Transcriptional profile of human thymus reveals IGFBP5 is correlated with age-related thymic involution.

Thymus is the main immune organ which is responsible for the production of self-tolerant and functional T cells, but it shrinks rapidly with age after birth. Although studies have researched thymus development and involution in mouse, the critical regulators that arise with age in human thymus remain unclear. We collected public human single-cell transcriptomic sequencing (scRNA-seq) datasets containing 350,678 cells from 36 samples, integrated them as a cell atlas of human thymus. Clinical samples were collected and experiments were performed for validation. We found early thymocyte-specific signaling and regulons which played roles in thymocyte migration, proliferation, apoptosis and differentiation. Nevertheless, signaling patterns including number, strength and path completely changed during aging, Transcription factors (FOXC1, MXI1, KLF9, NFIL3) and their target gene, IGFBP5, were resolved and up-regulated in aging thymus and involved in promoting epithelial-mesenchymal transition (EMT), responding to steroid and adipogenesis process of thymic epithelial cell (TECs). Furthermore, we validated that IGFBP5 protein increased at TECs and Hassall's corpuscle in both human and mouse aging thymus and knockdown of IGFBP5 significantly increased the expression of proliferation-related genes in thymocytes. Collectively, we systematically explored cell-cell communications and regulons of early thymocytes as well as age-related differences in human thymus by using both bioinformatic and experimental verification, indicating IGFBP5 as a functional marker of thymic involution and providing new insights into the mechanisms of thymus involution.

Pregnancy associated plasma protein-A2 (PAPP-A2) and stanniocalcin-2 (STC2) but not PAPP-A are associated with circulating total IGF-1 in a human adult population.

The pappalysins pregnancy associated plasma protein-A (PAPP-A) and -A2 (PAPP-A2) act as proteinases of insulin-like growth factor-1 (IGF-1) binding proteins, while stanniocalcin-2 (STC2) was identified as a pappalysin inhibitor. While there is some evidence from studies in children and adolescents, it is unclear whether these molecules are related to concentrations of IGF-1 and its binding proteins in adults. We investigated cross-sectionally the association of circulating PAPP-A, PAPP-A2 and STC2 with IGF-1 and its binding proteins (IGFBPs) in 394 adult pretest participants (20-69 years) of the German National Cohort Berlin North study center. Plasma PAPP-A, PAPP-A2, total and free IGF-1, IGFBP-1, IGFBP-2, IGFBP-3, IGFBP-5 and STC2 were measured by ELISAs. The associations of PAPP-A, PAPP-A2 and STC2 with IGF-1 or IGFBPs were investigated using multivariable linear regression analyses adjusting for age, sex, body mass index and pretest phase. We observed significant inverse associations of PAPP-A2 (difference in concentrations per 0.5 ng/mL higher PAPP-A2 levels) with total IGF-1 (- 4.3 ng/mL; 95% CI - 7.0; - 1.6), the IGF-1:IGFBP-3 molar ratio (- 0.34%; 95%-CI - 0.59; - 0.09), but not free IGF-1 and a positive association with IGFBP-2 (11.9 ng/mL; 95% CI 5.0; 18.8). PAPP-A was not related to total or free IGF-1, but positively associated with IGFBP-5. STC2 was inversely related to total IGF-1, IGFBP-2 and IGFBP-3 and positively to IGFBP-1. This first investigation of these associations in a general adult population supports the hypothesis that PAPP-A2 as well as STC2 play a role for IGF-1 and its binding proteins, especially for total IGF-1. The role of PAPP-A2 and STC2 for health and disease in adults warrants further investigation.

Protein Plasma Levels of the IGF Signalling System Are Altered in Major Depressive Disorder.

The Insulin-like growth factor 2 (IGF-2) has been recently proven to alleviate depressive-like behaviors in both rats and mice models. However, its potential role as a peripheral biomarker has not been evaluated in depression. To do this, we measured plasma IGF-2 and other members of the IGF family such as Binding Proteins (IGFBP-1, IGFBP-3, IGFBP-5 and IGFBP-7) in a depressed group of patients (n = 51) and in a healthy control group (n = 48). In some of these patients (n = 15), we measured these proteins after a period (19 ± 6 days) of treatment with antidepressants. The Hamilton Depressive Rating Scale (HDRS) and the Self-Assessment Anhedonia Scale (SAAS) were used to measure depression severity and anhedonia, respectively. The general cognition state was assessed by the Mini-Mental State Examination (MMSE) test and memory with the Free and Cued Selective Reminding Test (FCSRT). The levels of both IGF-2 and IGFBP-7 were found to be significantly increased in the depressed group; however, only IGF-2 remained significantly elevated after correction by age and sex. On the other hand, the levels of IGF-2, IGFBP-3 and IGFBP-5 were significantly decreased after treatment, whereas only IGFBP-7 was significantly increased. Therefore, peripheral changes in the IGF family and their response to antidepressants might represent alterations at the brain level in depression.

Time-Dependent Changes in Muscle IGF1-IGFBP5-PAPP System after Sciatic Denervation.

Denervation-induced muscle atrophy is a frequent cause of skeletal muscle diseases. However, the role of the most important muscle growth factor, insulin-like growth factor (IGF-1), in this process is poorly understood. IGF-1 activity is controlled by six IGF-1 binding proteins (IGFBPs). In skeletal muscle, IGFBP-5 seems to have an important role in atrophic processes. Furthermore, pappalysins (PAPP-A) modulate muscle growth by increasing IGF-1 bioavailability through IGFBP cleavage. We aimed to study the time-dependent changes in the IGF1-IGFBP5-PAPP system and its regulators in gastrocnemius muscle after sciatic denervation. Gastrocnemius atrophy and overexpression of IGF-1 was observed from day 3 post-denervation. The proteolytic factors measured were elevated from day 1 post-denervation onwards. Expression of both IGFBP-5 and pappalysins were increased on days 1 and 3. Subsequently, on days 7 to 14 pappalysins returned to control levels while IGFBP-5 remained elevated. The ratio IGFBP-5/PAPP-A was correlated with the main proteolytic markers. All data suggest that the initial increase of pappalysins could facilitate the IGF-1 action on muscle growth, whereas their subsequent decrease could lead to further muscle wasting.

Circ_0008450 regulates keloid-derived fibroblast proliferation, migration, invasion and apoptosis with increased IGFBP5 through sponging miR-1224-5p.

BACKGROUND: Keloids (KD) are benign fibroproliferative tumors and circular RNAs (circRNAs) may participate in KD progression. At present, whether circ_0008450 regulates keloid-derived fibroblast phenotypes remains unclear. This study aimed to explore the functions of circ_0008450 in keloid (KD)-derived fibroblast phenotypes and the underlying mechanism. METHODS: Quantitative real-time polymerase chain reaction (qRT-PCR) or western blot assay was performed to determine the expression of circ_0008450, miR-1224-5p, insulin like growth factor binding protein 5 (IGFBP5) and extracellular matrix (ECM)-related markers. 5-Ethynyl-2'-deoxyuridine (EdU) assay was conducted to assess cell proliferation ability. Flow cytometry analysis was used to analyze cell cycle and cell apoptosis. Scratch assay and transwell assay were utilized to examine cell migration and invasion. Mechanism assays were executed to verify the relations of circ_0008450, miR-1224-5p and IGFBP5. RESULTS: Circ_0008450 was highly expressed in KD tissues and KD-derived fibroblasts. Circ_0008450 silencing inhibited KD-derived fibroblast proliferation, cell cycle, and motility and promoted apoptosis. The effect of circ_0008450 knockdown on KD-derived fibroblast processes was ameliorated by miR-1224-5p downregulation. IGFBP5 was a target gene of miR-1224-5p. IGFBP5 upregulation abated miR-1224-5p-mediated effects on KD-derived fibroblast processes. CONCLUSION: Circ_0008450 promoted KD-derived fibroblast proliferation, migration, and invasion and repressed apoptosis via sponging miR-1224-5p and elevating IGFBP5.

Insulin-like growth factor binding protein 5 accelerate the senescence of periodontal ligament stem cells.

Evidences have showed stem cell mediated tissue regeneration is a promising method for the treatment of periodontitis. Insulin-like growth factor binding proteins-5 (IGFBP5) is a member of the insulin growth factor (IGFs) family and plays a regulatory role in cell proliferation and differentiation. Our previous study showed that IGFBP5 can promote osteogenic differentiation of periodontal ligament stem cells (PDLSCs) and enhance periodontal tissue regeneration mediated by PDLSCs. However, the function of IGFBP5 in the process of PDLSCs senescence remains unclear. The present study showed IGFBP5 mRNA level was highly expressed in passage-induced aged PDLSCs cells. IGFBP5 knockdown decreased the ratio of senescence associated ß-galactosidase (SA-ß-Gal) positive cells, enhanced the activity of TERT, and down-regulated the expression levels of P16, P21, P53 mRNA and protein. Overexpression of IGFBP5 increased the ratio of SA-ß-Gal positive staining PDLSCs, decreased the activity of telomerase TERT, and up-regulated the expression levels of P16, P21, P53 mRNA and protein related to PDLSCs senescence. In conclusion, IGFBP5 can accelerate the senescence of PDLSCs, indicating the potential target for maintaining the "young state" of stem cells.

CCCTC-Binding Factor Mediates the Transcription of Insulin-Like Growth Factor Binding Protein 5 Through EZH2 in Ulcerative Colitis.

BACKGROUND: Ulcerative colitis (UC) features chronic, non-infectious inflammation of the colon. Insulin-like growth factor binding protein 5 (IGFBP5) has been indicated to be related to various inflammation-related diseases. However, its association with UC remains largely unclear. AIMS: Here, we investigate the role of IGFBP5 in colonic mucosal epithelial cell injury in UC. METHODS: Differentially expressed genes in the colonic tissues of UC mice were screened using the Gene Expression Omnibus database, and IGFBP5 was identified. UC mice were developed using dextran sulfate sodium, and IGFBP5 expression in the colonic tissues of UC mice was confirmed by immunohistochemistry and RT-qPCR. The effects of IGFBP5 in vivo and in vitro were investigated by intraperitoneal injection of adeno-associated virus into UC mice or by transfection with an IGFBP5 overexpression plasmid into lipopolysaccharide-treated colonic mucosal epithelial cells. The mechanisms causing IGFBP5 deletion in UC were predicted by bioinformatics analysis and ChIP-qPCR and verified by rescue experiments. RESULTS: IGFBP5 was reduced in UC. IGFBP5 impaired the NFκB pathway in the colonic tissue of UC mice and ameliorated inflammatory infiltration and colonic mucosal cell injury. IGFBP5 depletion was associated with H3K27me3 modification, which was induced by EZH2. CTCF was responsible for recruiting EZH2 to the promoter region of IGFBP5. CTCF inhibition repressed UC progression by reducing H3K27me3 modification via the discouragement of the enrichment of EZH2 in the IGFBP5 promoter. CONCLUSIONS: CTCF modulates H3K27me3 modification of the IGFBP5 promoter by recruiting EZH2, thereby downregulating IGFBP5 to accentuate colonic mucosal epithelial cell injury in UC mice.

Evaluation of IGFBP5 expression and plasma osteopontin level in COVID-19 patients.

PURPOSE: The aim of this study is to investigate insulin-like growth factor binding protein 5 (IGFBP5) expression in coronavirus disease 2019 (COVID-19) patients and its relationships with COVID-19 laboratory findings and plasma osteopontin (OPN) levels. MATERIALS AND METHODS: We enrolled 60 patients with COVID-19 and 30 healthy individuals in this study. mRNA expression of IGFBP5 was measured by RT-PCR. Plasma OPN levels were measured via the ELISA method. RESULTS: Plasma OPN levels were higher and IGFBP5 expression levels were lower in COVID-19 patients than in the healthy individuals (p â€‹= â€‹0.0057 and p â€‹= â€‹0.0142, respectively). Critically ill patients had higher OPN and lower IGFBP5 than non-critically ill patients. Patients with affected lungs demonstrated increased OPN and decreased IGFBP5 (p â€‹= â€‹0.00032 and p â€‹= â€‹0.044, respectively). Receiver operating characteristic (ROC) analysis indicated that IGFBP5 expression and OPN levels can be used discriminate non-critically from critically ill patients (p â€‹= â€‹0.049; p â€‹= â€‹0.0016, respectively). CONCLUSION: This study demonstrated that patients with a poor prognosis had increased OPN and decreased IGFBP5. High values of OPN and low values of IGFBP5 may be considered as signs of disease severity. Tissue-specific IGFBP5 expression may contribute to understanding the role of IGFBP5 in the lungs in COVID-19 cases.

Alterations in insulin-like growth factor system in spinal muscular atrophy.

INTRODUCTION/AIMS: Spinal muscular atrophy (SMA) is an inherited neuromuscular disease caused by survival motor neuron (SMN) protein deficiency. Insulin-like growth factor-I (IGF-I) is a myotrophic and neurotrophic factor that has been reported to be dysregulated in in vivo SMA model systems. However, detailed analyses of the IGF-I system in SMA patients are missing. In this study, we analyzed the components of the IGF-I system in serum and archived skeletal muscle biopsies of SMA patients. METHODS: Serum IGF-I, IGF binding protein (IGFBP)-3, and IGFBP-5 levels were analyzed in 11 SMA patients and 13 healthy children by immunoradiometric and enzyme-linked immunosorbent assays. The expression of IGF-I, IGF-I receptor, and IGFBP-5 proteins was investigated by immunofluorescence analysis in the archived skeletal muscle biopsies of nine SMA patients, six patients with non-SMA-related neuromuscular disease and atrophic fibers in muscle biopsy, and four controls. RESULTS: A significant decrease in IGF-I levels (mean ± SD: -1.39 ± 1.46 vs. 0.017 ± 0.83, p = .02) and increase in IGFBP-5 levels (mean ± SD: 2358.5 ± 1617.4 ng/mL vs. 1003.4 ± 274.3 ng/mL, p = .03) were detected in serum samples of SMA patients compared to healthy controls. Increased expression of IGF-I, IGF-I receptor, and IGFBP-5 was detected in skeletal muscle biopsies of SMA patients and non-SMA neuromuscular diseases, indicating atrophy-specific alterations in the pathway. DISCUSSION: Our findings suggested that the components of the IGF-I system are altered in SMA patients at both the systemic and tissue-specific levels.

Exosome-Encapsulated microRNA-140-5p Alleviates Neuronal Injury Following Subarachnoid Hemorrhage by Regulating IGFBP5-Mediated PI3K/AKT Signaling Pathway.

Recent literature has highlighted the therapeutic implication of exosomes (Exos) released by adipose tissue-originated stromal cells (ADSCs) in regenerative medicine. Herein, the current study sought to examine the potential protective effects of ADSC-Exos on neuronal injury following subarachnoid hemorrhage (SAH) by delivering miR-140-5p. Firstly, isolated primary neurons were co-cultured together with well-identified ADSC-Exos. TDP-43-treated neurons were subsequently treated with PKH67-ADSC-Exos and Cy3-miR-140-5p to assess whether ADSC-Exos could transmit miR-140-5p to the recipient neurons to affect their behaviors. Moreover, a luciferase assay was carried out to identify the presumable binding of miR-140-5p to IGFBP5. IGFBP5 rescue experimentation was also performed to testify whether IGFBP5 conferred the impact of miR-140-5p on neuronal damage. The role of PI3K/AKT signaling pathway was further analyzed with the application of its inhibitor miltefosine. Lastly, SAH rat models were developed for in vivo validation. It was found that ADSC-Exos conferred protection against TDP-43-caused neuronal injury by augmenting viability and suppressing cell apoptosis. In addition, miR-140-5p was transmitted from ADSC-Exos to neurons and post-transcriptionally downregulated the expression of IGFBP5. As a result, by means of suppressing IGFBP5 and activating the PI3K/AKT signaling pathway, miR-140-5p from ADSC-Exos induced a neuroprotective effect. Furthermore, in vivo findings substantiated the aforementioned protective role of ADSC-Exos-miR-140-5p, contributing to protection against SAH-caused neurological dysfunction. Collectively, our findings indicated that ADSC-Exos-miR-140-5p could inhibit TDP-43-induced neuronal injury and attenuate neurological dysfunction of SAH rats by inhibiting IGFBP5 and activating the PI3K/Akt signaling pathway.

Biological effects and regulation of IGFBP5 in breast cancer.

The insulin-like growth factor receptor (IGF1R) pathway plays an important role in cancer progression. In breast cancer, the IGF1R pathway is linked to estrogen-dependent signaling. Regulation of IGF1R activity is complex and involves the actions of its ligands IGF1 and IGF2 and those of IGF-binding proteins (IGFBPs). Six IGFBPs are known that share the ability to form complexes with the IGFs, by which they control the bioavailability of these ligands. Besides, each of the IGFBPs have specific features. In this review, the focus lies on the biological effects and regulation of IGFBP5 in breast cancer. In breast cancer, estrogen is a critical regulator of IGFBP5 transcription. It exerts its effect through an intergenic enhancer loop that is part of the chromosomal breast cancer susceptibility region 2q35. The biological effects of IGFBP5 depend upon the cellular context. By inhibiting or promoting IGF1R signaling, IGFBP5 can either act as a tumor suppressor or promoter. Additionally, IGFBP5 possesses IGF-independent activities, which contribute to the complexity by which IGFBP5 interferes with cancer cell behavior.

Pappalysins and Stanniocalcins and Their Relationship With the Peripheral IGF Axis in Newborns and During Development.

CONTEXT: Pappalysins (PAPP-A, PAPP-A2) modulate body growth by increasing insulin-like growth factor I (IGF-I) bioavailability through cleavage of insulin-like growth factor binding proteins (IGFBPs) and are inhibited by stanniocalcins (STC1, STC2). Normative data on these novel factors, as well as on free IGF-I and uncleaved fractions of IGFBPs, are not well established. OBJECTIVE: This work aimed to determine serum concentrations of PAPP-A, PAPP-A2, STC1, and STC2 in relationship with other growth hormone (GH)-IGF axis parameters during development. METHODS: Full-term newborns (150; gestational age: 39.30 ±â€…1.10 weeks), 40 preterm newborns (30.87 ±â€…3.35 weeks), and 1071 healthy individuals (aged 1-30 years) were included in the study and divided according to their Tanner stages (males and females): I:163 males, 154 females; II:100 males, 75 females; III:83 males, 96 females; IV: 77 males, 86 females; and V:109 males,128 females. RESULTS: Serum concentrations of PAPP-A, PAPP-A2, STC1, STC2, IGFBP-2, total IGFBP-4, and total IGFBP-5 were elevated at birth and declined throughout childhood. In postnatal life, PAPP-A2 concentrations decreased progressively in concomitance with the free/total IGF-I ratio; however, stanniocalcin concentrations remained stable. PAPP-A2 concentrations positively correlated with the free/total IGF-I ratio (r = +0.28; P < .001) and negatively with the intact/total IGFBP-3 ratio (r = -0.23; P < .001). PAPP-A concentrations inversely correlated with intact/total IGFBP-4 ratio (r = -0.21; P < .001), with PAPP-A concentrations being lower in females at all ages. Association studies indicate the importance of stanniocalcins and pappalysins in the control of this axis in an age-specific manner. CONCLUSION: This study provides reference values of pappalysins and stanniocalcins, which modulate IGF-I activity by changing the concentrations of cleaved and uncleaved IGFBPs.

The expression of IGFBP-5 in the reproductive axis and effect on the onset of puberty in female rats.

Insulin-like growth factor-binding protein-5 (IGFBP-5) has recently been shown to alter the reproductive capacity by regulating insulin-like growth factor (IGF) bioavailability or IGF-independent effects. The present study aimed to investigate the effect and mechanism of IGFBP-5 on the onset of puberty in female rats. Immunofluorescence and real-time quantitative PCR were used to determine the expression and location of IGFBP-5 mRNA and protein distribution in the infant's hypothalamus-pituitary-ovary (HPO) axis prepuberty, peripuberty, puberty and adult female rats. Prepubertal rats with IGFBP-5 intracerebroventricular (ICV) were injected to determine the puberty-related genes expression and the concentrations of reproductive hormones. Primary hypothalamic cells were treated with IGFBP-5 to determine the expression of puberty-related genes and the Akt and mTOR proteins. Results showed that Igfbp-5 mRNA and protein were present on the HPO axis. The addition of IGFBP-5 to primary hypothalamic cells inhibited the expression of Gnrh and Igf-1 mRNAs (P < 0.05) and increased the expression of AKT and mTOR protein (P < 0.01). IGFBP-5 ICV-injection delayed the onset of puberty, reduced Gnrh, Igf-1, and Fshß mRNAs, and decreased the concentrations of E2, P4, FSH,serum LH levels and the ovaries weight (P < 0.05). More corpus luteum and fewer primary follicles were found after IGFBP-5 injection (P < 0.05).

Insulin-like growth factor 5 associates with human Aß plaques and promotes cognitive impairment.

Risk factors such as dysregulation of Insulin-like growth factor (IGF) signaling have been linked to Alzheimer's disease. Here we show that Insulin-like Growth Factor Binding Protein 5 (Igfbp5), an inhibitory binding protein for insulin-like growth factor 1 (Igf-1) accumulates in hippocampal pyramidal neurons and in amyloid plaques in brains of Alzheimer patients. We investigated the pathogenic relevance of this finding with transgenic mice overexpressing Igfbp5 in pyramidal neurons of the brain. Neuronal overexpression of Igfbp5 prevents the training-induced increase of hippocampal and cortical Bdnf expression and reduces the effects of exercise on memory retention, but not on learning acquisition. Hence, elevated IGFBP5 expression could be responsible for some of the early cognitive deficits that occur during the course of Alzheimer's disease.

microRNA-181a Promotes Mitochondrial Dysfunction and Inflammatory Reaction in a Rat Model of Intensive Care Unit-Acquired Weakness by Inhibiting IGFBP5 Expression.

This study investigated mechanisms by which microRNA (miR)-181a orchestrates mitochondrial dysfunction and inflammation in a rat model of intensive care unit-acquired weakness (ICU-AW). Expression of miR-181a and insulin-like growth factor binding protein 5 (IGFBP5) was detected and then miR-181a was overexpressed or inhibited and IGFBP5 was overexpressed in the ICU-AW rats. The expression of UCP-3, metaphase chromosome protein 1 (MCP1), mitochondrial DNA (mtDNA), inflammatory factors, phosphorylation (p)-JAK1, p-STAT1, and p-STAT2 were measured in skeletal muscle tissues; binding of miR-181a to IGFBP5 was evaluated by a dual-luciferase reporter assay. The results demonstrated high expression of miR-181a and low expression of IGFBP5 in ICU-AW versus control rats; IGFBP5 was identified as a target gene of miR-181a. Further experiments demonstrated that ICU-AW rats suffered from marked loss of grip strength and decreased adenosine triphosphate production, mtDNA content, and UCP-3 mRNA expression in skeletal muscles; this was accompanied by elevated TNF-α, IL-6, IL-1ß, MCP1, p-JAK1, p-STAT1, and p-STAT2 levels. Importantly, miR-181a suppression alleviated strength loss, inflammatory reaction, and mitochondrial dysfunction and diminished the phosphorylation levels of JAK1, STAT1, and STAT2 whereas IGFBP5 upregulation rescued the effect of miR-181a overexpression in ICU-AW rats. These results indicate that miR-181a promotes mitochondrial dysfunction and inflammation by activating the JAK/STAT pathway via IGFBP5 in ICU-AW model rats.

hsa_circ_0058122 knockdown prevents steroid-induced osteonecrosis of the femoral head by inhibiting human umbilical vein endothelial cells apoptosis via the miR-7974/IGFBP5 axis.

BACKGROUND: Steroid-induced osteonecrosis of femoral head (SONFH) is a serious complication of glucocorticoid overused. Recent evidence has demonstrated that circRNAs exert key pathophysiological roles in a variety of disease processes. However, the role of circRNA in SONFH remains largely unknown. The current study sought to evaluate how hsa_circ_0058122 affects SONFH in dexamethasone (DEX) treated human umbilical vein endothelial cells (HUVECs) model. METHODS: RT-PCR was used to demonstrate the hsa_circ_0058122 expression level in Dex-treated HUVECs cells. The effects of hsa_circ_0058122 on HUVECs apoptosis were evaluated via overexpression plasmid and siRNA. Using dual-luciferase and fluorescence in situ hybridization assays, we demonstrated that hsa_circ_0058122 binds to miR-7974 thereby facilitating HUVECs apoptosis. Bioinformatics analysis and western blot were performed to confirm target genes of hsa-miR-7974. RESULTS: In our previous work, we revealed the top 20 elevated circRNAs in SONFH patients were hsa_circ_0010027, hsa_circ_0058115, hsa_circ_0010026, hsa_circ_0058839, hsa_circ_0056886, hsa_circ_0056885, hsa_circ_0058146, hsa_circ_0058105, hsa_circ_0058112, hsa_circ_0058143, hsa_circ_0058102, hsa_circ_0058090, hsa_circ_0075353, hsa_circ_0058126, hsa_circ_0058130, hsa_circ_0058140, hsa_circ_0058122, hsa_circ_0058123, hsa_circ_0058103, and hsa_circ_0058121. Among these, hsa_circ_0058122 was finally selected for further investigation. We found hsa_circ_0058122 expression was markedly elevated in Dex-treated HUVECs cells, and the Dex-mediated HUVEC apoptosis was impaired in hsa_circ_0058122-silenced cells and increased in hsa_circ_0058122-overexpressing cells. hsa_circ_0058122 competitively binds to hsa-miR-7974, which in turn interacts with insulin-like growth factor binding protein 5 (IGFBP5). CONCLUSIONS: hsa_circ_0058122/miR-7974/IGFBP5 was proposed to be a key regulatory pathway for SONFH. DEX treatment upregulated hsa_circ_0058122 expression in HUVECs, which sponged miR-7974, thereby increasing IGFBP5 expression, the hsa_circ_0058122/miR-7974/IGFBP5 axis contributed to the Dex-mediated apoptosis. These findings may identify novel targets for SONFH molecular therapy.

Overexpression of long noncoding RNA MCM3AP-AS1 promotes osteogenic differentiation of dental pulp stem cells via miR-143-3p/IGFBP5 axis.

MCM3AP-AS1 regulates the cartilage repair in osteoarthritis, but how it regulates osteogenic differentiation of dental pulp stem cells (DPSCs) remains to be determined. DPSCs were isolated and induced for osteogenic differentiation. MCM3AP-AS1 expression was increased along with the osteogenic differentiation of DPSCs, whose expression was positive correlated with those of OCN, alkaline phosphatase (ALP) and RUNX2. On contrary, miR-143-3p expression was decreased along with the osteogenic differentiation and was negatively correlated with those of OCN, ALP and RUNX2. Dual-luciferase reporter gene assay showed that miR-143-3p can be negatively regulated by MCM3AP-AS1 and can regulate IGFBP5. MCM3AP-AS1 overexpression increased the expression levels of osteogenesis-specific genes, ALP activity and mineralized nodules during DPSC osteogenic differentiation, while IGFBP5 knockdown or miR-143-3p overexpression counteracted the effect of MCM3AP-AS1 overexpression in DPSCs. Therefore, this study demonstrated the role of MCM3AP-AS1/miR-143-3p/IGFBP5 axis in regulating DPSC osteogenic differentiation.

Identification of Impacted Pathways and Transcriptomic Markers as Potential Mediators of Pulmonary Fibrosis in Transgenic Mice Expressing Human IGFBP5.

Pulmonary fibrosis is a serious disease characterized by extracellular matrix (ECM) component overproduction and remodeling. Insulin-like growth factor-binding protein 5 (IGFBP5) is a conserved member of the IGFBP family of proteins that is overexpressed in fibrotic tissues and promotes fibrosis. We used RNA sequencing (RNAseq) to identify differentially expressed genes (DEGs) between primary lung fibroblasts (pFBs) of homozygous (HOMO) transgenic mice expressing human IGFBP5 (hIGFBP5) and wild type mice (WT). The results of the differential expression analysis showed 2819 DEGs in hIGFBP5 pFBs. Functional enrichment analysis confirmed the pro-fibrotic character of IGFBP5 and revealed its impact on fundamental signaling pathways, including cytokine-cytokine receptor interaction, focal adhesion, AGE-RAGE signaling, calcium signaling, and neuroactive ligand-receptor interactions, to name a few. Noticeably, 7% of the DEGs in hIGFBP5-expressing pFBs are receptors and integrins. Furthermore, hub gene analysis revealed 12 hub genes including Fpr1, Bdkrb2, Mchr1, Nmur1, Cnr2, P2ry14, and Ptger3. Validation assays were performed to complement the RNAseq data. They confirmed significant differences in the levels of the corresponding proteins in cultured pFBs. Our study provides new insights into the molecular mechanism(s) of IGFBP5-associated pulmonary fibrosis through possible receptor interactions that drive fibrosis and tissue remodeling.

LncRNA HOXA11-AS aggravates the keloid formation by targeting miR-148b-3p/IGFBP5 axis.

Long non-coding RNA (lncRNA) homeobox (HOX) A11 antisense (HOXA11-AS) mediates cell-biological phenotypes of keloid fibroblasts and influence the keloid progression, yet the underlying mechanism need to be further understood. HOXA11-AS, microRNA miR-148b-3p and Insulin like growth factor binding protein 5 (IGFBP5) expression were detected by RT-qPCR or western blot. CCK-8 and colony formation assays were applied to examine the cell proliferation. The cell migration was determined via Transwell migration assays. The cell apoptosis was determined by western blots with anti-Bax antibodies and anti-Cleaved Caspase-3 antibodies. The interplay between miR-148b-3p, HOXA11-AS and IGFBP5 was confirmed by luciferase reporter or RNA immunoprecipitation assay. The amplification of HOXA11-AS and IGFBP5 was detected in keloid and keloid fibroblasts, while miR-148b-3p expression was reduced. Moreover, downregulation of HOXA11-AS in keloid fibroblasts inhibited cell proliferation, migration and triggered apoptosis. Mechanically, HOXA11-AS was proved to sponge miR-148b-3p and abrogate the inhibition on miR-148b-3p target, IGFBP5 mRNA, thus promoting keloid fibroblasts proliferation, migration and inhibiting apoptosis. These results find that HOXA11-AS promotes keloid progression by miR-148b-3p/IGFBP5 axis, suggesting the potential of targeting HOXA11-AS/miR-148b-3p/IGFBP5 axis to combat keloid.

PAPPA2 Promote the Proliferation of Dermal Papilla Cells in Hu Sheep (Ovis aries) by Regulating IGFBP5.

Hu sheep (Ovis aries) is a rare white sheep breed, with four different types of lambskin patterns that have different values. However, the genetic mechanisms underlying different types of pattern formation remains unclear. This research aimed to characterize the molecular mechanism of differentially expressed gene PAPPA2 affecting the pattern type of Hu sheep's lambskin at the cellular level. Thus, RT-qPCR, EdU and Cell Cycle detection were used to explore the effect of PAPPA2 and IGFBP5 (a protein that can be hydrolyzed by PAPPA2) on the proliferation of dermal papilla cells (DPCs) after overexpression or interference with PAPPA2 and IGFBP5. The expression level of PAPPA2 in straight DPCs was 4.79 ± 1.84 times higher than curved. Overexpression of PAPPA2 promoted the proliferation of DPCs and also increased the expression of IGFBP5. Conversely, overexpression of IGFBP5 reduced the proliferation of DPCs. However, the proliferation of DPCs was restored by co-overexpression of PAPPA2 and IGFBP5 compared with overexpression of IGFBP5 alone. Thus, PAPPA2 can affect the proliferation of DPCs through regulating IGFBP5 and then participate in lambskin pattern determination. Overall, we preliminarily clarified the critical role played by PAPPA2 during the formation of different pattern in Hu sheep lambskin.