Insulin-like Growth factor-I Expression Research Articles

An investigation of the assumed efficacy of methionine hydroxy analogue compared to DL-methionine by measuring growth performance, carcass traits, and GHR and IGF-I expression in broilers

This experiment was conducted to investigate the assumed efficacy of 65% on the product basis of methionine hydroxy analog (OH-Met, 88% aqueous solution of DL-2-hydroxy-4-(methylthio) butanoic acid) relative to DL-methionine (DL-Met) in broiler chickens. A total of 792-day-old male chickens were randomly allotted to 7 dietary treatments consisting of a methionine deficient-basal diet based on corn-soybean meal and 6 different diets obtained by supplying the basal diet with methionine at 3 levels (25, 100 and 125%; levels of addition relative to the required amount of additional Met to meet SID Met + Cys requirements) from either DL-Met or OH-Met at a ratio of 65:100 (DL-Met to OH-Met on a product basis) in the corresponding treatments. Regardless of the source, methionine supplementation enhanced (p < .05) growth performance, carcase and breast meat yield. Supplemental level and the source of Met had no significant effect on the proximate chemical composition of breast meat (p > .05). Comparison of effects of OH-Met and DL-Met supplemented at 100–65% weight ratio revealed no differences at any Met + Cys level and for performance criterion confirming the applied concept. Expression of growth hormone receptor (GHR) mRNA, which showed a positive correlation with body weight gain, carcase yield and breast percentage, in broiler liver significantly increased with 100% and 125% relative addition of DL-Met, while only 100% of OH-Met addition did (p < .05) when compared to the basal diet. The expression of the insulin-like growth factor-I (IGF-I) gene was not significantly affected by either Met source or supplementation level. In conclusion, our data indicated that DL-Met can be substituted with a 1.54 times higher amount of OH-Met in corn-soybean meal based broiler diets.

Local application of engineered insulin-like growth factor I mRNA demonstrates regenerative therapeutic potential in vivo

Insulin-like growth factor I (IGF-I) is a growth-promoting anabolic hormone that fosters cell growth and tissue homeostasis. IGF-I deficiency is associated with several diseases, including growth disorders and neurological and musculoskeletal diseases due to impaired regeneration. Despite the vast regenerative potential of IGF-I, its unfavorable pharmacokinetic profile has prevented it from being used therapeutically. In this study, we resolved these challenges by the local administration of IGF-I mRNA, which ensures desirable homeostatic kinetics and non-systemic, local dose-dependent expression of IGF-I protein. Furthermore, IGF-I mRNA constructs were sequence engineered with heterologous signal peptides, which improved invitro protein secretion (2- to 6-fold) and accelerated invivo functional regeneration (16-fold) over endogenous IGF-I mRNA. The regenerative potential of engineered IGF-I mRNA was validated in a mouse myotoxic muscle injury and rabbit spinal disc herniation models. Engineered IGF-I mRNA had a half-life of 17-25h in muscle tissue and showed dose-dependent expression of IGF-I over 2-3days. Animal models confirm that locally administered IGF-I mRNA remained at the site of injection, contributing to the safety profile of mRNA-based treatment in regenerative medicine. In summary, we demonstrate that engineered IGF-I mRNA holds therapeutic potential with high clinical translatability in different diseases.

Bone-Derived IGF-I Regulates Radial Bone Growth in Adult Male Mice.

Insulin-like growth factor-I (IGF-I) levels, which are reduced by age, and cortical bone dimensions are major determinants of fracture risk in elderly subjects. Inactivation of liver-derived circulating IGF-I results in reduced periosteal bone expansion in young and older mice. In mice with lifelong depletion of IGF-I in osteoblast lineage cells, the long bones display reduced cortical bone width. However, it has not previously been investigated whether inducible inactivation of IGF-I locally in bone in adult/old mice affects the bone phenotype. Adult tamoxifen-inducible inactivation of IGF-I using a CAGG-CreER mouse model (inducible IGF-IKO mice) substantially reduced IGF-I expression in bone (-55%) but not in liver. Serum IGF-I and body weight were unchanged. We used this inducible mouse model to assess the effect of local IGF-I on the skeleton in adult male mice, avoiding confounding developmental effects. After tamoxifen-induced inactivation of the IGF-I gene at 9 months of age, the skeletal phenotype was determined at 14 months of age. Computed tomography analyses of tibia revealed that the mid-diaphyseal cortical periosteal and endosteal circumferences and calculated bone strength parameters were decreased in inducible IGF-IKO mice compared with controls. Furthermore, 3-point bending showed reduced tibia cortical bone stiffness in inducible IGF-IKO mice. In contrast, the tibia and vertebral trabecular bone volume fraction was unchanged. In conclusion, inactivation of IGF-I in cortical bone with unchanged liver-derived IGF-I in older male mice resulted in reduced radial growth of cortical bone. This suggests that not only circulating IGF-I but also locally derived IGF-I regulates the cortical bone phenotype in older mice.

Pyriproxyfen influences growth as well as thyroid hormone–related and gh/igf-1 gene expression during the early life stage of zebrafish (Danio rerio)

Pyriproxyfen is an agricultural chemical pesticide that has been detected in the aquatic environment. This study aimed to clarify the effects of pyriproxyfen on the growth as well as thyroid hormone– and growth-related gene expression of zebrafish (Danio rerio) during its early life stage. Pyriproxyfen exhibited a lethal effect in a concentration-dependent manner: the lowest and no effect concentrations were 250.7 and 111.7 μg/L, respectively. These concentrations were considerably higher than the residual environmental concentrations, indicating the low risk of this pesticide when present at such concentrations. In the zebrafish group treated with 56.6 μg/L pyriproxyfen, thyroid hormone receptor β gene expression levels remained unchanged, whereas thyroid-stimulating hormone β subunit, iodtyronin deiodinase 2, and thyroid hormone receptor α gene expression levels significantly decreased compared with the control group expression levels. In zebrafish treated with 111.7 or 250.7 μg/L pyriproxyfen, iodtyronin deiodinase 1 gene expression levels significantly increased. These results indicate that pyriproxyfen disrupts thyroid hormone activity in zebrafish. Furthermore, pyriproxyfen exposure inhibited zebrafish growth; consequently, we examined the expression of growth hormone (gh) and insulin-like growth factor-I (igf-1), which are important for growth. Pyriproxyfen exposure suppressed gh expression; however, the igf-1 expression levels remained unchanged. Therefore, growth inhibition due to pyriproxyfen exposure was attributed to the suppression of gh expression.

Abomasal Nitrogen Flow Affects the Relationship between Dietary Nitrogen and Insulin-Like Growth Factor-I in Growing Lambs

Twelve abomasally cannulated wether lambs were fed isocaloric diets containing 9, 12 or 15% crude protein to determine insulin-like growth factor-I (IGF-I) responses to altered abomasal nitrogen flow and nitrogen status. Lambs were offered 1100 g/d of their respective diets. Voluntary feed consumption was not affected by nitrogen intake. Ruminal and total tract digestibilities of dry matter, organic matter and nitrogen increased linearly (P < 0.05) with increased dietary nitrogen. Abomasal flows of total, bacterial and rumen escape nitrogen increased (linear, P < 0.01), whereas dry matter and organic matter flows decreased (linear, P < 0.01). Total amino acid flow was greater (linear, P < 0.01) in lambs fed additional nitrogen due to increased (linear, P < 0.01) flows of essential and nonessential amino acids. Nitrogen retention and blood urea nitrogen increased linearly (P < 0.01). Serum IGF-I concentrations and relative hybridization intensity of hepatic IGF-I mRNA increased (linear, P < 0.05) as lambs consumed more nitrogen. Serum IGF-I and hepatic IGF-I mRNA were correlated positively (P < 0.05) with nitrogen intake and abomasal flows of nitrogen and various amino acids. These data provide evidence of a relationship between abomasal amino acid flow, as influenced by nitrogen intake, and hepatic gene expression and serum concentrations of IGF-I in growing lambs.

In Vitro Investigation of Insulin-Like Growth Factor-I and Mechano-Growth Factor on Proliferation of Neural Stem Cells in High Glucose Environment

Objective: High glucose levels cause metabolic and vascular complications by affecting the nervous system with an increased risk of stroke and seizures. There are still no effective treatment modalities for the high morbidity and mortality rates detected in such situations. Neural stem cells (NSCs) provide neurogenesis in the nervous system, but high glucose is detrimental to NSCs. This study investigates the intrinsic and extrinsic effects of the growth factors insulin-like growth factor-I (IGF-I) and mechano-growth factor (MGF) on NSCs when exposed to high glucose levels. Thus, the possibility of new treatment options for diabetes patients is explored. Materials and Methods: Rat NSCs grown in cell culture conditions were exposed to a control glucose concentration of 17.5 mM and high concentrations of 27.75, 41.75, and 83.75 mM for 24 h. The high glucose concentrations were designed to recapitulate the in vivo conditions of diabetes mellitus, diabetic ketoacidosis, and hyperglycemia hyperosmolar status. Then, 0.2 μg/ml IGF-I and MGF growth factors were separately added and their expressions in the NCSs investigated by real-time reverse transcription-polymerase chain reaction. The effects of exogenous IGF-I and MGF administration on NSC proliferation under high glucose conditions were measured by BrdU incorporation assay using flow cytometry analysis. Results: A significant increase was detected in the relative gene expression fold changes of IGF-I and MGF in the NSCs. The MGF relative fold change was greater than the IGF-I for each high glucose condition. NSCs exposed to 27.75 mM glucose revealed a 17-fold and 40-fold increase in the IGF-I and MGF gene expressions, respectively; the 41.75 mM glucose similarly revealed 68-and 161-fold increases and the 83.75 mM glucose 75-and 137-fold increases. Exogenous IGF-I administration increased its expression profile, while the administration of MGF lowered its expression. The NSC was in the growth (G0/G1) phase of the cell cycle during the 24 h culture time. The percentage of proliferated NSC decreased to 89% (17.5 mM), 85% (27.75 mM), 50.30% (41.75 mM), and 28.97% (83.75 mM). Surprisingly, the increase in both IGF-I and MGF saved the NSCs from cell death. Conclusion: Exogenous IGF-I and MGF administrations via high glucose environments increased NSC proliferation at the time of injury and protected the NSCs from cell death. The neuroprotective effect of MGF was greater than that of IGF-I. Thus, due to their neurogenesis potential, exogenous IGF-I and MGF could be applied in the treatment of diabetes patients to relieve neural damage.

Nano Zinc Oxide Improves Performance, IGF-I mRNA Expression, Meat Quality, and Humeral Immune Response and Alleviates Oxidative Stress and NF-κB Immunohistochemistry of Broiler Chickens

A 35-day trial was set to explore the effects of different dietary zinc sources on growth, insulin-like growth factor I (IGF-I) mRNA expression, meat quality, immune response, antioxidant activity, and immunohistochemistry of nuclear factor kappa B (NF-κ7B) of broiler chickens. Ross 308 broiler chicks (n = 156) were randomly assigned into four experimental groups. The G1 received the basal control diet without zinc supplementation; the G2, G3, and G4 were supplemented with zinc oxide, zinc lysine, and nano zinc oxide, respectively, at a level of 40 mg Zn/kg diet. The data revealed that nano zinc oxide linearly improved the overall growth performance parameters. Nano zinc oxide linearly elevated (P < 0.001) mRNA expression of IGF-I followed by G3. The pH value of breast muscle in G4 shows a linearly decreasing value (P < 0.001). Also, the linearly highest expressible release volume percentage and lightness (L*) value with the lowest redness (a*) value (P < 0.05) were recorded in G4 and G3. A numerical increase in the total antibody titer was recorded on the 35th day in the G3 and G4. A numerical elevation in the superoxide dismutase (SOD) and a numerical reduction in the serum malondialdehyde (MDA) were recorded in the G4. The section of the liver from G4 revealed significantly very low expression of NF-κB staining. It is concluded that nano zinc oxide is considered the more trending zinc source. It had no negative effects on the health status and can be used in broiler diet premix.

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

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. 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. 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 ± 1617.4ng/mL vs. 1003.4 ± 274.3ng/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. Our findings suggested that the components of the IGF-I system are altered in SMA patients at both the systemic and tissue-specific levels.

The initial delay to mitotic activity in primary cultures of equine satellite cells is reduced by combinations of growth factors.

Satellite cell (SC) activation is defined as the time frame during which the stem cell becomes poised to reenter G1 of the cell cycle. The growth factors and events leading to full mitotic activation in equine SCs remain largely unknown. Insulin-like growth factor I (IGF-I), hepatocyte growth factor (HGF), and fibroblast growth factor 2 (FGF2) are sequentially transcribed during the muscle repair and recovery period following strenuous exercise in adult horses. Expression of IGF-I occurs within 24 h of the postexercise recovery period suggesting it may affect early SC actions. As a first step, gluteus medius muscle cryosections from adult horses (n = 9) were examined for the presence of central nuclei (CN), a marker of SC addition to the fiber. Results demonstrate few CN fibers prior to exercise with a 3-fold increase (P = 0.05) 24 h postexercise. Cultures of SC (n = 4 isolates) were treated with 100 ng/mL IGF-I for varying times prior to measurement of myogenic events. Results demonstrate that IGF-I does not affect the initial lag period, proliferation, or subsequent differentiation of equine SC in vitro (P > 0.05). However, media containing a combination of IGF-I and 10 ng/mL FGF2 and 25 ng/mL HGF hastens (P < 0.05) the time to S-phase entry in fresh isolates of SCs. Media supplementation with optimal concentrations of FGF2, HGF, or a combination of HGF and FGF2 suppresses (P < 0.05) the percentage of myogenin immunopositive SCs to levels below that found in control- or IGF-I-treated SCs. These results provide new insight into the combinatorial roles growth factors play during equine SC myogenesis.

Differentiation of Subclinical Ketosis and Liver Function Test Indices in Adipose Tissues Associated With Hyperketonemia in Postpartum Dairy Cattle.

Past studies suggested that during early lactation and the transition period, higher plasma growth hormone (GH) levels in subclinical ketosis (SCK) might involve the initiation of body adipose tissues mobilization, resulting in metabolic disorders in ruminants particularly hyperketonemia. The upregulated GH mRNA expression in adipose tissue may take part in the adipolysis process in SCK-affected cows that paves a way for study further. This study aimed to characterize the plasma levels of GH, β-hydroxybutyrate acid (BHBA) and non-esterified fatty acid (NEFA) and glucose (GLu) in ketotic cows and healthy control (CON) cows; to measure the liver function test (LFT) indices in ketotic and healthy CON cows, and finally the quantitative real-time PCR (qRT-PCR) assay of candidate genes expressed in adipose tissues of ketotic and healthy CON cows during 0 to 7 week postpartum. Three experiments were conducted. Experiment-1 involved 21 Holstein cows weighing 500–600 kg with 2–5 parities. Results showed that GH, BHBA, and NEFA levels in ketotic cows were significantly higher and the GLu level significantly lower. Pearson's correlation analysis revealed a significant positive correlation of GH with BHBA, NEFA, and GLu in ketotic and healthy CON cows. In experiment-2, dynamic monitoring of LFT indices namely, alanine aminotransferase (ALT), aspartate aminotransferase (AST), γ-glutamyl transpeptidase (GGT), total bilirubin (TBIL), direct bilirubin (DBIL), total protein (TP), albumin (ALB), globulin (GLOB) and albumin/globulin (A/G) were examined. The TBIL, DBIL, and GGT indices were significantly higher in ketotic cows and TP was significantly lower. In experiment-3, mRNA expression levels of GHR and peroxisome-proliferator-activated receptor alpha (PPARα) genes in adipose tissue were significantly upregulated in ketotic cows. However, the mRNA expression of insulin-like growth factor-I (IGF-1), insulin-like growth factor-I receptor (IGF-1R), and sterol regulatory element-binding protein-1c (SREBP-1c) genes in adipose tissue were downregulated in ketotic cows. Our study concluded that during postpartum, higher plasma GH levels in SCK cows might involve the initiation of body adipose tissue mobilization, resulting in hyperketonemia.

Muscle insulin-like growth factor-I modulates murine craniofacial bone growth.

Insulin-like growth factor I (IGF-I) is essential for muscle and bone development and a primary mediator of growth hormone (GH) actions. While studies have elucidated the importance of IGF-I specifically in muscle or bone development, few studies to date have evaluated the relationship between muscle and bone modulated by IGF-I in vivo, during post-natal growth. Mice with muscle-specific IGF-I overexpression (mIgf1+/+) were utilised to determine IGF-I- and muscle-mass-dependent effects on craniofacial skeleton development during post-natal growth. mIgf1+/+ mice displayed accelerated craniofacial bone growth when compared to wild-type animals. Virus-mediated expression of IGF-I targeting the masseter was performed to determine if post-natal modulation of IGF-I altered mandibular structures. Increased IGF-I in the masseter affected the mandibular base plane angle in a lateral manner, increasing the width of the mandible. At the cellular level, increased muscle IGF-I also accelerated cartilage thickness in the mandibular condyle. Importantly, mandibular length changes associated with increased IGF-I were not present in mice with genetic inhibition of muscle IGF-I receptor activity. These results demonstrated that muscle IGF-I could indirectly affect craniofacial growth through IGF-I-dependent increases in muscle hypertrophy. These findings have clinical implications when considering IGF-I as a therapeutic strategy for craniofacial disorders.

Growth, osmoregulatory and hypothalamic–pituitary–somatotropic (HPS) axis response of the juvenile largemouth bass (Micropterus salmoides), reared under different salinities

A 40 day experiment was conducted to investigate the effects of different salinities (0, 5 and 10 ppt) on the growth, osmoregulatory and hypothalamic–pituitary–somatotropic (HPS) axis response of juvenile largemouth bass (Micropterus salmoides). At the same time, two extra groups salinities (8 and 9 ppt) were used to explore the threshold of osmoregulation in M. salmoides to salinity stress. The survival were 94.45 %, 98.15 % and 32.00 % in 0, 5, 10 ppt, respectively. According the final body weight, specific growth rate (SGR), feed conversion ratio (FCR), condition factor (K) and chemical composition of muscle, largemouth bass should not be cultured at or above 10 ppt and 5 ppt is better than 0 ppt. The results found that the content of serum prolactin (PRL) and cortisol (COR) were no significant differences between groups of the 0, 5, 8, 9 and 10 ppt. Compared with the control group (0 ppt), the serum thyroxine (T4) content of 8 and 9 ppt groups decreased significantly and the serum triiodothyronine (T3) content all decreased significantly. Serum osmolality increased with increasing salinity. Na+-K+-ATP (NKA) and Ca2+-Mg2+-ATP (CMA) activities in the gills of largemouth bass at 0, 5, 8, 9 and 10 ppt showed tendency of ascend at first and descend at last, among which the activities in 10 ppt were significantly lowest. Gene expression of hepatic growth hormone (GH) at 10 ppt was highest. Meanwhile, insulin-like growth factor-I (IGF-I) expression at salinities of 8, 9 and 10 ppt were significantly higher than those at 0 and 5 ppt. Taken together, the findings of this study provide guidance for the practical rearing of largemouth bass in saline waters and contribute to research on stress physiology.

Expression and effect of microRNA-627 in human hypertrophic scar

Objective: To investigate the expression and effect of microRNA-627 (miR-627) in human hypertrophic scar. Methods: The experimental research method was used. From October 2019 to January 2020, hypertrophic scar tissue from 6 patients with hypertrophic scar (2 males and 4 females, aged (34±11) years) and the remaining normal skin tissue from 6 trauma patients (3 males and 3 females, aged (35±13) years) after flap transplantation were collected. The above-mentioned 12 patients were admitted to the General Hospital of Northern Theater Command and met the inclusion criteria. The mRNA expression of miR-627 was detected by real-time fluorescent quantitative reverse transcription polymerase chain reaction. The 3rd to 5th passages of fibroblasts (Fbs) were isolated from hypertrophic scar tissue and cultured for subsequent experiments after identification. Fbs from hypertrophic scar were divided into miR-627 negative control group, miR-627 mimic group, and miR-627 inhibitor group. The corresponding sequences were transfected respectively. At 0 (immediately), 12, 24, 36, and 48 h after transfection, the cell viability was detected by thiazolyl blue method; at 24 h after transfection, the apoptosis was detected by flow cytometry; at 24 h after transfection, the protein expression levels of insulin-like growth factor Ⅰ (IGF-Ⅰ), type Ⅰ collagen, and α smooth muscle actin (α-SMA) were detected by Western blotting. Two batches of Fbs from hypertrophic scar were used, one batch was divided into IGF-Ⅰ wild type+miR-627 negative control group and IGF-Ⅰ wild type+miR-627 mimic group, and the other batch was divided into IGF-Ⅰ mutant+miR-627 negative control group and IGF-Ⅰ mutant+miR-627 mimic group. The corresponding sequences were transfected respectively. At 48 h after transfection, the expressions of luciferase and renal luciferase were detected by luciferase reporter gene detection kit, and the ratio of the two was calculated to reflect the activity of IGF-Ⅰ. Fbs from hypertrophic scar were divided into miR-627 negative control group, miR-627 mimic alone group, and miR-627 mimic+IGF-Ⅰ group, and were transfected with the corresponding sequences respectively. At 24 h after transfection, the protein expression levels of IGF-Ⅰ, type Ⅰ collagen, and α-SMA were detected by Western blotting. The number of samples in cell experiment was 3. Data were statistically analyzed with analysis of variance for factorial design, one-way analysis of variance, independent sample t test, and chi-square test. Results: The expression of miR-627 mRNA in hypertrophic scar tissue was 0.47±0.06, which was significantly lower than 1.12±0.23 in normal skin tissue (t=15.090, P<0.01). At 12, 24, 36, and 48 hours after transfection, the cell viability of miR-627 mimic group was significantly lower than that of miR-627 negative control group (t=9.918, 34.370, 13.580, 61.550, P<0.05 or P<0.01); the cell viability of miR-627 inhibitor group was significantly higher than that of miR-627 negative control group (t=4.722, 8.616, 13.330, 14.000, P<0.05 or P<0.01). At 24 h after transfection, compared with the apoptosis rate (8.42±0.47)% in miR-627 negative control group, (10.89±0.35)% in miR-627 mimic group was significantly higher (t=7.301, P<0.01), and (5.00±0.22)% in miR-627 inhibitor group was significantly lower (t=11.510, P<0.01). At 24 h after transfection, compared with the cell protein expressions of IGF-Ⅰ, type Ⅰ collagen, and α-SMA in miR-627 negative control group, those in miR-627 mimic group were significantly lower (t=25.470, 5.282, 7.415, P<0.01), and those in miR-627 inhibitor group were significantly higher (t=15.930, 8.857, 9.763, P<0.01). At 48 h after transfection, the luciferase/renal luciferase ratio of IGF-Ⅰ of cells in IGF-Ⅰ wild type+miR-627 mimic group was 0.463±0.061, which was significantly lower than 0.999±0.011 in IGF-Ⅰ wild type+miR-627 negative control group (t=16.852, P<0.01); the luciferase/renal luciferase ratio of IGF-Ⅰ of cells in IGF-Ⅰ mutant+miR-627 mimic group was 0.934±0.021, which was similar to 0.930±0.023 in IGF-Ⅰ mutant+miR-627 negative control group (t=1.959, P>0.05). At 24 h after transfection, the protein expressions of IGF-Ⅰ, type Ⅰ collagen, and α-SMA of cells in miR-627 mimic alone group were 1.623±0.070, 1.363±0.042, and 1.617±0.025, which were significantly lower than 2.723±0.045, 2.147±0.067, and 2.533±0.055 in miR-627 negative control group (t=22.831, 7.280, 26.220, P<0.01); the protein expressions of IGF-Ⅰ, type Ⅰ collagen, and α-SMA of cells in mimic+IGF-Ⅰ group were 2.477±0.102, 1.760±0.046, and 2.387±0.049, which were significantly higher than those of miR-627 mimic alone group (t=3.830, 8.286, 3.436, P<0.05 or P<0.01). Conclusions: miR-627 expression in human hypertrophic scars is down-regulated; miR-627 can inhibit the proliferation and promote the apoptosis of Fbs in human hypertrophic scar by targeted inhibition of IGF-Ⅰ expression.

Effects of TGF-β1 on the expression of endometrial stromal cell-related protein and mRNA.

To investigate the effects of transforming growth factor β1 (TGF-β1) on α-smooth muscle actin (α-SMA), insulin-like growth factor I (IGF-I), and type I collagen (Col I) expression in endometrial stromal cells as well as on fibronectin (FN) level. 56 patients with normal endometrial tissue obtained from surgery were selected from June 2018 to November 2019. Endometrial stromal cells were isolated from patients and then assigned to the control group and observation group (addition of TGF-β1) followed by the analysis of cellular activity by Thiazole blue staining; and α-SMA, IGF-I, Col I, and FN mRNA and protein levels by real-time fluorescent PCR and Western blot. The cell proliferation rate at 12 h, 24 h, 36 h, and 72 h after culture in both groups was higher than 0 h (p < 0.05) with higher cell proliferation in the observation group than the control group (p < 0.05). Real-time fluorescence PCR results showed that the levels of α-SMA, IGF-I, Col I, and FN mRNA in endometrial stromal cells of the observation group after TGF-β1 intervention were higher than those in the control group (p < 0.05). Meanwhile, α-SMA, IGF-I, Col I, and FN protein level was also elevated in the observation group after TGF-β1 treatment (p < 0.05). TGF-β1 can stimulate the proliferation of endometrial stromal cells, which may be related to regulate α-SMA, IGF-I, Col I, and FN expression.

Somatotropic-Testicular Axis: A crosstalk between GH/IGF-I and gonadal hormones during development, transition, and adult age.

The hypothalamic-pituitary-gonadal (HPG) and hypothalamic-pituitary-somatotropic (HPS) axes are strongly interconnected. Interactions between these axes are complex and poorly understood. These interactions are characterized by redundancies in reciprocal influences at each level of regulation and the combination of endocrine and paracrine effects that change during development. To comprehensively review the crosstalk between the HPG and HPS axes and related pathological and clinical aspects during various life stages of male subjects. A thorough search of publications available in PubMed was performed using proper keywords. Molecular studies confirmed the expressions of growth hormone (GH) and insulin-like growth factor-I (IGF-I) receptors on the HPG axis and reproductive organs, indicating a possible interaction between HPS and HPG axes at various levels. Insulin growth factors participate in sexual differentiation during fetal development, indicating that normal HPS axis activity is required for proper testicular development. IGF-I contributes to correct testicular position during minipuberty, determines linear growth during childhood, and promotes puberty onset and pace through gonadotropin-releasing hormone activation. IGF-I levels are high during transition age, even when linear growth is almost complete, suggesting its role in reproductive tract maturation. Patients with GH deficiency (GHD) and insensitivity (GHI) exhibit delayed puberty and impaired genital development; replacement therapy in such patients induces proper pubertal development. In adults, few studies have suggested that lower IGF-I levels are associated with impaired sperm parameters. The role of GH-IGF-I in testicular development remains largely unexplored. However, it is important to evaluate gonadic development in children with GHD. Additionally, HPS axis function should be evaluated in children with urogenital malformation or gonadal development alterations. Correct diagnosis and prompt therapeutic intervention are needed for healthy puberty, attainment of complete gonadal development during transition age, and fertility potential in adulthood.

Mechanism study of dendritic epidermal T lymphocytes in promoting healing of full-thickness skin defects wound on mice by regulating the proliferation and differentiation of epidermal stem cells in mice

Mechanism study of dendritic epidermal T lymphocytes in promoting healing of full-thickness skin defects wound on mice by regulating the proliferation and differentiation of epidermal stem cells in mice

Identification of the cDNA Encoding the Growth Hormone Receptor (GHR) and the Regulation of GHR and IGF-I Gene Expression by Nutritional Status in Reeves' Turtle (Chinemys reevesii).

Chinemys reevesii (Reeves’ turtle) is a slow-growing reptile that is distributed widely across China. Prior to this study, the cDNA sequence of the growth hormone receptor (GHR) in the Reeve’s turtle, or how periods of starvation might influence the gene expression of GHR and insulin-like growth factor I (IGF-I) in this species, were unknown. Here, we identified the full-length sequence of the cDNA encoding GHR in Reeves’ turtle by using RT-PCR and RACE. The full-length GHR cDNA was identified to be 3936 base-pairs in length, with a 1848 base-pair open reading frame (ORF) that encodes a 615 amino acid protein. Analysis showed that GHR mRNA was detectable in a wide range of tissues; the highest and lowest levels of expression were detected in the liver and the gonad, respectively. IGF-I was also expressed in a range of tissues, but not in the gonad; the highest levels of IGF-I expression were detected in the liver. After 4 weeks of fasting, the expression levels of GHR and IGF-I in the liver had decreased significantly; however, these gradually returned to normal after refeeding. We report the first cloned cDNA sequence for the GHR gene in the Reeve’s turtle. Our findings provide a foundation from which to investigate the specific function of the GHR in Reeve’s turtle, and serve as a reference for studying the effects of different nutrient levels on GHR expression in this species.

The Effect of Capsaicin on IGF-I and IGF-IR Expression in Ovarian Granulosa Cells

Capsaicin (trans-8-methyl-N-vanillyl-6-noneadamide) is a pungent ingredient in red peppers from the Capsicum family. Insulin-like growth factor-I (IGF-I) is expressed in granulosa cells and has an important role in ovarian development. However, there are no data about the IGF-I expression in ovarian granulosa cells after capsaicin treatment. The aim of this study was to investigate the expression of IGF-I and its receptor (insulin-like growth factor-I receptor [IGF-IR]) in primary rat ovarian granulosa cells after low and high doses of capsaicin treatment. For this, granulosa cells were isolated and cultured from ovaries of 30-day-old female Sprague-Dawley rats. Granulosa cell plates were divided into four groups as cell control (C), vehicle control (V), and 50 μM and 150 μM capsaicin groups. In experimental groups, granulosa cells were exposed to capsaicin for 24 hours and immunocytochemistry was performed afterwards using anti-IGF-I and anti-IGF-IR antibodies. Both IGF-I and IGF-IR expressions were found to be significantly increased in parallel to the capsaicin doses. Elevated levels of IGF-I may be a risk factor for ovarian development. Because of the crucial role of IGF-I in ovary development, capsaicin treatment can be effective on follicular development and/or disorders characterized by high IGF-I levels.

The optimal arginine requirement in diets for juvenile humpback grouper, Cromileptes altivelis

An 8-week feeding trial was conducted to evaluate the effects of dietary arginine (Arg) levels on growth performance, gut micromorphology, oxidation resistance and immune responses of humpback grouper, Cromileptes altivelis. Seven isoenergetic (340 kcal per 100 g of dry matter), isoproteic (50% of dry matter) and isolipidic (10% of dry matter) experimental diets were formulated to contain 1.74%, 2.42%, 3.14%, 3.58%, 4.06%, 4.54% and 5.21% dietary Arg levels. Triplicate groups of 12 fish (average initial body weight: 6.55 ± 0.1 g) were fed to apparent satiation by hand twice daily (08:00 h and 16:00 h) in an indoor recirculating seawater system which was consisted of 21 glass tanks (length 60 cm × width 45 cm × height 50 cm) and mechanical and biological water filters. After the feeding trial, all remaining fish were challenged by 2.5 mg Cu(II)·L−1, and survival rates were recorded for 12 h. Results showed that weight gain% (WG%), protein efficiency ratio (PER) as well as protein productive value (PPV) of fish were improved with the increments in dietary Arg from 1.74% to 3.58%, and thereafter, values of these parameters displayed a declining trend as dietary Arg level continued to rise from 3.58% to 5.21%. Fish fed 3.14% and 3.58% dietary Arg had lower FCR and daily feed intake (DFI) than fish fed other dietary Arg levels. Quadratic regression analysis of WG% against dietary Arg levels indicated that optimal dietary Arg level for maximum growth of humpback grouper was 3.39% of dry matter (6.78% of dietary protein). Hepatosomatic index (HSI) was reduced as dietary Arg level increased. Fish fed 3.58% dietary Arg had higher whole-body protein content than fish fed other dietary Arg levels. Expression of hepatic insulin-like growth factor-I (IGF-1), target of rapamycin (TOR), S6 kinase1 (S6K1) and hypothalamus growth hormone receptor (GHR) in fish fed 3.14% and 3.58% dietary Arg was higher than that in fish fed other dietary Arg levels. Gut micromorphology was significantly influenced by dietary Arg levels. After the exposure to 2.5 mg Cu(II)·L−1 water for 12 h, fish fed 3.14% and 3.58% dietary Arg had higher survival ratios and expression of NF-E2-related factor 2 (Nrf2) and heat shock proteins genes 70 (HSP70) in head kiney. In serum, fish fed 3.58% dietary Arg had higher superoxide dismutase (SOD) and catalase (CAT) activities and immunoglobulinM (IgM) concentrations than fish fed other dietary Arg levels. In conclusion, the optimal dietary Arg requirement for maximal growth of humpback grouper was estimated to be 3.39% of dry matter (6.78% of dietary protein), and suitable dietary Arg supplementations improved growth performance, gut micromorphology, oxidation resistance as well as immunity of this species.

Pretreatment of Populus tomentiglandulosa protects hippocampal CA1 pyramidal neurons from ischemia-reperfusion injury in gerbils via increasing SODs expressions and maintaining BDNF and IGF-I expressions.

To examine the effects of Populus tomentiglandulosa (PT) extract on the expressions of antioxidant enzymes and neurotrophic factors in the cornu ammonis 1 (CA1) region of the hippocampus at 5 min after inducing transient global cerebral ischemia (TGCI) in gerbils, TGCI was induced by occlusion of common carotid arteries for 5 min. Before ischemic surgery, 200 mg·kg-1 PT extract was orally administrated once daily for 7 d. We performed neuronal nuclear antigen immunohistochemistry and Fluoro-Jade B staining. Furthermore, we determined in situ production of superoxide anion radical, expression levels of SOD1 and SOD2 as antioxidant enzymes and brain-derived neurotrophic factor (BDNF) and insulin-like growth factor I (IGF-I) as neurotrophic factors. Pretreatment with 200 mg·kg-1 PT extract prevented neuronal death (loss). Furthermore, pretreatment with 200 mg·kg-1 PT extract significantly inhibited the production of superoxide anion radical, increased expressions of SODs and maintained expressions of BDNF and IGF-I. Such increased expressions of SODs were maintained in the neurons after IRI. In summary, pretreated PT extract can significantly increase levels of SODs and protect the neurons against TGCI, suggesting that PT can be a useful natural agent to protect against TGCI.