1.When Hypoglycemia Speaks Louder Than the Chest: A Decade-Late Recurrence of IGF-2-Mediated Non-Islet Cell Tumor Hypoglycemia
Li Li Kwan ; Deviga Lachumanan
Journal of the ASEAN Federation of Endocrine Societies 2026;41(S1):67-68
Introduction:
Non-islet cell tumor hypoglycemia (NICTH) is a rare
paraneoplastic syndrome caused by tumor secretion of
insulin-like growth factor-2 (IGF-2), leading to recurrent
hypoinsulinemic hypoglycemia. It is most commonly
associated with large mesenchymal tumors, such as solitary fibrous tumor, particularly those arising from the pleura
or lungs. This phenomenon, also known as Doege–Potter
syndrome, may precede tumor detection or signal tumor
recurrence. We report a striking case of late malignant
recurrence presenting solely with hypoglycemia after
a decade of remission.
Case:
A 68-year-old female was initially presented in 2016
with respiratory symptoms and recurrent symptomatic
fasting and post-prandial hypoglycemia, and was found
to have a large left upper lobe mass. Tumor resection in
2017 resulted in complete resolution of hypoglycemia.
She remained asymptomatic for several years. In
2023, she developed recurrent hypoglycemia without
respiratory or constitutional symptoms. Biochemical
evaluation demonstrated hypoinsulinemic hypoglycemia
with suppressed insulin and C-peptide, low IGF-1, and
markedly elevated IGF-2, resulting in an IGF-2:IGF-1 ratio
of 25, consistent with IGF-2-mediated NICTH. Computed
tomography imaging revealed a large left thoracic mass
with invasion into the intercostal muscles and diaphragm
with extension toward the stomach, associated with
contralateral lung nodules and possible liver metastases,
suggesting recurrent malignant disease. Hypoglycemia
improved with glucocorticoid therapy, and the patient
was referred for oncological assessment. Despite initiation
of systemic chemotherapy, her disease progressed and she
succumbed during treatment.
Conclusion
This case highlights several important lessons: Firstly,
recurrent hypoinsulinemic hypoglycemia warrants
evaluation for NICTH even in the absence of tumor-related
symptoms. Secondly, solitary fibrous tumors may recur
or undergo malignant transformation after prolonged
disease-free intervals; and glucocorticoids provide effective
metabolic control but do not alter oncologic prognosis.
Long-term surveillance should be considered in patients
with prior solitary fibrous tumors due to the risk of delayed
recurrence and paraneoplastic complications.
Insulin-Like Growth Factor II
;
Hypoglycemia
;
Neoplasms
2.When IGF-1 Misleads: Discordant Biochemical Findings in Acromegaly
Ashwini Chandrasekaran ; Subashini Rajoo ; Gayathri Devi Krishnan ; Shazatul Reza ; Sharifah Noor Adrilla ; Xe Hui Lee
Journal of the ASEAN Federation of Endocrine Societies 2026;41(S1):90-
Introduction:
Acromegaly is an endocrine disorder caused by excess
growth hormone (GH), causing somatic overgrowth,
multiple comorbidities, and premature mortality. It is
confirmed biochemically by an elevated GH level, which
is not suppressed post oral glucose tolerance test (OGTT).
The serum level of insulin-like growth factor-1 (IGF-1) is
recommended for diagnosis, monitoring, and screening,
and a normal level effectively excludes the disease. We
report a patient with acromegaly who presented with
normal IGF-1.
Case:
A 21-year-old female, with no known medical illness,
presented with a persistent, progressive headache and
amenorrhea for the past 6 months. She also noticed
a change in facial appearance and an increase in the
size of her hands and feet. Blood parameters revealed
raised GH level of >50 ng/mL, normal IGF-1 30.3 nmol/L
(12.17–44.80), mildly raised prolactin 692 mIU/L, low am
cortisol 62 nmol/L (166–507), thyroid-stimulating hormone
of 0.63 mIU/L (0.27–4.20), free thyroxine 4 11 pmol/L
(12–22), low follicle-stimulating hormone 0.90 IU/L,
luteinizing hormone <0.30 IU/L, estradiol <18.4 pmol/L,
and fasting blood sugar of 17.7 mmol/L with hemoglobin
A1c 9%. In view of normal IGF-1 with a high index of
suspicion for acromegaly, she underwent OGTT which
showed unsuppressed GH. Magnetic resonance imaging
pituitary showed sellar mass 2.4 × 2.9 × 2.1 cm with
suprasellar extension as well as extension into the right
cavernous sinus, suggestive of pituitary macroadenoma.
She was diagnosed with acromegaly with secondary
adrenal insufficiency and central hypothyroidism with
hypogonadotropic hypogonadism, complicated with
poorly controlled diabetes. She was started on thyroxine
and hydrocortisone replacement and required basal bolus
insulin of 1.3 u/kg/day. Repeated IGF-1 showed a raised value, 85.4 nmol/L, after optimization of diabetes. She
underwent endoscopic transsphenoidal surgery with
normalization of blood sugar post-surgery. Blood pressure
was normal throughout.
Conclusion
False negative or normal IGF-1 levels may result in patients
with hepatic or renal failure, hypothyroidism, malnutrition, use of oral estrogen, severe infection, and poorly
controlled diabetes mellitus. Hence, a low or normal IGF1 does not exclude acromegaly in patients with a high
index of suspicion and warrants further investigation.
Acromegaly
;
Insulin-Like Growth Factor I
3.Abnormal elevation of growth hormone in patients with pituitary adenoma combined with cirrhosis: A case report.
Yanlei WANG ; Min DUAN ; Jianzhong XIAO ; Wenhui ZHAO
Journal of Peking University(Health Sciences) 2025;57(2):400-402
The oral glucose growth hormone suppression test is commonly used in the clinical diagnosis of acromegaly, but its results can be influenced by a variety of factors. This case report discusses a patient with a pituitary tumor and concurrent liver cirrhosis, highlighting the complexities in interpreting test results under such conditions. The patient, a 54-year-old male, presented with blurred vision as his primary complaint. Notably, the physical examination revealed no changes in facial features, no enlargement of hands or feet, and no other symptoms typically associated with acromegaly, which might otherwise suggest excessive growth hormone activity. Magnetic Resonance Imaging (MRI) of the pituitary gland indicated that the gland was within normal size parameters, but a small low-intensity lesion mea-suring approximately 3 mm×2 mm identified. This finding was consistent with a pituitary microadenoma. The patient's fasting growth hormone levels were significantly elevated at 8.470 μg/L, compared with the normal range of less than 2.47 μg/L. Conversely, fasting insulin-like growth factor-1 (IGF-1) levels were notably low, recorded at 41 and 52 μg/L, whereas the normal range for a person of his age was between 87 and 234 μg/L. Other pituitary hormones, including those regulating the thyroid, adrenal cortex, and sex hormones, were found to be within normal ranges. Despite this, during the glucose growth hormone suppression test, an abnormal elevation of growth hormone was observed. To investigate further, the patient was administered branched-chain amino acids, and the suppression test was repeated. However, the abnormal elevation of growth hormone persisted, indicating a failure to normalize the response. Given the patient's lack of clinical signs typically associated with elevated growth hormone secretion, the history of liver cirrhosis became a significant consideration. The disparity between elevated growth hormone levels and reduced IGF-1 levels suggested that the pituitary lesion was a non-functional adenoma rather than a source of excess hormone production. Consequently, it was concluded that the abnormal response of growth hormone to the glucose suppression test was likely related to the patient's liver cirrhosis. In addition to chronic liver disease, various other conditions could influence the results of the oral glucose tolerance growth hormone suppression test. According to the literature, factors such as puberty, diabetes, anorexia nervosa, and protein malnutrition could also affect test outcomes. These conditions could cause similar abnormalities in growth hormone dynamics, complicating the diagnosis. Therefore, clinicians must be vigilant and consider these potential influences when interpreting test results.For an accurate diagnosis of acromegaly, it is essential to combine clinical symptoms, detailed medical history, and imaging studies. The presence of conditions like liver cirrhosis should prompt careful interpretation of the test results, ensuring that other contributing factors are not overlooked. This comprehensive approach is crucial to avoid misdiagnosis and to ensure that appropriate treatment strategies are implemented based on a thorough understanding of the patient's overall health status.
Humans
;
Male
;
Middle Aged
;
Pituitary Neoplasms/blood*
;
Liver Cirrhosis/blood*
;
Adenoma/blood*
;
Human Growth Hormone/blood*
;
Insulin-Like Growth Factor I/metabolism*
;
Acromegaly/etiology*
;
Magnetic Resonance Imaging
4.Triptolide Ameliorates Collagen-Induced Arthritis and Bleomycin-Induced Pulmonary Fibrosis in Rats by Suppressing IGF1-Mediated Epithelial Mesenchymal Transition.
Pei-Pei LU ; Lan YAN ; Qi GENG ; Lin LIN ; Lu-Lu ZHANG ; Chang-Qi SHI ; Peng-Cheng ZHAO ; Xiao-Meng ZHANG ; Jian-Yu SHI ; Cheng LYU
Chinese journal of integrative medicine 2025;31(12):1069-1077
OBJECTIVE:
To investigate the common mechanisms among collagen-induced arthritis (CIA), bleomycin (BLM)-induced pulmonary fibrosis, and CIA+BLM to evaluate the therapeutic effect of triptolide (TP) on CIA+BLM.
METHODS:
Thirty-six male Sprague-Dawley rats were randomly assigned to 6 groups according to a random number table (n=6 per group): normal control (NC), CIA, BLM, combined CIA+BLM model, TP low-dose (TP-L, 0.0931 mg/kg), and TP high-dose (TP-H, 0.1862 mg/kg) groups. The CIA model was induced by intradermal injection at the base of the tail with emulsion of bovine type II collagen and incomplete Freund's adjuvant (1:1), with 200 µL administered on day 0 and a booster of 100 µL on day 7. Pulmonary fibrosis was induced via a single intratracheal injection of BLM (5 mg/kg). The CIA+BLM model combined both protocols, and TP was administered orally from day 14 to 35. After successful modeling, arthritis scores were recorded every 3 days, and pulmonary function was assessed once at the end of the treatment period. Lung tissues were collected for histological analysis (hematoxylin eosin and Masson staining), immunohistochemistry, measurement of hydroxyproline (HYP) content, and calculation of lung coefficient. In addition, HE staining was performed on the ankle joint. Total RNA was extracted from lung tissues for transcriptomic analysis. Differentially expressed genes (DEGs) were compared with those from the RA-associated interstitial lung diseases patient dataset GSE199152 to identify overlapping genes, which were then used to construct a protein-protein interaction network. Hub genes were identified using multiple topological algorithms.
RESULTS:
The successfully established CIA+BLM rat model exhibited significantly increased arthritis scores and severe pulmonary fibrosis (P<0.01). By intersecting the DEGs obtained from transcriptomic analysis of lung tissues in CIA, BLM, and CIA+BLM rats with DEGs from rheumatoid arthritis-interstitial lung disease patients (GSE199152 dataset), 50 upregulated and 44 downregulated genes were identified. Through integrated PPI network analysis using multiple topological algorithms, IGF1 was identified as a central hub gene. TP intervention significantly improved pulmonary function by increasing peak inspiratory flow (P<0.01), and reduced lung index and HYP content (P<0.01). Histopathological analysis showed that TP alleviated alveolar collapse, interstitial thickening, and collagen deposition in the lung tissues (P<0.01). Moreover, TP treatment reduced the expression of collagen type I and α-SMA and increased E-cadherin levels (P<0.01). TP also significantly reduced arthritis scores and ameliorated synovial inflammation (P<0.05). Both transcriptomic and immunohistochemical analyses confirmed that IGF1 expression was elevated in the CIA+BLM group and downregulated following TP treatment (P<0.05).
CONCLUSION
TP exerts protective effects in the CIA+BLM model by alleviating arthritis and pulmonary fibrosis through the inhibition of IGF1-mediated EMT.
Animals
;
Pulmonary Fibrosis/complications*
;
Bleomycin/adverse effects*
;
Phenanthrenes/pharmacology*
;
Male
;
Rats, Sprague-Dawley
;
Diterpenes/pharmacology*
;
Epoxy Compounds/therapeutic use*
;
Arthritis, Experimental/complications*
;
Insulin-Like Growth Factor I/metabolism*
;
Rats
;
Lung/physiopathology*
5.PLAGL1-IGF2 axis regulates osteogenesis of postnatal condyle development.
Jinrui SUN ; Jingyi XU ; Yue XU ; Yili LIU ; Enhui YAO ; Jiahui DU ; Xinquan JIANG
International Journal of Oral Science 2025;17(1):65-65
The mandibular condyle is a critical growth center in craniofacial bone development, especially during postnatal stages. Postnatal condyle osteogenesis requires precise spatiotemporal coordination of growth factor signaling cascades and hierarchical gene regulatory networks. Plagl1, which encodes a zinc finger transcription factor, is a paternally expressed gene. We demonstrate that PLAGL1 is highly expressed in cranial neural crest cell (CNCC)-derived lineage cells in mouse condyles. Using the CNCC-derived lineage-specific Plagl1 knockout mouse model, we evaluate the function of PLAGL1 during postnatal mouse condyle development. Our findings show that PLAGL1 contributes significantly to osteoblast differentiation, and its deficiency impairs osteogenic lineage differentiation, which consequently disrupts mandibular condyle development. Mechanistically, insulin-like growth factor 2 (IGF2) in complex with IGF-binding proteins (IGFBPs) has been identified as the principal PLAGL1 effector responsible for osteogenic regulation during postnatal condyle morphogenesis. Plagl1 deficiency significantly downregulates the IGF2/IGFBP pathway, leading to disordered glucose metabolism, defective extracellular matrix organization, and impaired ossification. Exogenous IGF2 treatment rescues impaired osteoblast differentiation caused by Plagl1 deficiency. In conclusion, the PLAGL1-IGF2 axis is a critical regulator of osteogenesis during mandibular condyle development.
Animals
;
Osteogenesis/genetics*
;
Insulin-Like Growth Factor II/metabolism*
;
Mice
;
Transcription Factors/metabolism*
;
Mice, Knockout
;
Cell Differentiation
;
DNA-Binding Proteins/genetics*
;
Mandibular Condyle/growth & development*
;
Osteoblasts/cytology*
;
Signal Transduction
;
Neural Crest/cytology*
6.Correlation of IGF2 levels with sperm quality, inflammation, and DNA damage in infertile patients.
Jing-Gen WU ; Cai-Ping ZHOU ; Wei-Wei GUI ; Zhong-Yan LIANG ; Feng-Bin ZHANG ; Ying-Ge FU ; Rui LI ; Fang WU ; Xi-Hua LIN
Asian Journal of Andrology 2025;27(2):204-210
Insulin-like growth factor 2 (IGF2) is a critical endocrine mediator implicated in male reproductive physiology. To investigate the correlation between IGF2 protein levels and various aspects of male infertility, specifically focusing on sperm quality, inflammation, and DNA damage, a cohort of 320 male participants was recruited from the Women's Hospital, Zhejiang University School of Medicine (Hangzhou, China) between 1 st January 2024 and 1 st March 2024. The relationship between IGF2 protein concentrations and sperm parameters was assessed, and Spearman correlation and linear regression analysis were employed to evaluate the independent associations between IGF2 protein levels and risk factors for infertility. Enzyme-linked immunosorbent assay (ELISA) was used to measure IGF2 protein levels in seminal plasma, alongside markers of inflammation (tumor necrosis factor-alpha [TNF-α] and interleukin-1β [IL-1β]). The relationship between seminal plasma IGF2 protein levels and DNA damage marker phosphorylated histone H2AX (γ-H2AX) was also explored. Our findings reveal that IGF2 protein expression decreased notably in patients with asthenospermia and teratospermia. Correlation analysis revealed nuanced associations between IGF2 protein levels and specific sperm parameters, and low IGF2 protein concentrations correlated with increased inflammation and DNA damage in sperm. The observed correlations between IGF2 protein levels and specific sperm parameters, along with its connection to inflammation and DNA damage, underscore the importance of IGF2 in the broader context of male reproductive health. These findings lay the groundwork for future research and potential therapeutic interventions targeting IGF2-related pathways to enhance male fertility.
Humans
;
Male
;
Insulin-Like Growth Factor II/metabolism*
;
Infertility, Male/genetics*
;
DNA Damage
;
Adult
;
Inflammation/metabolism*
;
Spermatozoa/metabolism*
;
Semen Analysis
;
Semen/metabolism*
;
Tumor Necrosis Factor-alpha/metabolism*
;
Histones/metabolism*
;
Interleukin-1beta/metabolism*
7.Peak growth hormone and insulin-like growth factor 1 levels in girls with isolated premature thelarche and their predictive value for central precocious puberty.
Jie CHEN ; Kun-Di WANG ; Rong HUANG ; Shu-Fang LIU ; Qi YANG ; Li YANG
Chinese Journal of Contemporary Pediatrics 2025;27(11):1360-1366
OBJECTIVES:
To compare serum insulin-like growth factor 1 (IGF-1) and peak growth hormone (GH) levels between girls with isolated premature thelarche (IPT) and central precocious puberty (CPP), to construct a prediction model for progression from IPT to CPP, and to assess its diagnostic value.
METHODS:
Girls diagnosed with IPT (<i>ni>=111) between January 2022 and August 2023 at the China-Japan Friendship Hospital and the Xinjiang Production and Construction Corps Hospital were retrospectively included. According to follow-up outcomes, participants were categorized into a CPP group (35 cases) and an IPT group (36 cases). A clinical prediction model for progression to CPP was constructed by multivariable logistic regression, and the contributions of IGF-1 and peak GH were evaluated. Restricted cubic spline analysis was used to assess the dose-response relationships of IGF-1 and peak GH with CPP. Decision curve analysis was applied to evaluate clinical utility.
RESULTS:
IGF-1 and peak GH were higher in the CPP group than in the IPT group (<i>Pi><0.05). Compared with model 1 (without IGF-1 and peak GH), model 2 (with IGF-1 and peak GH) showed significantly higher area under the curve, integrated discrimination improvement, and net reclassification improvement (all <i>Pi><0.05). Model 2 (χ 2=6.054, <i>Pi>=0.889) also demonstrated better goodness-of-fit than model 1 (χ 2=7.717, <i>Pi>=0.634). Nonlinear dose-response relationships were observed for peak GH and IGF-1 with CPP (<i>Pi> for overall trend <0.05; <i>Pi> for nonlinearity <0.05). Decision curve analysis indicated that combined prediction using IGF-1 and peak GH provided greater net benefit than either biomarker alone.
CONCLUSIONS
Peak GH and IGF-1 are closely associated with progression from IPT to CPP in girls. A clinical prediction model incorporating peak GH and IGF-1 can improve prediction of progression to CPP and yield higher net benefit.
Humans
;
Female
;
Puberty, Precocious/etiology*
;
Insulin-Like Growth Factor I/analysis*
;
Child
;
Retrospective Studies
;
Human Growth Hormone/blood*
;
Predictive Value of Tests
;
Child, Preschool
;
Logistic Models
8.Advances in pharmacological research for retinopathy of prematurity.
Yanxi XIE ; Suilian ZHENG ; Hui YANG
Journal of Zhejiang University. Medical sciences 2025;54(3):411-421
Retinopathy of prematurity (ROP) is a proliferative retinal vascular disease that threatens the vision of premature infants. Various novel drugs have demonstrated therapeutic potential for ROP by targeting signaling pathways associated with vascular endothelial growth factor (VEGF) [such as PI3K/AKT, hypoxia-inducible factor (HIF)-1α/VEGF], oxidative stress, tumor necrosis factor (TNF)-α, and Notch pathways. Propranolol, insulin-like growth factor-1, and celecoxib attenuate pathological neovascularization via the PI3K/Akt signaling pathway. Tripterine and melatonin inhibit retinal neovascularization by modulating the HIF-1α/VEGF signaling axis. Adiponectin mitigates the damage caused by oxidative stress and preserves endothelial function by enhancing endothelial nitric oxide synthase activity. Omega-3 polyunsaturated fatty acids suppress TNF-α-mediated inflammatory responses, modulate retinal development and angiogenesis, and reduce retinal neovascular lesions. DAPT, a γ-secretase inhibitor, blocks Notch signaling to suppress abnormal vascular proliferation. These agents exhibit synergistic multi-pathway anti-angiogenic effects in preclinical models and early-phase clinical trials, offering critical insights for advancing drug development and clinical translation in ROP management.
Retinopathy of Prematurity/metabolism*
;
Humans
;
Signal Transduction/drug effects*
;
Infant, Newborn
;
Vascular Endothelial Growth Factor A/metabolism*
;
Hypoxia-Inducible Factor 1, alpha Subunit/metabolism*
;
Tumor Necrosis Factor-alpha/metabolism*
;
Oxidative Stress/drug effects*
;
Fatty Acids, Omega-3/therapeutic use*
;
Phosphatidylinositol 3-Kinases/metabolism*
;
Proto-Oncogene Proteins c-akt/metabolism*
;
Receptors, Notch/metabolism*
;
Angiogenesis Inhibitors/therapeutic use*
;
Insulin-Like Growth Factor I/therapeutic use*
9.Clinical phenotype and genetic analysis of a child with Acid-labile subunit deficiency due to variant of IGFALS gene.
Yanli WANG ; Zhijin LU ; Shuangxi CHENG ; Yan WANG ; Haiming YUAN ; Huihua YUAN
Chinese Journal of Medical Genetics 2025;42(12):1465-1470
OBJECTIVE:
To explore the clinical phenotypes and genetic characteristics of a child with Acid-labile subunit deficiency (ALS).
METHODS:
A male child diagnosed with ALS at Dongguan Maternal and Child Health Care Hospital in March 2021 was selected as the study subject. Clinical data of his family was collected. Peripheral blood samples were collected from the child and his parents. Following extraction of genomic DNA, whole-exome sequencing (WES) was carried out, and Sanger sequencing was used for family verification of candidate variants. Based on guidelines from the American College of Medical Genetics and Genomics (ACMG), the pathogenicity of the candidate variant was classified. This study was approved by the Medical Ethics Committee of the hospital (Ethics No.: 2020-6).
RESULTS:
The patient, a 5-year-and-7-month-old boy, presented with short stature and delayed bone age. Endocrine examinations showed decreased serum concentrations of insulin-like growth factor-1 (IGF-1) and IGF binding protein-3 (IGFBP3). WES revealed that he has harbored compound heterozygous variants of the IGFALS gene, namely c.741_742del, p.Y248Pfs83 and c.272del, p.P91Rfs31. Sanger sequencing verified that the variants were inherited from his father and mother, respectively. According to the ACMG guidelines, c.741_742del, p.Y248Pfs83 and c.272del, p.P91Rfs31 variants were classified as likely pathogenic (PVS1+PM2_supporting). Based on the pre-set literature search strategy, 11 research literature on ALS were retrieved, which involved a total of 33 families and 62 patients. Combined with the patient in this study, 31 IGFALS gene variants were identified among the 63 patients, which mainly consisted of missense variants (20 types), with variant sites concentrated in exon 2. The main clinical features were short stature in conjunct with delayed puberty, with a significant genotype-phenotype correlation.
CONCLUSION
The IGFALS gene variants NM_004970.2: c.741_742del, p.Y248Pfs83 and c.272del, p.P91Rfs31 may be the genetic etiology in this family. This study has expanded the variant spectrum of the IGFALS gene and provided valuable information for the diagnosis, genetic counseling and clinical treatment of the disease.
Humans
;
Male
;
Phenotype
;
Child, Preschool
;
Carrier Proteins/genetics*
;
Glycoproteins/deficiency*
;
Exome Sequencing
;
Female
;
Mutation
;
Insulin-Like Growth Factor I/metabolism*
;
Growth Disorders/genetics*
10.Mechanism of acupuncture for chronic blunt injury of lumbar muscle based on IGF-1/PI3K/AKT pathway.
Qun CHEN ; Dongmei WANG ; Zhengyu YANG ; Xiulian ZHENG ; Jianping LIN ; Shaoqing CHEN
Chinese Acupuncture & Moxibustion 2025;45(12):1759-1769
OBJECTIVE:
To explore the effect and mechanism of acupuncture at "Weizhong" (BL40) on microcirculation of paravertebral skeletal muscle in rats with chronic blunt injury of lumbar muscle based on the insulin-like growth factor-1 (IGF-1)/phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) pathway.
METHODS:
Forty-eight SPF-grade SD rats were randomized into a blank group (8 rats) and a modeling group (40 rats). Chronic blunt injury model was established by weight impact method in the modeling group. Forty rats were successfully modeled, and were randomly divided into a model group, an acupuncture at Weizhong group (Weizhong group), an acupuncture at non-acupoint group (non-acupoint group), an inhibitor group, and an inhibitor+acupuncture at Weizhong group (inhibitor+Weizhong group), 8 rats in each group. In the Weizhong group and the inhibitor+Weizhong group, acupuncture was applied at bilateral "Weizhong" (BL40). In the non-acupoint group, acupuncture was applied at non-acupoints, i.e. points 0.5 cm inward from bilateral "Weizhong" (BL40). The acupuncture intervention was delivered 20 min each time, once a day for continuous 2 weeks. In the inhibitor group and the inhibitor+Weizhong group, intraperitoneal injection of IGF-1 receptor (IGF-1R) inhibitor was given once a day, at a dosage of 2 mg/100 g, for continuous 2 weeks. Before modeling and on the 1st, 7th and 14th days of intervention, the body mass was measured. Before and after modeling, and after intervention, the limb grip strength and paw withdrawal threshold (PWT) were measured. After intervention, the morphology of psoas muscle was observed by HE staining; the ultrastructure of psoas muscle capillaries was observed by electron microscopy; the levels of serum vascular endothelial growth factor (VEGF) and endothelial nitric oxide synthase (eNOS) were detected by ELISA; and the protein and mRNA expression of IGF-1, IGF-1R, PI3K, AKT of psoas muscle was detected by Western blot and real-time PCR.
RESULTS:
Compared with the blank group, in the model group, the body mass on the 7th and 14th days of intervention, the limb grip strength, and the PWT of left and right hind feet were decreased (<i>Pi><0.001, <i>Pi><0.01); the skeletal muscle cells showed enlarged intercellular space, loosely arranged and irregularly shaped, the capillaries in the psoas muscle tissues were edematous, and the lumen of the blood vessels was obviously atrophied; the levels of serum VEGF and eNOS were decreased (<i>Pi><0.001); in psoas muscle, the protein expression of IGF-1 and IGF-1R, as well as the p-PI3K/PI3K, p-AKT/AKT values were decreased (<i>Pi><0.001), the mRNA expression of IGF-1, IGF-1R, PI3K and AKT was decreased (<i>Pi><0.001, <i>Pi><0.05). Compared with the model group, in the Weizhong group, the body weight was increased on the 7th and 14th days of intervention (<i>Pi><0.001), the limb grip strength and the PWT of the left and right hind feet were increased (<i>Pi><0.001, <i>Pi><0.01); the arrangement of the skeletal muscle cells was relatively tight and the intercellular space was reduced, the blood vessels tended to be regular and the structure of the basement membrane was continuous, while the lumens of blood vessels were collapsed locally; the levels of serum VEGF and eNOS were increased (<i>Pi><0.001); in psoas muscle, the protein expression of IGF-1 and IGF-1R, as well as the p-PI3K/PI3K, p-AKT/AKT values were increased (<i>Pi><0.001), the mRNA expression of IGF-1, IGF-1R, PI3K and AKT was increased (<i>Pi><0.001, <i>Pi><0.01). Compared with the model group, in the inhibitor group, the body mass was decreased on the 7th and 14th days of intervention (<i>Pi><0.05, <i>Pi><0.01); the limb grip strength and the PWT of the left hind foot were decreased (<i>Pi><0.01, <i>Pi><0.001); the intercellular space of skeletal muscle cells was larger, the nuclei of the cells and erythrocytes were scattered in the intercellular space, the damage of the capillaries in the muscular tissues was serious, the collagen fibers were sparsely distributed and disorganized; the levels of serum VEGF and eNOS were decreased (<i>Pi><0.001, <i>Pi><0.01); in psoas muscle, the protein expression of IGF-1 and IGF-1R, as well as the p-PI3K/PI3K and p-AKT/AKT values were decreased (<i>Pi><0.01, <i>Pi><0.05, <i>Pi><0.001), the mRNA expression of IGF-1, IGF-1R, PI3K, and AKT was decreased (<i>Pi><0.01, <i>Pi><0.001, <i>Pi><0.05). Compared with the Weizhong group, in the non-acupoint group and the inhibitor+Weizhong group, the body mass was decreased on the 7th and 14th days of intervention (<i>Pi><0.001, <i>Pi><0.01), the limb grip strength was decreased (<i>Pi><0.001); the morphology of muscle cell was relatively poor, with generally irregular, there was mild collapse and atrophy in the vascular lumen, and mild edema in the endothelial cells; the levels of serum VEGF and eNOS were decreased (<i>Pi><0.001); in psoas muscle, the protein expression of IGF-1 and IGF-1R, as well as the p-PI3K/PI3K and p-AKT/AKT values were decreased (<i>Pi><0.01, <i>Pi><0.001), the mRNA expression of IGF-1, IGF-1R, PI3K, and AKT was decreased (<i>Pi><0.001, <i>Pi><0.01, <i>Pi><0.05). Compared with the Weizhong group, the PWT of the left hind foot was decreased in the non-acupoint group (<i>Pi><0.001), and PWT of the left and right hind feet was decreased in the inhibitor+Weizhong group (<i>Pi><0.001).
CONCLUSION
Acupuncture at "Weizhong" (BL40) promotes lumbar muscle repair in chronic low back pain, its mechanism may be related to the activation of the IGF-1/PI3K/AKT pathway, thereby improving the microcirculation.
Animals
;
Insulin-Like Growth Factor I/genetics*
;
Acupuncture Therapy
;
Rats, Sprague-Dawley
;
Rats
;
Proto-Oncogene Proteins c-akt/genetics*
;
Male
;
Humans
;
Muscle, Skeletal/metabolism*
;
Signal Transduction
;
Phosphatidylinositol 3-Kinases/genetics*
;
Wounds, Nonpenetrating/metabolism*
;
Acupuncture Points


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