miRNA-21-5p is an important contributor to the promotion of injured peripheral nerve regeneration using hypoxia-pretreated bone marrow-derived neural crest cells.

JOURNAL/nrgr/04.03/01300535-202501000-00035/figure1/v/2024-05-14T021156Z/r/image-tiff Our previous study found that rat bone marrow-derived neural crest cells (acting as Schwann cell progenitors) have the potential to promote long-distance nerve repair. Cell-based therapy can enhance peripheral nerve repair and regeneration through paracrine bioactive factors and intercellular communication. Nevertheless, the complex contributions of various types of soluble cytokines and extracellular vesicle cargos to the secretome remain unclear. To investigate the role of the secretome and extracellular vesicles in repairing damaged peripheral nerves, we collected conditioned culture medium from hypoxia-pretreated neural crest cells, and found that it significantly promoted the repair of sensory neurons damaged by oxygen-glucose deprivation. The mRNA expression of trophic factors was highly expressed in hypoxia-pretreated neural crest cells. We performed RNA sequencing and bioinformatics analysis and found that miR-21-5p was enriched in hypoxia-pretreated extracellular vesicles of neural crest cells. Subsequently, to further clarify the role of hypoxia-pretreated neural crest cell extracellular vesicles rich in miR-21-5p in axonal growth and regeneration of sensory neurons, we used a microfluidic axonal dissociation model of sensory neurons in vitro, and found that hypoxia-pretreated neural crest cell extracellular vesicles promoted axonal growth and regeneration of sensory neurons, which was greatly dependent on loaded miR-21-5p. Finally, we constructed a miR-21-5p-loaded neural conduit to repair the sciatic nerve defect in rats and found that the motor and sensory functions of injured rat hind limb, as well as muscle tissue morphology of the hind limbs, were obviously restored. These findings suggest that hypoxia-pretreated neural crest extracellular vesicles are natural nanoparticles rich in miRNA-21-5p. miRNA-21-5p is one of the main contributors to promoting nerve regeneration by the neural crest cell secretome. This helps to explain the mechanism of action of the secretome and extracellular vesicles of neural crest cells in repairing damaged peripheral nerves, and also promotes the application of miR-21-5p in tissue engineering regeneration medicine.

Anti-osteosarcoma trimodal synergistic therapy using NiFe-LDH and MXene nanocomposite for enhanced biocompatibility and efficacy.

Osteosarcoma is usually resistant to immunotherapy and, thus primarily relies on surgical resection and high-dosage chemotherapy. Unfortunately, less invasive or toxic therapies such as photothermal therapy (PTT) and chemodynamic therapy (CDT) generally failed to show satisfactory outcomes. Adequate multimodal therapies with proper safety profiles may provide better solutions for osteosarcoma. Herein, a simple nanocomposite that synergistically combines CDT, PTT, and chemotherapy for osteosarcoma treatment was fabricated. In this composite, small 2D NiFe-LDH flakes were processed into 3D hollow nanospheres via template methods to encapsulate 5-Fluorouracil (5-FU) with high loading capacity. The nanospheres were then adsorbed onto larger 2D Ti3C2 MXene monolayers and finally shielded by bovine serum albumin (BSA) to form 5-FU@NiFe-LDH/Ti3C2/BSA nanoplatforms (5NiTiB). Both in vitro and in vivo data demonstrated that the 5-FU induced chemotherapy, NiFe-LDH driven chemodynamic effects, and MXene-based photothermal killing collectively exhibited a synergistic "all-in-one" anti-tumor effect. 5NiTiB improved tumor suppression rate from <5% by 5-FU alone to ∼80.1%. This nanotherapeutic platform achieved higher therapeutic efficacy with a lower agent dose, thereby minimizing side effects. Moreover, the composite is simple to produce, enabling the fine-tuning of dosages to suit different requirements. Thus, the platform is versatile and efficient, with potential for further development.

Circulating immunotherapy strategy based on pyroptosis and STING pathway: Mn-loaded paclitaxel prodrug nanoplatform against tumor progression and metastasis.

Immunotherapy has emerged as a promising strategy against tumors. However, its efficacy is limited by low immunogenicity, poor antigen presentation, and inadequate lymphocyte infiltration. Herein, we develop a nanoplatform (Mn-HSP) loaded with manganese ions (Mn2+) and paclitaxel (PTX) prodrug based on hyaluronic acid. PTX in Mn-HSP induces DNA damage and pyroptosis to release tumor-associated antigens (TAAs), enhancing tumor-specific adaptive immunity. Meanwhile, Mn2+ in Mn-HSP, together with PTX-induced DNA damage, activates the stimulator of interferon gene (STING) pathway to amplify innate immunity. Mn-HSP combines with adaptive and innate immunity, effectively enhancing the presentation of antigen-presenting cells (APCs) and promoting tumor infiltration of cytotoxic T lymphocytes (CTLs). In turn, the granzyme B (GZMB) secreted by CTLs triggers pyroptosis again, thereby establishing a "circulating immunotherapy" against tumors. Our results demonstrate that Mn-HSP efficiently inhibits primary breast tumors, as well as rechallenge tumors and lung metastasis in vivo. Therefore, the circulating immunotherapy that combines pyroptosis mediated adaptive immunity and STING pathway amplified innate immunity provides a novel strategy for enhancing tumor immunotherapy.

Co-delivery of oxaliplatin prodrug liposomes with Bacillus Calmette-Guérin for chemo-immunotherapy of orthotopic bladder cancer.

To reduce recurrence rate after transurethral resection of bladder tumor, long-term intravesical instillations of Bacillus Calmette-Guérin (BCG) and/or chemotherapeutic drugs is the standard treatment for non-muscle invasive bladder carcinoma. However, the main challenges of intravesical therapy, such as short retention time and poor permeability of drugs in the bladder, often require frequent and high-dose administrations, leading to significant adverse effects and financial burden for patients. Aiming at addressing these challenges, we developed a novel approach, in which the cell-penetrating peptide modified oxaliplatin prodrug liposomes and a low-dose BCG were co-delivered via a viscous chitosan solution (LRO-BCG/CS). LRO-BCG/CS addressed these challenges by significantly improving the retention capability and permeability of chemotherapy agents across the bladder wall. Then, oxaliplatin triggered the immunogenic cell death, and the combination of BCG simultaneously further activated the systemic anti-tumor immune response in the MB49 orthotopic bladder tumor model. As a result, LRO-BCG/CS demonstrated superior anti-tumor efficacy and prolonged the survival time of tumor-bearing mice significantly, even at relatively low doses of oxaliplatin and BCG. Importantly, this combinational chemo-immunotherapy showed negligible side effects, offering a promising and well-tolerated therapeutic strategy for bladder cancer patients.

Loganin alleviated cognitive impairment in 3×Tg-AD mice through promoting mitophagy mediated by optineurin.

ETHNOPHARMACOLOGICAL RELEVANCE: Corni Fructus is a traditional Chinese herb and widely applied for treatment of age-related disorders in China. Iridoid glycoside was considered as the active ingredient of Corni Fructus. Loganin is one of the major iridoid glycosides and quality control components of Corni Fructus. Emerging evidence emphasized the beneficial effect of loganin on neurodegenerative disorders, such as Alzheimer's disease (AD). However, the detailed mechanism underlying the neuroprotective action of loganin remains to be unraveled. AIM OF THE STUDY: To explore the improvement of loganin on cognitive impairment in 3 × Tg-AD mice and reveal the potential mechanism. MATERIALS AND METHODS: Eight-month 3 × Tg-AD male mice were intraperitoneally injected with loganin (20 and 40 mg/kg) for consecutive 21 days. Behavioral tests were used to evaluated the cognition-enhancing effects of loganin, and Nissl staining and thioflavine S staining were performed to analyze neuronal survival and Aß pathology. Western blot analysis, transmission electron microscopy and immunofluorescence were utilized to explore the molecular mechanism of loganin in AD mice involved mitochondrial dynamics and mitophagy. Aß25-35-induced SH-SY5Y cells were applied to verify the potential mechanism in vitro. RESULTS: Loganin significantly mitigated the learning and memory deficit and amyloid ß-protein (Aß) deposition, and recovered synaptic ultrastructure in 3 × Tg-AD mice. Perturbed mitochondrial dynamics characterized by excessive fission and insufficient fusion were restored after loganin treatment. Meanwhile, loganin reversed the increase of mitophagy markers (LC3II, p62, PINK1 and Parkin) and mitochondrial markers (TOM20 and COXIV) in hippocampus of AD mice, and enhanced the location of optineurin (OPTN, a well-known mitophagy receptor) to mitochondria. Accumulated PINK1, Parkin, p62 and LC3II were also revealed in Aß25-35-induced SH-SY5Y cells, which were ameliorated by loganin. Increased OPTN in Aß25-35-treated SH-SY5Y cells was further upregulated by loganin incubation, along with the reduction of mitochondrial ROSand elevation ofmitochondrial membrane potential (MMP). Conversely, OPTN silence neutralized the effect of loganin on mitophagy and mitochondrial function, which is consistent with the finding that loganin presented strong affinity with OPTN measured by molecular docking in silico. CONCLUSIONS: Our observations confirmed that loganin enhanced cognitive function and alleviated AD pathology probably by promoting OPTN-mediated mitophagy,. Loganin might be a potential drug candidate for AD therapy via targeting mitophagy.

Research Progress of Traditional Chinese Medicine Monomers in Reversing Multidrug Resistance of Breast Cancer.

Breast cancer is a malignant disease with an increasing incidence. Chemotherapy is still an important means for breast cancer treatment, but multidrug resistance (MDR) greatly limits its clinical application. Therefore, the high-efficiency MDR reversal agents are urgently needed. Traditional Chinese medicine (TCM) monomers have unique advantages in reversing chemotherapeutic MDR because of its low toxicity, high efficiency, and ability to impact multiple targets. This review firstly summarizes the major mechanisms of MDR in breast cancer, including the reduced accumulation of intracellular chemotherapeutic drugs, the promoted inactivation of intracellular chemotherapeutic drugs, and the enhanced damage repair ability of DNA, etc., and secondly highlights the research progress of 15 kinds of TCM monomers, including curcumin, resveratrol, emodin, apigenin, tetrandrine, gambogic acid, matrine, paeonol, schisandrin B, [Formula: see text]-elemene, astragaloside IV, berberine, puerarin, tanshinone IIA, and quercetin, in reversing MDR of breast cancer. This review also provides the suggestion for the future research of MDR reversal agents in breast cancer.

Microbiologically influenced corrosion of X80 pipeline steel by nitrate reducing bacteria in artificial Beijing soil.

In this work, we investigated microbiologically influenced corrosion (MIC) of X80 pipeline steel caused by nitrate-reducing bacteria Brevibacterium frigoritolerans (B. frigoritolerans) in an artificial Beijing soil using electrochemical measurements and surface analyses under aerobic conditions. The B. frigoritolerans was isolated from the surrounding soil of the X80 pipeline steel specimen in Beijing using culturing and molecular biology techniques. Confocal laser scanning microscopy images showed that the largest pit depth after 14 days due to B. frigoritolerans was approximately 7.16 µm. Electrochemical tests showed that the B. frigoritolerans could change the stability of the corrosion products on the 7th day. Inhomogeneous biofilm and the conductivity of Fe2O3 accelerated the corrosion process. The presence of NH4+ on the surface of the X80 pipeline steel revealed that the B. frigoritolerans acted as a biological cathode to promote the cathodic reaction.

Apocynin Attenuates Acute Kidney Injury and Inflammation in Rats with Acute Hypertriglyceridemic Pancreatitis.

BACKGROUND: Acute hypertriglyceridemic pancreatitis (HTGP) is more likely to be severe and complicated with extrapancreatic organ injury. NOX may be involved in the occurrence and development of high fat acute pancreatitis, but the specific mechanism is not clear. AIMS: To investigate the protective effects of apocynin, an inhibitor of NOX, on kidney injury associated with the HTGP and its potential mechanisms in a rat model. METHODS: In this study, HTGP rat model was induced by intraperitoneal injection of P-407 and L-Arg in combination. Apocynin was given by subcutaneously injection 30 min before the model was induced. The pancreatic and renal histopathology changes were analyzed. Serum AMY, BUN, Cr levels were measured by the Automatic Biochemistry Analyzer. The expression levels of protein associated with NOX/Akt pathway in the kidney were detected. ROS level in kidney and serum was measured by DHE staining and MDA, SOD kits, respectively. Serum TNF-α and IL-6 were detected by ELISA kits. RESULTS: In HTGP group, the levels of serum AMY, BUN, Cr, TNF- α, and IL-6 were significantly increased, and the injury of pancreas and kidney was aggravated. The levels of NOX4, NOX2, ROS, p-Akt, GSK-3ß, NF-κB, and TNF-α in the kidney were detected, suggesting that NOX may regulate the activity of downstream p-Akt and GSK-3ß by regulating ROS levels, thereby affecting the release of inflammatory mediators and regulating HTGP-related kidney injury. After application of apocynin, the expression of NOX4 and NOX2 and the level of ROS in the kidney were reduced, the release of inflammatory mediators decreased, and the histopathology injury of pancreas and kidney was improved obviously. CONCLUSION: NOX may play an important role in HTGP-associated kidney injury through Akt/GSK-3ß pathway. Apocynin can significantly downregulate the level of NOX and play a protective role in HTGP-related kidney injury through Akt/GSK-3ß pathway.

Double-edge Role of B Cells in Tumor Immunity: Potential Molecular Mechanism.

B cells are a heterogeneous population, which have distinct functions of antigen presentation, activating T cells, and secreting antibodies, cytokines as well as protease. It is supposed that the balance among these B cells subpopulation (resting B cells, activated B cells, Bregs, and other differentiated B cells) will determine the ultimate role of B cells in tumor immunity. There has been increasing evidence supporting opposite roles of B cells in tumor immunity, though there are no general acceptable phenotypes for them. Recent years, a new designated subset of B cells identified as Bregs has emerged from immunosuppressive and/or regulatory functions in tumor immune responses. Therefore, transferring activated B cells would be possible to become a promising strategy against tumor via conquering the immunosuppressive status of B cells in future. Understanding the potential mechanism of double-edge role of B cells will help researchers utilize activated B cells to improve their anti-tumor response. Moreover, the molecular pathways related to B cell differentiation are involved in its tumor-promoting effect, such as NF-κB, STAT3, BTK. So, we review the molecular and signaling pathway mechanisms of B cells involved in both tumor-promoting and tumor-suppressive immunity, in order to help researchers optimize B cells to fight cancer better.

Glycogen synthase kinase-3 beta inhibitors protectagainst the acute lung injuries resulting from acute necrotizing pancreatitis.

PURPOSE: The research is intended for clarification of the efficacy as well as the underlying mechanism of GSK-3ß inhibitors on the advancement of acute lung injuries in acute necrotizing pancreatitis (ANP) in rats. METHODS: Seventy-two rats were randomly divided into 6 groups: (1)ANP-vehicle; (2)ANP-TDZD-8;(3)ANP-SB216763;(4)Sham-vehicle;(5)Sham-TDZD-8;(6)Sham-SB216763; Blood biochemical test, histopathological examination and immunohistochemical analysis of rats pancreas and lung tissues were performed. The protein expression of GSK-3ß, phospho-GSK-3ß (Ser9), iNOS, ICAM-1, TNF-α, and IL-10 were detected in lung tissues by Western-blot. RESULTS: The outcomes revealed that the intervention of GSK-3ß inhibitors alleviated the pathological damage of pancreas and lung (P<0.01), reduced serum amylase, lipase, hydrothorax and lung Wet-to-Dry Ratio, attenuated serum concentrations of IL-1ß and IL-6 (P<0.01), inhibited the activation of NF-κB, and abated expression of iNOS, ICAM-1 and TNF-α protein, but up-regulated IL-10 expression in lung of ANP rats (P<0.01). The inflammatory response and various indicators in ANP-TDZD-8 groups were lower than those in ANP-SB216763 groups. CONCLUSIONS: Inhibition of GSK-3ß weakens acute lung injury related to ANP via the inhibitory function of NF-κB signaling pathway. Different kinds of GSK-3ß inhibitors have different effects to ANP acute lung injury.

[Experimental study on the mechanism of glycogen synthase kinase-3ß inhibitor on acute kidney injury of acute necrotizing pancreatitis in rats].

OBJECTIVE: To explore the protective mechanism of glycogen synthase kinase-3ß (GSK-3ß) inhibitor TDZD-8 on acute necrotizing pancreatitis (ANP) associated kidney injury in rats. METHODS: SPF male Wistar rats were randomly divided into four groups (n = 20): sham operation group (Sham group), ANP model group, TDZD-8 intervention group and TDZD-8 control group. The rat ANP model was prepared by retrograde injection of 5% sodium taurocholate into the bile duct; the same volume of normal saline was injected into the pancreatic duct of the Sham group. The TDZD-8 intervention group and the TDZD-8 control group were injected with GSK-3ß inhibitor TDZD-8 (1 mL/kg) via the femoral vein 30 minutes before the model or sham operation; the ANP model group and the Sham group were injected equal volume of 10% dimethyl sulfoxide (DMSO). Rats in each group were sacrificed at 12 hours after operation to measure the serum amylase (AMY), blood lipase (LIPA), serum creatinine (SCr) and blood urea nitrogen (BUN) levels and to observe the pathological changes of pancreatic tissues and kidney tissues. Ultrastructural change of renal cells was analyzed by transmission electron microscopy. Serum interleukin-1ß (IL-1ß) and interleukin-6 (IL-6) levels were evaluated by enzyme linked immunosorbent assay (ELISA). The activation of nuclear factor-ΚBp65 (NF-ΚBp65) was evaluated by immunohistochemistry assay. The protein expressions of GSK-3ß, phospho-GSK-3ß (Ser 9), tumor necrosis factor-α (TNF-α), inducible nitric oxide synthase (iNOS), intercellular adhesion molecule-1 (ICAM-1) and interleukin-10 (IL-10) in the kidney were determined by Western Blot. RESULTS: Compared with the Sham group, the serum and inflammatory factors levels of the ANP model group were significantly increased, the pathological damage of the pancreas and kidney tissues were severe, the histopathological score was significantly increased, the expression of NF-ΚBp65 was enhanced in the nucleus of the kidney tissue, and the expressions of GSK-3ß, TNF-α, ICAM-1 and iNOS were significantly enhanced, and the expressions of p-GSK-3ß(Ser 9) and IL-10 were significantly attenuated. Compared with the ANP model group, TDZD-8 pretreatment significantly reduced serum and inflammatory factor levels in the ANP model group [AMY (kU/L): 5.60±0.30 vs. 10.07±0.34, LIPA (U/L): 1 111.0±110.8 vs. 2 375.0±51.1, SCr (µmol/L): 47.38±1.48 vs. 72.50±2.43, BUN (mmol/L): 17.6±1.0 vs. 26.0±1.0, IL-1ß (ng/L): 195.90±5.50 vs. 332.40±38.29, IL-6 (ng/L): 246.10±26.74 vs. 385.30±32.19, all P < 0.01]; pathological damage of pancreas and kidney tissue (histopathological score: 7.1±0.4 vs. 12.1±0.3, 301.2±7.5 vs. 433.5±13.8, both P < 0.01) and ultrastructural damage of renal cells were alleviated; the expression of NF-ΚBp65 in the nucleus was significantly decreased; the expression of p-GSK-3ß (Ser 9) was significantly increased, and blocking GSK-3ß activity could inhibit the expressions of TNF-α, ICAM-1, iNOS and increase the expression of IL-10, while the expression of GSK-3ß in renal tissues was not statistically significant. There were no significant differences between the TDZD-8 control group and the Sham group. CONCLUSIONS: Blockade of GSK-3ß activity by TDZD-8 exerts the protective effect against kidney injury by inhibiting the inflammation signaling pathway in ANP. It can alleviate histopathological and ultrastructural changes in kidney injury, which protection mechanism is mediated by NF-ΚB and its related inflammatory mediators.

LINC00052 functions as a tumor suppressor through negatively modulating miR-330-3p in pancreatic cancer.

Pancreatic cancer is a serious solid malignant tumor worldwide. Increasing evidence has pointed out that abnormal expressions of long noncoding RNAs are involved in various tumors. Meanwhile, LINC00052 is reported as a famous tumor regulator in several cancers. Nevertheless, the biological role of LINC00052 in pancreatic cancer progression is still unknown. Our study was to explore the specific mechanism of LINC00052 in pancreatic cancer. First, we observed that the LINC00052 was obviously downregulated in several pancreatic cancer cell lines. Overexpression of LINC00052 greatly repressed AsPC-1 and SW1990 cell proliferation, triggered the apoptosis and prevented cell cycle in the G1 phase. For another, AsPC-1 and SW1990 cell migration and invasion capacity were also obviously repressed by LINC00052 upregulation. Moreover, miR-330-3p was elevated in pancreatic cancer cells and can function as a target of LINC00052 confirmed by luciferase reporter and RNA Immunoprecipitation (RIP) experiments. Inhibition of miR-330-3p could depress pancreatic cancer progression while overexpressed miR-330-3p exhibited an opposite process. Finally, our data indicated that the LINC00052 also remarkably suppressed pancreatic tumor growth via modulating miR-330-3p in vivo. To conclude, our study revealed that the LINC00052 might provide a new perspective for pancreatic cancer therapy.

Glycogen synthase kinase-3 beta inhibitors protectagainst the acute lung injuries resulting from acute necrotizing pancreatitis

Abstract Purpose The research is intended for clarification of the efficacy as well as the underlying mechanism of GSK-3β inhibitors on the advancement of acute lung injuries in acute necrotizing pancreatitis (ANP) in rats. Methods Seventy-two rats were randomly divided into 6 groups: (1)ANP-vehicle; (2)ANP-TDZD-8;(3)ANP-SB216763;(4)Sham-vehicle;(5)Sham-TDZD-8;(6)Sham-SB216763; Blood biochemical test, histopathological examination and immunohistochemical analysis of rats pancreas and lung tissues were performed. The protein expression of GSK-3β, phospho-GSK-3β (Ser9), iNOS, ICAM-1, TNF-α, and IL-10 were detected in lung tissues by Western-blot. Results The outcomes revealed that the intervention of GSK-3β inhibitors alleviated the pathological damage of pancreas and lung (P<0.01), reduced serum amylase, lipase, hydrothorax and lung Wet-to-Dry Ratio, attenuated serum concentrations of IL-1β and IL-6 (P<0.01), inhibited the activation of NF-κB, and abated expression of iNOS, ICAM-1 and TNF-α protein, but up-regulated IL-10 expression in lung of ANP rats (P<0.01). The inflammatory response and various indicators in ANP-TDZD-8 groups were lower than those in ANP-SB216763 groups. Conclusions Inhibition of GSK-3β weakens acute lung injury related to ANP via the inhibitory function of NF-κB signaling pathway. Different kinds of GSK-3β inhibitors have different effects to ANP acute lung injury.

Histone demethylase JMJD1A promotes colorectal cancer growth and metastasis by enhancing Wnt/ß-catenin signaling.

The histone demethylase Jumonji domain containing 1A (JMJD1A) is overexpressed in multiple tumors and promotes cancer progression. JMJD1A has been shown to promote colorectal cancer (CRC) progression, but its molecular role in CRC is unclear. Here, we report that JMJD1A is overexpressed in CRC specimens and that its expression is positively correlated with that of proliferating cell nuclear antigen (PCNA). JMJD1A knockdown decreased the expression of proliferative genes such as c-Myc, cyclin D1, and PCNA, suppressed CRC cell proliferation, arrested cell cycle progression, and reduced xenograft tumorigenesis. Furthermore, JMJD1A knockdown inhibited CRC cell migration, invasion, and lung metastasis by decreasing matrix metallopeptidase 9 (MMP9) expression and enzymatic activity. Moreover, bioinformatics analysis of GEO profile datasets revealed that JMJD1A expression in human CRC specimens is positively correlated with the expression of Wnt/ß-catenin target genes, including c-Myc, cyclin D1, and MMP9. Mechanistically, JMJD1A enhanced Wnt/ß-catenin signaling by promoting ß-catenin expression and interacting with ß-catenin to enhance its transactivation. JMJD1A removed the methyl groups of H3K9me2 at the promoters of c-Myc and MMP9 genes. In contrast, the JMJD1AH1120Y variant, which lacked demethylase activity, did not demethylate H3K9me2 at these promoters, failed to assist ß-catenin to induce the expression of Wnt/ß-catenin target genes, and failed to promote CRC progression. These findings suggest that JMJD1A's demethylase activity is required for Wnt/ß-catenin activation. Of note, high JMJD1A levels in CRC specimens predicted poor cancer outcomes. In summary, JMJD1A promotes CRC progression by enhancing Wnt/ß-catenin signaling, implicating JMJD1A as a potential molecular target for CRC management.

Polychlorinated biphenyl quinone induces mitochondrial-mediated and caspase-dependent apoptosis in HepG2 cells.

Polychlorinated biphenyl (PCB) quinones are known to cause toxic effects, but their mechanisms are quite unclear. In this study, we examined whether 2,3,5-trichloro-6-phenyl-[1,4]benzoquinone, PCB29-pQ, induces cell death via apoptosis pathway. Our result showed PCB29-pQ exposure decreased HepG2 cell viability in a time-dependent manner. Lactate dehydrogenase leakage assay also implied the cytotoxicity of PCB29-pQ. 4',6-Diamidino-2-phenylindole dihydrochloride staining and flow cytometry assays both confirmed PCB29-pQ caused dose-dependent apoptotic cell death in HepG2 cells. Furthermore, we found that PCB29-pQ exposure increased cellular reactive oxygen species (ROS) level, decreased mitochondrial membrane potential and induced the translocation of cytochrome c from mitochondria into cytosol in HepG2 cells. Moreover, PCB29-pQ exposure induced B-cell lymphoma 2 (Bcl-2) downregulation and Bcl-2-associated X (Bax) upregulation, poly(ADP-ribose) polymerase cleavage, accompanied with the increased caspase-3/9 and p53 expressions. Taking together, these results suggested PCB29-pQ induced HepG2 cells apoptosis through a ROS-driven, mitochondrial-mediated and caspase-dependent pathway.

A CAPE analogue as novel antiplatelet agent efficiently inhibits collagen-induced platelet aggregation.

OBJECTIVE: Platelet activation plays a pivotal role in the pathogenesis of thrombosis, which can lead to fatal diseases such as myocardial or cerebral infarction, and atherosclerosis. The present study focused on investigating the effect of CAPE-NO2 against collagen-induced platelet aggregation. METHODS: Caffeic acid phenethyl ester (CAPE) is an active component in propolis. CAPE-NO2 is a nitro derivative of CAPE. Its effects on rat platelet aggregation induced by collagen were tested in vitro and the potential mechanisms underlying the activities were investigated. RESULTS: CAPE-NO2 significantly inhibited collagen-induced platelet aggregation in a concentration-dependent manner. It also reduced TXB2 formation and COX-1 activity in collagen-activated platelets. Moreover, CAPE-NO2 caused an increase in NO production and cGMP levels and attenuated 5-HT release in the collagen-activated platelets. CONCLUSION: These findings suggest that the inhibitory mechanism of CAPE-NO2 on collagen-induced platelet aggregation might be associated with the down-regulation of TXB2, COX-1 and 5-HT and the elevation of NO and cGMP production. These indicators are closely related to platelet function. So CAPE-NO2 may be a promising candidate for the extension of the current spectrum of antiplatelet drugs.