Cardamonin attenuates iron overload-induced osteoblast oxidative stress through the HIF-1α/ROS pathway.

BACKGROUND: Osteoporosis(OP) is a bone disease under research. Iron overload is a significant risk factor. Iron balance is crucial for bone metabolism and biochemical processes. When there is an excess of iron in the body, it tends to produce reactive oxygen species (ROS) which can cause oxidative damage to cells. The flavonoid compound, Cardamonin (CAR), possesses potent anti-inflammatory and anti-iron overload properties that can be beneficial in mitigating the risk of OP. PURPOSE: This study investigates the potential therapeutic interventions and underlying mechanisms of CAR for treating OP in individuals with iron overload. METHODS: The model of iron-overloaded mice was established by intraperitoneally injecting iron dextran(ID) into the mice. OP severity was evaluated with micro-CT and Hematoxylin-Eosin (HE) staining in vivo. In vitro, the iron-overloaded osteoblast model was induced by ferric ammonium citrate. Cell counting kit 8 assay to evaluate cell viability, Annexin V-FITC/PI assay to detect cell apoptosis. A range of cellular markers were detected, including the variation in mitochondrial membrane potential (MMP), levels of malondialdehyde (MDA), ROS, and lipid hydroperoxide (LPO). RESULTS: CAR can reverse bone loss in iron overload-induced OP mouse models in vivo. CAR attenuates the impairment of iron overload on the activity and apoptosis of MC3T3-E1 cells as well as the accumulation of ROS and LPO activation via HIF-1α/ROS pathways. CONCLUSION: CAR downregulating HIF-1α pathways prevents inhibition of iron overload-induced osteoblasts dysfunctional by attenuating ROS accumulation, reducing oxidative stress, promotes bone formation, and alleviates OP.

Naringin Affects Caspase-3, IL-1ß, and HIF-1α Levels in Experimental Kidney Ischemia-reperfusion in Rats.

BACKGROUND: Microvascular dysfunction develops in tissues after Ischemia-Reperfusion (I/R). The current study aimed to determine the effect of naringin supplementation on kidney caspase-3, IL-1ß, and HIF-1α levels and kidney histology in rats undergoing unilateral nephrectomy and kidney-ischemia reperfusion. METHODS: The study was conducted on 8-12 weeks old 40 Wistar-type male rats. Experimental renal ischemia- reperfusion and unilateral nephrectomy were performed under general anesthesia in rats. Experimental groups were formed as follows: 1-Control group, 2-Sham control + Vehicle group, 3- Renal ischemia-reperfusion (Renal I+R) + Vehicle group, 4-Renal I+R + Naringin (50 mg/kg/day) group (3 days application) group, 5-Renal I+R + Naringin (100 mg/kg/day) group (3 days supplementation). Nephrectomy in the left kidneys and the ischemia for 45 minutes and reperfusion in the right kidneys followed by 72 hours of reperfusion. Naringin was administered intraperitoneally at the beginning of the reperfusion, 24 hours and 48 hours later. At the end of the experiments, blood was first taken from the heart in animals under general anesthesia. Then, the animals were killed by cervical dislocation, and kidney tissue samples were taken. Tissues were evaluated for caspase-3, IL-1ß, and HIF-1α as well as histologically. RESULTS: As a result of ischemia in kidney tissues, HIF-1α decreased, while caspase-3 and IL-1ß increased. I/R also caused damage to the kidney tissue. However, naringin supplementation corrected the deterioration to a certain extent. CONCLUSION: The results of the study showed that naringin may have protective effects on kidney damage due to anti-inflammatory and antiapoptosis mechanisms caused by unilateral nephrectomy and I/R in rats.

The activation of the HIF-1α-VEGFA-Notch1 signaling pathway by Hydroxysafflor yellow A promotes angiogenesis and reduces myocardial ischemia-reperfusion injury.

Hydroxyl Safflower Yellow A (HSYA) is the primary bioactive compound derived from Safflower, which has been scientifically proven to possess anti-inflammatory, anti-apoptotic, and ameliorative properties against mitochondrial damage during acute myocardial ischemia-reperfusion injury (MIRI); however, its effects during the recovery stage remain unknown. Angiogenesis plays a crucial role in the rehabilitation process. AIM OF THE STUDY: The objective of this study was to investigate the long-term angiogenic effect of HSYA and its contribution to recovery after myocardial ischemia, as well as explore its underlying mechanism using non-targeted metabolomics and network pharmacology. MATERIALS AND METHODS: The MIRI model in rat was established by ligating the left anterior descending branch of the coronary artery. The effect of HSYA was assessed based on myocardial infarction volume and histopathology. Immunofluorescence staining was employed to evaluate angiogenesis, while ELISA was used to detect markers of myocardial injury. Additionally, a rat myocardial microvascular endothelial cell (CMECs) injury model was established using oxygen-glucose deprivation/reoxygenation (OGD/R), followed by scratch assays, migration assays, and tube formation experiments to assess angiogenesis. Western blot analysis was conducted to validate the underlying mechanism. RESULTS: Our findings provide compelling evidence for the therapeutic efficacy of HSYA in reducing myocardial infarction size, facilitating cardiac functional recovery, and reversing pathological alterations within the heart. Furthermore, we elucidate that HSYA exerts its effects on promoting migration and generation of myocardial microvascular endothelial cells through activation of the HIF-1α-VEGFA-Notch1 signaling pathway. CONCLUSION: These results underscore how HSYA enhances cardiac function via angiogenesis promotion and activation of the aforementioned signaling cascade.

TCEB2/HIF1A signaling axis promotes chemoresistance in ovarian cancer cells by enhancing glycolysis and angiogenesis.

Ovarian cancer is an extremely malignant gynaecological tumour with a poor patient prognosis and is often associated with chemoresistance. Thus, exploring new therapeutic approaches to improving tumour chemosensitivity is important. The expression of transcription elongation factor B polypeptide 2 (TCEB2) gene is reportedly upregulated in ovarian cancer tumour tissues with acquired resistance, but the specific mechanism involved in tumour resistance remains unclear. In this study, we found that TCEB2 was abnormally highly expressed in cisplatin-resistant tumour tissues and cells. TCEB2 silencing also inhibited the growth and glycolysis of SKOV-3/cisplatin (DDP) and A2780/DDP cells. We further incubated human umbilical vein endothelial cells (HUVECs) with culture supernatants from cisplatin-resistant cells having TCEB2 knockdown. Results revealed that the migration, invasion, and angiogenesis of HUVECs were significantly inhibited. Online bioinformatics analysis revealed that the hypoxia-inducible factor-1A (HIF-1A) protein may bind to TCEB2, and TCEB2 silencing inhibited SKOV-3/DDP cell growth and glycolysis by downregulating HIF1A expression. Similarly, TCEB2 promoted HUVEC migration, invasion, and angiogenesis by upregulating HIF1A expression. In vivo experiments showed that TCEB2 silencing enhanced the sensitivity of ovarian cancer nude mice to cisplatin and that TCEB2 knockdown inhibited the glycolysis and angiogenesis of tumour cells. Our findings can serve as a reference for treating chemoresistant ovarian cancer.

Parthenolide Inhibits Synthesis and Promotes Degradation of Programmed Cell Death Ligand 1 and Enhances T Cell Tumor-Killing Activity.

Parthenolide is a germacrane sesquiterpene lactone separated from the traditional medicinal plant feverfew. Previous studies have shown that parthenolide possesses many pharmacological activities, involving anti-inflammatory and anticancer activities. However, the antitumor mechanism of parthenolide has not been fully elucidated. Thus, we investigate the potential antitumor mechanisms of parthenolactone. We predicted through network pharmacology that parthenolide may target HIF-1α to interfere with the occurrence and development of cancer. We found that parthenolide inhibited PD-L1 protein synthesis through mTOR/p70S6K/4EBP1/eIF4E and RAS/RAF/MEK/MAPK signaling pathways and promoted PD-L1 protein degradation through the lysosomal pathway, thereby inhibiting PD-L1 expression. Immunoprecipitation and Western blotting results demonstrated that parthenolide inhibited PD-L1 expression by suppressing HIF-1α and RAS cooperatively. We further proved that parthenolide inhibited cell proliferation, migration, invasion, and tube formation via down-regulating PD-L1. Moreover, parthenolide increased the effect of T cells to kill tumor cells. In vivo xenograft assays further demonstrated that parthenolide suppressed the growth of tumor xenografts. Collectively, we report for the first time that parthenolide enhanced T cell tumor-killing activity and suppressed cell proliferation, migration, invasion, and tube formation by PD-L1. The current study provides new insight for the development of parthenolide as a novel anticancer drug targeting PD-L1.

Role of HIF-1α-Activated IL-22/IL-22R1/Bmi1 Signaling Modulates the Self-Renewal of Cardiac Stem Cells in Acute Myocardial Ischemia.

Impaired tissue regeneration negatively impacts on left ventricular (LV) function and remodeling after acute myocardial infarction (AMI). Little is known about the intrinsic regulatory machinery of ischemia-induced endogenous cardiac stem cells (eCSCs) self-renewing divisions after AMI. The interleukin 22 (IL-22)/IL-22 receptor 1 (IL-22R1) pathway has emerged as an important regulator of several cellular processes, including the self-renewal and proliferation of stem cells. However, whether the hypoxic environment could trigger the self-renewal of eCSCs via IL-22/IL-22R1 activation remains unknown. In this study, the upregulation of IL-22R1 occurred due to activation of hypoxia-inducible factor-1α (HIF-1α) under hypoxic and ischemic conditions. Systemic IL-22 administration not only attenuated cardiac remodeling, inflammatory responses, but also promoted eCSC-mediated cardiac repair after AMI. Unbiased RNA microarray analysis showed that the downstream mediator Bmi1 regulated the activation of CSCs. Therefore, the HIF-1α-induced IL-22/IL-22R1/Bmi1 cascade can modulate the proliferation and activation of eCSCs in vitro and in vivo. Collectively, investigating the HIF-1α-activated IL-22/IL-22R1/Bmi1 signaling pathway might offer a new therapeutic strategy for AMI via eCSC-induced cardiac repair.

Activation of the LKB1/AMPK/HIF-1α Pathway by Metformin to Promote Neovascularisation in Cerebral Ischaemia.

As a difficult-to-treat neurological condition, cerebral ischemia is currently limited to treatments such as intravenous recombinant tissue plasminogen activator thrombolysis and thrombectomy. Metformin, a potent antidiabetic drug, has been reported to have an independent function in enhancing the prognosis of stroke patients, in addition to its glucose-lowering effects. However, the mechanism of action of metformin in this context remains unclear. In vivo, a rat model of permanent middle cerebral artery occlusion was established, and after administration of a low dose of 10.5 mg/mL metformin, infarct area was measured by TTC staining, and cortical blood flow was determined by laser Doppler imaging. In vitro, the study established human umbilical vein endothelial cells treated with cobalt chloride. Immunofluorescence, immunohistochemistry, and Western blot experiments were performed to observe the expression of angiogenic factors, tight junction proteins, and apoptotic factors. A TUNEL assay was utilized to appraise cell death by apoptosis. A tube formation assay and scratch assay were conducted to determine the endothelial neovascularization status. Animal experiments have revealed that the administration of the AMPK activator metformin significantly reduced the infarct area, promoted the expression of angiogenic factors, and maintained the stability of tight junction proteins in endothelial cells. Moreover, metformin reduces nerve cells apoptosis by affecting the expression of the apoptotic protein cleaved-caspase3 via the HIF-1α pathway. In vitro, the LKB1/AMPK signaling pathway is activated after hypoxic stimulation, attaining its peak within the early stages of hypoxia (1-12 h) and gradually weakening thereafter. The administration of AMPK pharmacological agonists (between 36 and 48 h) can enhance AMPK activity, which can lead to the expression of angiogenic factors, maintain the stability of tight-junction proteins in endothelial cells, and facilitate endothelial cell migration and vascular structure formation. Conversely, the AMPK inhibitors exert the opposite effects. The activation of the LKB1/AMPK/HIF-1α signaling pathway by metformin in cerebral ischemia contributes to angiogenesis, promotes tissue repair in the injured area, and enhances neurologically functional symptoms.

Sodium butyrate blocks the growth of colorectal cancer by inhibiting the aerobic glycolysis mediated by SIRT4/HIF-1α.

The prevalence and mortality rates of colorectal cancer have been increasing in recent years, driven in part by the reliance of cancerous cells on aerobic glycolysis for growth. Sodium butyrate (NaB) has been shown to impede this process in colorectal cancer cells, although its mechanism of action remains unclear. In this study, we used cobalt chloride (CoCl2) to simulate a hypoxic environment and demonstrated that NaB downregulated hypoxia-inducible factor-1α (HIF-1α) protein levels under both normoxic and hypoxic conditions. By employing cycloheximide (CHX), MG132, and chloroquine (CQ), we investigated whether NaB affects HIF-1α protein levels via the autophagy pathway. Importantly, siRNA-mediated SIRT4 knockdown revealed that NaB promotes HIF-1α autophagic degradation by upregulating SIRT4 expression. This subsequently inhibits HIF-1α-mediated expression of GLUT1 and LDHA, reducing glucose uptake, lactate production, and ATP generation, ultimately suppressing aerobic glycolysis and cell proliferation in colorectal cancer cells. Furthermore, a human colorectal cancer xenograft model confirmed that butyric acid inhibited tumor growth in vivo, correlating with SIRT4 and HIF-1α modulation. In conclusion, our findings indicate that NaB hinders colorectal cancer progression by disrupting aerobic glycolysis mediated by SIRT4/HIF-1α.

KLF6 negatively regulates HIF-1α in extravillous trophoblasts under hypoxia.

INTRODUCTION: HIF-1α, the master regulator of hypoxia cellular response, is stabilized under low oxygen levels and degraded in the presence of oxygen but its transcription, translation, and degradation are tightly regulated by numerous pathways. KLF6 is a transcription factor involved in proliferation, differentiation, and apoptosis in several cell systems. Under hypoxia it is upregulated in a HIF-1α-dependent manner in extravillous trophoblasts. Considering the importance of hypoxia modulation of EVT behavior through HIF1-α we aimed to study whether KLF6 modulates HIF-1α expression in HTR8/SVneo cells. METHODS: HTR8/SVneo cells were cultured in a 1 % oxygen chamber or in 3D format where a spontaneous oxygen gradient is generated. qRT-PCR and Western blot were performed to analyze mRNA and protein expression, respectively. SiRNA, shRNA, or plasmids were used to down- or up-regulate gene expression. Wound healing assay was performed under hypoxia to evaluate migration. The NFκB pathway was modulated with dominant negative mutants and a chemical inhibitor. Cobalt chloride was used to block HIF-1α degradation. RESULTS: KLF6 up- and down-regulation in HTR8/SVneo cells exposed to acute hypoxia revealed a negative regulation on HIF-1α. KLF6 silencing led to a partially HIF-1α-dependent increase in MMP9 and VEGF. The NF-κB pathway and HIF-1α degradation were involved in KLF6-dependent HIF-1α regulation. HTR8/SVneo-3D culture showed that KLF6 negatively regulates HIF-1α in a microenvironment with naturally generated hypoxia. DISCUSSION: Present results reveal that KLF6 contributes to a fine tune modulation of HIF-1α level under hypoxia. Thus, sustaining a HIF-1α homeostatic level, KLF6 might contribute to control EVT adaptation to hypoxia.

Design, synthesis, and evaluation of antitumor activity in Pseudolaric acid B Azole derivatives: Novel and potent angiogenesis inhibitor via regulation of the PI3K/AKT and MAPK mediated HIF-1/VEGF signaling pathway.

Tumor proliferation and metastasis are intricately linked to blood vessel formation, with vascular endothelial growth factor (VEGF) playing a pivotal role in orchestrating angiogenesis throughout tumor progression. Pseudolaric acid B (PAB) has emerged as a potent inhibitor of tumor cell proliferation, migration, and angiogenesis. In efforts to enhance its efficacy, 37 derivatives of PAB were synthesized and assessed for their capacity to suppress VEGF secretion in SiHa cells under hypoxic conditions. Notably, majority of these derivatives exhibited significant inhibition of VEGF protein secretion without inducing cytotoxicity. Among them, compound M2 displayed the most potent inhibitory activity, with an IC50 value of 0.68 µM, outperforming the lead compound PAB (IC50 = 5.44 µM). Compound M2 not only curbed the migration and angiogenesis of HUVECs under hypoxic conditions but also hindered the invasion of SiHa cells. Mechanistic investigations unveiled that compound M2 may impede the accumulation and nuclear translocation of hypoxia-inducible factor 1α (HIF-1α) in SiHa cells, thereby downregulating VEGF expression. This inhibitory effect on HIF-1α was corroborated by experiments utilizing the protease inhibitor MG-132 and protein synthesis inhibitor CHX, indicating that compound M2 diminishes HIF-1α levels by reducing its synthesis. Furthermore, compound M2 was observed to modulate the PI3K/AKT/mTOR and MAPK signaling pathways in tumor cells, thereby regulating HIF-1α translation and synthesis. In vivo studies demonstrated that compound M2 exhibited low toxicity and effectively curbed tumor growth. Immunohistochemistry analyses validated that compound M2 effectively suppressed the expression of HIF-1α and VEGF in tumor tissues, underscoring its potential as a promising therapeutic agent for targeting tumor angiogenesis.

The novel HSP90 monoclonal antibody 9B8 ameliorates articular cartilage degeneration by inhibiting glycolysis via the HIF-1 signaling pathway.

Osteoarthritis (OA) is a prevalent chronic degenerative disease that affects the bones and joints, particularly in middle-aged and elderly individuals. It is characterized by progressive joint pain, swelling, stiffness, and deformity. Notably, treatment with a heat shock protein 90 (HSP90) inhibitor has significantly curtailed cartilage destruction in a rat model of OA. Although the monoclonal antibody 9B8 against HSP90 is recognized for its anti-tumor properties, its potential therapeutic impact on OA remains uncertain. This study investigated the effects of 9B8 on OA and its associated signaling pathways in interleukin-1ß (IL-1ß)-stimulated human chondrocytes and a rat anterior cruciate ligament transection (ACLT) model. A specific concentration of 9B8 preserved cell viability against IL-1ß-induced reduction. In vitro, 9B8 significantly reduced the expression of extracellular matrix-degrading enzyme such as disintegrin and metallopeptidase-4 (ADAMTS4) of thrombospondin motifs, matrix metalloproteinase-13 (MMP-13), as well as cellular inflammatory factors such as tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6), which were upregulated by IL-1ß. In vivo, 9B8 effectively protected the articular cartilage and subchondral bone of the rat tibial plateau from ACLT-induced damage. Additionally, gene microarray analysis revealed that IL-1ß substantially increased the expression of SLC2A1, PFKP, and ENO2 within the HIF-1 signaling pathway, whereas 9B8 suppressed the expression of these genes. Thus, 9B8 effectively mitigates ACLT-induced osteoarthritis in rats by modulating the HIF-1 signaling pathway, thereby inhibiting overexpression involved in glycolysis. These results collectively indicate that 9B8 is a promising novel drug for the prevention and treatment of OA.

Role of HIF1A gene polymorphisms with serum uric acid and HIF-1α levels in monosodium urate crystal-induced arthritis.

BACKGROUND: Gouty arthritis is a metabolic disease characterized by the deposition of monosodium urate crystals in the joints, which triggers the release of interleukin-1ß (IL-ß) by activating the NLRP3 inflammasome. Hypoxia-inducible factor-1α (HIF-1α) is a transcription factor involved in IL-ß production and as a regulator of NLRP3. OBJECTIVES: The aims were to analyze the association of HIF1A rs11549465, rs11549467, and rs2057482 variants in patients with gouty arthritis, and to evaluate the correlation between urate and HIF-1α levels according to the associated genotypes. METHODS: Cases and controls were genotyped using TaqMan probes, and urate and HIF-1α levels were quantified. Data were analyzed using SPSS v21 software and P-values < 0.05 were considered statistically significant. RESULTS: Urate and HIF-1α levels were higher in patients than in controls (P < 0.05). Under the three inheritance models (codominant, dominant, and recessive), the AA genotype of the rs11549467 variant was associated with gout risk (OR = 5.74, P = 0.009, OR = 3.33, P = 0.024, and OR = 9.09, P = 0.003, respectively). There were significant differences in the distribution of serum levels of both HIF-1α (P < 0.0001) and urate (P = 0.016) according to the genotypes of the rs11549467 variant. CONCLUSION: These results suggest that the HIF1A rs11549467 variant may play a key role in the pathogenesis of gouty arthritis. Key Points • The pathogenesis of gouty arthritis involves the HIF1A gene. • In patients with gout, the AA genotype of the rs11549467 (HIF1A) variant is associated with increased serum levels of urate and HIF-1α. • HIF-1α is involved in the regulation of IL-1ß and NLRP3.

SARS-CoV-2 NSP16 promotes IL-6 production by regulating the stabilization of HIF-1α.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the etiologic agent of coronavirus disease 2019 (COVID-19). Severe and fatal COVID-19 cases often display cytokine storm i.e. significant elevation of pro-inflammatory cytokines and acute respiratory distress syndrome (ARDS) with systemic hypoxia. Understanding the mechanisms of these pathogenic manifestations would be essential for the prevention and especially treatment of COVID-19 patients. Here, using a dual luciferase reporter assay for hypoxia-response element (HRE), we initially identified SARS-CoV-2 nonstructural protein 5 (NSP5), NSP16, and open reading frame 3a (ORF3a) to upregulate hypoxia-inducible factor-1α (HIF-1α) signaling. Further experiments showed NSP16 to have the most prominent effect on HIF-1α, thus contributing to the induction of COVID-19 associated pro-inflammatory response. We demonstrate that NSP16 interrupts von Hippel-Lindau (VHL) protein interaction with HIF-1α, thereby inhibiting ubiquitin-dependent degradation of HIF-1α and allowing it to bind HRE region in the IL-6 promoter region. Taken together, the findings imply that SARS-CoV-2 NSP16 induces HIF-1α expression, which in turn exacerbates the production of IL-6.

PPARγ Agonist Pioglitazone Prevents Hypoxia-induced Cardiac Dysfunction by Reprogramming Glucose Metabolism.

The heart relies on various defense mechanisms, including metabolic plasticity, to maintain its normal structure and function under high-altitude hypoxia. Pioglitazone, a peroxisome proliferator-activated receptor γ (PPARγ), sensitizes insulin, which in turn regulates blood glucose levels. However, its preventive effects against hypoxia-induced cardiac dysfunction at high altitudes have not been reported. In this study, pioglitazone effectively prevented cardiac dysfunction in hypoxic mice for 4 weeks, independent of its effects on insulin sensitivity. In vitro experiments demonstrated that pioglitazone enhanced the contractility of primary cardiomyocytes and reduced the risk of QT interval prolongation under hypoxic conditions. Additionally, pioglitazone promoted cardiac glucose metabolic reprogramming by increasing glycolytic capacity; enhancing glucose oxidation, electron transfer, and oxidative phosphorylation processes; and reducing mitochondrial reactive ROS production, which ultimately maintained mitochondrial membrane potential and ATP production in cardiomyocytes under hypoxic conditions. Notably, as a PPARγ agonist, pioglitazone promoted hypoxia-inducible factor 1α (HIF-1α) expression in hypoxic myocardium. Moreover, KC7F2, a HIF-1α inhibitor, disrupted the reprogramming of cardiac glucose metabolism and reduced cardiac function in pioglitazone-treated mice under hypoxic conditions. In conclusion, pioglitazone effectively prevented high-altitude hypoxia-induced cardiac dysfunction by reprogramming cardiac glucose metabolism.

Histone H3K9 Methylation Features under Hypoxic Conditions after the HIF1A Knockdown in Mesenchymal Stromal Cells In Vitro.

The effects of HIF1A knockdown by RNA interference on the histone H3K9 methylation in human umbilical cord mesenchymal stromal cells in vitro under conditions of 24-h exposure to hypoxia (1% O2) were studied. Evaluation of transcriptional activity of genes involved in the regulation of H3K9 methylation (KDM3A, KDM4A, and EHMT2) and the cytofluorimetric analysis of the expression of the corresponding antigens and H3K9 methylation level demonstrated a pronounced stimulating effect of hypoxic exposure. Moreover, the expression of KDM4A and EHMT2 was regulated by HIF1A-mediated mechanism, unlike KDM3A; the level of the corresponding proteins depended on HIF1A. In addition, the HIF-1-dependent regulation of KDM3A, KDM4A, and EHMT2/G9a, and directly the H3K9 methylation level in mesenchymal stromal cells also took place under normoxia conditions.

A drug delivery system of HIF-1α siRNA nanoparticles loaded by mesenchymal stem cells on choroidal neovascularization.

Aim: To assess mesenchymal stem cells (MSCs) as carriers for HIF-1α siRNA-loaded nanoparticles (NPs) for targeted therapy of experimental choroidal neovascularization (CNV).Materials & methods: A poly (lactic-co-glycolic acid) (PLGA)-core/lipid-shell hybrid NP was designed. The transfection efficacy of MSCs with the hybrid NPs was assessed. Mice were intravenously injected with MSCs after laser photocoagulation and CNV was assessed at 7 days post-injection.Results & conclusion: The transfection efficiency of hybrid NPs into MSCs was 72.7%. HIF-1α mRNA expression in 661w cells co-cultured with MSC-hybrid-siRNA NPs was significantly lower. Intravenous delivery of MSC-hybrid-siRNA NPs greatly reduced CNV area and length. Intravenous injection of MSC-hybrid-siRNA NPs achieved therapeutic efficacy in reducing CNV area. The MSC-mediated homing enabled targeted inhibition of ocular angiogenesis.

[Box: see text].

Evaluation of placental bed uterine in L-NAME-induced early-onset preeclampsia (EO-PE) like the rat model.

Objective: Preeclampsia (PE) is the leading cause of maternal death worldwide and is associated with long-term morbidity in both mothers and newborns. Animal modeling is considered a functional source for understanding PE pathogenesis, diagnostic standards, and therapeutic approaches. Materials and Methods: This study aimed to demonstrate and evaluate the use of N-nitro-L-arginine methyl ester (L-NAME) in a Wistar rat model under conditions similar to PE. A total of 12 rats were divided into 4 groups, each consisting of 3 members, including the pregnant control group and treatment groups administered low-dose (PE 25 mg/kg L-NAME/day), medium-dose (PE 50 mg/kg L-NAME/day), and high-dose L-NAME (PE 75 mg/kg L-NAME/day) L-NAME from gestational day 4 to 19. Measurements included blood pressure, creatinine, and proteinuria levels, placental histological changes, and placental tissue hypoxia-inducible factor 1-alpha, and plasma endothelial nitric oxide synthase levels. Results: The results showed that intervention with L-NAME at 75 mg/kg body weight/day (PE3) induced PE earlier than that with 50 mg/kg body weight/day L-NAME. Conclusion: The model conditions also support further research into PE pathogenesis.

N-palmitoyl-d-glucosamine limits mucosal damage and VEGF-mediated angiogenesis by PPARα-dependent suppression of pAkt/mTOR/HIF1α pathway and increase in PEA levels in AOM/DSS colorectal carcinoma in mice.

Chronic intestinal inflammation and neo-angiogenesis are interconnected in colorectal carcinoma (CRC) pathogenesis. Molecules reducing inflammation and angiogenesis hold promise for CRC prevention and treatment. N-Palmitoyl-d-glucosamine (PGA), a natural glycolipid analog with anti-inflammatory properties, has shown efficacy against acute colitis. Micronized PGA (mPGA) formulations exhibit superior anti-inflammatory activity. This study investigates the in vivo anti-angiogenic and protective effects of mPGA in a mouse model of colitis-associated CRC induced by azoxymethane/dextran sodium sulfate (AOM/DSS). CRC was induced in C57BL/6J mice using intraperitoneal azoxymethane followed by three cycles of 2.5% dextran sodium sulfate (DSS) in drinking water. Mice were treated with mPGA (30-150 mg/kg) with or without the PPARα inhibitor MK886 (10 mg/kg). At Day 70 post-azoxymethane injection, mice underwent anesthetized endoscopic colon evaluation. Post-mortem analysis of tumorigenesis and angiogenesis was performed using histological, immunohistochemical, and immunoblotting techniques. mPGA improved disease progression and survival rates in a dose- and PPARα-dependent manner in AOM/DSS-exposed mice. It reduced polyp formation, decreased pro-angiogenic CD31, pro-proliferative Ki67, and pro-inflammatory TLR4 expression levels, and inhibited VEGF and MMP-9 secretion by disrupting the pAkt/mTOR/HIF1α pathway. mPGA increased colon PEA levels, restoring anti-tumoral PPARα and wtp53 protein expression. Given its lack of toxicity, mPGA shows potential as a nutritional intervention to counteract inflammation-related angiogenesis in CRC.

Hypoxia-induced BNIP3 facilitates the progression and metastasis of uveal melanoma by driving metabolic reprogramming.

Uveal melanoma (UM) is an aggressive intraocular malignancy derived from melanocytes in the uvea tract of the eye. Up to 50% of patients with UM develop distant metastases which is usually fatal within one year; preventing metastases is therefore essential. Metabolic reprogramming plays a critical role in UM progression and metastasis. However, the metabolic phenotype of UM cells in the hypoxic tumor is not well understood. Here, we report that hypoxia-induced BNIP3 reprograms tumor cell metabolism, promoting their survival and metastasis. In response to hypoxia, BNIP3-mediated mitophagy alleviates mitochondrial dysfunction and enhances mitochondrial oxidative phosphorylation (OXPHOS) while simultaneously reducing mitochondrial reactive oxygen species (mtROS) production. This, in turn, impairs HIF1A/HIF-1α protein stability and inhibits glycolysis. Inhibition of mitophagy significantly suppresses BNIP3-induced UM progression and metastasis in vitro and in vivo. Collectively, these observations demonstrate a novel mechanism whereby BNIP3 promotes UM metabolic reprogramming and malignant progression by mediating hypoxia-induced mitophagy and suggest that BNIP3 could be an important therapeutic target to prevent metastasis in patients with UM.Abbreviations: AOD: average optical density; BNIP3: BCL2/adenovirus E1B interacting protein 3; CQ: chloroquine; CoCl2: cobalt chloride; GEPIA: Gene Expression Profiling Interactive Analysis; HIF1A: hypoxia inducible factor 1, alpha subunit; IHC: immunohistochemistry; mtROS: mitochondrial reactive oxygen species; NAC: N-acetylcysteine; OCR: oxygen consumption rate; OXPHOS: oxidative phosphorylation; ROS: reactive oxygen species; TCGA: The Cancer Genome Atlas; UM: uveal melanoma.

PHD2 shRNA-Modified Bone Marrow Mesenchymal Stem Cells Facilitate Periodontal Bone Repair in Response to Inflammatory Condition.

OBJECTIVE: To investigate whether bone marrow mesenchymal stem cells (BMMSCs) modulate periodontal bone repair through the hydroxylase domain-containing protein 2 (PHD2)/hypoxia- inducible factor-1 (HIF-1) signalling pathway in response to inflammatory conditions. METHODS: Osteogenic differentiation of PHD2 shRNA-modified BMMSCs and the possible mechanism were explored in an inflammatory microenvironment stimulated by porphyromonas gingivalis lipopolysaccharide (Pg-LPS) in vitro. The effect of PHD2 gene-modified BMMSCs on periodontal bone loss was evaluated with experimental periodontitis. RESULTS: Pg-LPS stimulation greatly impaired the osteogenic differentiation of BMMSCs, whereas the silence of PHD2 significantly enhanced the osteogenesis of BMMSCs. More importantly, increased level of vascular endothelial growth factor (VEGF) was detected under Pg-LPS stimulation, which was verified to be associated with the augmented osteogenesis. In experimental periodontitis, PHD2-modified BMMSCs transplantation elevated osteogenic parameters and the expression of VEGF in periodontal tissue. CONCLUSION: This study highlighted that PHD2 gene silencing could be a feasible approach to combat inflammatory bone loss by rescuing the dysfunction of seed cells.