HIF-1α Pathway Research Articles

Design, Synthesis, and Hypoxia-Inducible Factor-1α Inhibitory Activity Evaluation of Panaxadiol Derivatives Containing a Thiazole Moiety.

The hypoxia-inducible factor-1α (HIF-1α) pathway has been implicated in tumor angiogenesis, growth, and metastasis. Therefore, the inhibition of this pathway is an important therapeutic target for cancer. Thiazole derivatives have been reported to have diverse biological activities, especially in terms of anti-tumor. Consequently, we hypothesized that the introduction of a thiazole functional group in PD was likely to improve the biological potency. Here, three series of PD derivatives containing a thiazole moiety were synthesized, including (a) sulfonyl-containing thiazole derivatives (5 a-l), (b) urea-containing thiazole derivatives (7 a-i), and (c) thiourea-containing thiazole derivatives (9 a-i), and evaluated for HIF-1α inhibitory activity using a Hep3B cell-based luciferase reporter assay. The results showed that about 1/3 of the target compounds showed moderate or strong HIF-1α inhibitory activity, among which compounds 5 d and 7 b showed the strongest inhibitory activity with IC50 values of 17.37 and 6.42 μM, respectively, and did not show any significant cytotoxicity. Western blot assay results indicated that these two compounds exhibited more potent inhibition, compared with panaxadiol, of the expression of HIF-1α protein in Hep3B cells at a concentration of 50 μM. Molecular docking experiments were also performed to investigate the structure-activity relationship. Compounds 5 d and 7 b can be used as leads for further study and development of novel antitumor drugs.

Myocardial ischemia-reperfusion injury upregulates nucleostemin expression via HIF-1α and c-Jun pathways and alleviates apoptosis by promoting autophagy

Myocardial ischemia-reperfusion (I/R) injury, often arising from interventional therapy for acute myocardial infarction, leads to irreversible myocardial cell death. While previous studies indicate that nucleostemin (NS) is induced by myocardial I/R injury and mitigates myocardial cell apoptosis, the underlying mechanisms are poorly understood. Here, our study reveals that NS upregulation is critical for preventing cardiomyocyte death following myocardial I/R injury. Elevated NS protein levels were observed in myocardial I/R injury mouse and rat models, as well as Hypoxia/reoxygenation (H/R) cardiac cell lines (H9C2 cells). We identified binding sites for c-Jun and HIF-1α in the NS promoter region. Inhibition of JNK and HIF-1α led to a significant decrease in NS transcription and protein expression. Furthermore, inhibition of autophagy and NS expression promoted myocardial cell apoptosis in H/R. Notably, the cell model showed reduced LC3I transformation to LC3II, downregulated Beclin1, upregulated p62, and altered expression of autophagy-related proteins upon NS interference in H/R cells. These findings suggest that NS expression, driven by c-Jun and HIF-1α pathways, facilitates autophagy, providing protection against both myocardial I/R injury and H/R-induced cardiomyocyte apoptosis.

Electroacupuncture improves cognitive function by modulating hippocampal lactate-mediated HIF-1α signaling pathway and inhibiting inflammation response in vascular dementia rats

To observe the effects of electroacupuncture (EA) stimulation of "Sishencong"(EX-HN1) and "Fengchi"(GB20) on lactate (Lac) content, expression of proline hydroxylase 2 (PHD2), hypoxia-inducible factor-1α (HIF-1α)/nuclear transcription factor- κB (NF- κB)/NOD-like receptor thermoprotein structural domain-associated protein 3 (NLRP3) signaling pathway, and inflammatory factors in hippocampal tissue of vascular dementia (VD) rats, so as to explore its mechanisms underlying improvement of VD. Male SD rats screened by Morris water maze tests were randomly divided into blank control, sham-operation, VD model and EA groups (12 rats in each group). The VD model was replicated using the 4-vessel occlusion (VO) method. EA (2 Hz, 1 mA) was applied to EX-HN1 and bilateral GB20 for 30 min, once daily for consecutive 21 days. Morris water maze test was employed to test the rat's memory learning ability before and after modeling and after the intervention. The hippocampal tissue was sampled for observing histopathologic changes with H.E. staining；and detecting Lac content with colorimetric method, and the contents of tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, and IL-18 (also in serum) by using ELISA, respectively. The immunoactivity levels of PHD2, HIF-1α, and p-NF-κB p65 in hippocampal tissue were detected by immunohistochemistry, and the expression levels of PHD2, HIF-1α, NF-κB p65, p-NF-κB p65 and NLRP3 proteins in hippocampal tissue were detected by Western blot. Compared with the blank control and sham-operation groups, the escaping latency, Lac content in hippocampus, the TNF-α, IL-1β, and IL-18 contents in both hippocampus and serum, the immunoactivity of HIF-1α and p-NF-κB p65 and expression levels of HIF-1α, NF-κB p65, p-NF-κB p65, and NLRP3 proteins were significantly increased (P<0.01), while the number of original platform crossing, and PHD2 immunoactivity and protein expression level were significantly decreased (P<0.05, P<0.01) in the model group. Following EA intervention, modeling induced increase and decrease of the indexes mentioned above were all reversed in the EA group (P<0.05, P<0.01). H.E. staining showed disordered arrangement of neurons, uneven cytoplasm stain, blurred nucleolus or disappearance of nucleolus, dilated capillaries, many apoptotic bodies and increased inflammatory cells in the hippocampus tissue of the model group, which was improved to a certain extent in the EA group, including relatively regular arrangement of neurons, reduced apoptotic bodies and inflammatory cells, etc. in the hippocampus. EA stimulation of EX-HN1 and GB20 can improve the cognitive function in VD rats, which may be related to its functions in reducing Lac content, regulating the expression of HIF-1α pathway related proteins, and inhibiting inflammatory responses in the hippocampus tissue.

Hypoxia-inducible Factor-1α Pathway in Cerebral Ischemia: From Molecular Mechanisms to Therapeutic Targets.

Ischemic injury to the brain can result in a variety of life-threatening conditions, mortality, or varying degrees of disability. Hypoxia-inducible factor 1α (HIF 1α), an oxygen- sensitive transcription factor that controls the adaptive metabolic response to hypoxia, is a critical constituent of cerebral ischemia. It participates in numerous processes, such as metabolism, proliferation, and angiogenesis, and plays a major role in cerebral ischemia. Through the use of a number of different search engines like Scopus, PubMed, Bentham, and Elsevier databases, a literature review was carried out for investigating the pharmacological modulation of HIF-1α pathways for the treatment of cerebral ischemia. Various signalling pathways, such as Mitogen-activated protein kinase (MAPK), Janus kinase/ signal transducers and activators (JAK/STAT), Phosphoinositide-3-kinase (PI3-K), and cAMPresponse element binding protein (CREB) play a vital role in modulation of HIF-1α pathway, which helps in preventing the pathogenesis of cerebral ischemia. The pharmacological modulation of the HIF-1α pathway via various molecular signalling pathways, such as PI3-K, MAPK, CREB, and JAK/STAT activators, offer a promising prospect for future interventions and treatment for cerebral ischemia.

USP28 promotes tumor progression and glycolysis by stabilizing PKM2/Hif1-α in cholangiocarcinoma.

Ubiquitination is one of the important modification of proteins which can be reversed by deubiquitinating enzymes (DUBs). Ubiquitin specific protease 28 (USP28) belongs to the deubiquitinase family, which plays a cancer-promoting function in many types of cancers such as pancreatic cancer and breast cancer. So far, the molecular function and significance of USP 28 in cholangiocarcinoma remain unclear. In this study, we evaluated the expression of USP28 using tissue microarray (TMA), reverse transcription polymerase chain reaction (qRT-PCR), and online databases. We investigated the effect of USP28 on the progression of CCA through in vitro and in vivo functional experiments. In addition, we explored downstream molecular pathways using Western blotting (WB), immunofluorescence (IF), and mass spectrometry techniques. Here, we found that cholangiocarcinoma tissue had higher USP 28 expression than normal bile duct tissue, and that high USP 28 levels were significantly associated with a malignant phenotype and poorer prognosis in cholangiocarcinoma patients. Both in vitro and in vivo, USP28 could mediate the deubiquitination of PKM2, thereby activating the downstream Hif1-α signaling pathway, promoting glycolysis and energy supply, and finally promoting tumor progression. In summary, USP28 activated downstream Hif1-α by reducing the ubiquitination level of PKM2, furthermore, promoting the level of glycolysis in CCA cells for tumor progression.

Effects of Nitric Oxide on Bladder Detrusor Overactivity through the NRF2 and HIF-1α Pathways: A Rat Model Induced by Metabolic Syndrome and Ovarian Hormone Deficiency.

Metabolic syndrome (MetS) includes cardiovascular risk factors like obesity, dyslipidemia, hypertension, and glucose intolerance, which increase the risk of overactive bladder (OAB), characterized by urgency, frequency, urge incontinence, and nocturia. Both MetS and ovarian hormone deficiency (OHD) are linked to bladder overactivity. Nitric oxide (NO) is known to reduce inflammation and promote healing but its effect on bladder overactivity in MetS and OHD is unclear. This study aimed to investigate NO's impact on detrusor muscle hyperactivity in rats with MetS and OHD. Female Sprague-Dawley rats were divided into seven groups based on diet and treatments involving L-arginine (NO precursor) and L-NAME (NOS inhibitor). After 12 months on a high-fat, high-sugar diet with or without OVX, a cystometrogram and tracing analysis of voiding behavior were used to identify the symptoms of detrusor hyperactivity. The MetS with or without OHD group had a worse bladder contractile response while L-arginine ameliorated bladder contractile function. In summary, MetS with or without OHD decreased NO production, reduced angiogenesis, and enhanced oxidative stress to cause bladder overactivity, mediated through the NF-kB signaling pathway, whereas L-arginine ameliorated the symptoms of detrusor overactivity and lessened oxidative damage via the NRF2/HIF-1α signaling pathway in MetS with or without OHD-induced OAB.

MDM2 induces pro-inflammatory and glycolytic responses in M1 macrophages by integrating iNOS-nitric oxide and HIF-1α pathways in mice.

M1 macrophages induce protective immunity against infection, but also contribute to metabolic and inflammatory diseases. Here we show that the E3 ubiquitin ligase, MDM2, promotes the glycolytic and inflammatory activities of M1 macrophage by increasing the production of IL-1β, MCP-1 and nitric oxide (NO). Mechanistically, MDM2 triggers the ubiquitination and degradation of E3 ligase, SPSB2, to stabilize iNOS and increases production of NO, which s-nitrosylates and activates HIF-1α for triggering the glycolytic and pro-inflammatory programs in M1 macrophages. Myeloid-specific haplodeletion of MDM2 in mice not only blunts LPS-induced endotoxemia and NO production, but also alleviates obesity-induced adipose tissue-resident macrophage inflammation. By contrast, MDM2 haplodeletion induces higher mortality, tissue damage and bacterial burden, and also suppresses M1 macrophage response, in the cecal ligation and puncture-induced sepsis mouse model. Our findings thus identify MDM2 as an activator of glycolytic and inflammatory responses in M1 macrophages by connecting the iNOS-NO and HIF-1α pathways.

Role of Hypoxic Secretome from Mesenchymal Stem Cells in Enhancing Tissue Repair: Regulatory Effects on HIF-1α, VEGF, and Fibroblast in a Sphincterotomy Rat Model.

Fecal incontinence (FI) is the inability to control bowel movements, resulting in fecal leakage. If left untreated, FI can seriously impact the long-term well-being of individuals affected. Recently, using secretome has become a promising new treatment method. The secretome combines growth factors released outside cells during stem cell development, such as mesenchymal stem cells. It consists of soluble proteins, nucleic acids, fats, and extracellular vesicles, which contribute to different cell processes. The primary aim is to assess the impact of hypoxic secretome administration on accelerating wound healing through the HIF-1α pathway in a post-sphincterotomy rat model. The study was conducted with two distinct groups of 10 rats each, the control and treatment groups, which were injected with hypoxic secretome at 0.3 mL. The inclusion criteria for the rats were as follows: male gender, belonging to the Sprague-Dawley strain, aged between 12 to 16weeks, with an average body weight ranging from 240 to 250 grams. There was an increase in HIF-1α gene expression in both groups. The treatment group 37 was significantly higher on day 42 (p = 0.001). VEGF increased significantly in the treatment 38 group on day 42 (p = 0.015). The neovascularization score increased significantly in the treatment 39 group during the first 24hours (p = 0.004). The fibroblast score increased significantly in the 40 treatment group in the first 24hours (p = 0.000) and 42 days (p = 0.035). After being given secretome, there was a higher increase in % collagen area and collagen area (µm2) in the treatment group compared to the control group (27,77 vs 11.01) and (419.027,66 vs 186.694,16). The use of hypoxic secretome has a significant effect as a choice for the treatment of anal sphincter injury after sphincterotomy through the HIF-1α-VEGF-Fibroblast pathway.

Dedicator of cytokinesis 8 (DOCK8) mutation impairs the differentiation of helper T cells by regulating the glycolytic pathway of CD4+ T cells.

Dedicator of cytokinesis 8 (DOCK8) deficiency is a primary immunodeficiency disease caused by mutations in exon 45 of the DOCK8 gene. The clinical signs primarily consist of increased serum IgE levels, eczema, repeated skin infections, allergies, and upper respiratory tract infections. Using CRISPR/Cas9 technology, we generated a DOCK8 exon 45 mutation in mice, mirroring the mutation found in patients. The results indicated that DOCK8 mutation impairs peripheral T cell homeostasis, disrupts regulatory T cells (Tregs) development, increases ICOS expression in Tregs within peripheral lymph nodes (pLn), and promotes Th17 cell differentiation within the spleen and pLn. Upon virus infection, DOCK8 mutation CD4+ T cells have a Th2 effector fate. RNA-bulk sequencing data revealed alternations in the mTOR pathway of DOCK8 mutant CD4+ T cells. We observed that DOCK8 mutation upregulates the glycolysis levels in CD4+ T cells, which is related to the Akt/mTOR/S6/HIF-1α pathway. In summary, our research elucidates that DOCK8 regulates the differentiation of helper T cells by modulating the glycolytic pathway in CD4+ T cells, thereby advancing the comprehension and offering potential treatment of diseases in DOCK8-deficient patients.

The p-MYH9/USP22/HIF-1α axis promotes lenvatinib resistance and cancer stemness in hepatocellular carcinoma

Lenvatinib is a targeted drug used for first-line treatment of hepatocellular carcinoma (HCC). A deeper insight into the resistance mechanism of HCC against lenvatinib is urgently needed. In this study, we aimed to dissect the underlying mechanism of lenvatinib resistance (LR) and provide effective treatment strategies. We established an HCC model of acquired LR. Cell counting, migration, self-renewal ability, chemoresistance and expression of stemness genes were used to detect the stemness of HCC cells. Molecular and biochemical strategies such as RNA-sequencing, immunoprecipitation, mass spectrometry and ubiquitination assays were used to explore the underlying mechanisms. Patient-derived HCC models and HCC samples from patients were used to demonstrate clinical significance. We identified that increased cancer stemness driven by the hypoxia-inducible factor-1α (HIF-1α) pathway activation is responsible for acquired LR in HCC. Phosphorylated non-muscle myosin heavy chain 9 (MYH9) at Ser1943, p-MYH9 (Ser1943), could recruit ubiquitin-specific protease 22 (USP22) to deubiquitinate and stabilize HIF-1α in lenvatinib-resistant HCC. Clinically, p-MYH9 (Ser1943) expression was upregulated in HCC samples, which predicted poor prognosis and LR. A casein kinase-2 (CK2) inhibitor and a USP22 inhibitor effectively reversed LR in vivo and in vitro. Therefore, the p-MYH9 (Ser1943)/USP22/HIF-1α axis is critical for LR and cancer stemness. For the diagnosis and treatment of LR in HCC, p-MYH9 (Ser1943), USP22, and HIF-1α might be valuable as novel biomarkers and targets.

The role of IL-17 and Th17 cells in keloid pathogenesis.

Keloids are characterized histologically by excessive fibroblast proliferation and connective tissue deposition, and clinically by scar tissue extending beyond the original site of skin injury. These scars can cause pruritus, pain, physical disfigurement, anxiety, and depression. As a result, keloid patients often have a diminished quality of life with a disproportionate burden on ethnic minorities. Despite advances in understanding keloid pathology, there is no effective Food and Drug Administration (FDA)-approved pharmacotherapy. Recent studies have highlighted the possible pathologic role of T helper (Th)17 cells and interleukin (IL)-17 in keloid formation, as well as their implication in other inflammatory disorders. This systematic review characterizes the role of Th17 cells and IL-17 in keloid pathogenesis, highlighting this pathway as a potential therapeutic target. Adhering to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we conducted a comprehensive search on PubMed, Embase, MEDLINE, and Web of Science databases on June 5, 2024. The search included terms related to Th17 cells, IL-17, and keloids. Thirteen studies met the inclusion criteria, comprising basic science and bioinformatic studies focusing on Th17 cells and IL-17. Key findings include increased Th17 cell infiltration and IL-17 expression in keloids, IL-17's role in amplifying the inflammatory and fibrotic response via the promotion of IL-6 expression, and IL-17's involvement in upregulating fibrotic markers via SDF-1 and HIF-1α pathways. IL-17 also activates the transforming growth factor beta (TGF-β)/Smad pathway in keloid fibroblasts. Th17 cells and IL-17 significantly contribute to the inflammatory and fibrotic processes in keloid pathogenesis. Therefore, targeting the IL-17 pathway offers a potential new therapeutic target to improve keloid patients' outcomes. Future research could further elucidate the role of Th17 cells and IL-17 in keloid pathogenesis and assess the safety and efficacy of targeting this pathway in human studies.

TRPA1 Influences Staphylococcus aureus Skin Infection in Mice and Associates with HIF-1a and MAPK Pathway Modulation.

Infections caused by methicillin-resistant Staphylococcus aureus (MRSA) are a major public health burden. Emerging antibiotic resistance has heightened the need for new treatment approaches for MRSA infection such as developing novel antimicrobial agents and enhancing the host's defense response. The thermo-ion channels Transient Receptor Potential (TRP-) A1 and V1 have been identified as modulators of S. aureus quorum sensing in cell culture models. However, their effects on in vivo infection control are unknown. In this study, we investigated the therapeutic effect of natural TRP ion channel inhibitors on MRSA skin infection in mice. While deletion of TRPV1 did not affect lesion size or inflammatory markers, TRPA1-/- mice demonstrated significantly reduced infection severity and abscess size. Treatment with natural inhibitors of TRPA1 with or without blockade of TRPV1 also reduced abscess size. Tissue transcriptomic data coupled with immunohistochemistry revealed that TRPA1 inhibition impacted heat shock protein expression (HSP), modulated the HIF-1a and MAPK pathways, and reduced IL4 expression. Additionally, metabolomics data showed an impact on purine and glycosaminoglycan pathways. Multi-omic integration of transcriptomic and metabolic data revealed that diacylglycerol metabolism was the likely bridge between metabolic and immunological impacts. Our findings suggest that TRPA1 antagonism could provide a promising and cost-effective therapeutic approach for reducing the severity of MRSA infection, and presents a novel underlying molecular mechanism.

One-carbon metabolism supports S-adenosylmethionine and m6A methylation to control the osteogenesis of bone marrow stem cells and bone formation.

The skeleton is a metabolically active organ undergoing continuous remodeling initiated by bone marrow stem cells (BMSCs). Recent research has demonstrated that BMSCs adapt the metabolic pathways to drive the osteogenic differentiation and bone formation, but the mechanism involved remains largely elusive. Here, using a comprehensive targeted metabolome and transcriptome profiling, we revealed that one-carbon metabolism was promoted following osteogenic induction of BMSCs. Methotrexate (MTX), an inhibitor of one-carbon metabolism that blocks S-adenosylmethionine (SAM) generation, led to decreased N6-methyladenosine (m6A) methylation level and inhibited osteogenic capacity. Increasing intracellular SAM generation through betaine addition rescued the suppressed m6A content and osteogenesis in MTX-treated cells. Using S-adenosylhomocysteine (SAH) to inhibit the m6A level, the osteogenic activity of BMSCs was consequently impeded. We also demonstrated that the pro-osteogenic effect of m6A methylation mediated by one-carbon metabolism could be attributed to HIF-1α and glycolysis pathway. This was supported by the findings that dimethyloxalyl glycine rescued the osteogenic potential in MTX-treated and SAH-treated cells by upregulating HIF-1α and key glycolytic enzymes expression. Importantly, betaine supplementation attenuated MTX-induced m6A methylation decrease and bone loss via promoting the abundance of SAM in rat. Collectively, these results revealed that one-carbon metabolite SAM was a potential promoter in BMSC osteogenesis via the augmentation of m6A methylation, and the cross talk between metabolic reprogramming, epigenetic modification, and transcriptional regulation of BMSCs might provide strategies for bone regeneration.

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

BackgroundOsteoporosis(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. PurposeThis study investigates the potential therapeutic interventions and underlying mechanisms of CAR for treating OP in individuals with iron overload. MethodsThe 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). ResultsCAR 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. ConclusionCAR 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.

Profiling of chromatin accessibility and regulatory elements toward understanding the mechanisms underlying growth regulation in the Pacific oyster (Crassostrea gigas)

Changes in phenotype are precisely controlled by transcriptional regulators, which depend on chromatin remodeling. Although artificial genetic breeding has significantly improved the growth performance of the Pacific oyster (Crassostrea gigas), the identification of gene regulatory elements and transcription factors related to growth is obscure. In this study, we performed a genome-wide characterization of chromatin accessibility using two strains of C. gigas that exhibit significant differences in growth. The results showed that accessible chromatin regions were mainly distributed in the noncoding regions of the genome, with a greater proportion of distal intergenic regions than that of promoters and introns. A total of 2044 differentially accessible regions and 2574 differentially expressed genes were identified through comparative analysis. Genes annotated from regions with differential chromatin accessibility were enriched in cell adhesion molecules, JAK-STAT, insulin resistance, HIF-1α, and platelet activation signaling pathways. Correlation analysis of ATAC-seq and RNA-seq data showed that differential gene expression was positively correlated with differential chromatin accessibility. Furthermore, motif screening and identification of accessible chromatin regions revealed a set of transcription factors, including LHX3, TCF7L2, and LEF1, that may play important roles in the growth of C. gigas. Integrated analysis with public Hi-C datasets allowed the identification of a differential peak located 47 kb upstream of angiopoietin-2, which may act as a potential enhancer that affects the growth of C. gigas. In summary, our work contributes to a better understanding of growth-related regulation in C. gigas and provides valuable information for deciphering the economic traits underlying growth, which is conducive to the development of the breeding industry of C. gigas in the future.

The impact and mechanism study of Sijunzi decoction and Rg1 on proliferation and differentiation of human umbilical cord mesenchymal stem cells: An experimental study.

Previous researches have demonstrated that the traditional Chinese medicine could therapeutically treat inflammatory and hypoxic diseases by enhancing the functionality of mesenchymal stem cells. However, its mechanism was not yet clear. This research aimed to investigate the impact of the traditional Chinese medicine Sijunzi decoction and its herb monomer ginsenoside Rg1 on the proliferation and differentiation of human umbilical cord mesenchymal stem cells (hUC-MSCs) and explore the underlying mechanisms. Different concentrations of Sijunzi decoction and Rg1 were applied to differentiating induced hUC-MSCs. The CCK-8 test was utilized to evaluate cell proliferation activity and identify suitable drug concentrations. Alizarin Red staining was employed to detect the formation of calcium nodules, and Oil Red O staining was used to assess the formation of lipid droplets. PCR was utilized to examine gene expression related to osteogenic differentiation, adipogenic differentiation, and the HIF-1α signaling pathway in hUC-MSCs. Western blot analysis was conducted to evaluate protein expression in osteogenic differentiation and HIF-1α. ELISA was performed to measure HIF-1α signaling factors and inflammatory cytokine expression. Biochemical assays were used to assess changes in oxidative stress indicators. The Sijunzi decoction and Rg1 both demonstrated a dose-dependent promotion of hUC-MSC proliferation. The Sijunzi decoction significantly increased the expression of genes and proteins relevant to osteogenesis, such as osterix, osteocalcin, RUNX2, and osteopontin, and activated the HIF-1α pathway in hUC-MSCs. (P < .05). Similar effects were observed at the gene level after treatment with Rg1. Simultaneously, Sijunzi decoction significantly reduced the secretion of pro-inflammatory cytokines TNF-α, IL-6, and IL-1β, while increasing the secretion of the anti-inflammatory cytokine IL-10 during osteogenic differentiation (P < .05). Moreover, Sijunzi decoction lowered oxidative stress levels and enhanced the antioxidant capacity of hUC-MSCs during osteogenic differentiation (P < .05). However, the impact of Sijunzi decoction on hUC-MSCs toward adipogenic differentiation was not significant (P > .05). Sijunzi decoction promotes the proliferation and osteogenic differentiation of hUC-MSCs, potentially through the activation of the HIF-1α signaling pathway and by modulating the microenvironment via reducing inflammation and oxidative stress levels. Rg1 might be involved in this process.

Sciatic nerve stimulation alleviates neuropathic pain and associated neuroinflammation in the dorsal root ganglia in a rodent model

BackgroundSatellite glial cells (SGCs) in the dorsal root ganglia (DRG) play a pivotal role in the formation of neuropathic pain (NP). Sciatic nerve stimulation (SNS) neuromodulation was reported to alleviate NP and reduce neuroinflammation. However, the mechanisms underlying SNS in the DRG remain unclear. This study aimed to elucidate the mechanism of electric stimulation in reducing NP, focusing on the DRG.MethodsL5 nerve root ligation (NRL) NP rat model was studied. Ipsilateral SNS performed 1 day after NRL. Behavioral tests were performed to assess pain phenotypes. NanoString Ncounter technology was used to explore the differentially expressed genes and cellular pathways. Activated SGCs were characterized in vivo and in vitro. The histochemical alterations of SGCs, macrophages, and neurons in DRG were examined in vivo on post-injury day 8.ResultsNRL induced NP behaviors including decreased pain threshold and latency on von Frey and Hargreaves tests. We found that following nerve injury, SGCs were hyperactivated, neurotoxic and had increased expression of NP-related ion channels including TRPA1, Cx43, and SGC-neuron gap junctions. Mechanistically, nerve injury induced reciprocal activation of SGCs and M1 macrophages via cytokines including IL-6, CCL3, and TNF-α mediated by the HIF-1α-NF-κB pathways. SNS suppressed SGC hyperactivation, reduced the expression of NP-related ion channels, and induced M2 macrophage polarization, thereby alleviating NP and associated neuroinflammation in the DRG.ConclusionsNRL induced hyperactivation of SGCs, which had increased expression of NP-related ion channels. Reciprocal activation of SGCs and M1 macrophages surrounding the primary sensory neurons was mediated by the HIF-1α and NF-κB pathways. SNS suppressed SGC hyperactivation and skewed M1 macrophage towards M2. Our findings establish SGC activation as a crucial pathomechanism in the gliopathic alterations in NP, which can be modulated by SNS neuromodulation.

Canadine Platinum(IV) Complexes Targeting Epithelial-Mesenchymal Transition as Antiproliferative and Antimetastatic Agents.

Epithelial-mesenchymal transition (EMT) is a critical process for cancer progression, which is crucial in inhibiting the immunity in tumors and further boosting tumor metastasis. The suppression of EMT represents a promising strategy for inhibiting metastatic tumors. Herein, a series of new canadine platinum(IV) conjugates with potent antiproliferative and antimetastatic activities were developed, which activated by suppressing EMT and provoking immune response in tumors besides causing DNA injury. The complexes could covalently conjugate to DNA and induce mitochondria-mediated apoptosis via Bcl-2/Bax/caspase3 signaling. The EMT process was remarkably inhibited by suppressing the Wnt/β-catenin pathway, reversing the inflammatory tumor microenvironment, and inhibiting the HIF-1α pathway, which further resulted in the inhibited angiogenesis in tumors. Moreover, the antitumor immunity was elevated by blocking immune checkpoints PD-L1 and CD47 accompanied by the improvement of CD3+ and CD8+ T lymphocytes and the macrophage polarization from M2- toward M1-type simultaneously in tumors.

Clinical implications of activation of the LIMD1-VHL-HIF1α pathway during head-&-neck squamous cell carcinoma development.

Background & objectives Given the importance of the role of hypoxia induced pathway in different cancers including head-and-neck squamous cell carcinoma (HNSCC), this study delved into elucidating the molecular mechanism of hypoxia-inducible factor-1α (HIF1α) activation in HNSCC. Additionally, it analyzes the alterations of its regulatory genes [von Hippel-Lindau (VHL) and LIM domain containing 1 (LIMD1)] and target gene vascular endothelial growth factor (VEGF) in head-and-neck lesions at different clinical stages in relation with human papillomavirus (HPV) infection. Methods Global mRNA expression profiles of HIF1α, VHL, LIMD1 and VEGF were evaluated from public datasets of HNSCC, followed by validation of their expression (mRNA/protein) in an independent set of HPV+ve/-ve HNSCC samples of different clinical stages. Results A diverse expression pattern of the HIF1α pathway genes was observed, irrespective of HPV infection, in the datasets. In validation in an independent set of HNSCC samples, high mRNA expressions of HIF1α/VEGF were observed particularly in HPV positive samples. However, VHL/LIMD1 mRNA expression was low in tumours regardless of HPV infection status. In immunohistochemical analysis, high/medium (H/M) expression of HIF1α/VEGF was observed in basal/parabasal layers of normal epithelium, with significantly higher expression in tumours, especially in HPV-positive samples. Conversely, high cytoplasmic VHL expression in these layers gradually decreased with the progression of HNSCC, regardless of HPV infection. A similar trend was noted in LIMD1 expression (nuclear/cytoplasmic) during the disease development. The methylation pattern of VHL and LIMD1 promoters in the basal/parabasal layers of normal epithelium correlated with their expression, exhibiting a gradual increase with the progression of HNSCC. The H/M expression of HIF1α/VEGF proteins and reduced VHL expression was associated with poor clinical outcomes. Interpretation & conclusions The results of this study showed differential regulation of the LIMD1-VHL-HIF1α pathway in HPV positive and negative HNSCC samples, illustrating the molecular distinctiveness of these two groups.

HIF-1α Pathway Orchestration by LCN2: A Key Player in Hypoxia-Mediated Colitis Exacerbation.

In this study, we investigated the role of hypoxia in the development of chronic inflammatory bowel disease (IBD), focusing on its impact on the HIF-1α signaling pathway through the upregulation of lipocalin 2 (LCN2). Using a murine model of colitis induced by sodium dextran sulfate (DSS) under hypoxic conditions, transcriptome sequencing revealed LCN2 as a key gene involved in hypoxia-mediated exacerbation of colitis. Bioinformatics analysis highlighted the involvement of crucial pathways, including HIF-1α and glycolysis, in the inflammatory process. Immune infiltration analysis demonstrated the polarization of M1 macrophages in response to hypoxic stimulation. In vitro studies using RAW264.7 cells further elucidated the exacerbation of inflammation and its impact on M1 macrophage polarization under hypoxic conditions. LCN2 knockout cells reversed hypoxia-induced inflammatory responses, and the HIF-1α pathway activator dimethyloxaloylglycine (DMOG) confirmed LCN2's role in mediating inflammation via the HIF-1α-induced glycolysis pathway. In a DSS-induced colitis mouse model, oral administration of LCN2-silencing lentivirus and DMOG under hypoxic conditions validated the exacerbation of colitis. Evaluation of colonic tissues revealed altered macrophage polarization, increased levels of inflammatory factors, and activation of the HIF-1α and glycolysis pathways. In conclusion, our findings suggest that hypoxia exacerbates colitis by modulating the HIF-1α pathway through LCN2, influencing M1 macrophage polarization in glycolysis. This study contributes to a better understanding of the mechanisms underlying IBD, providing potential therapeutic targets for intervention.