Cooperative STAT3-NFkB signaling modulates mitochondrial dysfunction and metabolic profiling in hepatocellular carcinoma

PLOD1 promotes the malignancy of hepatocellular carcinoma by facilitating the NF-κB/IL-6/STAT3-dependent TCA cycle

Background & Aims

Procollagen lysyl hydroxylase 1 (PLOD1) is crucial in regulating collagen synthesis and cross-linking. However, its roles and underlying mechanisms in the progression of hepatocellular carcinoma (HCC) remain unclear. Herein, we aimed to investigate the underlying biological functions and mechanisms of PLOD1 in HCC.

Methods

The expression levels of PLOD1 in HCC were measured by qPCR, Western blot, and immunohistochemistry. Cell proliferation, apoptosis, and stemness were examined by CCK8, flow cytometry, sphere formation, and aldehyde dehydrogenase activity assays. The subcutaneous tumorigenicity model, orthotopic tumorigenicity model, and hepatotoxin-induced HCC model were used for in vivo experiments. RNA-sequence and untargeted metabolomics analysis were performed to identify underlying mechanisms.

Results

PLOD1 is found to be highly expressed in both human (p <0.0001) and mouse HCC (p <0.01) and is associated with a poor prognosis (p = 0.047). In vitro and in vivo experiments reveal that overexpression of PLOD1 promotes the proliferation and stemness of HCC cells. Meanwhile, the depletion of PLOD1 attenuates the occurrence and growth of HCC, leading to cell cycle arrest (p <0.01) and apoptosis (p <0.001) in HCC. Mechanistically, PLOD1 positively regulates the NF-κB/IL-6/STAT3 signaling pathway and accelerates TCA cycle metabolic reprogramming. Blocking the NF-κB/IL-6/STAT3 signaling pathway and TCA cycle can effectively mitigate PLOD1-induced proliferation and stemness of HCC cells.

Conclusions

Our study uncovers the PLOD1/NF-κB/IL-6/STAT3 axis as a therapeutic target for inhibiting the progression and stemness of HCC.

Impact and implications

The roles and underlying mechanisms of PLOD1 in the progression of HCC remain unclear. In this study, we report that PLOD1 is highly expressed in patients with HCC and promotes the proliferation and stemness of HCC cells by activating the NF-κB/IL-6/STAT3-dependent TCA cycle. Knocking down hepatic PLOD1 using adeno-associated virus results in reduced progression of HCC in mice, suggesting that PLOD1 may serve as a potential therapeutic target for HCC.

Non-immune targeting of CXCR3 compromises mitochondrial function and suppresses tumor growth in glioblastoma

The chemokine receptor CXCR3 is traditionally recognized for its role in immune cell trafficking. However, emerging evidence suggests that its functions may extend beyond the immune system, particularly in cancer, where its roles remain to be elucidated. In this study, we demonstrated that CXCR3 expression correlates with glioblastoma (GBM) grading, with CXCR3-A isoform being associated with poorer patient prognosis compared to CXCR3-B. Ablation of both CXCR3 isoforms significantly impaired GBM cell proliferation, migration, and tumor growth both in vitro and in immunodeficient mice. To elucidate the mechanistic role of CXCR3, we conducted transcriptomic profiling of tumor xenografts, revealing that CXCR3 depletion would disrupt mitochondrial homeostasis. This was further supported by our findings that CXCR3 would localize to the mitochondrial membrane, and that inhibition of CXCR3 would lead to mitochondrial depolarization and increased reactive oxygen species production. Notably, activation of phosphorylated-STAT3 rescued cell viability in CXCR3-depleted cells, suggesting that CXCR3 may modulate mitochondrial function through a STAT3-dependent mechanism, consistent with the known functional role of STAT3 in maintaining mitochondrial redox balance. Furthermore, treatment with the selective CXCR3 antagonist AMG487 reduced tumor growth and disrupted mitochondrial function in vitro, in vivo, and in patient-derived GBM stem cells. Our findings reveal CXCR3 as a previously unrecognized regulator of mitochondrial function in cancer cells, positioning the CXCR3-mitochondrial signaling axis as a promising therapeutic target for GBM. Chemokine receptors are well-established mediators of inflammatory responses, emerging evidence suggests that these receptors may play roles beyond the immune system. In this study, we have demonstrated that CXCR3 would localize to the mitochondrial membrane and exert a previously unrecognized function in regulating cancer metabolism and mitochondrial function. Figure created using BioRender ( https://biorender.com ).

Neem leaf extract alleviates LPS/D-GalN induced acute hepatitis in mice through its anti-inflammatory effects and activation of autophagy

Acute hepatitis, characterized by rapid onset and high mortality, can result from infections, toxins, and other factors. However, current treatment options have significant side effects, necessitating further research into alternative therapies. This study investigated the extraction method of neem extract and found that its ethanolic extract effectively reduced mortality and decreased ALT and AST levels in mice serum, improving liver pathology. HPLC analysis identified azadirachtin and nimbolide in the extract. It also downregulated NF-κB, NLRP3, and p62 levels, while upregulating Lc3B and Atg5 levels. Experiments in Atg5 knockout mice showed that the absence of Atg5 weakened the extract's efficacy in reducing liver damage and inflammation and affected the extent of NLRP3 protein downregulation. However, it did not affect the extract's ability to reduce NF-κB. Overall, the ethanolic extract of neem leaves primarily modulates the inflammatory response through the NF-κB signaling pathway. The extract's efficacy in reducing NLRP3 is associated with autophagy. These discoveries offer a new theoretical basis for the role of neem in treating acute hepatitis.

Aspartame increases the risk of liver cancer through CASP1 protein: A comprehensive network analysis insights

BACKGROUND

Aspartame is a widely used artificial sweetener in food and beverages. Its safety concerns and potential carcinogenic risks have garnered increasing attention. This study aims to systematically explore the carcinogenic potential and mechanisms of aspartame on the liver through a comprehensive analysis based on network toxicology, mendelian randomization, molecular dynamics and single-cell RNA sequencing.

METHODS

ProTox 3.0 and ADMEtlab 2.0 platforms were used to predict the toxicity and drug metabolism levels of aspartame. Network toxicology methods were employed to investigate the pathogenic pathways and mechanisms of aspartame in liver cancer. Mendelian randomization (MR) was used to verify the causal relationship between aspartame's carcinogenic targets and liver cancer. Furthermore, molecular docking and molecular dynamics (MD) simulations were conducted to explore the binding efficiency and stability of aspartame with the validated targets from MR. Single-cell technology further explores which types of liver cells have the highest expression of CASP1.

RESULTS

Combining the results from two prediction platforms, it was found that aspartame exhibits significant neurological, nephrotoxic, and hepatotoxic effects. Network toxicology results indicated that aspartame promotes the development of liver cancer by affecting multiple key proteins and regulatory factors PTGS2, IL1β and CASP1, in the Necroptosis, NF-κB and TNF signaling pathways. MR was used to discover that among the core targets of aspartame, REN, HLA-A, CASP1, and MME have causal relationships with liver cancer, while CASP1 is a risk factor for liver cancer. The binding affinity of aspartame to these four proteins was investigated by molecular docking, and it was found that the binding to CASP1 was the strongest at -18.45 kJ/mol. MD further verified that over a 50 ns period, the protein-target complex of aspartame and CASP1 exhibited excellent binding stability. Additionally, the single-cell sequencing found that CASP1 is most highly expressed in endothelial cells. In summary, these findings suggested that aspartame may increase the possibility of liver cancer by modulating the CASP1 protein.

CONCLUSIONS

This study identifies CASP1 as a potential target for aspartame-induced liver cancer, which is of a significant public health importance. The potential carcinogenic risk of aspartame and reliability need to be re-evaluated. The study provides a new method for assessing the safety of food additives and offers novel scientific insights into the toxicological effects of aspartame. Furthermore, subsequent experimental validation is crucial for further research into the carcinogenic mechanisms of aspartame.

Aging, ROS, and cellular senescence: a trilogy in the progression of liver fibrosis

Ageing is an inevitable and multifaceted biological process that impacts a wide range of cellular and molecular mechanisms, leading to the development of various diseases, such as liver fibrosis. Liver fibrosis progresses to cirrhosis, which is an advanced form due to high amounts of extracellular matrix and restoration of normal liver structure with failure to repair damaged tissue and cells, marking the end of liver function and total liver failure, ultimately death. The most important factors are reactive oxygen species (ROS) and cellular senescence. Oxidative stress is defined as an impairment by ROS, which are by-products of the mitochondrial electron transport chain and other key molecular pathways that induce cell damage and can activate cellular senescence pathways. Cellular senescence is characterized by pro-inflammatory cytokines, growth factors, and proteases secreted by senescent cells, collectively known as the senescence-associated secretory phenotype (SASP). The presence of senescent cells, which disrupt tissue architecture and function and increase senescent cell production in liver tissues, contributes to fibrogenesis. Hepatic stellate cells (HSCs) are activated in response to chronic liver injury, oxidative stress, and senescence signals that drive excessive production and deposition of extracellular matrix. This review article aims to provide a comprehensive overview of the pathogenic role of ROS and cellular senescence in the aging liver and their contribution to fibrosis.

Structure, function, signaling pathways and clinical therapeutics: The translational potential of STAT3 as a target for cancer therapy

Cancer remains one of the most difficult human diseases to overcome because of its complexity and diversity. Signal transducers and transcriptional activators 3 (STAT3) protein has been found to be overexpressed in a wide range of cancer types. Hyperactivation of STAT3 is particularly associated with low survival in cancer patients. This review summarizes the specific molecular mechanisms of STAT3 in cancer development. STAT3 is activated by extracellular signals in the cytoplasm, interacts with different enzymes in the nucleus, mitochondria or endoplasmic reticulum, and subsequently participates in cancer development. The phosphorylated STAT3 at tyrosine 705 site (YP-STAT3) enters the nucleus and regulates a number of tumor-related biological processes such as angiogenesis, migration invasion, cell proliferation and cancer cell stemness. In contrast, the phosphorylated STAT3 at serine 727 site (SP-STAT3) is found on the mitochondria, affects electron respiration transport chain activity and thereby prevents tumor cell apoptosis. SP-STAT3 also appears on the mitochondria-associated endoplasmic reticulum membrane, influences the flow of Ca2+, and affects tumor progression. In addition, we summarize the direct and indirect inhibitors of STAT3 which are currently undergoing clinical studies. Some of them such as TTI101 and BBI608 have been approved by the FDA for the treatment of certain cancers. All in all, STAT3 plays an important role in cancer progression and becomes a potential target for cancer treatment.

The genetically predicted causal associations between circulating 3-hydroxybutyrate levels and malignant neoplasms: A pan-cancer Mendelian randomization study

OBJECTIVE

The ketogenic diet or exogenous supplementation with 3-hydroxybutyrate (3HB) is progressively gaining recognition as a valuable therapeutic or health intervention strategy. However, the effects of 3HB on cancers have been inconsistent in previous studies. This study aimed to comprehensively investigate the causal effects of circulating 3HB levels on 120 cancer phenotypes, and explore the 3HB mediation effect between liver fat accumulation and cancers.

METHODS

Univariate Mendelian randomization (UVMR) was used in this study to investigate the causal impact of circulating 3HB levels on cancers. We conducted meta-analyses for 3HB-cancer associations sourced from different exposure data. In multivariate MR(MVMR), the body mass index, alcohol frequency and diabetes were included as covariates to investigate the independent effect of 3HB on cancer risk. Additionally, utilizing mediation MR analysis, we checked the potential mediating role of 3HB in the association between liver fat and cancer.

RESULTS

Integrating findings from UVMR and MVMR, we observed that elevated circulating 3HB levels were associated with reduced risk of developing diffuse large B-cell lymphoma(DLBCL) (OR[95%CI] = 0.28[0.14-0.57] p = 3.92e-04), biliary malignancies (OR[95%CI] = 0.30[0.15-0.60], p = 7.67e-04), hepatocellular carcinoma(HCC) (OR[95%CI] = 0.25[0.09-0.71], p = 9.33e-03), primary lymphoid and hematopoietic malignancies (OR[95%CI] = 0.76[0.58-0.99], p = 0.045). Further UVMR analysis revealed that an increase in the percent liver fat was associated with reduced 3HB levels (Beta[95%CI] = -0.073[-0.122∼-0.024], p = 0.0034) and enhanced susceptibility to HCC (OR[95%CI] = 13.9[9.76-19.79], p = 3.14e-48), biliary malignancies (OR[95%CI] = 4.04[3.22-5.07], p = 1.64e-33), nasopharyngeal cancer (OR[95%CI] = 3.26[1.10-9.67], p = 0.03), and primary lymphoid and hematopoietic malignancies (OR[95%CI] = 1.27[1.13-1.44], p = 1.04e-4). Furthermore, 3HB fully mediated the effect of liver fat on susceptibility to DLBCL (OR[95%CI] = 1.076[1.01-1.15], p = 0.034).

CONCLUSIONS

Circulating 3HB is associated with a reduced susceptibility to developing DLBCL, HCC, biliary malignancies, and primary lymphoid and hematopoietic malignancies. The impaired ketogenesis induced by metabolic-dysfunction associated fatty liver disease (MAFLD) contributes to risk of DLBCL.

Silencing of PCK1 mitigates the proliferation and migration of vascular smooth muscle cells and vascular intimal hyperplasia by suppressing STAT3/DRP1-mediated mitochondrial fission

The pathological proliferation and migration of vascular smooth muscle cells (VSMCs) are key processes during vascular neointimal hyperplasia (NIH) and restenosis. Phosphoenolpyruvate carboxy kinase 1 (PCK1) is closely related to a variety of malignant proliferative diseases. However, the role of PCK1 in VSMCs has rarely been investigated. This study aims to examine the role of PCK1 in the proliferation and migration of VSMCs and vascular NIH after injury. In vivo, extensive NIH and increased expression of PCK1 within the neointima are observed in injured arteries. Interestingly, the administration of adeno-associated virus-9 (AAV-9) carrying Pck1 short hairpin RNA (sh Pck1) significantly attenuates NIH and stenosis of the vascular lumen. In vitro, Pck1 small interfering RNA (si Pck1)-induced PCK1 silencing inhibits VSMC proliferation and migration. Additionally, silencing of PCK1 leads to reduced expression of dynamin-related protein 1 (DRP1) and attenuated mitochondrial fission. Lentivirus-mediated DRP1 overexpression markedly reverses the inhibitory effects of PCK1 silencing on VSMC proliferation, migration, and mitochondrial fission. Finally, PCK1 inhibition attenuates the phosphorylation of signal transducer and activator of transcription 3 (STAT3). Activation of STAT3 abolishes the suppressive effects of PCK1 silencing on DRP1 expression, mitochondrial fission, proliferation, and migration in VSMCs. In conclusion, PCK1 inhibition attenuates the mitochondrial fission, proliferation, and migration of VSMCs by inhibiting the STAT3/DRP1 axis, thereby suppressing vascular NIH and restenosis.

Solanum nigrum Toxicity and Its Neuroprotective Effect Against Retinal Ganglion Cell Death Through Modulation of Extracellular Matrix in a Glaucoma Rat Model

Purpose: Glaucoma is a complex degenerative optic neuropathy characterized by loss of retinal ganglion cells (RGCs) leading to irreversible vision loss and blindness. Solanum nigrum has been used for decades in traditional medicine system. However, no extensive studies were reported on its antiglaucoma properties. Therefore, this study was designed to investigate the neuroprotective effects of S. nigrum extract on RGC against glaucoma rat model. Methods: High performance liquid chromatography and liquid chromatography tandem mass spectrometry was used to analyze the phytochemical profile of aqueous extract of S. nigrum (AESN). In vitro, {3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide} (MTT) and H2DCFDA assays were used to determine cell viability and reactive oxygen species (ROS) production in Statens Seruminstitut Rabbit Cornea cells. In vivo, AESN was orally administered to carbomer-induced rats for 4 weeks. Intraocular pressure, antioxidant levels, and electrolytes were determined. Histopathological and immunohistochemical analysis was carried out to evaluate the neurodegeneration of RGC. Results: MTT assay showed AESN exhibited greater cell viability and minimal ROS production at 10 μg/mL. Slit lamp and funduscopy confirmed glaucomatous changes in carbomer-induced rats. Administration of AESN showed minimal peripheral corneal vascularization and restored histopathological alterations such as minimal loss of corneal epithelium and moderate narrowing of the iridocorneal angle. Immunohistochemistry analysis showed increased expression of positive BRN3A cells and decreased matrix metalloproteinase (MMP)-9 activation in retina and cornea, whereas western blot analysis revealed downregulation of extracellular matrix proteins (COL-1 and MMP-9) in AESN-treated rats compared with the diseased group rats. Conclusions: AESN protects RGC loss through remodeling of MMPs and, therefore, can be used for the development of novel neurotherapeutics for the treatment of glaucoma.