/MEK/ERK signalling pathways.

IGF1-Stimulated Posttraumatic Hippocampal Remodeling Is Not Dependent on mTOR.

Adult hippocampal neurogenesis is stimulated acutely following traumatic brain injury (TBI). However, many hippocampal neurons born after injury develop abnormally and the number that survive long-term is debated. In experimental TBI, insulin-like growth factor-1 (IGF1) promotes hippocampal neuronal differentiation, improves immature neuron dendritic arbor morphology, increases long-term survival of neurons born after TBI, and improves cognitive function. One potential downstream mediator of the neurogenic effects of IGF1 is mammalian target of rapamycin (mTOR), which regulates proliferation as well as axonal and dendritic growth in the CNS. Excessive mTOR activation is posited to contribute to aberrant plasticity related to posttraumatic epilepsy, spurring preclinical studies of mTOR inhibitors as therapeutics for TBI. The degree to which pro-neurogenic effects of IGF1 depend upon upregulation of mTOR activity is currently unknown. Using immunostaining for phosphorylated ribosomal protein S6, a commonly used surrogate for mTOR activation, we show that controlled cortical impact TBI triggers mTOR activation in the dentate gyrus in a time-, region-, and injury severity-dependent manner. Posttraumatic mTOR activation in the granule cell layer (GCL) and dentate hilus was amplified in mice with conditional overexpression of IGF1. In contrast, delayed astrocytic activation of mTOR signaling within the dentate gyrus molecular layer, closely associated with proliferation, was not affected by IGF1 overexpression. To determine whether mTOR activation is necessary for IGF1-mediated stimulation of posttraumatic hippocampal neurogenesis, wildtype and IGF1 transgenic mice received the mTOR inhibitor rapamycin daily beginning at 3 days after TBI, following pulse labeling with bromodeoxyuridine. Compared to wildtype mice, IGF1 overexpressing mice exhibited increased posttraumatic neurogenesis, with a higher density of posttrauma-born GCL neurons at 10 days after injury. Inhibition of mTOR did not abrogate IGF1-stimulated enhancement of posttraumatic neurogenesis. Rather, rapamycin treatment in IGF1 transgenic mice, but not in WT mice, increased numbers of cells labeled with BrdU at 3 days after injury that survived to 10 days, and enhanced the proportion of posttrauma-born cells that differentiated into neurons. Because beneficial effects of IGF1 on hippocampal neurogenesis were maintained or even enhanced with delayed inhibition of mTOR, combination therapy approaches may hold promise for TBI.

Exosomal miR-486-5p derived from human placental microvascular endothelial cells regulates proliferation and invasion of trophoblasts via targeting IGF1

Preeclampsia (PE) is a serious complication of pregnancy. Exosomes are known to be upregulated in PE. In this study, we sought to investigate the effect of miR-486-5p from human placental microvascular endothelial cells, on the function of trophoblast cells. To investigate the function of human placental microvascular endothelial cell (HPVEC)-derived exosomes on trophoblast cells, HPVECs were treated with hypoxia/reoxygenation (H/R). The separation efficiency of exosomes was determined by transmission electron microscopy, nanosight and Western blot. Cell Counting Kit-8, EdU staining, wound-healing, and transwell assay were performed to detect the effect of exosomally transferred miR-486-5p inhibitor on proliferation, migration and invasion of trophoblast cells. MiRDB and dual-luciferase report assay were used to find the target of miR-486-5p. Our data revealed that miR-486-5p was significantly upregulated in H/R-treated HPVEC-Exo, and miR-486-5p was enriched in HPVEC-Exo. miR-486-5p inhibitor carried by HPVEC-Exo significantly inhibited the proliferation, migration and invasion of trophoblast cells. Insulin-like growth factor 1 (IGF1) was found to be the target of miR-486-5p, and IGF1 overexpression notably reversed the effect of miR-486-5p inhibitor from HPVEC-Exo on trophoblast cell function. In summary, H/R-treated HPVEC-derived exosomally expressing miR-486-5p inhibitor significantly inhibited the proliferation, migration and invasion of trophoblast cells via downregulation of IGF1. The findings from the present study may be useful in the development of treatments for PE.

IGF-1-Expressing Placenta-Derived Mesenchymal Stem Cells Promote Scalding Wound Healing

Stem cell-based regenerative therapy is a novel approach to severe damaged skin. Perinatal tissues such as placenta are considered as promising alternatives. The present study aimed to investigate the effect of insulin-like growth factor-1 (IGF-1)-expressing placenta-derived mesenchymal stem cells (hPMSCs) on healing of burn wounds. hPMSCs were isolated from human placenta, and IGF-1 was transducted into hPMSCs via lentivirus. Flow cytometry and MTT assay were performed to assess cell apoptosis and viability, respectively. Immunostaining of CK19 and ki67 was for evaluating epithelial differentiation ability and cell proliferation. For in vivo studies, we established a mouse model of scalding and performed local administration of IGF-1-expressing hPMSCs via subcutaneous injection. Wound histology was analyzed with H&E staining. The expression of fibrogenic cytokines was detected by western blot. The production of pro-inflammatory factors was measured by ELISA. Overexpression of IGF-1 promoted cell proliferation and epithelial differentiation of hPMSCs in vitro and in vivo. Mice with burn injury displayed increased wound contraction and healing rates following treatment with IGF-1-expressing hPMSCs. There was less inflammatory infiltration and reduced collagen disposition in the presence of IGF-1 at the wound site. Administration of IGF-1-expressing hPMSCs suppressed inflammation by decreasing the levels of pro-inflammatory cytokines including tumor necrosis factor-α, interleukin-1β, and interleukin-6. Besides, IGF-1 increased VEGF expression, and decreased TGF-β1, collagen I and collagen III expressions in vivo. IGF-1-expressing PMSCs promotes cell proliferation and epithelial differentiation, inhibits inflammation and collagen deposition, and thus contributes to wound healing.

MiR-613 inhibits the proliferation of human ovarian granulosa cells by arresting cell cycle progression via the targeting of IGF-1.

Polycystic ovary syndrome(PCOS) is a prevalent endocrine disorder, and microRNA (miRNA) molecules have been implicated in the pathological process of PCOS. The aim of the present study was to elucidate the regulatory effects of miR-613 and insulin-like growth factor-1(IGF-1) on the pathological process of polycystic ovary syndrome(PCOS). The targeting of IGF-1 by miR-613 was investigated by dual-luciferase reporter assay. The regulatory effect of miR-613 on the mRNA and protein levels of IGF1 was determined by reverse transcription-quantitative PCR and western blot analysis. The regulatory effects of miR-613 and IGF-1 on the proliferation and cell cycle progression of KGN cells were evaluated by colony formation assay and flowcytometric analysis. The results revealed that miR-613 targeted IGF-1 and reduced its translational level. In KGN cells, miR-613 arrested cell cycle progression in the G2/M phase and downregulated the expression of cyclinD1 and CDK1. The overexpression of IGF-1 attenuated the inhibitory effects of miR-613 on cell cycle arrest, cyclinD1 and CDK1 expression, and the proliferation of KGN cells. In conclusion, the present study demonstrated that miR-613 targets IGF-1 and thus suppresses its translation. It arrests cell cycle progression and attenuates the proliferation of KGN cells via the targeting of IGF-1. Therefore, it is suggested that miR-613 and IGF-1 could potentially be diagnostic biomarkers and therapeutic targets for PCOS.

Circular RNA circPLK1 promotes breast cancer cell proliferation, migration and invasion by regulating miR-4500/IGF1 axis

BackgroundCircular RNAs (circRNAs) can regulate gene expression in different malignancies. However, the biological functions of circRNA polo-like kinase-1 (circPLK1) in the tumorigenesis of breast cancer (BC) and its potential mechanisms have not been well elucidated yet.MethodsThe expression levels of circPLK1, microRNA-4500 (miR-4500), insulin-like growth factor 1 (IGF1) were measured by quantitative real-time polymerase chain reaction (qRT-PCR) or western blot. Cell viability, cell cycle distribution, cell migration and invasion were determined by Cell Counting Kit-8 (CCK-8) assay, flow cytometry and transwell assay, respectively. Western blot assay was used to analyze the protein levels of cyclin-dependent kinase (CDK) 4 and CDK-6. The relationship between miR-4500 and circPLK1 or IGF1 was predicted by starBase v3.0 and verified by dual-luciferase reporter assay and RNA pull-down assay. The mice xenograft model was established to investigate the roles of circPLK1 in vivo.ResultsCircPLK1 and IGF1 were upregulated and miR-4500 was downregulated in BC tissues and cells. Interference of circPLK1 inhibited BC cell growth, migration and invasion, which was reversed by overexpression of IGF1. Moreover, circPLK1 could directly bind to miR-4500 and IGF1 was verified as a direct target of miR-4500. Furthermore, IGF1 overexpression abated the inhibitory effects of miR-4500 upregulation on proliferation, migration and invasion of BC cells. Mechanically, circPLK1 was a sponge of miR-4500 to regulate IGF1 expression in BC cells. Besides, circPLK1 knockdown suppressed tumor growth via upregulating miR-4500 and downregulating IGF1.ConclusionsCircPLK1 silence inhibited BC cell growth, migration and invasion by regulating miR-4500/IGF1 axis, suggesting circPLK1/miR-4500/IGF axis might be a potential therapeutic target.

Insulin‐like growth factor 1 (IGF1) gene therapy modulates behavior, neurogenesis, and synaptic proteins in a rat model of sporadic Alzheimer's disease

AbstractBackgroundSporadic Alzheimer’s disease (SAD) is the most prevalent neurodegenerative disorder worldwide and it is characterized by progressive memory loss and cognitive impairment. Brain activation of insulin signaling preserves memory in animal models and appears beneficial for patients. In contrast, the role of insulin‐like growth factor 1 (IGF1) remains controversial. Our aim was to determine the possible protective actions of IGF1 in a rat SAD model induced by intracerebroventricular injection of streptozotocin (icv‐STZ). To this end, we drove the expression of IGF1 using a recombinant adenoviral vector, RAd‐IGF1.MethodWe evaluated 3 animal groups: Sham, STZ and STZ+IGF1. STZ and STZ+IGF1 groups were injected with 3 mg/kg icv‐STZ and, 7 days later, the STZ+IGF1 group received the icv‐RAd‐IGF1. During the last two weeks until the end of the study (day 24 post icv‐STZ), we performed several behavioral tests. Additionally, we analyzed neuroblast cells, synaptic proteins and IGF1‐signaling pathway proteins in the hippocampus.ResultIGF1 improved marble‐burying behavior, hippocampus‐dependent spatial memory, object recognition memory and decreased depression‐like behavior, all features affected by STZ. Also, brain IGF1 overexpression restored neurogenesis, enhanced SYT2, PSD95 and GAD65/67 levels, and modulated the IGF1 receptor signaling pathway in STZ animals.ConclusionResults indicate a protective role of IGF1 in our SAD model, as it was effective against behavior deficits and ameliorated hippocampal protein alterations induced by STZ. We conclude that IGF1 therapy has an interesting potential for SAD treatment.

Initiation of PI3K/AKT pathway by IGF-1 decreases spinal cord injury-induced endothelial apoptosis and microvascular damage

AimApoptosis of endothelial cells (ECs) is a crucial factor in blood-spinal cord barrier (BSCB) disruption post spinal cord injury (SCI). Insulin-like growth factor-1 (IGF-1) is a protective cytokine that plays an important role in multiple diseases, whereas the distinct role in SCI-induced remains critical questions to address. Here we designed to explore the role and underlying mechanism of IGF-1 in endothelial damage after SCI. Main methodsIn the current study, we established mouse microvascular endothelial cells (MVECs) injury model via LPS and cDNA of IGF-1 was transfected into MVECs. In vivo SCI mice, overexpression of IGF-1 (SCI-IGF-1) and its corresponding empty vehicle (SCI-NC) were conducted using lentivirus, then apoptosis degree, component of tight junction, and inflammatory damage were evaluated. Key findingsIGF-1 treatment in MVECs displayed a milder apoptosis and cell damage under LPS insult. IGF-1 increased the level of PI3K/AKT pathway, which impeded the procedure of apoptosis. Blocking of PI3K/AKT pathway markedly neutralized the effect of IGF-1 treatment. Transfection of excess IGF-1 into SCI mice significantly corrected microenvironment of neural tissue repair, reduced area of injured core and improved functional recovery with greater activation of PI3K/AKT pathway. SignificanceThe results above argue that the promising roles played by IGF-1 is potentially vital for developing effective future therapies in SCI.

Effects of IGF-1 on Proliferation, Angiogenesis, Tumor Stem Cell Populations and Activation of AKT and Hedgehog Pathways in Oral Squamous Cell Carcinoma.

(1) Background: Activation of the PI3K-AKT pathway controls most hallmarks of cancer, and the hedgehog (HH) pathway has been associated with oral squamous cell carcinoma (OSCC) development and progression. We hypothesized that fibroblast-derived insulin-like growth factor-1 (IGF-1) acts in oral squamous cell carcinoma (OSCC) cells, leading to the non-canonical activation of the HH pathway, maintaining AKT activity and promoting tumor aggressiveness. (2) Methods: Primary fibroblasts (MF1) were genetically engineered for IGF-1 overexpression (MF1-IGF1) and CRISPR/Cas9-mediated IGF1R silencing was performed in SCC-4 cells. SCC-4 cells were co-cultured with fibroblasts or incubated with fibroblast conditioned medium (CM) or rIGF-1 for functional assays and the evaluation of AKT and HH pathways. (3) Results: Gene expression analysis confirmed IGF-1 overexpression in MF1-IGF1 and the absence of IGF-1 expression in SCC-4, while elevated IGF1R expression was detected. IGF1R silencing was associated with decreased survival of SCC-4 cells. Ihh was expressed in both MF1 and MF1-IGF1, and increased levels of GLI1 mRNA were observed in SCC-4 after stimulation with CM-MF1. Activation of both PI3K-AKT and the HH pathway (GLI1, Ihh and SMO) were identified in SCC-4 cells cultured in the presence of MF1-IGF1-CM. rIGF-1 promoted tumor cell proliferation, migration, invasion and tumorsphere formation, whereas CM-MF1 significantly stimulated angiogenesis. (4) Conclusions: IGF-1 exerts pro-tumorigenic effects by stimulating SCC-4 cell proliferation, migration, invasion and stemness. AKT and HH pathways were activated by IGF-1 in SCC-4, reinforcing its influence on the regulation of these signaling pathways.

Up‐regulation of SNHG16 induced by CTCF accelerates cardiac hypertrophy by targeting miR‐182‐5p/IGF1 axis

Long non-coding RNA (lncRNA) SNHG16 has been reported to be significant regulators in multiple cancers. However, never has the relationship between it and cardiac hypertrophy been studied until now. In this study, angiotensin II (Ang II)-treated cardiomyocytes isolated from neonatal mice were used as a model of cardiac hypertrophy in vitro. Real-time quantitative polymerase chain reaction was performed to measure the expression of SNHG16, miR-182-5p, and insulin-like growth factor 1 (IGF1). The relationship between SNHG16 and its downstream genes were corroborated by RNA pull-down and luciferase reporter experiments. Western blot was conducted to detect the expression of markers of hypertrophy. The results disclosed that SNHG16 expression was in a high level in the cardiac hypertrophic model. Down-regulation of SNHG16 could decline the expression of hypertrophic markers and reduce cell surface area induced by Ang II. Moreover, SNHG16 was discovered to be activated by transcription factor CCCTC-binding factor. In addition, SNHG16 could enlarge cell surface area and increase the expression of hypertrophic markers by inhibiting miR-182-5p expression in Ang II-treated cardiomyocytes. Finally, overexpression of IGF1 could rescue the effects of silenced SNHG16 on cardiac hypertrophy cells. In brief, our study illustrated that silenced SNHG16 repressed Ang II-imposed cardiac hypertrophy via targeting miR-182-5p/IGF1 axis.

Insulin-like growth factor-1 overexpression increases long-term survival of posttrauma-born hippocampal neurons while inhibiting ectopic migration following traumatic brain injury

Cellular damage associated with traumatic brain injury (TBI) manifests in motor and cognitive dysfunction following injury. Experimental models of TBI reveal cell death in the granule cell layer (GCL) of the hippocampal dentate gyrus acutely after injury. Adult-born neurons residing in the neurogenic niche of the GCL, the subgranular zone, are particularly vulnerable. Injury-induced proliferation of neural progenitors in the subgranular zone supports recovery of the immature neuron population, but their development and localization may be altered, potentially affecting long-term survival. Here we show that increasing hippocampal levels of insulin-like growth factor-1 (IGF1) is sufficient to promote end-stage maturity of posttrauma-born neurons and improve cognition following TBI. Mice with conditional overexpression of astrocyte-specific IGF1 and wild-type mice received controlled cortical impact or sham injury and bromo-2′-deoxyuridine injections for 7d after injury to label proliferating cells. IGF1 overexpression increased the number of GCL neurons born acutely after trauma that survived 6 weeks to maturity (NeuN+BrdU+), and enhanced their outward migration into the GCL while significantly reducing the proportion localized ectopically to the hilus and molecular layer. IGF1 selectively affected neurons, without increasing the persistence of posttrauma-proliferated glia in the dentate gyrus. IGF1 overexpressing animals performed better during radial arm water maze reversal testing, a neurogenesis-dependent cognitive test. These findings demonstrate the ability of IGF1 to promote the long-term survival and appropriate localization of granule neurons born acutely after a TBI, and suggest these new neurons contribute to improved cognitive function.

Circular RNA Circ100084 functions as sponge of miR‑23a‑5p to regulate IGF2 expression in hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) has become a major cause of cancer-related mortality worldwide. Circular RNAs (circRNAs) are non-coding RNAs that serve important roles in multiple cancers. However, the role of circRNAs in HCC remains largely unknown. In the present study, a circRNA microarray dataset of HCC samples, GSE97332, was downloaded from the gene expression omnibus database. Following data preprocessing, differentially expressed circRNAs between HCC tissues and normal tissues were determined using GEO2R. The circRNA-miRNA interactions were predicted by the miRanda database. The miRTarbase database was used to search for target genes of the miRNAs. A circRNA-miRNA-mRNA network was constructed using Cytoscape based on the obtained circRNA, miRNA and mRNA. In this network, the upregulated circRNA hsa_circRNA_100084 was found to be involved in a competing endogenous relationship of hsa_circRNA_100084-hsa-miR-23a-5p- insulin-like growth factor 2 (IGF2). The differential expression of hsa_circRNA_100084, hsa-miR-23a-5p and IGF2 in HCC tissues and liver cancer cells was validated by reverse transcription-quantitative PCR. Additionally, the interactions between hsa-miR-23a-5p with hsa_circRNA_100084 and IGF2 were validated by dual-luciferase reporter assays. Knocking down hsa_circRNA_100084 inhibited the proliferation, migration and invasion of liver cancer cells, while the simultaneous overexpression of IGF2 reversed the effects of hsa_circRNA_100084 knockdown. The results show that hsa_circRNA_100084 could promote the expression of IGF2 by acting as a sponge of hsa-miR-23a-5p in liver cancer cells.