HIF-1α Protein Expression Research Articles

Adamantaniline Derivatives Target ATP5B to Inhibit Translation of Hypoxia Inducible Factor-1α.

Hypoxia inducible factor-1α (HIF-1α) plays a critical role in cellular adaptation to hypoxia and it is a potential therapeutic target for anti-cancer drugs. Applying high-throughput screening, here it is found that HI-101, a small molecule containing an adamantaniline moiety, effectively reduces HIF-1α protein expression. With the compound as a hit, a probe (HI-102) is developed for target identification by affinity-based protein profiling. The catalytic β subunit of mitochondrial FO F1 -ATP synthase, ATP5B, is identified as the binding protein of HI-derivatives. Mechanistically, HI-101 promotes the binding of HIF-1α mRNA to ATP5B, thus inhibiting HIF-1α translation and the following transcriptional activity. Further modifications of HI-101 lead to HI-104, a compound with good pharmacokinetic properties, exhibiting antitumor activity in MHCC97-L mice xenograft model, and HI-105, the most potent compound with an IC50 of 26nm. The findings provide a new strategy for further developing HIF-1α inhibitors by translational inhibition through ATP5B.

No benefit of HIF prolyl hydroxylase inhibition for hypertensive renal damage in renovascular hypertensive rats.

Introduction: We previously reported that malignant hypertension is associated with impaired capillary density of target organs. Here, we tested the hypothesis that stabilization of hypoxia-inducible factor (HIF) in a modified "preconditioning" approach prevents the development of malignant hypertension. To stabilize HIF, we employed pharmacological inhibition of HIF prolyl hydroxylases (PHD), that profoundly affect HIF metabolism. Methods: Two-kidney, one-clip renovascular hypertension (2K1C) was induced in rats; controls were sham operated. 2K1C rats received either intermittent injections of the PHD inhibitor ICA (2-(1-chloro-4-hydroxyisoquinoline-3-carboxamido) acetate) or placebo. Thirty-five days after clipping, the frequency of malignant hypertension was assessed (based on weight loss and the occurrence of characteristic vascular lesions). In addition, kidney injury was compared between all ICA treated versus all placebo treated 2K1C, regardless of the occurrence of malignant hypertension. HIF stabilization was evaluated by immunohistochemistry, and HIF target gene expression by RT-PCR. Results: Blood pressure was elevated to the same degree in ICA- and placebo-treated 2K1C compared to control rats. ICA treatment did not affect the frequency of malignant hypertension or the extent of kidney tissue fibrosis, inflammation, or capillary density. There was a trend towards higher mortality and worse kidney function in ICA-treated 2K1C rats. ICA increased the number of HIF-1α-positive renal tubular cell nuclei and induced several HIF-1 target genes. In contrast, expression of HIF-2α protein as well as HIF-2 target genes were markedly enhanced by 2K1C hypertension, irrespective of ICA treatment. Discussion: We conclude that intermittent PHD inhibition did not ameliorate severe renovascular hypertension in rats. We speculate that the unexpected strong renal accumulation of HIF-2α in renovascular hypertension, which could not be further augmented by ICA, may contribute to the lack of a benefit from PHD inhibition.

The Effect of GLUT1 and HIF-1α Expressions on Glucose Uptake and Patient Survival in Non-Small-Cell Lung Carcinoma

Lung cancer is the second-most-common cancer while being the leading cause of cancer deaths worldwide. It has been found that glucose transporter 1 (GLUT1) and hypoxia-inducible factor 1α (HIF-1α) are overexpressed in various malignancies and that they correlate with the maximum standard uptake values (SUVmax) on 18F-fluorodeoxyglucose-positron emission tomography/computed tomography (18F-FDG PET/CT) and poor prognosis. In this study, we aim to evaluate the relationship between the SUVmax, GLUT1, and HIF-1α expression with primary tumor size, histological type, lymph node metastases, and patient survival. Of the 48 patients with non-small-cell lung cancer, those with squamous cell carcinomas (SCCs) had significantly higher GLUT1 and HIF-1α immunohistochemical expressions in comparison to adenocarcinomas (ACs), while there was no statistically significant difference in FDG accumulation between them. No significant correlation was noted between either GLUT1 or HIF-1α protein expression and FDG uptake and overall survival. However, an analysis of tumor transcriptomics showed a significant difference in overall survival depending on mRNA expression; patients with SCC and high HIF-1α levels survived longer compared to those with low HIF-1α levels, while patients with AC and low GLUT1 levels had a higher average survival time than those with high GLUT1 levels. Further studies are needed to determine the prognostic value of the expression of these factors depending on the histologic type.

11-OR: Fetal Renal Hypoxia Response to Maternal Overnutrition

Currently, 50% of women of reproductive age are obese, and one in seven live births is affected by hyperglycemia in mothers with gestational diabetes. To examine the impact of intrauterine overnutrition on the kidneys of the offspring, we generated a novel mouse model by feeding female C57BL6J mice with either control diet (CD) or high-fat diet (HFD, 60% Lipid) during gestation and feeding the male offspring with CD after weaning, allocated to two groups of male offspring, CD and HFD. CD and HFD had similar body weights, blood pressure and urinary albumin levels, but lower serum creatinine levels in HFD (CD; n=17, HFD; n=11, p<0.001), which might be due to renal hyperfiltration. Histologically, HFD presented renal tubular vacuolation at 4 weeks of age and glomerulosclerosis and intrarenal arteriosclerotic lesions at 15 weeks of age. Moreover, perirenal beige fat phenotype was lost in HFD at 4 week of age, presenting white adipose cells unlike the small adipose cells in CD, suggesting that maternal overnutrition induced systemic metabolic abnormality in offspring. Synchrotron phase-contrast micro-CT showed that HFD at 14.5 dpc showed asignificant increase in total kidney volume (CD; n=4, HFD; n=6, p<0.001). On the contrary, no significant difference in renal artery diameter was observed (p=0.52). Blood flow is determined by the supplying vascular diameter due to Murrays’ minimum energy hypothesis. Therefore, we studied the ratio of blood flow as the 3rd power of the diameter of fetal renal artery per renal volume, indicating no significant difference between CD and HFD (p=0.42). Despite of preserved blood supply, the protein expression of HIF-1α, the key hypoxic transcription factor, was higher in HFD than that in CD, suggesting increased oxygen demand due to maternal overnutrition-induced renal metabolism. Maternal overnutrition induces supply-demand mismatch leading to renal hypoxia in the fetus, which persists into adulthood in the offspring, which might promote susceptibility to diabetic nephropathy. Disclosure T.Takiyama: None. Y.Takiyama: None. R.Bessho: None. H.Kitsunai: None. Y.Takiyama: Research Support; Boehringer Ingelheim Japan, Inc., Taisho Pharmaceutical Holdings Co., Ltd., Ono Pharmaceutical Co., Ltd., Abbott Japan Co., Ltd., Roche Diabetes Care, MSD Life Science Foundation, Japan Society for the Promotion of Science, Teijin Pharma Limited, Kyowa Kirin Co., Ltd., Sumitomo Dainippon Pharma Co., Ltd., Eli Lilly Japan K.K.

The association of hypoxia-inducible factor-1α and hypoxia-inducible factor-2α protein expression with clinicopathological characteristics in papillary thyroid carcinoma: A meta-analysis.

To investigate the correlation of hypoxia-inducible factor-1α (HIF-1α) and hypoxia-inducible factor-2α (HIF-2α) protein expression with clinicopathologic characteristics in patients with papillary thyroid carcinoma (PTC) through a meta-analysis. PubMed, Embase, Web of Science, Cochrane, CNKI, Wanfang, and VIP databases were searched from the establishment of the database to February 2023. The New castle-Ottawa Scale was used to evaluate the quality of the literature. Rev Man 5.3 and Stata14.0 were used to conduct a meta-analysis of the included studies. Twenty-eight articles with 2346 samples were included in the Meta-analysis. Compared with normal thyroid tissues, HIF-1α and HIF-2α proteins were highly expressed in PTC tumor tissues. High expression of HIF-1α protein was associated with tumor size (odds ratio [OR] = 4.50, 95% confidence interval [CI]: 2.88-7.04, P < .00001), lymph node metastasis (OR = 4.76, 95% CI: 3.78-5.99, P < .00001), TNM stage (OR = 3.67, 95% CI: 2.68-5.03, P < .00001), capsular invasion (OR = 2.30, 95% CI: 1.43-3.71, P = .0006 < .05), and extrathyroidal extension (OR = 10.96, 95% CI: 4.80-25.02, P < .00001). High expression of HIF-2α protein was associated with lymph node metastasis (OR = 4.18, 95% CI: 2.63-6.65, P < .00001), TNM stage (OR = 2.56, 95% CI: 1.36-4.82, P = .004 < .05), and capsular invasion (OR = 3.84, 95% CI: 1.66-8.88, P = .002 < .05). In addition, we concluded for the first time that there was a statistically significant difference in the expression of HIF-1α and HIF-2α in PTC patients (OR = 2.36, 95% CI: 1.26-4.42, P = .007 < .05). The high expression of HIF-1α and HIF-2α proteins is closely related to some clinicopathological parameters of PTC, and can provide potential biological indicators for the diagnosis and prognosis of PTC.

Berberine inhibits breast carcinoma proliferation and metastasis under hypoxic microenvironment involving gut microbiota and endogenous metabolites

A potential role of berberine, a benzyl isoquinoline alkaloid, in cancer therapy is apparent. Its underlying mechanisms of berberine against breast carcinoma under hypoxia have not been elucidated. We focused on the doubt how berberine restrains breast carcinoma under hypoxia in vitro and in vivo. A molecular analysis of the microbiome via 16 S rDNA gene sequencing of DNA from mouse faeces confirmed that the abundances and diversity of gut microbiota were significantly altered in 4T1/Luc mice with higher survival rate following berberine treatment. A metabolome analysis liquid chromatography-mass spectrometer/mass spectrometer (LC-MS/MS) revealed that berberine regulated various endogenous metabolites, especially L-palmitoylcarnitine. Furthermore, the cytotoxicity of berberine was investigated in MDA-MB-231, MCF-7, and 4T1 cells. In vitro to simulate under hypoxic environment, MTT assay showed that berberine inhibited the proliferation of MDA-MB-231, MCF-7, and 4T1 cells with IC50 values of 4.14 ± 0.35 μM, 26.53 ± 3.12 μM and 11.62 ± 1.44 μM, respectively. Wound healing and trans-well invasion studies revealed that berberine inhibited the invasion and migration of breast cancer cells. RT-qPCR analysis shed light that berberine reduced the expression of hypoxia-inducible factor-1α (HIF-1α) gene. Immunofluorescence and western blot demonstrated that berberine decreased the expression of E-cadherin and HIF-1α protein. Taken together, these results provide evidence that berberine efficiently suppresses breast carcinoma growth and metastasis in a hypoxic microenvironment, highlighting the potential of berberine as a promising anti-neoplastic agent to combat breast carcinoma.

Hypoxia activates autophagy by Akt/FoxO1 pathway in fish cells

Hypoxia, a common environmental condition, can affect cell survival and physiological function by triggering oxidative stress. Akt/FoxO pathway has been proven to play a non-negligible role in the regulation of autophagy. However, the role of Akt/FoxO pathway in hypoxia-induced autophagy is unclear in fish. Therefore, in this study, grass carp hepatocyte cells (L8824) were treated by CoCl2 to simulate hypoxia, and the results showed that CoCl2 can increase the expression of Hif-1α protein at different concentrations or different treatment time. Further study found that hypoxia increased intracellular reactive oxygen species (ROS) level, and the expression of autophagy-related genes (LC3-II, pink1, beclin-1 and p62) and foxO1a/1b. The mitochondrial membrane potential (Δψm) was also depolarized, and autophagosomes were intriguingly detected by transmission electron microscope (TEM) after the treatment of hypoxia. Moreover, hypoxia inhibited Akt phosphorylation, while PI3K/Akt pathway inhibitor, LY294002 significantly up-regulated the expression of foxO1a/1b and autophagy-related genes. Additionally, silencing foxo1b also resulted in down-regulation of autophagy-related genes. It was demonstrated that hypoxia induced autophagy via Akt/FoxO1 pathway. These results will provide a new light on further understanding the role of Akt/FoxO pathway in the response to hypoxia in fish.

Protective effect of dihydromyricetin against lipopolysaccharide-induced HK2 cells by upregulating HIF-1α

ABSTRACT Sepsis complicated by acute kidney injury (AKI) carries an extremely high mortality rate. The present study aimed to investigate the protective effect and underlying mechanism of dihydromyricetin (DHM) on human renal tubular epithelial cells (HK2) during AKI. To simulate an in vitro model of AKI, HK2 cells were treated with lipopolysaccharide (LPS) and divided into four groups: Control, LPS, LPS+DHM, and LPS+DHM+si-HIF-1α. The cellular viability of HK2 cells was determined by the CCK-8 assay after treatment with LPS and DHM (60 μmol/L). The expression of Bcl-2, Bax, Cleaved Caspase-3, and HIF-1α was measured by Western blotting. The expression of Bcl-2, Bax, and HIF-1α mRNA was assessed by PCR. The apoptosis rate of each group was determined by flow cytometry, while different kits were used to measure the levels of MDA, SOD, and LDH in each group of HK2 cells. DHM was found to increase the expression of HIF-1α in HK2 cells after treatment with LPS. the expression of HIF-1α mRNA and protein, Cleaved Caspase-3, Bax protein, MDA and LDH levels, and apoptosis rate were significantly decreased, while Bcl-2 protein, cell viability, and SOD activity were markedly increased in the LPS+DHM group compared with the LPS and LPS+DHM+si-HIF-1α groups. Thus, DHM can reduce apoptosis and oxidative stress damage in HK2 cells by increasing HIF-1α expression after LPS treatment. DHM may be a treatment for AKI, but in vitro studies must be validated in animal models and clinical trials before drawing conclusions. Caution must be exercised in interpreting in vitro results.

Prolonged stretching of rat uteri causes hypoxia and inhibits contractility via potassium channel TREK1.

During pregnancy, uterine kept quiescence along with uterine overdistention before labor. Prolonged stretching induced uterus myometrial hypoxia, increased TREK1 expression, and relaxed the myometrium, which may contribute to uterine quiescence and atony during pregnancy. The mechanisms underlying pre-labor uterine quiescence and uterine atony during overdistention are unclear. TREK1 (a two-pore domain potassium channel) and hypoxia-inducible factor-1α (HIF-1α) are activated by mechanical stretch, and their expression is upregulated by decreased uterine contractility. HIF-1α is a nuclear factor which regulates numerous target proteins, but whether it regulates TREK1 during the uterine stretch to cause uterine quiescence and/or atony is unclear. We investigated uterine contractility at different gestational stages in rats, as well as in non-pregnant uteri, which were induced by prolonged stretching and hypoxia. We also assessed the effects of incubating the uteri with or without echinomycin or l-methionine. Moreover, we analyzed HIF-1α and TREK1 expression levels in each group, as well as at various gestational stages of pregnant human uteri. We found that contractility was significantly decreased in pregnant uteri when compared with non-pregnant uteri, and this decrease was associated with increases in HIF-1α and TREK1 expression levels. HIF-1α and TREK1 expression levels in human uteri increased with the gestational length. Decreased uterine contractility and increased HIF-1α and TREK1 expression levels were also observed in non-pregnant rat uteri under 8 g of stretching tension or hypoxia. Inhibition of hypoxia with echinomycin restored normal uterine contractility, while HIF-1α and TREK1 protein expression remained reduced. TREK1 inhibition with l-methionine also restored uterine contractility under tension or hypoxia. In conclusion, we demonstrated that prolonged stretching induces myometrial hypoxia, increases TREK1 expression, and relaxes the myometrium, which may contribute to uterine quiescence and atony.

Association between HIF-1α, BNIP3, and autophagy in the chorionic villi of missed abortion.

To investigate the expression of autophagy mediated by the hypoxia-inducible factor 1α (HIF-1α)/BNIP3 signaling pathway in villus tissues of missed abortion and HTR-8/SVneo cells and to elucidate the association of HIF-1α and BNIP3 in autophagy of missed abortion. Villus tissues from 30 healthy women with induced abortion and 35 patients with missed abortion were collected, and HTR-8/SVneo cells were cultured under hypoxia and transfected with HIF-1α-siRNA. Real-time polymerase chain reaction was utilized to measure the mRNA levels of HIF-1α and BNIP3; Western blotting was performed to determine the protein levels of HIF-1α, BNIP3, LC3 II/I, and Beclin 1 in villus tissues and HTR-8/SVneo cells. Cellular invasion activity was detected by transwell matrigel assay. The level of autophagy was confirmed by transmission electron microscopy of autophagosome formation. The mRNA levels of HIF-1α and BNIP3 were significantly lower in the missed abortion villi than in the induced abortion samples. The protein levels of HIF-1α, BNIP3, Beclin 1, and LC3II/I were significantly decreased in villus tissues from missed abortion, and autophagosomes were significantly decreased in villus tissues from missed abortion. Under hypoxia, the mRNA expression of HIF-1α and BNIP3 was inhibited after silencing HIF-1α by RNAi, while the protein expression of HIF-1α, BNIP3, Beclin1, and LC3II/I was significantly downregulated. The number of invading cells was significantly decreased, and autophagosomes were significantly decreased after silencing HIF-1α by RNAi in HTR-8/SVneo cells. Autophagy mediated by the HIF-1α/BNIP3 signaling pathway in villous trophoblast cells may be associated with the progression and development of missed abortion.

Protective effect of Nardostachys jatamansi extract against lithium-pilocarpine-induced spontaneous recurrent seizures and associated cardiac irregularities in a rat model.

Nardostachys jatamansi (D.Don) DC. is a perennial herbaceous medicinal plant widely used for the ethnomedical treatment of various ailments. The underground parts of the plants are used in traditional medicine to manage epilepsy and other cardiovascular conditions. The present study was undertaken to investigate the efficacy of a characterized hydroalcoholic extract (NJET) of Nardostachys jatamansi in the lithium-pilocarpine rat model of spontaneous recurrent seizures (SRS) and associated cardiac irregularities. NJET was prepared by percolation using 80% ethanol. The dried NEJT was subjected to UHPLC-qTOF-MS/MS for chemical characterization. Molecular docking studies were performed using the characterized compounds to understand mTOR interactions. The animals showing SRS following lithium-pilocarpine administration were treated with NJET for 6 weeks. Afterward, seizure severity, cardiac parameters, serum biochemistry, and histopathological parameters were studied. The cardiac tissue was processed for specific protein and gene expression studies. The UHPLC-qTOF-MS/MS characterized 13 compounds in NJET. The identified compounds subjected to molecular docking showed promising binding affinities toward mTOR. There was a dose-dependent decrease in the severity of SRS following the extract administration. A reduction in mean arterial pressure and serum biochemical markers (lactate dehydrogenase and creatine kinase) was also observed following NJET treatment in epileptic animals. Histopathological investigations revealed reduced degenerative changes and decreased fibrosis following the extract treatment. The cardiac mRNA level of Mtor, Rps6, Hif1a, and Tgfb3 was reduced in the extract-treated groups. Further, a similar reduction in the protein expression of p-mTOR and HIF-1α was also observed following NJET treatment in the cardiac tissue. The results concluded that NJET treatment reduces lithium-pilocarpine-induced recurrent seizures and associated cardiac irregularities via downregulation of the mTOR signalling pathway.

Hypoxia-induced UBE2K promotes the malignant progression of HCC.

Hypoxia critically drives malignant tumor development and is characteristic of hepatocellular carcinoma (HCC), where HIF-1α plays a crucial role. The ubiquitin-conjugating enzyme E2K (UBE2K) is known to participate in the advancement of several human cancers. However, the role of UBE2K in HCC or whether it is a hypoxia-responsive gene remains to be further identified. We performed a microarray to measure the gene expression differences between normoxia and hypoxia. CoCl2 mimicked the hypoxic condition. The protein and RNA expression of HIF-1α, UBE2K, and Actin in HCC cells were measured by western blotting(WB) and RT-qPCR, respectively. Immunohistochemical (IHC) staining analyzed the expression of UBE2K and HIF-1α in HCC tissues. CCK-8 and colony formation assay evaluated the HCC cell growth. Scratch healing and transwell assays were used to detect the migration capability of the cells. Lipofectamine 3000 was used to transfect the plasmids or siRNAs to HCC cells. We identified UBE2K as a potential hypoxia-responsive gene. Our study showed that hypoxia induced HIF-1α-mediated increase of UBE2K levels in HCC cells, which decreased under HIF-1α deficiency under hypoxia. Further bioinformatics analysis based on UALCAN and GEPIA databases confirmed that UBE2K was highly expressed in HCC tissues and positively associated with HIF-1α expression. Functionally, Hep3B and Huh7 cell proliferation and migration were stimulated upon UBE2K overexpression, while the UBE2K knockdown suppressed such effect. Furthermore, functional rescue experiment proved that depletion of UBE2K inhibited hypoxia-induced cell proliferation and migration in HCC cells. In contrast, enhancing UBE2K levels rescued cell proliferation and migration repression caused by HIF-1α deficiency in hypoxia. Our results established UBE2K as a potential hypoxia-inducible gene in HCC cells, positively regulated by HIF-1α in hypoxia. Moreover, UBE2K served as an oncogene and cooperated with HIF-1α to form a functional HIF-1α/UBE2K axis to trigger HCC progression, highlighting a potential application of UBE2K as a therapeutic target for HCC treatment.

Expression, Prognostic Value and Correlation with HPV Status of Hypoxia-Induced Markers in Sinonasal Squamous Cell Carcinoma.

(1) Background: In head and neck squamous cell carcinoma, tumor hypoxia has been associated with radio/chemoresistance and poor prognosis, whereas human papillomavirus (HPV)-positive status has a positive impact on treatment response and survival outcomes. The aim of this study was to evaluate the expression and the potential prognostic value of hypoxia-induced endogenous markers in patients treated for squamous cell carcinoma of the nasal cavity and paranasal sinuses (SNSCC), and their correlation with HPV status. (2) Methods: In this monocentric study, patients treated in a curative intent for a SNSCC were screened retrospectively. Protein expression of CA-IX, GLUT-1, VEGF, VEGF-R1, and HIF-1α was determined by immunohistochemical staining, scored, and then correlated with overall survival (OS) and locoregional recurrence free survival (LRRFS). HPV status was assessed and correlated with hypoxic markers. (3) Results: 40 patients were included. A strong expression of CA-IX, GLUT-1, VEGF, and VEGF-R1 was detected in 30%, 32.5%, 50%, and 37.5% of cases, respectively. HIF-1α was detected in 27.5% of cases. High CA-IX expression was associated in univariate analysis with poor OS (p = 0.035), but there was no significant association between GLUT-1, VEGF, VEGF-R1, and HIF-1α expression, and OS/LRRFS. There was no correlation found between HPV status and hypoxia-induced endogenous markers (all p > 0.05). (4) Conclusions: This study provides data on the expression of hypoxia-induced endogenous markers in patients treated for SNSCC and underlines the potential role of CA-IX as a prognostic biomarker for SNSCC.

Efficacy of puerarin in rats with focal cerebral ischemia through modulation of the SIRT1/HIF-1α/VEGF signaling pathway and its effect on synaptic plasticity

This study aimed to evaluate the efficacy of puerarin and its effect on synaptic plasticity in rats with focal cerebral ischemia (FCI) by modulating the silent mating type information regulation 2 homolog (SIRT1)/hypoxia-inducible factor-1α (HIF-1α)/vascular endothelial growth factor (VEGF) signaling pathway. Fifty specific pathogen-free-grade healthy male rats were randomly divided into sham operation group (SOG), model group, low-dose group, medium-dose group, and high-dose group, with 10 rats in each group. The SOG group received sham operation and saline treatment, while the other four groups received the same amount of saline, 25 mg/kg, 50 mg/kg, and 100 mg/kg of puerarin injection, respectively. After modeling, the rats exhibited higher neurological deficit, inflammation, cerebral infarction rate, and lower forelimb motor function as well as lower protein expressions of SIRT1, HIF-1α, VEGF, synaptophysin (SYN), and postsynaptic density protein (PSD)-95. With the treatment of different doses of puerarin, the degree of neurological impairment, impaired motor function, cerebral infarction rate, and the levels of inflammatory factors (interleukin [IL]-1β, IL-6, and intercellular adhesion molecule 1) in brain tissues were reduced; the protein expressions of SIRT1, HIF-1α, VEGF, SYN, and PSD-95 in brain tissues were enhanced, and the synaptic volume density, numerical density, surface density, width of synaptic cleft, and curvature of the synaptic interface in the cerebral cortex were also improved. Notably, the effects of puerarin on the above-mentioned indicators were dose-dependent. Puerarin can improve neurological impairment and forelimb motor function, reduce inflammatory response, inhibit brain edema, regulate synaptic plasticity, and restore the curvature of synaptic interface in rats with FCI, and its mechanism of action may be related to the activation of SIRT1/HIF-1α/VEGF signaling pathway.

Effect of moxibustion on the expressions of hypoxia inducible factor-1α and vascular endothelial growth factor in ankle synovial tissue of rats with adjuvant arthritis

To observe the effect of moxibustion on the expressions of hypoxia inducible factor-1α (HIF-1α) and vascular endothelial growth factor (VEGF) in ankle synovial tissue of rats with adjuvant arthritis(AA), so as to explore the mechanism of moxibustion in inhibiting synovial angiogenesis and improving joint symptoms of rheumatoid arthritis. Sixty healthy male SD rats were randomly divided into normal group, model group, moxibustion group and medication group, with 15 rats in each group. AA rat model was established by subcutaneous injection of Freund's complete adjuvant into the right hind paw. Rats in the moxibustion group were treated with "Zusanli" (ST36), "Guanyuan" (CV4) and "Ashi" point moxibustion, 20 min each time, once a day, for consecutive 3 weeks. Rats in the medication group were given methotrexate (0.35 mg/kg) intragastric administration, twice a week, for consecutive 3 weeks. Foot plantar volume of rats was measured by toe volume mea-suring instrument. HE staining was used to observe the histopathology of ankle synovium. The protein expressions of HIF-1α and VEGF in ankle synovial tissue were detected by immunohistochemistry and Western blot. Compared with the normal group, the foot plantar volume and the protein expressions of HIF-1α and VEGF in synovial tissue of ankle joint were significantly increased (P<0.01) in the model group, the synovial tissue showed obvious hyperplasia and a large number of neovasculogenesis. Following the interventions, the foot plantar volume and the protein expressions of HIF-1α and VEGF in synovial tissue of ankle joint were significantly decreased (P<0.05, P<0.01) in both moxibustion and medication groups in contrast to the model group, and there was no obvious proliferation of synovial tissue, and only a few neovascularization was observed. Compared with the medication group, the foot plantar volume was decreased (P<0.05) in the moxibustion group. Moxibustion can improve joint swelling and inhibit synovial angiogenesis in AA rats, and its mechanism may be related to down-regulating of HIF-1α and VEGF protein expressions.

Synergistic actions of Alpelisib and Melatonin in breast cancer cell lines with PIK3CA gene mutation

AimsBreast cancer (BC) presents high mortality rate and about 25–46 % have mutation in the PIK3CA gene. Alpelisib is a PI3K inhibitor that acts on p110α, which is a subunit of the PI3K protein. The melatonin shown important anti-neoplastic effects and may increase the effectiveness of chemotherapy. This study evaluated the synergistic action of Alpelisib and Melatonin in BC lines carrying the H1047R mutation in PIK3CA, relative to the cellular dynamics and the PI3K/AKT/mTOR pathway. Main methodsMDA-MB-468 (triple-ernegative), MDA-MB-453 (H1047R PIK3CA, HER2+) and T-47D cells (H1047R PIK3CA, ER+/PR+) were divided into four treatment groups: control; Melatonin (1 mM); Alpelisib (1 μM); and Alpelisib (1 μM) + Melatonin (1 mM). Cell viability and migration were investigated using the MTT assay and Transwell assay, respectively. Protein expression of PI3K, p-AKT, mTOR, HIF-1α, and caspase-3, was verified using immunocytochemistry. Key findingsMTT assay revealed that MDA-MB-453 and T-47D showed reduction in cell viability in all groups, especially in the MDA-MB-453 treated with Melatonin + Alpelisib. MDA-MB-468 presents reduction in cell migration only with Melatonin, while in the lines with mutation, the treatment of Melatonin + Alpelisib caused inhibition of cell migration. PI3K, p-AKT, mTOR and HIF-1α were inhibited after treatment with Melatonin + Alpelisib in MDA-MB-453 and T-47D lines. The expression of caspase-3 increased in all groups in MDA-MB-453 and T-47D cells, being the increase more pronounced in the Melatonin + Alpelisib group. SignificanceThese results indicate that the combined use of Melatonin and Alpelisib may be more effective in inhibiting BC in women carrying the PIK3CA gene mutation than either treatment alone.

FTY-720 alleviates diabetes-induced liver injury by inhibiting oxidative stress and inflammation.

We aimed to investigate the protective effect of FTY-720 on liver injury and explore its potential mechanism in diabetic mice. The diabetic mouse model was induced with streptozotocin and FTY-720 was administered for 12 weeks. We assayed biocharacters and liver function, and used histopathology staining to evaluate the protective effects of FTY-720 against diabetic liver injury. Levels of oxidative stress and inflammation in the liver were observed. mRNA and protein levels of essential enzymes for glucose metabolism were quantified in the liver and the protein expression of TLR4, HIF1α, and NF-κB was determined. In vivo results revealed that FTY-720 significantly lowered blood glucose and lipids, and improved liver function and alleviated liver fibrosis in diabetic mice. FTY-720 reduced oxidative stress and inflammation, with the increased catalase activity and reduced levels of malondialdehyde, myeloperoxidase, IL-1β, IL-6, TNF-α, TGF-β and MCP1. Furthermore, FTY-720 modulated glucose metabolism in liver and elevated the ATP production, showing the promotion of glycogenesis and glycolysis and inhibition of gluconeogenesis. Moreover, FTY-720 inhibited the expression of TLR4 and HIF1α, contributing to restoration of liver function. In conclusion, FTY-720 ameliorates diabetes-induced liver injury and improves glucose homeostasis by inhibiting oxidative stress and inflammation, and may be a promise drug for treatment of liver disease.

Autologous blood transfusion promotes autophagy and inhibits hepatocellular carcinoma progression through HIF-1α signalling pathway.

To explore the molecular mechanism of autologous blood transfusion promoting autophagy of hepatocellular carcinoma (HCC) cells and inhibiting the HCC progression through HIF-1α signalling pathway. This is a research paper. Rat hepatocellular carcinoma model and HepG2 cell model were built. The rats with HCC were conducted a surgery, and their blood was collected for detection to detect the recurrence and metastasis of the rats. Western blot was used to analysed the expression of HIF-1α, TP53, MDM2, ATG5 and ATG14 protein. The apoptosis rate of HepG2 cells was detected by flow cytometry, and autophagosomes were observed by transmission electron microscopy. HIF-1α expression was measured by immunofluorescence assay. The expressions of HIF-1α, TP53, MDM2, ATG5 and ATG14 protein were highest in model + autoblood group compared with the model group. HIF-1α content of model group was higher, but content of TP53, MDM2, ATG5 and ATG14 in the model group is the second. The highest apoptosis rate was found in HepG2 + autoblood group. The number of autophagosomes in HepG2 + autoblood was obviously larger than that of HepG2 + autoblood + inhibitor. HIF-1α expression of immunofluorescence assay showed that high expression of HIF-1α was clearly observed in HepG2 and HepG2 + autoblood group from confocal observation. However, there was no HIF-1α protein expression in HepG2 + autoblood + inhibitor group. The migration rate in HepG2 group, HepG2 + autoblood group and HepG2 + autoblood + inhibitor group was 85.71 ± 7.38%, 14.36 ± 6.54% and 61.25 ± 5.39%, respectively. Autologous blood transfusion promotes autophagy of HCC cells through HIF-1α signalling pathway, which further inhibits HCC migration and erosion.

Abstract 4808: Hypoxic HIF-1α stabilization dependent on β3-adrenoceptor localization in Ewing sarcoma

Abstract Hypoxia is a condition of oxygen deficiency which occurs in most growing solid tumors and stimulates a cascade of cell signals through a family of transcription factors named as hypoxia inducible factors (HIFs) that transactivate several regulatory genes involved in tumor proliferation. β3-adrenoceptors (β3-ARs) are involved in several hypoxic scenarios and in pathological conditions where hypoxia leads to important steps for cancer progression. Studies showed that β-AR blockade of mice suppressed hypoxia induction of renal HIF-1α accumulation, erythropoietin production, and erythropoiesis in vivo. In this work we assumed that β3-AR mediates hypoxia sensing and that it was necessary for HIF-1α stabilization thus we investigated a putative correlation between β3-AR/HIF-1α. Data showed a similar outcome of β3-ARs and HIF-1α at short time of hypoxia, and that β3-AR antagonist, SR59230A reduced HIF-1α protein expression under hypoxia. β3-AR silencing under hypoxia revealed an evident reduction of HIF-1α protein expression that confirmed the β3-AR modulation of HIF-1α expression. SR59230A treatment strongly reduced the HIF-1α target genes as GLUT1, HK-2 and HIF-1α expression at long time treatment confirming the β3-AR modulation of HIF-1α transcriptional activity. Conversely, the HIF-1α-transcriptional inhibitor Topotecan did not affect β3-AR expression confirming that is β3-AR that mediates HIF-1α activation. Immunofluorescence analysis showed that β3-AR co-localized with the nucleus under hypoxia more than normoxia. These results were confirmed by nuclear-cytoplasmic fragmentation that showed the presence of both β3-AR and HIF-1α proteins in the nucleus under hypoxia. Co-immunoprecipitation of β3-AR/HIF-1α revealed that under hypoxia, HIF-1α dissociates from β3-AR binding, but this process was abrogated by SR59230A. HIF-1α, released under hypoxia from the link with β3-AR, can play its transcriptional activity in the nucleus, while the binding with β3-AR blocks its transcriptional activity. Moreover, β3-AR regulation on HIF-1α was exerted through PHD2 activity at short time as SR59230A treatment under hypoxia increased the PHD2 protein expression but not at long time treatment, thus showing a different regulation of HIF-1α at different time points. In conclusion, the β3-AR upstream of the signaling β3-AR/HIF-1α axis exerts its role by PHD2 activity. Citation Format: Amada Pasha, Claudia Masi, Francesco Carrozzo, Martina Rosati, Alessia Boaretto, Alessandro Pini, Claudio Favre, Maura Calvani. Hypoxic HIF-1α stabilization dependent on β3-adrenoceptor localization in Ewing sarcoma. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4808.

Abstract 5087: Combination therapy of immune checkpoint inhibitor and HIF1α/c-MET peptide vaccine suppresses metastasis by modulating tumor microenvironment in triple-negative breast cancer

Abstract Triple-negative breast cancer (TNBC) accounts for 20% of all breast cancer and has limited therapeutic option except for immunotherapy because ER, PR, and HER2 targeted for treatment are absent. It also tends to be more aggressive meaning more likely to metastasize faster to other organs such as lungs, liver, and bone, and its recurrence rate is high which leads to a poor prognosis. Immunotherapy is an option to treat TNBC such as programmed death ligand 1 (PD-L1) antibody. However, tumor cells use various immune evasion mechanisms in addition to PD-1/PD-L1 pathway to interrupt the effect of immunotherapy. Moreover, tumor microenvironment (TME) is one of the important factors for the effective anti-tumor immune responses from immunotherapy. Hypoxia is a typical event in TNBC. Hypoxia inducible factor 1-alpha (HIF1α) is a transcription factor that regulates angiogenesis by expressing VEGF, and in addition, upregulates the c-MET which increases the proliferation, migration, and survival of tumor cells. Moreover, HIF1α directly regulates the expression of CD47. CD47 is a transmembrane protein that binds to SIRPα of macrophages to inhibit the phagocytosis of macrophages. Therefore, the efficacy of immune checkpoint inhibitors decreases even if there is a higher degree of tumor-infiltrating lymphocytes (TILs). Combination therapy with immune checkpoint and tumor associated antigens (TAAs) derived peptide vaccine could inhibit metastasis. In present study, we found that HIF1α/c-MET peptide vaccination delayed metastasis in C3(1)Tag mouse. We also investigated whether combination therapy with immune checkpoint inhibitors and peptide vaccine inhibited metastasis. Next, we observed that combination strategy of HIF1α/c-MET peptide vaccine and treated anti-PD-L1 antibody or/and anti-CD47 antibody was more effective in systemically inoculated M6 cells growth in C3(1)Tag mice. Immunohistochemical analysis of the tumors showed that the protein expression of CD47, HIF1α, and c-MET were significantly decreased. On the other hand, CD4+ T cells, CD8+ T cells and M1 macrophages increased, but M2 macrophages decreased, resulting in delayed metastasis in combination therapy group compared to single therapy and control group. In addition, IFNγ ELISPOT showed that peptide vaccination significantly increased the HIF1α/c-MET specific IFNγ-secreting T cell response in splenocytes. We also assessed osteoclastogenesis in bones, which showed reduction of osteoclast in combination therapy group compared to single therapy and control group.Taken together, combination therapy with immune checkpoint inhibitor targeting PD-L1 and CD47 and peptide vaccine appears to be a promising strategy that inhibit metastasis by modulating tumor microenvironment in triple negative breast cancer. Citation Format: JinHwa Hong, Jimin Lee, Soon Young Lim, Ju Won Kim, Ah Reum Lim, Kyong Hwa Park. Combination therapy of immune checkpoint inhibitor and HIF1α/c-MET peptide vaccine suppresses metastasis by modulating tumor microenvironment in triple-negative breast cancer. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5087.