Dysregulated GLUT1 results in the pathogenesis of preeclampsia by impairing the function of trophoblast cells.

Preeclampsia (PE) is a common placental-origin complication of pregnancy and a major cause of morbidity and mortality among pregnant women and fetuses. However, its pathogenesis has not been elucidated. Effective strategies for prevention, screening, and treatment are still lacking. Studies have indicated that dysfunction of placental trophoblast cells, such as impaired syncytialization, proliferation, and epithelial-mesenchymal transition processes, plays a crucial role in the development of PE. Glucose transporter 1 (GLUT1) is a key protein regulating glucose transport in placental tissues. However, the effect of GLUT1 on the function of trophoblast cells in PE is not well understood. In this study, we found that GLUT1 expression is reduced in PE placental tissues. GLUT1 promotes the syncytialization process by increasing the glucose uptake ability of BeWo cells. Additionally, GLUT1 promotes the proliferation, migration, and invasion capabilities of HTR-8/SVneo cells by regulating MAPK and PI3K/AKT signaling pathways. Overall, these findings provide a new insight into understanding the biological functions of GLUT1, clarifying the pathogenesis of PE, and identifying diagnostic and therapeutic targets for PE.

Glucose Transporter 1 Inhibitors Induce Autophagy and Synergize With Lenvatinib in Thyroid Cancer Cells.

BACKGROUND: Less differentiated thyroid cancer may upregulate the expression of glucose transporter 1 (GLUT1) and increase glycolytic activity. However, it is uncertain whether GLUT1 can be used as a target for therapy. METHODS: Thyroid cancer cell lines were treated with two different GLUT1 inhibitors, STF-31 and BAY-876. Functional assays were conducted to evaluate the effects of these inhibitors on cell biology. RESULTS: GLUT1 inhibitors dose-dependently decreased cell growth and clonogenicity of thyroid cancer cells. Cell cycle analysis showed that these inhibitors caused G2/M arrest instead of apoptosis. Additionally, treatment with GLUT1 inhibitors led to the activation of autophagy. In both the Transwell and spheroid models, GLUT1 inhibitors significantly suppressed cell invasiveness. Moreover, GLUT1 inhibitors demonstrated synergistic interactions when combined with lenvatinib. CONCLUSIONS: Treatment with GLUT1 inhibitors activates autophagy and provokes cell cycle arrest, accompanied by a decrease in colony formation and invasive capacity in thyroid cancer cells.

Comment on, "Hypoxia preconditioning protects neuronal cells against traumatic brain injury through stimulation of glucose transport mediated by HIF-1α/GLUTs signaling pathway in rat".

Wu et al. (2021) investigated the neuroprotective effects of hypoxia preconditioning (HPC) in a rat model of traumatic brain injury (TBI). The study demonstrated that HPC enhances brain resilience to TBI by upregulating glucose transporters GLUT1 and GLUT3 through the HIF-1α signaling pathway. Comprehensive molecular and histological analyses confirmed increased expression of these transporters, correlating with reduced neuronal apoptosis and cerebral edema. The robust methodology, including rigorous statistical validation and time-course assessments, underscores HPC's potential therapeutic role in mitigating neuronal loss and improving glucose transport post-injury. However, the study could be strengthened by incorporating additional preconditioning controls, comparative analyses with other neuroprotective strategies, and exploring downstream metabolic effects in greater detail. Furthermore, expanding the research to include diverse animal models and examining sex-dependent responses would enhance the generalizability and translational relevance of the findings. Future studies should also integrate metabolic flux analysis and advanced imaging techniques to further elucidate HPC's mechanisms of action.

Gestational exposure to BPA alters the expression of glucose and lipid metabolic mediators in the placenta: role in programming offspring for obesity.

Bisphenol A (BPA) exposure during pregnancy is known to predispose offspring to obesity in later life. Our previous studies demonstrated obesogenic effects in BPA-exposed offspring, including excess body fat, increased feed efficiency, adipocyte hypertrophy, and altered leptin signaling. However, the role of the placenta in mediating these effects remained unclear. This study investigates the mechanisms by which BPA exposure affects placental glucose and lipid transporters and their impact on offspring adiposity in Wistar rats. Dams were orally gavaged with BPA [0.4 (low dose-LD) and 4.0 (high dose-HD) µg/kg body weight] from gestational day (gD) 4 to 14. Gestational exposure to LD BPA increased the expression of 11ß hydroxysteroid dehydrogenase 1 (11ß HSD1) and estrogen receptor alpha (ERα) proteins (p<0.05) in the placenta compared to control and HD BPA. Similar changes were observed in the expression of mTOR signaling mediators, fatty acid transporters, and intracellular fatty acid-binding proteins. There were no changes in the dam's body weight or lipid and glucose profiles. However, there was a dose dependent increase in glucose transporter (GLUT1) expression in the placenta. While LD BPA increased hexokinase 2 expression in the placenta, HD BPA had no effect. Both doses of BPA increased IL6 expression, but only LD BPA exposure increased PPAR-gamma expression. Additionally, BPA exposure induced ADRP expression and localization, suggesting potential lipid overload in the placenta. Furthermore, BPA exposure altered the placental epigenetic profile, with increased expression of DNA methyltransferases (DNMTs). Overall, gestational BPA exposure led to dose-specific alterations in placental glucose and lipid metabolic activities, possibly playing an role in increasing the supply of these macronutrients to the fetus and predisposing the offspring to obesity.

Endothelial metabolic control of insulin sensitivity through resident macrophages.

Endothelial cells (ECs) not only form passive blood conduits but actively contribute to nutrient transport and organ homeostasis. The role of ECs in glucose homeostasis is, however, poorly understood. Here, we show that, in skeletal muscle, endothelial glucose transporter 1 (Glut1/Slc2a1) controls glucose uptake via vascular metabolic control of muscle-resident macrophages without affecting transendothelial glucose transport. Lowering endothelial Glut1 via genetic depletion (Glut1ΔEC) or upon a short-term high-fat diet increased angiocrine osteopontin (OPN/Spp1) secretion. This promoted resident muscle macrophage activation and proliferation, which impaired muscle insulin sensitivity. Consequently, co-deleting Spp1 from ECs prevented macrophage accumulation and improved insulin sensitivity in Glut1ΔEC mice. Mechanistically, Glut1-dependent endothelial glucose metabolic rewiring increased OPN in a serine metabolism-dependent fashion. Our data illustrate how the glycolytic endothelium creates a microenvironment that controls resident muscle macrophage phenotype and function and directly links resident muscle macrophages to the maintenance of muscle glucose homeostasis.

Digitonin-Loaded Nanoscale Metal-Organic Framework for Mitochondria-Targeted Radiotherapy-Radiodynamic Therapy and Disulfidptosis.

The efficacy of radiotherapy (RT) is limited by inefficient X-ray absorption and reactive oxygen species generation, upregulation of immunosuppressive factors, and a reducing tumor microenvironment (TME). Here, the design of a mitochondria-targeted and digitonin (Dig)-loaded nanoscale metal-organic framework, Th-Ir-DBB/Dig, is reported to overcome these limitations and elicit strong antitumor effects upon low-dose X-ray irradiation. Built from Th6O4(OH)4 secondary building units (SBUs) and photosensitizing Ir(DBB)(ppy)2 2+ (Ir-DBB, DBB = 4,4'-di(4-benzoato)-2,2'-bipyridine; ppy = 2-phenylpyridine) ligands, Th-Ir-DBB exhibits strong RT-radiodynamic therapy (RDT) effects via potent radiosensitization with high-Z SBUs for hydroxyl radical generation and efficient excitation of Ir-DBB ligands for singlet oxygen production. Th-Ir-DBB/Dig releases digitonin in acidic TMEs to trigger disulfidptosis of cancer cells and sensitize cancer cells to RT-RDT through glucose and glutathione depletion. The released digitonin simultaneously downregulates multiple immune checkpoints in cancer cells and T cells through cholesterol depletion. As a result, Th-Ir-DBB/dig plus X-ray irradiation induces strong antitumor immunity to effectively inhibit tumor growth in mouse models of colon and breast cancer.

Hyaluronan and Glucose Dual-targeting Probe: Synthesis and Application.

In this work, we developed a dual-targeting probe consisted of well-defined hyaluronan (HA) oligosaccharide and glucose (Glc) labeled with Rhodamine B (HGR). The probe was designed to enhance tumor targeting both in vitro and in vivo, by simultaneously targeting CD44 and Glc transporter 1 (GLUT1). The HA oligosaccharide component was crucial for accurately assessing the impact of sugar chain structure on targeting efficacy, while its unoccupied carboxyl groups could minimize interference with HA's binding affinity to CD44. In vitro studies demonstrated that HGR possessed remarkable cytocompatibility and superior targeting abilities compared to single-targeting probes. It displayed a marked preference for CD44high/GLUT1high cells rather than CD44low/GLUT1low cells. In vivo studies using murine models further confirmed the significantly enhanced targeting efficacy and excellent biocompatibility of HGR. Therefore, this designed dual-targeting probe holds potential for clinical tumor detection.

Glut1 Functions in Insulin-Producing Neurons to Regulate Lipid and Carbohydrate Storage in Drosophila.

Obesity remains one of the largest health problems in the world, arising from the excess storage of triglycerides (TAGs). However, the full complement of genes that are important for regulating TAG storage is not known. The Glut1 gene encodes a Drosophila glucose transporter that has been identified as a potential obesity gene through genetic screening. Yet, the tissue-specific metabolic functions of Glut1 are not fully understood. Here, we characterized the role of Glut1 in the fly brain by decreasing neuronal Glut1 levels with RNAi and measuring glycogen and TAGs. Glut1RNAi flies had decreased TAG and glycogen levels, suggesting a nonautonomous role of Glut1 in the fly brain to regulate nutrient storage. A group of hormones that regulate metabolism and are expressed in the fly brain are Drosophila insulin-like peptides (Ilps) 2, 3, and 5. Interestingly, we observed blunted Ilp3 and Ilp5 expression in neuronal Glut1RNAi flies, suggesting Glut1 functions in insulin-producing neurons (IPCs) to regulate whole-organism TAG and glycogen storage. Consistent with this hypothesis, we also saw fewer TAGs and glycogens and decreased expression of Ilp3 and Ilp5 in flies with IPC-specific Glut1RNAi. Together, these data suggest Glut1 functions as a nutrient sensor in IPCs, controlling TAG and glycogen storage and regulating systemic energy homeostasis.

Hypoxia-Inducible Factor 1-Alpha (HIF-1α): An Essential Regulator in Cellular Metabolic Control.

The element that causes hypoxia when the von Hippel-Lindau (VHL) protein is not functioning is hypoxia-inducible factor 1-alpha (HIF-1α), which is the essential protein linked to cell control under hypoxia. Consequently, in situations where cells are oxygen-deficient, HIF-1α carries out a variety of essential functions. Citations to relevant literature support the notion that HIF-1α regulates the mitochondrial and glycolytic pathways, as well as the transition from the former to the latter. Cells with limited oxygen supply benefit from this change, which is especially beneficial for the inhibition of the mitochondrial electron transport chain and enhanced uptake of glucose and lactate. During hypoxic stress, HIF-1α also controls proline and glycolytic transporters such as lactate dehydrogenase A (LDHA) and glucose transporter 1 (GLUT1). These mechanisms help the cell return to homeostasis. Therefore, through metabolic change promoting adenosine triphosphate (ATP) synthesis and reducing reactive oxygen species (ROS) creation, HIF-1α may have a role in reducing oxidative stress in cells. This evidence, which describes the function of HIF-1α in many molecular pathways, further supports the notion that it is prognostic and that it contributes to hypoxic cell adaption. Understanding more about disorders, including inflammation, cancer, and ischemia, is possible because of HIF-1α's effect on metabolic changes. Gaining knowledge about the battle between metabolism, which is directed by HIF-1α, would help advance the research on pathophysiological situations involving dysregulated hypoxia and metabolism.

Physiology of peritoneal dialysis; pathophysiology in long-term patients.

The microvascular wall of peritoneal tissues is the main barrier in solute and water transport in the initial phase of peritoneal dialysis (PD). Small solute transport is mainly by diffusion through inter-endothelial pores, as is hydrostatic fluid transport with dissolved solutes. Water is also transported through the intra-endothelial water channel aquaporin-1(AQP-1) by a glucose-induced crystalloid osmotic gradient (free water transport). In the current review the physiology of peritoneal transport will be discussed both during the first years of PD and after long-term treatment with emphasis on the peritoneal interstitial tissue and its role in free water transport. Attention will be paid to the role of glucose-induced pseudohypoxia causing both increased expression of fibrogenetic factors and of the glucose transporter GLUT-1. The former leads to peritoneal fibrosis, the latter to a reduced crystalloid osmotic gradient, explaining the decrease in free water transport as a cause of ultrafiltration failure. These phenomena strongly suggest that the extremely high dialysate glucose concentrations are the driving force of both morphologic and functional peritoneal alterations that may develop during long-term PD.

Hypoxia-Regulated Proteins: Expression in Endometrial Cancer and Their Association with Clinicopathologic Features.

BACKGROUND: Hypoxia-regulated proteins (HIF-1α and GLUT-1) have been identified as prognostic markers in various cancers; however, their role in endometrial cancer remains unclear. This study aimed to evaluate HIF-1α and GLUT-1 expression in endometrial cancer and correlate their expression with clinicopathological features. MATERIALS AND METHODS: A tissue microarray (TMA) was constructed using specimens from a retrospective cohort of 51 endometrial cancer patients who underwent hysterectomy at the Gyeongsang National University Hospital between 2002 and 2009. Clinicopathologic data were collected from electronic medical records, and HIF-1α and GLUT-1 expressions were assessed in the tumor tissue. RESULTS: GLUT-1 expression in endometrial cancer was categorized as mosaic, central, or diffuse. Most patients (56.0%) exhibited a central pattern, followed by diffuse (32.0%) and mosaic (12.0%) patterns. GLUT-1 expression was not significantly associated with histologic grade (p = 0.365). HIF-1α expression in immune cells, but not tumor cells, was significantly associated with a higher histologic grade. A higher proportion of HIF-1α-positive immune cells, using both thresholds (≤1% vs. >1% and ≤5% vs. >5%), was significantly associated with higher histologic grade (p = 0.032 and p = 0.048, respectively). In addition, a higher proportion of HIF-1α-positive immune cells was significantly associated with a diffuse GLUT-1 expression pattern using >5% as a threshold. There were no significant differences in the proportion of HIF-1α-positive immune cells between groups stratified by age, tumor size, or invasion depth, regardless of whether the 1% or 5% threshold for HIF-1α positivity was used. CONCLUSIONS: A higher proportion of HIF-1α-positive immune cells is associated with endometrial cancers with higher histologic grade and diffuse GLUT1 expression patterns. These findings suggest a potential role for HIF-1α as a prognostic marker and highlight the need for further studies into the role of HIF-1α in the tumor microenvironment.

IL-17A Cytokine-Regulated Glut1 Expression in Placenta Cells.

Trophoblasts, the principal cellular component of the placenta, play an important role in nutrient and gas exchange. Previous studies have indicated that maternal immune activation (MIA) leads to an elevation in IL-17A cytokine levels in maternal serum, subsequently influencing fetal brain development during pregnancy. In this study, we aimed to elucidate the impact of the IL-17A cytokine on placental function. First, we treated JAR and JEG-3, which is a placenta cell line, with IL-17A in a concentration-dependent or time-dependent manner and observed cell morphology and viability. It was confirmed that treatment with IL-17A or a double-stranded RNA mimic (PolyI:C) had no effect on the morphology or cell viability. IL-17A treatment increased the expression of IL-17R at the mRNA and protein levels, and Poly(I:C) increased the levels of IFNγ and TNFα. Additionally, PPARγ, known as a metabolism regulator, was increased by IL-17A treatment. Also, we observed that the expression of Glut1 and Glut3 was increased by IL-17A treatment. To confirm this, we examined the expression of transporters in the placental tissue of the MIA rodent model, and we observed that mRNA expression of glut1 and glut3 was significantly increased. However, the expression of Gltu1 and Glut3 was observed to be significantly inhibited in the brains of MIA-induced offspring. This study suggests that IL-17A increases signaling through IL-17R in the placenta and fetal brain tissue; however, there is a mechanism for regulating the expression of glucose transporters by increased IL-17A in the placenta.

Bone marrow derived mesenchymal stem cells restored GLUT1 expression in the submandibular salivary glands of ovariectomized rats.

OBJECTIVE: Loss of ovarian function in menopause is commonly associated with salivary gland dysfunction. The aim is to study the possible therapeutic effect of bone marrow mesenchymal stem cells (BM-MSCs) on the altered structure of the submandibular salivary glands (SMGs) of ovariectomized rats. DESIGN: Twenty-four female, adult, Wistar rats were used and distributed into three groups (8 rats/group). The control group included sham-operated rats. The ovariectomized group consisted of rats with removed ovaries. The third group consisted of ovariectomized rats received injections, via tail, of MSCs extracted from bone marrow of 3-weeks-old rat hind limb (BM-MSC group). Four weeks after BM-MSC transplantation, the bone mineral density (BMD) of the femur was detected. The SMG was dissected and processed for histological, immunohistochemical, and histomorphometric analyses. RESULTS: The ovariectomized rats depicted low BMD in the femur. The SMG acini revealed atrophy. The ductal and acinar cells depicted vacuolization and abnormal nuclear histology. GLUT1 immunostaining was decreased in SMG ducts. The BM-MSC group resumed the normal SMG histology and GLUT1 immunolabelling. CONCLUSIONS: BM-MSC therapy restored the normal SMG structure and GLUT1 immunostaining in the treated ovariectomized rats, suggesting improved glucose transporting function.

In-silico screening of bioactive compounds of Moringa oleifera as potential inhibitors targeting HIF-1α/VEGF/GLUT-1 pathway against Breast Cancer.

OBJECTIVES: Breast cancer is among the most heterogeneous and aggressive diseases and a foremost cause of death in women globally. Hypoxic activation of HIF-1α in breast cancers triggers the transcription of a battery of genes encoding proteins that facilitate tumor growth and metastasis and is correlated with a poor prognosis. Based on the reported cytotoxic and anti-cancer properties of Moringa oleifera (Mo), this study explores the inhibitory effect of bioactive compounds from M. oleifera and breast cancer target proteins HIF-1α, VEGF, and GLUT-1 in silico. METHODS: The X-ray crystallographic structures of HIF-1α, VEGF, and GLUT1 were sourced from the Protein Data Bank (PDB) and docked with 70 3D PubChem structures of bioactive compounds of M. oleifera using AutoDock Vina, and binding modes were analyzed using Discovery Studio. Five compounds with the highest binding energies were selected and further drug-likeness, oral bioavailability, ADME, and toxicity profiles were analyzed using SwissADME, ADMETSaR, and ADMETlab 3.0 web server. RESULTS: Out of the screened 70 bioactive compounds, the top five compounds with the best binding energies were identified namely Apigenin, Ellagic Acid, Isorhamnetin, Luteolin, and Myricetin with each receptor. Molecular docking results indicated that the ligands interact strongly with the target HIF-1α, VEGF, and GLUT-1 receptors through hydrogen bonds and hydrophobic interactions. These compounds showed favorable drug-like and pharmacokinetic properties, possessed no substantial toxicity, and were fairly bioavailable. CONCLUSIONS: Results suggested that the compounds possess strong potential in developing putative lead compounds targeting HIF-1α that are safe natural plant-based drugs against breast cancer.

Guía mexicana para el diagnóstico y el tratamiento del hemangioma infantil.

Infantile hemangioma is a benign vascular tumor, the most common in childhood, whose natural evolution is the disappearance of the lesion in the pediatric age and which has effective and safe treatments that limit its growth and favor its disappearance at younger ages. Infantile hemangioma continues to be a reason for attention to complications, due to erroneous diagnoses, lack of knowledge of the condition, late referral or fear of the effects of the medications used for its treatment. Furthermore, its presence is normalized without taking into account that it can cause uncertainty, anxiety, feelings of guilt and, as a consequence, a significant impact on the quality of life, mainly in the parents or caregivers of the child. The need for a clinical practice guideline in our country arises from the high presentation of late-remitted complications in infantile hemangioma even with the availability of adequate treatments, the continuous evolution of medicine and the appearance of new evidence. Throughout the guide you will find recommendations regarding the diagnosis, treatment and follow-up of patients with infantile hemangioma, taking into account the paraclinical tests that can be performed, topical or systemic management options, as well as adjuvant therapies. For the first time, objective tools for patient follow-up are included in a guide for the management of infantile hemangioma, as well as to help the first contact doctor in timely referral.

El hemangioma infantil es un tumor vascular benigno, el más frecuente de la infancia, cuya evolución natural favorece la desaparición de la lesión en la misma edad pediátrica y que cuenta con tratamientos eficaces y seguros que limitan su crecimiento y favorecen su desaparición a edades más tempranas. Continúa siendo motivo de atención de complicaciones, debido a diagnósticos erróneos, desconocimiento del padecimiento, referencia tardía o temor de los efectos de los fármacos utilizados para su tratamiento. Además, se normaliza su presencia sin tomar en cuenta que puede llegar a causar incertidumbre, ansiedad, sentimientos de culpa y, como consecuencia, importante afectación de la calidad de vida, principalmente en los padres o cuidadores del niño. La necesidad de una guía de práctica clínica en nuestro país surge ante la alta presentación de complicaciones del hemangioma infantil referidas de manera tardía aun con la disponibilidad de tratamientos adecuados, la evolución continua de la medicina y la aparición de nueva evidencia. A lo largo de la guía se encontrarán recomendaciones en relación con el diagnóstico, el tratamiento y el seguimiento de los pacientes con hemangioma infantil, tomando en cuenta los paraclínicos que pueden realizarse, las opciones de manejo tópico o sistémico, y las terapias adyuvantes. Por primera vez se incluyen en una guía para el manejo del hemangioma infantil herramientas objetivas para el seguimiento de los pacientes, así como para ayudar al médico de primer contacto en su referencia oportuna.

Acidic Pepsin Affects Laryngeal Carcinoma Cell Growth and Invasion Through Glycolysis.

OBJECTIVE: The pathogenic mechanism underlying the effects of acidic pepsin in laryngeal cancer remains unclear. This study investigated whether acidic pepsin influences Glut-1 expression and glycolytic activity in laryngeal carcinoma cells and whether it plays a role in the growth and migration of these cells through glycolysis. STUDY DESIGN: In vitro study. SETTING: A university-affiliated hospital. METHODS: Laryngeal carcinoma TU 212 and TU 686 cells were treated with acidic pepsin and 2-deoxy-d-glucose (2-DG), then transfected with Glut-1 small interfering RNA (siRNA). Glucose uptake was detected by a radioimmunoassay counter, lactate secretion was detected by a lactic acid kit, and Glut-1 expression was detected by western blotting. Cell viability, migration and invasion, and clonal formation were assessed using the Cell Counting Kit-8, Transwell chamber, and clonal formation assays, respectively. RESULTS: Acidic pepsin significantly increased Glut-1 expression in laryngeal carcinoma cells compared with the control group (P < .01). It also significantly enhanced 18F-fluorodeoxyglucose (Cin/Cout) uptake, lactate secretion, cell viability, migration, invasion, and clonal formation in laryngeal carcinoma cells compared with the control group (P < .01). The glycolytic inhibitor 2-DG and Glut-1 siRNA significantly reversed the effects of acidic pepsin on laryngeal carcinoma cells (P < .01). CONCLUSION: Acidic pepsin enhances the growth and migration of laryngeal carcinoma cells by upregulating Glut-1, thus promoting glycolysis.

Ginsenoside CK cooperates with bone mesenchymal stem cells to enhance angiogenesis post-stroke via GLUT1 and HIF-1α/VEGF pathway.

The transplantation of bone marrow mesenchymal stem cells (MSCs) in stroke is hindered by the restricted rates of survival and differentiation. Ginsenoside compound K (CK), is reported to have a neuroprotective effect and regulate energy metabolism. We applied CK to investigate if CK could promote the survival of MSCs and differentiation into brain microvascular endothelial-like cells (BMECs), thereby alleviating stroke symptoms. Therefore, transwell and middle cerebral artery occlusion (MCAO) models were used to mimic oxygen and glucose deprivation (OGD) in vitro and in vivo, respectively. Our results demonstrated that CK had a good affinity for GLUT1, which increased the expression of GLUT1 and the production of ATP, facilitated the proliferation and migration of MSCs, and activated the HIF-1α/VEGF signaling pathway to promote MSC differentiation. Moreover, CK cooperated with MSCs to protect BMECs, promote angiogenesis and vascular density, enhance neuronal and astrocytic proliferation, thereby reducing infarct volume and consequently improving neurobehavioral outcomes. These results suggest that the synergistic effects of CK and MSCs could potentially be a promising strategy for stroke.

Electroacupuncture improves articular microcirculation and attenuates cartilage hypoxia in a male rabbit model of knee osteoarthritis.

Background and aim: Hypoxia of the cartilage has been considered as a potential pathogenic factor in knee osteoarthritis (KOA). Studies have shown that impaired blood perfusion of joint leads to cartilage hypoxia. Electroacupuncture (EA) has proven effects on pain relief and improving microcirculation. This study aimed to explore the effect of EA on articular microcirculation and cartilage anoxic and the underlying mechanisms. Procedures: Videman's method was used for 6 weeks to establish the KOA model. EA intervention was performed in four points around the knee for 3 weeks after KOA modeling. The Lequesne MG score was used to assess ethology. We recorded the oxygen tension of synovial fluid and the synovial microcirculation in vivo. HE-staining was used to assess cartilage morphology, and immunohistochemistry (IHC), Western blotting, and RT-PCR were used to assess expression of the major glycolytic enzymes glucosetransporter1 (GLUT1), pyruvate kinase M2(PKM2), and lactate dehydrogenase A (LDHA). Enzyme-linked immunosorbent assay (Elisa) was used to detect lactate content. Results and conclusion: There was a significant decrease in Lequesne MG score and improvement in Mankin score after EA intervention (P < 0.01), a significant increase in synovial microcirculation (P < 0.05) and synovial fluid oxygen tension (P < 0.01), and there was significant decrease in the expression of GLUT1, PKM2 and LDHA (P < 0.01) and lactate (P < 0.05). This study suggested that EA ameliorate cartilage hypoxia and regulate glycolytic metabolism in chondrocytes in KOA model rabbits by improving articular microcirculation and oxygen tension.