FMRP regulates postnatal neuronal migration via MAP1B.

The fragile X syndrome (FXS) represents the most prevalent form of inherited intellectual disability and is the first monogenic cause of autism spectrum disorder. FXS results from the absence of the RNA-binding protein FMRP (fragile X messenger ribonucleoprotein). Neuronal migration is an essential step of brain development allowing displacement of neurons from their germinal niches to their final integration site. The precise role of FMRP in neuronal migration remains largely unexplored. Using live imaging of postnatal rostral migratory stream (RMS) neurons in Fmr1-null mice, we observed that the absence of FMRP leads to delayed neuronal migration and altered trajectory, associated with defects of centrosomal movement. RNA-interference-induced knockdown of Fmr1 shows that these migratory defects are cell-autonomous. Notably, the primary Fmrp mRNA target implicated in these migratory defects is microtubule-associated protein 1B (MAP1B). Knocking down MAP1B expression effectively rescued most of the observed migratory defects. Finally, we elucidate the molecular mechanisms at play by demonstrating that the absence of FMRP induces defects in the cage of microtubules surrounding the nucleus of migrating neurons, which is rescued by MAP1B knockdown. Our findings reveal a novel neurodevelopmental role for FMRP in collaboration with MAP1B, jointly orchestrating neuronal migration by influencing the microtubular cytoskeleton.

Stromal interaction molecule 1/microtubule-associated protein 1A/1B-light chain 3B complex induces metastasis of hepatocellular carcinoma by promoting autophagy.

Metastasis is the leading cause of death in hepatocellular carcinoma (HCC) patients, and autophagy plays a crucial role in this process by orchestrating epithelial-mesenchymal transition (EMT). Stromal interaction molecule 1 (STIM1), a central regulator of store-operated calcium entry (SOCE) in nonexcitable cells, is involved in the development and spread of HCC. However, the impact of STIM1 on autophagy regulation during HCC metastasis remains unclear. Here, we demonstrate that STIM1 is temporally regulated during autophagy-induced EMT in HCC cells, and knocking out (KO) STIM1 significantly reduces both autophagy and EMT. Interestingly, STIM1 enhances autophagy through both SOCE-dependent and independent pathways. Mechanistically, STIM1 directly interacts with microtubule-associated protein 1A/1B-light chain 3B (LC3B) to form a complex via the sterile-α motif (SAM) domain, which promotes autophagosome formation. Furthermore, deletion of the SAM domain of STIM1 abolishes its binding with LC3B, leading to a decrease in autophagy and EMT in HCC cells. These findings unveil a novel mechanism by which the STIM1/LC3B complex mediates autophagy and EMT in HCC cells, highlighting a potential target for preventing HCC metastasis.

Meta­analysis of the autophagy­associated protein LC3 as a prognostic marker in colorectal cancer.

Microtubule-associated protein 1 light chain 3 (LC3) is an autophagy-associated gene, which is involved in the progression of a number of human malignancies. Such as Breast Cancer, Liver Cancer, and Lung Cancer. However, the role of LC3 in colorectal cancer (CC) remains to be fully elucidated. Therefore, the prognostic role of LC3 expression in CC was evaluated in the present study, with an emphasis on the clinicopathology and prognosis. Expression of LC3 in CC was examined using PubMed, Cochrane Library, Excerpta Medica Database, China Knowledge Infrastructure and Wanfang Data. Newcastle-Ottawa scale was used to screen the literature quality, and RevMan 5.4 and STATA 14.0 were used for the meta-analysis. A total of 1,689 patients from 10 studies were included in the present meta-analysis. The findings of the present study suggested that increased LC3 expression levels were associated with histological grade [odds ratio (OR)=0.91, 95% confidence interval (CI) (0.47, 1.77), P<0.001] and TNM stage [OR=0.91, 95% CI (0.47, 1.77), P<0.001], but were not associated with sex [OR=1.14, 95% CI (0.90, 1.51)], age [OR=0.89, 95% CI (0.67, 1.20)], tumor size [OR=0.78, 95% CI (0.30, 2.34)], histological grade [OR=0.82, 95% CI (0.43, 1.95)] and lymph node metastasis [OR=2.05, 95% CI (1.19, 3.60)] in CC. In addition, the increased expression of LC3 was revealed to be a prognostic factor for the overall survival of patients with CC. In conclusion, the autophagy-associated protein LC3 may be a prognostic indicator of human CC.

NEDD4 activates mitophagy by interacting with LC3 to restrain reactive oxygen species and apoptosis in Apostichopus japonicus challenged with Vibrio splendidus.

Mitophagy, the selective degradation of damaged mitochondria by autophagy, plays a crucial role in the survival of coelomocytes in Apostichopus japonicus following Vibrio splendidus infection by suppressing the generation of reactive oxygen species (ROS) and attenuating cell apoptosis. A recent study revealed that reducing the expression of the neural precursor cell-expressed developmentally downregulated gene 4 (NEDD4), an enzyme 3 (E3) ubiquitin ligase, significantly affects mitochondrial degradation. Prior to the present study, the functional role of NEDD4 in marine invertebrates was largely unexplored. Therefore, we investigated the role of NEDD4 in the activation of mitophagy, modulation of ROS levels, and induction of apoptosis in A. japonicus infected with V. splendidus. The results demonstrated that V. splendidus infection and lipopolysaccharide (LPS) challenge significantly increased the mRNA levels of NEDD4 in A. japonicus coelomocytes, which was consistent with changes in mitophagy under the same conditions. Knockdown of AjNEDD4 using specific small interfering RNAs (siRNAs) impaired mitophagy and caused accumulation of damaged mitochondria, as observed using transmission electron microscopy (TEM) and confocal microscopy. Furthermore, AjNEDD4 was localized to the mitochondria in both coelomocytes and HEK293T cells. Simultaneously, coelomocytes were treated with the inhibitor indole-3-carbinol (I3C) to confirm the regulatory role of AjNEDD4 in mitophagy. The accumulation of AjNEDD4 in the mitochondria and the level of mitophagy decreased. Subsequent investigations demonstrated that AjNEDD4 interacts directly with the microtubule-associated protein light chain 3 (LC3), a key regulator of autophagy and mitophagy, indicating its involvement in the mitophagy pathway. Moreover, AjNEDD4 interference hindered the interaction between AjNEDD4 and LC3, thereby impairing the engulfment and subsequent clearance of damaged mitochondria. Finally, AjNEDD4 interference led to a significant increase in intracellular ROS levels, followed by increased apoptosis. Collectively, these findings suggest that NEDD4 acts as a crucial regulator of mitophagy in A. japonicus and plays a vital role in maintaining cellular homeostasis following V. splendidus infection. NEDD4 suppresses ROS production and subsequent apoptosis by promoting mitophagy, thereby safeguarding the survival of A. japonicus under pathogenic conditions. Further investigation of the mechanisms underlying NEDD4-mediated mitophagy may provide valuable insights into the development of novel strategies for disease control in aquaculture farms.

Choline dehydrogenase interacts with SQSTM1 to activate mitophagy and promote coelomocyte survival in Apostichopus japonicus following Vibrio splendidus infection.

Previous studies have shown that Vibrio splendidus infection causes mitochondrial damage in Apostichopus japonicus coelomocytes, leading to the production of excessive reactive oxygen species (ROS) and irreversible apoptotic cell death. Emerging evidence suggests that mitochondrial autophagy (mitophagy) is the most effective method for eliminating damaged mitochondria and ROS, with choline dehydrogenase (CHDH) identified as a novel mitophagy receptor that can recognize non-ubiquitin damage signals and microtubule-associated protein 1 light chain 3 (LC3) in vertebrates. However, the functional role of CHDH in invertebrates is largely unknown. In this study, we observed a significant increase in the mRNA and protein expression levels of A. japonicus CHDH (AjCHDH) in response to V. splendidus infection and lipopolysaccharide (LPS) challenge, consistent with changes in mitophagy under the same conditions. Notably, AjCHDH was localized to the mitochondria rather than the cytosol following V. splendidus infection. Moreover, AjCHDH knockdown using siRNA transfection significantly reduced mitophagy levels, as observed through transmission electron microscopy and confocal microscopy. Further investigation into the molecular mechanisms underlying CHDH-regulated mitophagy showed that AjCHDH lacked an LC3-interacting region (LIR) for direct binding to LC3 but possessed a FB1 structural domain that binds to SQSTM1. The interaction between AjCHDH and SQSTM1 was further confirmed by immunoprecipitation analysis. Furthermore, laser confocal microscopy indicated that SQSTM1 and LC3 were recruited by AjCHDH in coelomocytes and HEK293T cells. In contrast, AjCHDH interference hindered SQSTM1 and LC3 recruitment to the mitochondria, a critical step in damaged mitochondrial degradation. Thus, AjCHDH interference led to a significant increase in both mitochondrial and intracellular ROS, followed by increased apoptosis and decreased coelomocyte survival. Collectively, these findings indicate that AjCHDH-mediated mitophagy plays a crucial role in coelomocyte survival in A. japonicus following V. splendidus infection.

Assays of Monitoring and Measuring Autophagic Flux for iPSC-Derived Human Neurons and Other Brain Cell Types.

Autophagy is a highly conserved, cytoprotective, catabolic process induced in response to conditions of cellular stress and nutrient deprivation. It is responsible for the degradation of large intracellular substrates such as misfolded or aggregated proteins and organelles. This self-degradative mechanism is crucial for proteostasis in post-mitotic neurons, requiring its careful regulation. Due to its homeostatic role and the implications, it has for certain disease pathologies, autophagy has become a growing area of research. We describe here two assays that can be used as part of a tool kit for measuring autophagy-lysosomal flux in human iPSC-derived neurons.One way to measure autophagic flux is through a western blotting assay, which can be used to analyze two important autophagy proteins: microtubule-associated protein 1 light chain 3 (LC3) and p62. In this chapter, we describe a western blotting assay for use in human iPSC neurons that can be used to quantify these two proteins of interest to measure autophagic flux.In addition to conventional western blotting techniques, more sophisticated tools have come available to readout autophagic flux in a sensitive and high-throughput manner. In the latter portion of this chapter, we describe a flow cytometry assay which utilizes a pH-sensitive fluorescent reporter which can also be used to measure autophagic flux.

Effect of Zhiwei Fuwei Pills on autophagy in gastric antrum tissue of rats with precancerous lesions of gastric cancer based on mTOR/Beclin1/LC3 signaling axis / 中国临床药理学与治疗学

To investigate the effect of Zhiwei Fuwei Pills (ZWFW) on the expression of mammalian target of rapamycin (mTOR)/autophagy key molecule yeast Atg6 homologue (Beclin1)/microtubuleassociated protein 1 light chain 3 (LC3) signaling axis key molecules in gastric antrum tissue of rats with precancerous gastric lesions (PLGC). METHODS: SPF SD rats were randomly divided into normal group, model group, folic acid group, ZWFW low-dose, medium-dose, high-dose group. In addition to the normal group, the model group, folic acid group, ZWFW low-dose, medium-dose and high-dose groups, were used to establish the PLGC rat model by five factors compound modeling methods: N-methyl-N ' - nitro-n-nitroguanidine (MNNG) combined with hunger and satiation, ethanol intragastric administration, free drinking of ammonia and ranitidine feed. The rats were treated with normal saline, folic acid tablet aqueous solution (0.002 g/kg), ZWFW low-dose, medium-dose, high-dose aqueous solution (0.42, 0.84, 1.67 g/kg) for 4 weeks, and the stomach was removed by laparotomy. Hematoxylineosin (HE) staining was used to observe the histopathological changes in the antrum of rats, and real-time polymerase chain reaction (real-time PCR), Western blot (WB) and immunohistochemistry (IHC) were used to detect the expression of mammalian target of rapamycin mTOR, yeast Atg6 homologue 1 (Beclin1), microtubule-associated protein 1 light chain 3β (LC3B) mRNA and protein in the antrum of rats. RESULTS: Compared with the normal group, the Gastric antrum tissue of the model group was distended, thinner gastric wall, palegastric mucosa, atrophic and flat folds, disordered course and nodules and vegetations were visible. HE staining showed that compared with the normal group, the gastric mucosal glands in the model group were crowded and disordered, and the cell morphology was different, including a large number of goblet cells, basophilic cytoplasm, large, hyper-chromatic and irregular nuclei, and mucosal muscle infiltration and destruction. Compared with the model group, treated by ZWFW can significantly improve the pathological manifestations of gastric mucosal gland structure disorder and cell atypia. Compared with the normal group, mTOR mRNA and protein expression were significantly increased (P< 0.05) and Beclin1 and LC3B mRNA and protein expression were significantly decreased (P<0.05) in the antral tissue of rats in the model group; compared with the model group, mTOR mRNA and protein expression were decreased (P<0.05) in the medium and high dose groups of ZWFW, Beclin1 and LC3B protein expression in the antral tissue of rats in the low dose group of ZWFW and Beclin1 and LC3B mRNA and protein expression were increased (P<0.05) in the medium and high dose groups. CONCLUSION: Zhiwei Fuwei Pills can significantly improve the abnormal histopathological findings of gastric mucosa in PLGC model rats, and the mechanism may be related to the down-regulation of mTOR expression, up-regulation of Beclin1 and LC3B expression and then promoting autophagy.

[Acupuncture regulates autophagic flux to antagonize cerebral ischemic injury in rats].

OBJECTIVE: To observe the effect of acupuncture on the cerebral infarct volume and expressions of Beclin1, microtubule-associated protein 1 light chain 3 (LC3) and p62 proteins related to cell autophagy in rats with cerebral ischemia (CI), so as to explore its mechanisms underlying improvement of CI injury. METHODS: Male SD rats were randomized into 3 groups: sham operation, model and acupuncture which were further divided into 4 subgroups according to different ischemia time-points: 3, 6, 12 and 24 h (n=7 in each subgroup). The CI model was established by occlusion of the middle cerebral artery (MCAO) with surgical suture-embolus. For rats of the acupuncture group, acupuncture was applied to "Shuigou" (GV26) and bilateral "Neiguan" (PC6), and twirled for 1-3 min every time, 10 times altogether, and kept for 30 min. The neurological deficit score accoding to Longa's method was used for assessing the neurological function. The CI volume was measured after 2, 3, 5-triphenyltetrazolium chloride staining. The expression levels of autophagy-related proteins Beclin1，LC3 and p62 in the brain tissue were detected using Western blot. RESULTS: Compared with those of the sham operation group，the neurological deficit scores at 2, 3, 6， 12 and 24 h after CI, and the infarct volumes, the expression levels of Beclin1 and the ratios of LC3-Ⅱ/LC3-Ⅰ at 3, 6, 12 and 24 h were considerably increased (P<0.01, P<0.05), and the expression levels of p62 at 3, 6, 12 and 24 h were significantly decreased (P<0.01) in the model group. Relevant to the model group, acupuncture stimulation of GV26 and PC6 induced an obvious decrease in the neurological deficit scores at 6, 12 and 24 h, CI volumes at 3, 6, 12 and 24 h, and the expression levels of Beclin1 and the ratios of LC3-Ⅱ/LC3-Ⅰ both at 6 and 12 h (P<0.01, P<0.05), and an evident increase in the expression levels of p62 at 6, 12 and 24 h after CI (P<0.05, P<0.01). CONCLUSION: Acupuncture stimulation of GV26 and PC6 can reduce the CI volume and improve neurological function in CI rats， which may be related to its efficacy in down-regulating the expression of Beclin1 and the ratio of LC3-Ⅱ/LC3-Ⅰ, and up-regulating the expression of p62 in the ischemic brain tissue， thereby improving autophagy flux.

Association of CFH and MAP1LC3B gene polymorphisms with age-related macular degeneration in a high-altitude population.

AIM: To evaluate the association of complement factor H (CFH) and microtubule-associated protein 1 light chain 3 beta (MAP1LC3B) gene polymorphisms with the risk of age-related macular degeneration (AMD) in a high-altitude population. METHODS: The study group consisted of 172 participants with symptoms of AMD who were examined and diagnosed between January 2019 and June 2020. The control group was composed of 120 healthy individuals. Each participant was required to provide two milliliters of peripheral blood for DNA extraction. Two single nucleotide polymorphisms (SNPs) of CFH (rs1061170 and rs800292) and two SNPs of MAP1LC3B (rs8044820 and rs9903) were genotyped. The genotypes and allele frequencies of the SNPs in the study and control groups were further compared using Chi-square and Fisher's exact tests. RESULTS: In a high-altitude population, the nominally significant differences of rs800292 and rs9903's genotype AG frequencies were observed in the AMD group (P=0.034 and 0.004, respectively). The frequencies of allele G of rs800292 and allele A of rs9903 were also significantly different in the AMD group compared to the control [(P=0.034, OR=0.70, 95%CI: 0.50-0.98) and (P=0.004, OR=1.60, 95%CI: 1.15-2.22), respectively]. No significant differences in the genotype distributions (P=0.16 and 0.40, respectively) and allele frequencies (P>0.05) of rs1061170 and rs8044820 were observed in the AMD group. CONCLUSION: Genotype AG of rs800292 may be a protective factor for AMD. Conversely, rs9903 seems to be a risk factor for AMD. Therefore, allele G of rs800292 may be a protective factor, and allele A of rs9903, a risk factor for AMD in Qinghai high-altitude population.

XBP1-mediated activation of the STING signalling pathway in macrophages contributes to liver fibrosis progression.

Background & Aims: XBP1 modulates the macrophage proinflammatory response, but its function in macrophage stimulator of interferon genes (STING) activation and liver fibrosis is unknown. X-box binding protein 1 (XBP1) has been shown to promote macrophage nucleotide-binding oligomerization domain, leucine-rich repeat and pyrin domain-containing 3 (NLRP3) activation in steatohepatitis. Herein, we aimed to explore the underlying mechanism of XBP1 in the regulation of STING signalling and the subsequent NLRP3 activation during liver fibrosis. Methods: XBP1 expression was measured in the human fibrotic liver tissue samples. Liver fibrosis was induced in myeloid-specific Xbp1-, STING-, and Nlrp3-deficient mice by carbon tetrachloride injection, bile duct ligation, or a methionine/choline-deficient diet. Results: Although increased XBP1 expression was observed in the fibrotic liver macrophages of mice and clinical patients, myeloid-specific Xbp1 deficiency or pharmacological inhibition of XBP1 protected the liver against fibrosis. Furthermore, it inhibited macrophage NLPR3 activation in a STING/IRF3-dependent manner. Oxidative mitochondrial injury facilitated cytosolic leakage of macrophage self-mtDNA and cGAS/STING/NLRP3 signalling activation to promote liver fibrosis. Mechanistically, RNA sequencing analysis indicated a decreased mtDNA expression and an increased BCL2/adenovirus E1B interacting protein 3 (BNIP3)-mediated mitophagy activation in Xbp1-deficient macrophages. Chromatin immunoprecipitation (ChIP) assays further suggested that spliced XBP1 bound directly to the Bnip3 promoter and inhibited the transcription of Bnip3 in macrophages. Xbp1 deficiency decreased the mtDNA cytosolic release and STING/NLRP3 activation by promoting BNIP3-mediated mitophagy activation in macrophages, which was abrogated by Bnip3 knockdown. Moreover, macrophage XBP1/STING signalling contributed to the activation of hepatic stellate cells. Conclusions: Our findings demonstrate that XBP1 controls macrophage cGAS/STING/NLRP3 activation by regulating macrophage self-mtDNA cytosolic leakage via BNIP3-mediated mitophagy modulation, thus providing a novel target against liver fibrosis. Lay summary: Liver fibrosis is a typical progressive process of chronic liver disease, driven by inflammatory and immune responses, and is characterised by an excess of extracellular matrix in the liver. Currently, there is no effective therapeutic strategy for the treatment of liver fibrosis, resulting in high mortality worldwide. In this study, we found that myeloid-specific Xbp1 deficiency protected the liver against fibrosis in mice, while XBP1 inhibition ameliorated liver fibrosis in mice. This study concluded that targeting XBP1 signalling in macrophages may provide a novel strategy for protecting the liver against fibrosis.

Hepatitis B Virus Induces Microtubule Stabilization to Promote Productive Infection through Upregulating Microtubule-associated Protein 1S.

Background and Aims: Continuous release and transmission of hepatitis B virus (HBV) is one of the main factors leading to chronic hepatitis B (CHB) infection. However, the mechanism of HBV-host interaction for optimal viral transport is unclear. Hence, we aimed to explore how HBV manipulates microtubule-associated protein 1S (MAP1S) and microtubule (MT) to facilitate its transport and release. Methods: The expression of MAP1S or acetylated MT was investigated by immunofluorescence, RT-PCR, immunoblotting, and plasmid transfection. MAP1S overexpression or knockdown was performed by lentiviral infection or sh-RNA transfection, respectively. HBV DNA was quantified using q-PCR. Results: Significantly higher level of MAP1S in HepG2215 cells compared with HepG2 cells was detected using RT-PCR (p<0.01) and immunoblotting (p<0.001). Notably, stronger MAP1S expression was observed in the liver tissues of patients with CHB than in healthy controls. MAP1S overexpression or knockdown demonstrated that MAP1S promoted MT acetylation and reduced the ratio of HBV DNA copies inside to outside cells. Further, transfection with the hepatitis B virus X protein (HBx)-expressing plasmids induced significantly higher level of MAP1S than that in controls (p<0.0001), whereas HBVX- mutant-encoding HBV proteins (surface antigen, core protein, and viral DNA polymerase) hardly affected its expression. Conclusions: These results demonstrate that HBx induces the formation of stable MTs to promote the release of HBV particles through upregulating MAP1S. Thus, our studies delineate a unique molecular pathway through which HBV manipulates the cytoskeleton to facilitate its own transportation, and indicate the possibility of targeting MAP1S pathway for treatment of patients with CHB.

MicroRNA-34c-5p provokes isoprenaline-induced cardiac hypertrophy by modulating autophagy via targeting ATG4B.

Pathological cardiac hypertrophy serves as a significant foundation for cardiac dysfunction and heart failure. Recently, growing evidence has revealed that microRNAs (miRNAs) play multiple roles in biological processes and participate in cardiovascular diseases. In the present research, we investigate the impact of miRNA-34c-5p on cardiac hypertrophy and the mechanism involved. The expression of miR-34c-5p was proved to be elevated in heart tissues from isoprenaline (ISO)-infused mice. ISO also promoted miR-34c-5p level in primary cultures of neonatal rat cardiomyocytes (NRCMs). Transfection with miR-34c-5p mimic enhanced cell surface area and expression levels of foetal-type genes atrial natriuretic factor (Anf) and ß-myosin heavy chain (ß-Mhc) in NRCMs. In contrast, treatment with miR-34c-5p inhibitor attenuated ISO-induced hypertrophic responses. Enforced expression of miR-34c-5p by tail intravenous injection of its agomir led to cardiac dysfunction and hypertrophy in mice, whereas inhibiting miR-34c-5p by specific antagomir could protect the animals against ISO-triggered hypertrophic abnormalities. Mechanistically, miR-34c-5p suppressed autophagic flux in cardiomyocytes, which contributed to the development of hypertrophy. Furthermore, the autophagy-related gene 4B (ATG4B) was identified as a direct target of miR-34c-5p, and miR-34c-5p was certified to interact with 3' untranslated region of Atg4b mRNA by dual-luciferase reporter assay. miR-34c-5p reduced the expression of ATG4B, thereby resulting in decreased autophagy activity and induction of hypertrophy. Inhibition of miR-34c-5p abolished the detrimental effects of ISO by restoring ATG4B and increasing autophagy. In conclusion, our findings illuminate that miR-34c-5p participates in ISO-induced cardiac hypertrophy, at least partly through suppressing ATG4B and autophagy. It suggests that regulation of miR-34c-5p may offer a new way for handling hypertrophy-related cardiac dysfunction.

ROS-mediated BNIP3-dependent mitophagy promotes coelomocyte survival in Apostichopus japonicus in response to Vibrio splendidus infection.

Organisms produce high levels of reactive oxygen species (ROS) to kill pathogens or act as signaling molecules to induce immune responses; however, excessive ROS can result in cell death. To maintain ROS balance and cell survival, mitophagy selectively eliminates damaged mitochondria via mitophagy receptors in vertebrates. In marine invertebrates, however, mitophagy and its functions remain largely unknown. In the current study, Vibrio splendidus infection damaged mitochondrial morphology in coelomocytes and reduced mitochondrial membrane potential (ΔΨm) and mitophagosome formation. The colocalization of mitochondria and lysosomes further confirmed that lipopolysaccharide (LPS) treatment increased mitophagy flux. To explore the regulatory mechanism of mitophagy, we cloned Bcl2/adenovirus E1B 19 kDa protein-interacting protein 3 (BNIP3), a common mitophagy receptor, from sea cucumber Apostichopus japonicus (AjBNIP3) and confirmed that AjBNIP3 was significantly induced and accumulated in mitochondria after V. splendidus infection and LPS exposure. At the mitochondrial membrane, AjBNIP3 interacts with microtubule-associated protein 1 light chain 3 (LC3) on phagophore membranes to mediate mitophagy. After AjBNIP3 interference, mitophagy flux decreased significantly. Furthermore, AjBNIP3-mediated mitophagy was activated by ROS following the addition of exogenous hydrogen peroxide (H2O2), ROS scavengers, and ROS inhibitors. Finally, inhibition of BNIP3-mediated mitophagy by AjBNIP3 small interfering RNA (siRNA) or high concentrations of lactate increased apoptosis and decreased coelomocyte survival. These findings highlight the essential role of AjBNIP3 in damaged mitochondrial degradation during mitophagy. This mitophagy activity is required for coelomocyte survival in A. japonicus against V. splendidus infection.

Intracellular Toxic Advanced Glycation End-Products in 1.4E7 Cell Line Induce Death with Reduction of Microtubule-Associated Protein 1 Light Chain 3 and p62.

BACKGROUND: The death of pancreatic islet ß-cells (ß-cells), which are the insulin-producing cells, promote the pathology in both Type 1 and Type 2 diabetes mellitus (DM) (T1DM and T2DM), and they are protected by autophagy which is one of the mechanisms of cell survival. Recently, that some advanced glycation end-products (AGEs), such as methylglyoxial-derived AGEs and Nε-carboxymethyllysine, induced the death of ß-cells were revealed. In contrast, we had reported AGEs derived from glyceraldehyde (GA, the metabolism intermediate of glucose and fructose) are considered to be toxic AGEs (TAGE) due to their cytotoxicity and role in the pathogenesis of T2DM. More, serum levels of TAGE are elevated in patients with T1 and T2DM, where they exert cytotoxicity. AIM: We researched the cytotoxicity of intracellular and extracellular TAGE in ß-cells and the possibility that intracellular TAGE were associated with autophagy. METHODS: 1.4E7 cells (a human ß-cell line) were treated with GA, and analyzed viability, quantity of TAGE, microtubule-associated protein 1 light chain 3 (LC3)-I, LC3-II, and p62. We also examined the viability of 1.4E7 cells treated with TAGE-modified bovine serum albumin, a model of TAGE in the blood. RESULTS: Intracellular TAGE induced death of 1.4E7 cells, decrease of LC3-I, LC3-II, and p62. Extracellular TAGE didn't show cytotoxicity in the physiological concentration. CONCLUSION: Intracellular TAGE induced death of ß-cells more strongly than extracellular TAGE, and may suppress autophagy via reduction of LC3-I, LC3-II, and p62 to inhibit the degradation of them.

A Proteomic Approach Reveals That miR-423-5p Modulates Glucidic and Amino Acid Metabolism in Prostate Cancer Cells.

Recently, we have demonstrated that miR-423-5p modulates the growth and metastases of prostate cancer (PCa) cells both in vitro and in vivo. Here, we have studied the effects of miR-423-5p on the proteomic profile in order to identify its intracellular targets and the affected pathways. Applying a quantitative proteomic approach, we analyzed the effects on the protein expression profile of miR-423-5p-transduced PCa cells. Moreover, a computational analysis of predicted targets of miR-423-5p was carried out by using several target prediction tools. Proteomic analysis showed that 63 proteins were differentially expressed in miR-423-5-p-transfected LNCaP cells if compared to controls. Pathway enrichment analysis revealed that stable overexpression of miR-423-5p in LNCaP PCa cells induced inhibition of glycolysis and the metabolism of several amino acids and a parallel downregulation of proteins involved in transcription and hypoxia, the immune response through Th17-derived cytokines, inflammation via amphorin signaling, and ion transport. Moreover, upregulated proteins were related to the S phase of cell cycle, chromatin modifications, apoptosis, blood coagulation, and calcium transport. We identified seven proteins commonly represented in miR-423-5p targets and differentially expressed proteins (DEPs) and analyzed their expression and influence on the survival of PCa patients from publicly accessible datasets. Overall, our findings suggest that miR-423-5p induces alterations in glucose and amino acid metabolism in PCa cells paralleled by modulation of several tumor-associated processes.

Effect of Danggui Niantongtang on Expression of Autophagy-related Proteins LC3， Beclin1 and p62 in Rats with Adjuvant Arthritis Differentiated into Wind-damp-heat Impediment / 中国实验方剂学杂志

ObjectiveTo observe the preventive and control effects of Danggui Niantongtang against adjuvant arthritis differentiated into wind-damp-heat impediment in rats and its influences on the expression of autophagy-related proteins microtubule-associated protein 1 light chain 3 （LC3）， homolog of yeast Atg6 （Beclin1） and p62. MethodThe six-week-old male SD rats were randomly divided into the normal group， wind-damp-heat impediment model group， low-， medium-， and high-dose Danggui Niantongtang （5.67， 11.34， 22.68 g·kg-1） groups， and methotrexate （MTX， 1.35 mg·kg-1） group， with 10 rats in each group. A rat model of adjuvant arthritis was established by subcutaneous injection of inactivated Mycobacterium tuberculosis into the tail root， followed by exposure to the manual climatic box for 16 d for inducing the wind-damp-heat impediment. The drugs were administered intragastrically on the day of immunization for 28 d. The general conditions of rats were observed and the swelling degree of toes and arthritis index （AI） were detected. The pathological changes in the synovial tissues of the knee joints were observed by hematoxylin-eosin （HE） staining. The mRNA expression levels of LC3， Beclin1， and p62 in the synovial tissues were measured by real-time fluorescence quantitative polymerase chain reaction （Real-time PCR）， followed by the assay of their protein expression by Western blot and immunohistochemistry. ResultCompared with the normal group， the wind-damp-heat impediment model group exhibited significantly increased swelling degree of toes （P<0.01）， increased AI （P<0.01）， proliferated synovial cells （P<0.01）， up-regulated LC3 and Beclin1 protein and mRNA expression （P<0.01）， and down-regulated p62 protein and mRNA expression （P<0.01） after 16， 20， 24， 28-d medication. Compared with the wind-damp-heat impediment model group， each medication group displayed alleviated toe swelling and synovial hyperplasia to different degrees， decreased mRNA and protein expression levels of LC3 and Beclin1 （P<0.01）， and increased p62 mRNA and protein expression （P<0.05，P<0.01）， with the best outcomes observed in the medium-dose Danggui Niantongtang group. ConclusionDanggui Niantongtang effectively relieves adjuvant arthritis due to wind-damp-heat impediment in rats， which may be related to its regulation of the expression of autophagy-related proteins LC3， Beclin1， and p62 and the inhibition of autophagy.

The value of serum levels of Apo B/A1, MAP1-LC3 and ICAM-1 in early assessment of acute pancreatitis / 中华急诊医学杂志

Objective:To investigate the early evaluation potential of serum levels of apolipoprotein B/apolipoprotein A1 (Apo B/A1), microtubule-associated protein 1-light chain 3 (MAP1-LC3) and intercellular adhesion molecule-1 (ICAM-1) in acute pancreatitis (AP) patients.Methods:A total of 413 AP patients who were treated at the Second Affiliated Hospital of Anhui Medical University between January 2019 and August 2020 were enrolled. Serum samples were collected from AP patients within 24 h of admission. Patients were divided into the non-severe acute pancreatitis (Non-SAP, n=315) and severe acute pancreatitis (SAP, n=98) groups according to the severity of the disease. Sixty healthy controls were recruited. The differences of serum Apo B/A1, MAP1-LC3 and ICAM-1 among the three groups were compared by one-way analysis of variance, and the correlation between Apo B/A1, MAP1-LC3 and ICAM-1 and the severity of AP was analyzed by Pearson correlation analysis. Sensitivity and specificity in assessing AP severity were predicted by receiver operating characteristic curve (ROC). Results:The early levels of Apo B/A1, MAP1-LC3 and ICAM-1 were all significantly higher for AP patients than for healthy controls ( P<0.05), and the levels of Apo B/A1, MAP1-LC3 and ICAM-1 in SAP patients were significantly higher than those in non-SAP patients[Apo B/A1: 2.21±1.40 vs. (0.96±0.34); MAP1-LC3: 0.92±0.29 vs. (0.48±0.24) ng/mL and ICAM-1: (235.57±54.50 ) vs. (120.28±61.69)ng/mL; P<0.05]. Pearson correlation analysis showed that levels of Apo B/A1, MAP1-LC3 and ICAM-1 were positively correlated with the first Ranson score after admission ( P<0.05), and ICAM-1 showed the highest degree of correlation with AP severity ( r=0.519). Areas under the receiver operating characteristic curve (AUROC) were 0.769 for Apo B/A1, 0.811 for MAP1-LC3, 0.828 for ICAM-1, and 0.938 for combined detection. Conclusions:Serum levels of Apo B/A1, MAP1-LC3 and ICAM-1 within 24 h after admission are significantly correlated with the severity of AP, which has clinical significance for early prediction of the severity of AP.

Effect of Aspergillus fumigatus on the autophagic flux in murine macrophages: a preliminary study / 中华皮肤科杂志

Objective:To explore the effect of Aspergillus fumigatus ( A. fumigatus) on the autophagic flux in murine bone marrow-derived macrophages (BMDM) . Methods:Murine BMDM were in vitro cultured with heat-killed A. fumigatus for 0, 0.5, 4, and 12 hours. Then, cellular proteins were extracted, and Western blot analysis was performed to detect the conversion of the key autophagy protein microtubule-associated protein 1 light chain 3 (LC3) -Ⅰ to LC3-Ⅱ, and to determine the protein expression of phosphorylated mammalian target of rapamycin (p-mTOR) Ser2481. Additionally, murine BMDM were in vitro cultured with A. fumigatus alone or in combination with different lysosomal inhibitors, including the cysteine cathepsin inhibitor E-64d + pepstatin, bafilomycin-A1 (BAF-A1) , ammonium chloride (NH 4Cl) , and chloroquine, for 4 or 12 hours. Then, Western blot analysis was performed to investigate the effect of A. fumigatus on newly formed LC3-Ⅱ and basal autophagic flux, and confocal laser scanning fluorescence microscopy to analyze the colocalization of A. fumigatus with LC3 and Rubicon (a RUN domain Beclin-1-interacting and cysteine-rich-domain-containing protein) . Experimental results at different treatment time points were analyzed by using unpaired t test, and results of experiments evaluating the effect of two factors ( A. fumigatus spores and autophagosome inhibitors) were analyzed by 2 × 2 factorial analysis. Results:After in vitro co-culture with A. fumigatus for 0.5, 4, 12 hours, Western blot analysis showed that the conversion of LC3-Ⅰ to LC3-Ⅱ increased over time in murine BMDM compared with the control (0 hour) group ( t = 6.58, 3.28, 3.02, respectively, all P < 0.05) , but the protein expression level of p-mTOR (Ser2481) did not significantly differ at different treatment time points ( t = 0.441, 0.477, 0.382, P = 0.682, 0.660, 0.722, respectively) . After 4- and 12-hour in vitro treatment, the accumulation levels of LC3-Ⅱ in BMDM significantly increased in the A. fumigatus + chloroquine group compared with the chloroquine-alone group ( t = 2.13, 2.78, respectively, both P < 0.05) , in the A. fumigatus + NH 4Cl group compared with the NH 4Cl-alone group ( t = 2.92, 2.92, respectively, both P < 0.05) , in the A. fumigatus + BAF-A1 group compared with the BAF-A1-alone group ( t = 2.13, 2.13, respectively, both P < 0.05) , and in the A. fumigatus + E-64d + pepstatin group compared with the E-64d + pepstatin group ( t = 2.13, 2.92, respectively, both P < 0.05) . After 8-hour treatment with calcofluor white-labeled A. fumigatus spores, confocal laser scanning fluorescence microscopy showed that LC3 and Rubicon mainly surrounded A. fumigatus, suggesting their colocalization with A. fumigatus. Conclusion:A. fumigatus can in vitro increase the basal autophagic flux in murine BMDM.

Andrographolide derivative as antagonist of vitamin D receptor to induce lipidation of microtubule associate protein 1 light chain 3 (LC3).

Lipidation of microtubule associated protein 1 light chain 3 (LC3) is the critical step in autophagosome formation, numerous efforts have been made to design and develop small molecules that trigger LC3 lipidation to activate autophagy. In this study, we discovered a series of andrographolide derivatives as potent antagonists of vitamin D receptor (VDR) by luciferase reporter assay. Structure-activity-relationship study revealed that andrographolide derivative ZAV-12 specifically inhibited VDR signaling but not NF-κB or STAT3 activation. Western blot analysis indicates that ZAV-12 markedly triggered lipidation of LC3 in MPP+-induced Parkinsonism in vitro in an mTOR-independent manner. The ZAV-12 triggered lipidation was mediated through SREBP2 activation instead of changing expression levels of lipid synthesis genes. Furthermore, ZAV-12 treatment increased the ratio of LC3-II/LC3-I and oligomerization of A53T α-synuclein (SNCA) in SNCA triggered neurotoxicity. Taken together, these results demonstrate the therapeutic potential of VDR antagonist as novel drug candidate for neurodegenerative diseases.

Cholesterol-associated lysosomal disorder triggers cell death of hematological malignancy: Dynamic analysis on cytotoxic effects of LW-218.

The integrity of lysosomes is of vital importance to survival of tumor cells. We demonstrated that LW-218, a synthetic flavonoid, induced rapid lysosomal enlargement accompanied with lysosomal membrane permeabilization in hematological malignancy. LW-218-induced lysosomal damage and lysosome-dependent cell death were mediated by cathepsin D, as the lysosomal damage and cell apoptosis could be suppressed by depletion of cathepsin D or lysosome alkalization agents, which can alter the activity of cathepsins. Lysophagy, was initiated for cell self-rescue after LW-218 treatment and correlated with calcium release and nuclei translocation of transcription factor EB. LW-218 treatment enhanced the expression of autophagy-related genes which could be inhibited by intracellular calcium chelator. Sustained exposure to LW-218 exhausted the lysosomal capacity so as to repress the normal autophagy. LW-218-induced enlargement and damage of lysosomes were triggered by abnormal cholesterol deposition on lysosome membrane which caused by interaction between LW-218 and NPC intracellular cholesterol transporter 1. Moreover, LW-218 inhibited the leukemia cell growth in vivo. Thus, the necessary impact of integral lysosomal function in cell rescue and death were illustrated.