Excessive Apoptosis Research Articles

The angiotensin II type 1 receptor mediates the induction of oxidative stress, apoptosis, and autophagy in HUVECs induced by angiotensin II

Angiotensin (Ang) II, which is the central effector of the renin-angiotensin system (RAS), is one of the principal mediators of vascular dysfunction in hypertension and cardiovascular diseases. Proper vascular function is mediated by oxidative stress, cell apoptosis, and autophagy. However, the underlying signaling pathways and the major RAS components involved in this process are still not fully understood. In the present study, the effect of Ang II on reactive oxygen species (ROS) production, apoptosis induction, and autophagy in human umbilical vein endothelial cells (HUVECs) was investigated. An Annexin V kit was used for the apoptosis analysis, and caspase-3/7 activities were measured with the Caspase-Glo 3/7 Assay Kit. ROS production was measured using a 2,7-dichlorodihydrofluorescein diacetate probe whereas detection of autophagy was performed using acridine orange staining. We found that Ang II increases oxidative stress via ROS production, cell apoptosis via caspase 3/7, and the mitochondrial membrane potential (MMP). Interestingly, losartan, being an antagonist of the angiotensin II type 1 receptor (AT1R), has demonstrated the ability to restore autophagy levels to that of the control group subsequent to its induction by Ang II. The latter can thus induce endothelial cell damage, through excessive oxidative stress and defective autophagy-related apoptosis, which can be inhibited by losartan. These findings reinforce the pivotal role played by the Ang II/AT1R axis in the pathogenesis of vascular damage and bolster our knowledge of the role played by ROS/autophagy-related apoptosis via AT1R in the pathogenesis of hypertension and vascular diseases.

RIPK3 cleavage is dispensable for necroptosis inhibition but restricts NLRP3 inflammasome activation.

Caspase-8 activity is required to inhibit necroptosis during embryogenesis in mice. In vitro studies have suggested that caspase-8 directly cleaves RIPK1, CYLD and the key necroptotic effector kinase RIPK3 to repress necroptosis. However, recent studies have shown that mice expressing uncleavable RIPK1 die during embryogenesis due to excessive apoptosis, while uncleavable CYLD mice are viable. Therefore, these results raise important questions about the role of RIPK3 cleavage. To evaluate the physiological significance of RIPK3 cleavage, we generated Ripk3D333A/D333A mice harbouring apoint mutation in the conserved caspase-8 cleavage site. These mice are viable, demonstrating that RIPK3 cleavage is not essential for blocking necroptosis during development. Furthermore, unlike RIPK1 cleavage-resistant cells, Ripk3D333A/D333A cells were not significantly more sensitive to necroptotic stimuli. Instead, we found that the cleavage of RIPK3 by caspase-8 restricts NLRP3 inflammasome activation-dependent pyroptosis and IL-1β secretion when Inhibitors of APoptosis (IAP) are limited. These results demonstrate that caspase-8 does not inhibit necroptosis by directly cleaving RIPK3 and further underscore a role for RIPK3 in regulating the NLRP3 inflammasome.

Polysaccharide of Atractylodes macrocephala Koidz alleviates LPS-induced proliferation, differentiation inhibition and excessive apoptosis in chicken embryonic myogenic cells.

Lipopolysaccharide (LPS) can induce systemic inflammation and affect the growth and development of poultry. As a kind of traditional Chinese medicine, polysaccharide of Atractylodes macrocephala Koidz (PAMK) can effectively improve the growth performance of animals and improve the immunity of animal bodies. The purpose of this study was to investigate the effects of PAMK on LPS-induced inflammatory response, proliferation, differentiation and apoptosis of chicken embryonic myogenic cells. We used chicken embryonic myogenic cells as a model by detecting EdU/MYHC immunofluorescence, the expression of inflammation, proliferation, differentiation-related genes and proteins and the number of apoptotic cells in the condition of adding LPS, PAMK, belnacasan (an inhibitor of Caspase1) or their combinations. The results showed that LPS stimulation increased the expression of inflammatory factors, inhibited proliferation and differentiation, and excessive apoptosis in chicken embryonic myogenic cells, and PAMK alleviated these adverse effects induced by LPS. After the addition of belnacasan (inhibitor of Caspase1), apoptosis in myogenic cells was inhibited, and therefore, the number of apoptotic cells and the expression of pro-apoptotic genes Caspase1 and Caspase3 were increased. In addition, belnacasan inhibited the increased expression of inflammatory factors, inhibited proliferation, differentiation and excessive apoptosis in chicken embryonic myogenic cells induced by LPS. This study provides a theoretical basis for further exploring the mechanism of action of PAMK and exogenous LPS on chicken embryonic myogenic cells and lays the foundation for the development and application of green feed additives in animal husbandry industry.

TFEB ameliorates DEHP-induced neurotoxicity by activating GAL3/TRIM16 axis dependent lysophagy and alleviating lysosomal dysfunction.

Di-(2-ethylhexyl) phthalate (DEHP) is a commonly used plasticizer with known neurotoxic effects. However, the specific mechanism underlying this neurotoxicity remains unclear. This study aimed to investigate the role of lysosomal function and lysophagy in DEHP-induced neurotoxicity, with a particular focus on the regulatory role of Transcription factor EB (TFEB). To achieve this, we utilized in vitro models of DEHP-exposed SH-SY5Y cells and HT22 cells. Our findings revealed that DEHP exposure led to lysosomal damage and dysfunction. Moreover, we observed impaired autophagic degradation, characterized by elevated levels of LC3II and p62. DEHP treatment downregulated the expression of TFEB, GAL3, and TRIM16, while upregulating the expression of PARP. This led to the inhibition of GAL3/TRIM16 axis dependent lysophagy and ultimately excessive apoptosis in neuronal cells. Importantly, TFEB overexpression alleviated lysosomal dysfunction, activated lysophagy, and mitigated DEHP-induced apoptosis. Overall, our results suggest that DEHP induces not only lysosomal dysfunction, but also inhibits lysophagy through the suppression of GAL3/TRIM16 axis. Consequently, impaired clearance of damaged lysosomes occurs, culminating in neuronal apoptosis. Taken together, our findings highlight the critical role of TFEB in regulating lysophagy and lysosomal function. Furthermore, TFEB may serve as a potential therapeutic target for mitigating DEHP-induced neuronal toxicity.

Circ_0098823 binding with IGF2BP3 regulates DNM1L stability to promote metastasis of hepatocellular carcinoma via mitochondrial fission.

Hepatocellular carcinoma (HCC) is highly metastatic and invasive. CircRNA participates in gene regulation of multiple tumor metastases, but little is known whether it is a bystander or an actual player in HCC metastasis. We aim to explore the molecular mechanisms of novel circRNAs in HCC metastasis. RT-qPCR was used to detect the expression of 13 circRNAs derived by the ERBB3 gene. The function of circ_0098823 and DNM1L in HCC cells were estimated by CCK-8, transwell assays, flow cytometry, electron microscope, and in vivo experiments. RNA binding protein of circ_0098823 was confirmed by RNA pull-down, mass spectrometry, and RNA immunoprecipitation. The expression of DNM1L after IGF2BP3 knockdown was detected by RT-qPCR and western blot. Circ_0098823 was significantly up-regulated both in HCC tissues and HGF induced cell lines. Circ_0098823 overexpression significantly enhanced proliferation, migration, and invasion but decreased apoptosis of HCC cells, particularly promoted mitochondrial fission. Compared with the control group, the tumors in the circ_0098823 knockdown mice were significantly smaller and lighter. Circ_0098823 silencing suppressed DNM1L expression, a key molecule for fission, which enhanced proliferation, migration and invasion, and inhibited apoptosis of HCC cell. IGF2BP3 was a binding protein of circ_0098823. The expression and mRNA stability of DNM1L were down-regulated by IGF2BP3 knockdown. IGF2BP3 knockdown significantly alleviated the excessive migration, invasion and apoptosis of HCC cells caused by circ_0098823 overexpression. This study uncovered a novel circ_0098823 with tumor-promoting effect, and the mechanism by which circ_0098823 participates in HCC progression through IGF2BP3-guided DNM1L. Our study broadens molecular understanding of HCC progression.

Exposure to high dose of polystyrene nanoplastics causes trophoblast cell apoptosis and induces miscarriage

BackgroundWith rapid increase in the global use of various plastics, microplastics (MPs) and nanoplastics (NPs) pollution and their adverse health effects have attracted global attention. MPs have been detected out in human body and both MPs and NPs showed female reproductive toxicological effects in animal models. Miscarriage (abnormal early embryo loss), accounting for 15-25% pregnant women worldwide, greatly harms human reproduction. However, the adverse effects of NPs on miscarriage have never been explored.ResultsIn this study, we identified that polystyrene (PS) plastics particles were present in women villous tissues. Their levels were higher in villous tissues of unexplained recurrent miscarriage (RM) patients vs. healthy control (HC) group. Furthermore, mouse assays further confirmed that exposure to polystyrene nanoplastics (PS-NPs, 50 nm in diameter, 50 or 100 mg/kg) indeed induced miscarriage. In mechanism, PS-NPs exposure (50, 100, 150, or 200 µg/mL) increased oxidative stress, decreased mitochondrial membrane potential, and increased apoptosis in human trophoblast cells by activating Bcl-2/Cleaved-caspase-2/Cleaved-caspase-3 signaling through mitochondrial pathway. The alteration in this signaling was consistent in placental tissues of PS-NPs-exposed mouse model and in villous tissues of unexplained RM patients. Supplement with Bcl-2 could efficiently suppress apoptosis in PS-NPs-exposed trophoblast cells and reduce apoptosis and alleviate miscarriage in PS-NPs-exposed pregnant mouse model.ConclusionsExposure to PS-NPs activated Bcl-2/Cleaved-caspase-2/Cleaved-caspase-3, leading to excessive apoptosis in human trophoblast cells and in mice placental tissues, further inducing miscarriage.Graphical

Silybin Alleviated Hepatic Injury by Regulating Redox Balance, Inflammatory Response, and Mitochondrial Function in Weaned Piglets under Paraquat-Induced Oxidative Stress.

Silybin (Si) is the main element of silymarin isolated from the seeds of Silybum marianum L. Gaernt., which has superior antioxidant properties. However, the protective role of Si in maintaining liver health under oxidative stress remains ambiguous. This study aimed to investigate the underlying mechanism of the beneficial effect of dietary Si against hepatic oxidative injury induced by paraquat (PQ) in weaned piglets. A total of 24 piglets were randomly allocated to four treatments with six replicates per treatment and 1 piglet per replicate: the control group; Si group; PQ group; and Si + PQ group. Piglets in the control group and PQ group were given a basal diet, while piglets in the Si and Si + PQ groups were given a Si-supplemented diet. On the 18th day, the pigs in the PQ treatment group received an intraperitoneal injection of PQ, and the others were intraperitoneally injected with the same volume of saline. All piglets were sacrificed on day 21 for plasma and liver sample collection. The results showed that dietary Si supplementation mitigated PQ-induced liver damage, as proven by the reduction in liver pathological changes and plasma activity of alanine transaminase and aspartate transaminase. Si also improved superoxide dismutase and glutathione peroxidase activities and total antioxidant capacity, as well as decreased malondialdehyde and hydrogen peroxide concentration in the liver, which were closely related to the activation of the nuclear factor-erythroid 2-related factor 2 signaling pathway. Meanwhile, Si reduced tumor necrosis factor-α and interleukin-8 production and their transcript levels as well as abrogated the overactivation of nuclear factor-κB induced by PQ. Importantly, Si improved mitochondrial function by maintaining mitochondrial energetics and mitochondrial dynamics, which was indicated by the elevated activity of mitochondrial complexes I and V and adenosine triphosphate content, decreased expression of dynamin 1 protein, and increased expression of mitofusin 2 protein. Moreover, Si inhibited excessive hepatic apoptosis by regulating the B-cell lymphoma-2 (Bcl-2)/Bcl-2-associated-X-protein signaling pathway. Taken together, these results indicated that Si potentially mitigated PQ-induced hepatic oxidative insults by improving antioxidant capacity and mitochondrial function and inhibiting inflammation and cell apoptosis in weaned piglets.

Human amniotic mesenchymal stromal cell-derived exosomes promote neuronal function by inhibiting excessive apoptosis in a hypoxia/ischemia-induced cerebral palsy model: A preclinical study

BackgroundCerebral palsy (CP) is a condition resulting from perinatal brain injury and can lead to physical disabilities. Exosomes derived from human amniotic mesenchymal stromal cells (hAMSC-Exos) hold promise as potential therapeutic options. ObjectiveThis study aimed to investigate the impact of hAMSC-Exos on neuronal cells and their role in regulating apoptosis both in vitro and in vivo. MethodshAMSC-Exos were isolated via ultracentrifugation and characterized via transmission electron microscopy, particle size analysis, and flow cytometry. In vitro, neuronal damage was induced by lipopolysaccharide (LPS). CP rat models were established via left common carotid artery ligation. Apoptosis levels in cells and CP rats were assessed using flow cytometry, quantitative reverse transcription polymerase chain reaction (RT–qPCR), Western blotting, and TUNEL analysis. ResultsThe results demonstrated successful isolation of hAMSC-Exos via ultracentrifugation, as the isolated cells were positive for CD9 (79.7%) and CD63 (80.2%). Treatment with hAMSC-Exos significantly mitigated the reduction in cell viability induced by LPS. Flow cytometry revealed that LPS-induced damage promoted apoptosis, but this effect was attenuated by treatment with hAMSC-Exos. Additionally, the expression of caspase-3 and caspase-9 and the Bcl-2/Bax ratio indicated that excessive apoptosis could be attenuated by treatment with hAMSC-Exos. Furthermore, tail vein injection of hAMSC-Exos improved the neurobehavioral function of CP rats. Histological analysis via HE and TUNEL staining showed that apoptosis-related damage was attenuated following hAMSC-Exo treatment. ConclusionsIn conclusion, hAMSC-Exos effectively promote neuronal cell survival by regulating apoptosis, indicating their potential as a promising therapeutic option for CP that merits further investigation.

Does a therapeutical dose of ivermectin impairs testicular homeostasis of rats via excessive apoptosis?

Ivermectin is a medication used to treat parasite infestations in humans and in veterinary medicine. Previously we showed that therapeutical doses of ivermectin impaired spermatogenesis and spermiogenesis in adult rats. The present study was proposed to understand the pathophysiological mechanism that triggered these impairments induced by ivermectin. It was a particular objective to study if ivermectin induced excessive apoptosis. Adult rats were treated with a therapeutical dose of ivermectin (subcutaneously). Their testis was evaluated for the expression of caspase-3 (a marker of apoptosis), using immunohistochemistry techniques. Results revealed that ivermectin treatment increased the expression of caspase-3 (labeled seminiferous tubules and strongly labeled tubules), as well as increased the number of tubules that presented labeled cells in the tubular lumen, compared to the data of the control group. In conclusion, a therapeutical dose of ivermectin induced expressive apoptosis in cells of the seminiferous tubules of rats, affecting the testicular natural homeostasis process, which resulted in the spermatogenesis and spermiogenesis impairments previously reported.

Amphiregulin improves ventricular remodeling after myocardial infarction by modulating autophagy and apoptosis.

Myocardial infarction (MI) is defined as sudden ischemic death of myocardial tissue. Amphiregulin (Areg) regulates cell survival and is crucial for the healing of tissues after damage. However, the functions and mechanisms of Areg after MI remain unclear. Here, we aimed to investigate Areg's impact on myocardial remodeling. Mice model of MI was constructed and Areg-/- mice were used. Expression of Areg was analyzed using western blotting, RT-qPCR, flow cytometry, and immunofluorescence staining. Echocardiographic analysis, Masson's trichrome, and triphenyltetrazolium chloride staining were used to assess cardiac function and structure. RNA sequencing was used for unbiased analysis. Apoptosis and autophagy were determined by western blotting, TUNEL staining, electron microscopy, and mRFP-GFP-LC3 lentivirus. Lysosomal acidity was determined by Lysotracker staining. Areg was elevated in the infarct border zone after MI. It was mostly secreted by macrophages. Areg deficiency aggravated adverse ventricular remodeling, as reflected by worsening cardiac function, a lower survival rate, increased scar size, and interstitial fibrosis. RNA sequencing analyses showed that Areg related to the epidermal growth factor receptor (EGFR), phosphoinositide 3-kinase/protein kinase B (PI3K-Akt), mammalian target of rapamycin (mTOR) signaling pathways, V-ATPase and lysosome pathways. Mechanistically, Areg exerts beneficial effects via increasing lysosomal acidity to promote autophagosome clearance, and activating the EGFR/PI3K/Akt/mTOR signaling pathway, subsequently inhibiting excessive autophagosome formation and apoptosis in cardiomyocytes. This study provides a novel evidence for the role of Areg in inhibiting ventricular remodeling after MI by regulating autophagy and apoptosis and identifies Areg as a potential therapeutic target in ventricular remodeling after MI.

Fucoxanthin Alleviates Dextran Sulfate Sodium-Induced Colitis and Gut Microbiota Dysbiosis in Mice.

The purpose of this study was to evaluate the preventive role and underlying mechanisms of fucoxanthin (Fx) on dextran sulfate sodium (DSS)-induced colitis in mice. The present data demonstrated that oral administration of Fx (50 and 200 mg/kg body weight/day) for 36 days significantly alleviated the severity of colitis in DSS-treated mice, as evidenced by attenuating body weight loss, bloody stool, diarrhea, shortened colon length, colonic epithelium distortion, a thin mucus layer, goblet cell depletion, damaged crypts, and extensive infiltration of inflammatory cells in the colonic mucosa. Additionally, Fx notably relieved DSS-induced intestinal epithelial barrier dysfunction via maintaining the tight junction function and preventing excessive apoptosis of colonic epithelial cells. Moreover, Fx effectively diminished colonic inflammation and oxidative stress in DSS-treated mice, and its mechanisms might be due to blunting the activation of NF-κB and NLRP3 inflammasome signaling pathways. Furthermore, Fx also modulates DSS-induced gut microbiota dysbiosis via recovering the richness and diversity of gut microbiota and reshaping the structure of gut microbiota, such as increasing the Firmicutes and Bacteroidota (F/B) ratio and elevating the relative abundance of some potential beneficial bacteria, including Lactobacillaceae and Lachnospiraceae. Overall, Fx might be developed as a promising functional ingredient to prevent colitis and maintain intestinal homeostasis.

Explore on the Mechanism of miRNA-146a/TAB1 in the Regulation of Cellular Apoptosis and Inflammation in Ulcerative Colitis Based on NF-κB Pathway.

Ulcerative colitis (UC) is a chronic non-specific inflammatory disease of the rectum and colon with unknown etiology. A growing number of evidence suggest that the pathogenesis of UC is related to excessive apoptosis and production of inflammatory cytokines. However, the functions and molecular mechanisms associated with UC remain unclear. The in vivo and in vitro models of UC were established in this study. MiRNA or gene expression was measured by qRT-PCR assay. ELISA, CCK-8, TUNEL, and flow cytometry assays were applied for analyzing cellular functions. The interactions between miR-146a and TAB1 were verified by luciferase reporter and miRNA pull-down assays. MiR-146a was obviously increased in UC patients, DSS-induced colitis mice, and TNF-ɑ-induced YAMC cells, when compared to the corresponding controls. MiR- 146a knockdown inhibited the inflammatory response and apoptosis in DSS-induced colitis mice and TNF-ɑ-induced YAMC cells. Mechanistically, we found that TAB1 was the target of miR-146a and miR-146a knockdown suppressed the activation of NF-κB pathway in UC. More importantly, TAB1 could overturn the inhibitory effect of antagomiR-146a on cell apoptosis and inflammation in UC. MiR-146a knockdown inhibited cell apoptosis and inflammation via targeting TAB1 and suppressing NF-κB pathway, suggesting that miR-146a may be a new therapeutic target for UC treatment.

The role of ERp29/FOS/EMT pathway in excessive apoptosis of placental trophoblast cells in intrahepatic cholestasis of pregnancy

BackgroundAbnormal bile acid metabolism leading to changes in placental function during pregnancy. To determine whether endoplasmic reticulum protein 29 (ERp29) can mediate the pregnancy effects of cholestasis by altering the level of trophoblast cell apoptosis. MethodsERp29 in serum of 66 intrahepatic cholestasis of pregnancy (ICP) pregnant women and 74 healthy were detected by ELISA. Subcutaneous injection of ethinyl estradiol (E2) was used to induce ICP in pregnant rats. Taurocholic acid (TCA) was used to simulate the ICP environment, and TGF-β1 was added to induce the epithelial mesenchymal transformation (EMT) process. The scratch, migration, and invasion test were used to detect the EMT process. ERp29 overexpression/knockdown vector were constructed and transfected to verify the role of ERp29 in the EMT process. Downstream gene was obtained through RNA-seq. ResultsCompared with the healthy pregnant women, the expression levels of ERp29 in serum of ICP pregnancy women were significantly increased (P < 0.001). ERp29 in the placenta tissue of the ICP pregnant rats increased significantly, and the level of apoptosis increased. The placental tissues of the ICP had high expression of E-cadherin and low expression of N-cadherin, snail1, vimentin. After HTR-8/SVneo cells were induced by TCA, EMT was inhibited, while the ERp29 increased. Cell and animal experiments showed that, knockdown of ERp29 reduced the inhibition of EMT, the ICP progress was alleviated. Overexpression of FOS salvaged the inhibitory effects of ERp29 on cell EMT. DiscussionThe high level of ERp29 in placental trophoblast cells reduced FOS mRNA levels, inhibited the EMT process and aggravated the occurrence and development of ICP.

Antioxidative Potential and Activity of Potassium Polyacrylate and Coenzyme Q10 on Rat Hepatic Mitochondrial Permeability Transition Pores

Multiple biological activities of coenzyme Q10 have been demonstrated, opening up opportunities for research and development. The biological action of potassium polyacrylate and its impact on the mitochondrial permeability transition (mPT) pores, however, are both poorly understood. Therefore, this study investigated the in vitro antioxidative potential of potassium polyacrylate (PCK) and coenzyme Q10 (CoQ10) and their effects on mitochondrial permeability transition pores. In vitro antioxidant and angiotensin-converting enzyme inhibitory activities were determined using standard procedures, and lipid peroxidation was also determined. Mitochondrial swelling was assessed as the change in absorbance under succinate-energized conditions. Cytochrome c release and mitochondrial ATPase activity were assessed as previously reported. The results showed that PCK and CoQ10 significantly scavenged DPPH and nitric oxide radicals in a concentration-dependent manner and exhibited a greater ferric-reducing antioxidant potential. PCK showed a high DPPH radical scavenging ability with the lowest IC50 value of 54.05 µg/mL while CoQ10 exhibited higher reducing power with the IC50 value of 82.14 µg/mL. It was also observed that they both inhibited angiotensin-converting enzyme activity. Moreover, PCK and CoQ10 significantly (p&lt;0.05) prevented lipid peroxidation, modulated the opening of mitochondrial permeability transition (mPT) pores and caused no significant release of cytochrome c. However, CoQ10 showed a mild inductive effect on mPT pores at higher concentrations. PCK and CoQ10 also enhanced mitochondrial ATPase activity. The findings from this study suggest that both PCK and CoQ10 could be useful in the management of diseases in which excessive apoptosis is characterized by excessive tissue degeneration, such as neurodegenerative conditions.

Astaxanthin Inhibits H2O2-Induced Excessive Mitophagy and Apoptosis in SH-SY5Y Cells by Regulation of Akt/mTOR Activation.

Oxidative stress, which damages cellular components and causes mitochondrial dysfunction, occurs in a variety of human diseases, including neurological disorders. The clearance of damaged mitochondria via mitophagy maintains the normal function of mitochondria and facilitates cell survival. Astaxanthin is an antioxidant known to have neuroprotective effects, but the underlying mechanisms remain unclear. This study demonstrated that astaxanthin inhibited H2O2-induced apoptosis in SH-SY5Y cells by ameliorating mitochondrial damage and enhancing cell survival. H2O2 treatment significantly reduced the levels of activated Akt and mTOR and induced mitophagy, while pretreatment with astaxanthin prevented H2O2-induced inhibition of Akt and mTOR and attenuated H2O2-induced mitophagy. Moreover, the inhibition of Akt attenuated the protective effect of astaxanthin against H2O2-induced cytotoxicity. Taken together, astaxanthin might inhibit H2O2-induced apoptosis by protecting mitochondrial function and reducing mitophagy. The results also indicate that the Akt/mTOR signaling pathway was critical for the protection of astaxanthin against H2O2-induced cytotoxicity. The results from the present study suggest that astaxanthin can reduce neuronal oxidative injury and may have the potential to be used for preventing neurotoxicity associated with neurodegenerative diseases.

E3 ligase TRIM65 alleviates intestinal ischemia/reperfusion injury through inhibition of TOX4-mediated apoptosis

Intestinal ischemia-reperfusion (II/R) injury is an urgent clinical disease with high incidence and mortality, and impaired intestinal barrier function caused by excessive apoptosis of intestinal cells is an important cause of its serious consequences. Tripartite motif-containing protein 65 (TRIM65) is an E3 ubiquitin ligase that is recently reported to suppress the inflammatory response and apoptosis. However, the biological function and regulation of TRIM65 in II/R injury are totally unknown. We found that TRIM65 was significantly decreased in hypoxia-reoxygenation (H/R) induced intestinal epithelial cells and II/R-induced intestine tissue. TRIM65 knockout mice markedly aggravated intestinal apoptosis and II/R injury. To explore the molecular mechanism of TRIM65 in exacerbating II/R-induced intestinal apoptosis and damage, thymocyte selection-associated high mobility group box factor 4 (TOX4) was screened out as a novel substrate of TRIM65 using the yeast two-hybrid system. TRIM65 binds directly to the N-terminal of TOX4 through its coiled-coil and SPRY structural domains. Immunofluorescence confocal microscopy showed that they can co-localize both in the cytoplasm and nucleus. Furthermore, TRIM65 mediated the K48 ubiquitination and degradation of TOX4 depending on its E3 ubiquitin ligase activity. In addition, TRIM65 inhibits H/R-induced intestinal epithelial apoptosis via TOX4. In summary, our results indicated that TRIM65 promotes ubiquitination and degradation of TOX4 to inhibit apoptosis in II/R. These findings provide a promising target for the clinical treatment of II/R injury.

Mechanism study of oleanolic acid derivative, K73-03, inducing cell apoptosis in hepatocellular carcinoma

Oleanolic acid (3β-hydroxyolean-12-en-28-oic acid, OA) is a kind of pentacyclic triterpene, which widely distributes in nature. OA possesses a powerful anti-cancer effect; however, its low solubility limits its bioavailability and application. In this study, a new OA derivative, K73-03, was used to determine its effect on liver cancer cells and detailed molecular mechanisms. Here, we show that K73-03 may lead to the disorder of mitochondria in HepG2 cells, leading to excessive ROS production and apoptosis in cells. Meanwhile, K73-03 could induce cell apoptosis by inhibiting JAK2/STAT3 pathway and NF-κB/P65 pathway. Collectively, this study may provide a preliminary basis for further cancer treatment of hepatocellular carcinoma.

Inhibition of miR-144-3p/FOXO1 Attenuates Diabetic Keratopathy Via Modulating Autophagy and Apoptosis.

Diabetic keratopathy (DK) is a vision-threatening disease that occurs in people with diabetes. Mounting evidence indicates that microRNAs (miRNAs) are indispensable in nerve regeneration within DK. Herein, the role of miRNAs associated with DK, especially focusing on autophagy and apoptosis regulation, was investigated. To identify differentially expressed miRNAs, we performed miRNA sequencing on trigeminal ganglion (TG) tissues derived from streptozotocin-induced type 1 diabetic mellitus (T1DM) and normal mice. MiR-144-3p was chosen for the subsequent experiments. To explore the regulatory role of miR-144-3p in DK, miRNA antagomir was utilized to inhibit miR-144-3p expression. Bioinformatic tools were used to predict the target genes of miR-144-3p, and a dual-luciferase reporter assay was then applied for validation. Autophagy and apoptosis activities were measured utilizing TUNEL staining, immunofluorescence staining, and Western blotting. Overall, 56 differentially expressed miRNAs were detected in diabetic versus control mice. In the diabetic mouse TG tissue, miR-144-3p expression was aberrantly enhanced, whereas decreasing its expression contributed to improved diabetic corneal re-epithelialization and nerve regeneration. Fork-head Box O1 (FOXO1) was validated as a target gene of miR-144-3p. Overexpression of FOXO1 could prevent both inadequate autophagy and excessive apoptosis in DK. Consistently, a specific miR-144-3p inhibition enhanced autophagy and prevented apoptosis in DK. In this study, our research confirmed the target binding relationship between miR-144-3p and FOXO1. Inhibiting miR-144-3p might modulate autophagy and apoptosis, which could generate positive outcomes for corneal nerves via targeting FOXO1 in DK.

Fucoxanthin alleviates lipopolysaccharide-induced intestinal barrier injury in mice.

The aim of this study was to evaluate the preventive role and underlying mechanisms of fucoxanthin (Fx) on lipopolysaccharide (LPS)-induced intestinal barrier injury in mice. Our results demonstrated that the oral administration of Fx (50 and 200 mg per kg body weight per day) for consecutive 7 days significantly alleviated the severity of LPS-induced intestinal barrier injury in mice, as evidenced by attenuating body weight loss, improving intestinal permeability, and ameliorating intestinal morphological damage such as reduction in the ratio of the villus length to the crypt depth (V/C), intestinal epithelium distortion, goblet cell depletion, and low mucin 2 (MUC2) expression. Fx also significantly mitigated LPS-induced excessive apoptosis of intestinal epithelial cells (IECs) and curbed the decrease of tight junction proteins including claudin-1, occludin, and zonula occludens-1 in the ileum and colon. Additionally, Fx effectively alleviated LPS-induced extensive infiltration of macrophages and neutrophils into the intestinal mucosa, the overproduction of pro-inflammatory cytokines such as tumor necrosis factor-alpha (TNF-α), interleukin 1beta (IL-1β) and IL-6, and gasdermin D (GSDMD)-mediated pyroptosis of IECs. The underlying mechanisms might be associated with inhibiting the activation of nuclear factor-kappa B (NF-κB), mitogen-activated protein kinases (MAPKs) and nod-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome signaling pathways. Moreover, Fx also notably restrained intestinal reactive oxygen species (ROS), malondialdehyde and protein carbonylation levels in LPS-treated mice, and it might be mediated by activating the nuclear factor-erythroid 2 related factor 2 (Nrf2) signaling pathway. Overall, these findings indicated that Fx might be developed as a potential effective dietary supplement to prevent intestinal barrier injury.

Alleviation of Splenic Injury by CB001 after Low-Dose Irradiation Mediated by NLRP3/Caspase-1-BAX/Caspase-3 Axis.

Low-dose radiation has been extensively employed in clinical practice, including tumor immunotherapy, chronic inflammation treatment and nidus screening. However, the damage on the spleen caused by low-dose radiation significantly increases the risk of late infection-related mortality, and there is currently no corresponding protective strategy. In the present study, a novel compound preparation named CB001 mainly constituted of Acanthopanax senticosus (AS) and Oldenlandia diffusa (OD) was developed to alleviate splenic injury caused by fractionated low-dose exposures. As our results show that, white pulp atrophy and the excessive apoptosis in spleen tissue induced by radiation exposure were significantly ameliorated by CB001. Mechanistically, BAX-caspase-3 signaling and nucleotide-binding domain and leucine-rich-repeat-containing family pyrin 3 (NLRP3) inflammasome signaling were demonstrated to be involved in the radio-protective activity of CB001 with the selective activators. Furthermore, the crosstalk between apoptosis signaling and NLRP3 inflammasome signaling in mediating the radio-protective activity of CB001 was clarified, in which the pro-apoptotic protein BAX but not the anti-apoptotic protein Bcl2 was found to be downstream of NLRP3. Our study demonstrated that the use of a novel drug product CB001 can potentially facilitate the alleviation of radiation-induced splenic injury for patients receiving medical imaging diagnosis or fractionated radiation therapy.