线粒体自噬及其在肺脏疾病中的作用研究进展

肺脏是人体重要的器官,其病变可严重危机人类的健康及生命。线粒体自噬是自噬的一部分,是目前研究的热点,参与了肺脏疾病的发生发展,本文就线粒体自噬分子机制及其在肺脏疾病中的作用做一综述。

Formononetin Enhances Autophagy Flux in The Penumbra of Cerebral Ischemia and Improves Nerve Damage

Objective Formononetin(FOR),a traditional Chinese medicine,has been widely used for nerve protection and nerve function rehabilitation after cerebral stroke.However,the role of FOR in autophagic lysosome function in cerebral ischemiareperfusion damage has not been investigated.This study aimed to explore whether the therapeutic benefits of FOR were influenced by the regulation of autophagy flux.Methods Male Sprague-Dawley rats were separated into sham,model,and MCAO+FOR(30 mg/kg)groups after undergoing middle cerebral artery occlusion(MCAO)and ischemia-reperfusion(I/R).Then,the brain tissues in the ischemic penumbra were obtained to detect the proteins in autophagic/lysosomal pathway with antibodies of Beclin-1,LC3,SQSTM1/P62,Ubiquitin,LAMP-2,Cathepsin B(CTSB)and Cathepsin D(CTSD)by Western blot and immunofluorescence,respectively.Meanwhile,the therapeutic effectiveness was evaluated by measuring infarct volume,neurological impairments,and neuronal necrosis.Results The findings of this study demonstrate that FOR treatment exhibits a dual effect by enhancing the autophagic activities of Beclin-1 and LC3 in neurons,while simultaneously improving the autophagic clearance function,as evidenced by reinforced lysosomal activities of LAMP-2,CTSB,and CTSD,as well as reduced autophagic accumulation of Ubiquitin and P62 in the MCAO+FOR group compared to the MCAO group.Additionally,7 d of FOR treatment dramatically reduced neurological deficits,infarct volume,and neuronal death caused by cerebral ischemia.Conclusion These findings suggest that the neuroprotective mechanism of FOR therapy in accelerating recovery from ischemic stroke may involve the increase of autophagy flux in the penumbra.

Linggui Zhugan Decoction Improves High Glucose-Induced Autophagy in Podocytes

Objective To explore the influence of Linggui Zhugan Decoction(LGZGD) on high glucose induced podocyte autophagy.Methods LGZGD containing serum was prepared by intragastric administation of 4.2 g/kg(low dose), 8.4 g/kg(medium dose), and 12.6 g/kg(high dose) LGZGD into SD rats respectively. MPC5 and AB8/13 podocyte cells were treated with 60 mmol/L glucose to establish diabetic nephropathy podocyte model in vitro. Both podocytes were divided into control group, high glucose group, low dose LGZGD group, medium dose LGZGD group, and high dose LGZGD group, respectively. For the three LGZGD groups, before LGZGD intervention, podocytes were treated with 60 mmol/L glucose for 3 days. After treated with LGZGD containing serum, cells were collected to analyze cell migration using Transwell assay, proliferation using CCK8, apoptosis and cell cycle using flow cytometry, autophagosome formation using transmission electron microscopy, and expression levels of Beclin-1, Atg5, LC3II/I, and P62 proteins using Western blot.Results Compared with the control group, the proliferation and migration of MPC5 and AB8/13 cells in the high glucose group slightly decreased, whereas these parameters restored after intervention with low and medium concentrations of LGZGD, with the medium dose LGZGD having the better effect(P < 0.05). Flow cytometry showed that the medium dose LGZGD group had a significantly lower apoptosis rate(P < 0.05) and higher survival rate(P > 0.05) compared to the high dose LGZGD group. High glucose arrested podocytes in G1 phase, whereas LGZGD shifted podocytes from being predominant in G1 phase to G2 phase. High dose LGZGD significanly reduced high glucose-increased autophagosome formation in both podocytes(P < 0.05). Western blot analysis showed that Beclin-1, Atg5, LC3II/I, and P62 expressions were increased in MPC5 cells treated with high glucose and reversed after adminstration of low and medium doses of LGZGD(P < 0.05).Conclusion LGZGD reduced apoptosis and enhanced autophagy in high glucose treated podocytes via regulating Beclin-1/LC3II/I/Atg5 expression.

Skin brightening benefit of 4-hexylresorcinol in vivo and in vitro and its underlying mechanism

4-Hexylresorcinol(4-HR),a potent tyrosinase inhibitor,has been used as an even-tone active ingredient for skin care application since 2007.While the skin brightening efficacy of 4-HR in Chinese population has not been thoroughly investigated and its significance in keratinocytes has not been fully raveled.This study aims to evaluate the skin brightening potential of 4-HR in vivo and in vitro and explore its new mechanism of action through transcriptome approach.The skin brightening effect of 0.4%4-HR in a facial serum was assessed in an 8-week,double-blinded,placebo-controlled,and randomized clinical study in 67 Chinese participants.ITA°,melanin index(MI)and visual grading were measured at baseline and 2,4 and 8 weeks after use.A pigmented living skin equivalent(pLSE)model constructed from Asian skin cells was utilized to assess the brightening efficacy of 0.4%4-HR by measuring the model’s brightness(L^(*)value)and melanin content.Then,transcriptomic analysis of 4-HR treated human epidermal keratinocytes was conducted,and the two in vitro models were adopted for hypothesis validation afterwards.In the clinical study,the result shows both 0.4%4-HR serum and placebo chassis can significantly improve all measures as compared to baseline at the 2,4,and 8 weeks.Furthermore,0.4%HR serum demonstrates a better performance in increasing ITA°as early as 2 weeks of application and decreasing MI value than the placebo group at Week 2.In the pLSE model,0.4%4-HR with topical application evidently increases L^(*)value by 15.88%and decreases melanin content by 47.61%compared to UVB group.RNA-sequencing analysis implies that 4-HR can regulate multiple biological processes including skin development,keratinocyte differentiation,oxidant activity and autophagy function.In the blue-light challenged human keratinocytes model,4-HR shows a significant ROS suppression capacity.In the keratinocytes-melanocytes co-culture model,4-HR prompts autophagy activity and decreases melanin content.Most importantly,the melanin inhibitory activity of 4-HR is compromised after co-treating with Chloroquine,an autophagy inhibitor,suggesting autophagy regulation property of 4-HR may partially contribute to its skin brightening efficacy.Taken together,these data demonstrate skin brightening efficacy of 0.4%4-HR in vivo and in vitro,in addition to acting as a tyrosinase inhibitor,4-HR can contribute to skin brightening benefit via enhancing cellular antioxidant capacity and autophagy activation.

Autophagy is activated and might protect neurons from degeneration after traumatic brain injury

Objective To investigate changes of autophagy after traumatic brain injury （TBI） and its possible role. Methods Rat TBI model was established by controlled cortical injury system. Autophagic double membrane structure was detected by transmission electronic microscope. Microtubule-associated protein 1 light chain 3 （LC3） and Beclin 1 were also used to investigate the activation of autophagy post-TBI. Double labeling with LC3 and caspase-3, or Beclin 1 and Fluoro-Jade, to show the relationship between autophagy and apoptosis or neuron degeneration after TBI. Results An increase of autophagic double membrane structure was observed in early stage （1 h）, and the increase lasted for at least 32 d post-TBI. LC3 and Beclin 1 proteins also began to elevate at 1 h time point post-TBI in neurons, 3 d later in astrocytes, and peaked at about 8 d post-TBI. In both cell types, LC3 and Beclin l maintained at a high level until 32 d post-TBI. Most LC3 and Beclin 1 positive cells were near the side （including hippocampus）, but not in the core of the injury. In addition, in the periphery of the injury site, not all caspase-3 positive （＋） cells merged with LC3 （＋） cells post-TBI; In hippocampal area, almost all Beclin 1 （＋） neurons did not merge with Fluoro-Jade （＋） neurons from 1 h to 48 h post-TBI. Conclusion Autophagy is activated and might protect neurons from degeneration at early stage post-TBI and play a continuous role afterwards in eliminating aberrant cell components.

Mechanisms of lysosomal proteases participating in cerebral ischemia-induced neuronal death

There are three different types of cell death, including apoptosis （Type I）, autophagic cell death （Type II）, and necrosis （Type III）. Ischemic neuronal death influences stroke development and progression. Lysosomes are important organelles having an acidic milieu to maintain cellular metabolism by degrading unneeded extra- and intracellular substances. Lysosomal enzymes, including cathepsins and some lipid hydrolases, when secreted following rupture of the lysosomal membrane, can be very harmful to their environment, which results in pathological destruction of cellular structures. Since lysosomes contain catalytic enzymes for degrading proteins, carbohydrates and lipids, it seems natural that they should participate in cellular death and dismantling. In this review, we discuss the recent developments in ischemic neuronal death, and present the possible molecular mechanisms that the lysosomal enzymes participate in the three different types of cell death in ischemic brain damage. Moreover, the research related to the selective cathepsin inhibitors may provide a novel therapeutic target for treating stroke and promoting recovery.

Overview of macroautophagy regulation in mammalian cells

Macroautophagy is a multistep, vacuolar, degradation pathway terminating in the lysosomal compartment, and it is of fundamental importance in tissue homeostasis. In this review, we consider macroautophagy in the light of recent advances in our understanding of the formation of autophagosomes, which are double-membrane-bound vacuoles that sequester cytoplasmic cargos and deliver them to lysosomes. In most cases, this final step is preceded by a maturation step during which autophagosomes interact with the endocytic pathway. The discovery of AuTophaGyrelated genes has greatly increased our knowledge about the mechanism responsible for antophagosome formation, and there has also been progress in the understanding of molecular aspects of autophagosome maturation. Finally, the regulation of autophagy is now better understood because of the discovery that the activity of Atg complexes is targeted by protein kinases, and owing to the importance of nuclear regulation via transcription factors in regulating the expression of autophagy genes.

Blocking NF-kB nuclear translocation leads to p53-related autophagy activation and cell apoptosis

AIM: To investigate the anti-tumor effects of nuclear factor-κB (NF-κB) inhibitor SN50 and related mechanisms of SGC7901 human gastric carcinoma cells. METHODS: MTT assay was used to determine the cytotoxic effects of SN50 in gastric cancer cell line SGC7901. Hoechst 33258 staining was used to detect apoptosis morphological changes after SN50 treatment. Activation of autophagy was monitored with monodansylcadaverine (MDC) staining after SN50 treatment.Immunofluorescence staining was used to detect the expression of light chain 3 (LC3). Mitochondrial membrane potential was measured using the fluorescent probe JC-1. Western blotting analysis were used to determine the expression of proteins involved in apoptosis and autophagy including p53, p53 upregulated modulator of apoptosis (PUMA), damage-regulated autophagy modulator (DRAM), LC3 and Beclin 1. We detected the effects of p53-mediated autophagy activation on the apoptosis of SGC7901 cells with the p53 inhibitor pifithrin-α. RESULTS: The viability of SGC7901 cells was inhibited after SN50 treatment. Inductions in the expression of apoptotic protein p53 and PUMA as well as autophagic protein DRAM, LC3 and Beclin 1 were detected with Western blotting analysis. SN50-treated cells exhibited punctuate microtubule-associated protein 1 LC3 in immunoreactivity and MDC-labeled vesicles increased after treatment of SN50 by MDC staining. Collapse of mitochondrial membrane potential Δψ were detected for 6 to 24 h after SN50 treatment. SN50-induced increases in PUMA, DRAM, LC3 and Beclin 1 and cell death were blocked by the p53 specific inhibitor pifithrin-α. CONCLUSION: The anti-tumor activity of NF-κB inhibitors is associated with p53-mediated activation of autophagy.

S100A8/A9 induces autophagy and apoptosis via ROS-mediated cross-talk between mitochondria and lysosomes that involves BNIP3

The complex formed by two members of the S100 calcium-binding protein family, S100A8/A9, exerts apoptosisinducing activity in various cells of different origins. Here, we present evidence that the underlying molecular mechanisms involve both programmed cell death I （PCD I, apoptosis） and PCD II （autophagy）-like death. Treatment of cells with S100A8/A9 caused the increase of Beclin-1 expression as well as Atgl2-Atg5 formation. S100A8/A9-induced cell death was partially inhibited by the specific PI3-kinase class Ⅲ inhibitor, 3-methyladenine （3-MA）, and by the vacuole H＋-ATPase inhibitor, bafilomycin-A1 （Baf-A1）. S100A8/A9 provoked the translocation of BNIP3, a BH3 only pro-apoptotic Bcl2 family member, to mitochondria. Consistent with this finding, ATM-BNIP3 overexpression partially inhibited S100A8/A9-induced cell death, decreased reactive oxygen species （ROS） generation, and partially pro- tected against the decrease in mitochondrial transmembrane potential in S100A8/A9-treated ceils. In addition, either ATM-BNIP3 overexpression or N-acetyl-L-cysteine co-treatment decreased lysosomal activation in cells treated with S100A8/A9. Our data indicate that S100A8/A9-promoted cell death occurs through the cross-talk of mitochondria and lysosomes via ROS and the process involves BNIP3.

The role and modulation of autophagy in experimental models of myocardial ischemia-reperfusion injury

A physiological sequence called autophagy qualitatively determines cellular viability by removing protein aggregates and damaged cyto-plasmic constituents, and contributes significantly to the degree of myocardial ischemia-reperfusion （I/R） injury. This tightly orchestrated cata-bolic cellular‘housekeeping’ process provides cells with a new source of energy to adapt to stressful conditions. This process was first described as a pro-survival mechanism, but increasing evidence suggests that it can also lead to the demise of the cell. Autophagy has been implicated in the pathogenesis of multiple cardiac conditions including myocardial I/R injury. However, a debate persists as to whether autophagy acts as a protec-tive mechanism or contributes to the injurious effects of I/R injury in the heart. This controversy may stem from several factors including the va-riability in the experimental models and species, and the methodology used to assess autophagy. This review provides updated knowledge on the modulation and role of autophagy in isolated cardiac cells subjected to I/R, and the growing interest towards manipulating autophagy to increase the survival of cardiac myocytes under conditions of stress-most notably being I/R injury. Perturbation of this evolutionarily conserved intracellular cleansing autophagy mechanism, by targeted modulation through, among others, mammalian target of rapamycin （mTOR） inhibitors, adenosine monophosphate-activated protein kinase （AMPK） modulators, calcium lowering agents, resveratrol, longevinex, sirtuin activators, the proapoptotic gene Bnip3, IP3 and lysosome inhibitors, may confer resistance to heart cells against I/R induced cell death. Thus, therapeutic ma-nipulation of autophagy in the challenged myocardium may benefit post-infarction cardiac healing and remodeling.

Autophagy and ethanol-induced liver injury

The majority of ethanol metabolism occurs in the liver. Consequently, this organ sustains the greatest damage from ethanol abuse. Ethanol consumption disturbs the delicate balance of protein homeostasis in the liver, causing intracellular protein accumulation due to a disruption of hepatic protein catabolism. Evidence indicates that ethanol or its metabolism impairs trafficking events in the liver, including the process of macroautophagy, which is the engulfment and degradation of cytoplasmic constituents by the lysosomal system. Autophagy is an essential, ongoing cellular process that is highly regulated by nutrients, endocrine factors and signaling pathways. A great number of the genes and gene products that govern the autophagic response have been characterized and the major metabolic and signaling pathways that activate or suppress autophagy have been identified. This review describes the process of autophagy, its regulation and the possible mechanisms by which ethanol disrupts the process of autophagic degradation. The implications of autophagic suppression are discussed in relation to the pathogenesis of alcohol-induced liver injury.

BNIP3 is essential for mediating 6-thioguanine- and 5-fluorouracil-induced autophagy following DNA mismatch repair processing

DNA mismatch repair （MMR） processes the chemically induced mispairs following treatment with clinically important nucleoside analogs such as 6-thioguanine （6-TG） and 5-fluorouracil （5-FU）. MMR processing of these drugs has been implicated in activation of a prolonged G2/M cell cycle arrest for repair and later induction of apoptosis and/or autophagy for irreparable DNA damage. In this study, we investigated the role of Bcl2 and adenovirus EIB Nineteen-kilodalton Interacting Protein （BNIP3） in the activation of autophagy, and the temporal relationship between a G2/M cell cycle arrest and the activation of BNIP3-mediated autophagy following MMR processing of 6-TG and 5-FU. We found that BNIP3 protein levels are upregulated in a MLHI （MMR＋）-dependent manner following 6-TG and 5-FU treatment. Subsequent small-interfering RNA （siRNA）-mediated BNIP3 knockdown abrogates 6-TG- induced autophagy. We also found that p53 knockdown or inhibition of mTOR activity by rapamycin cotreatment impairs 6-TG- and 5-FU-induced upregulation of BNIP3 protein levels and autophagy. Furthermore, suppression of Checkpoint kinase 1 （Chkl） expression with a subsequent reduction in 6-TG-induced G2/M cell cycle arrest by Chkl siRNA promotes the extent of 6-TG-induced autophagy. These findings suggest that BNIP3 mediates 6-TG- and 5-FU-induced autophagy in a p53- and mTOR-dependent manner. Additionally, the duration of Chkl-activated G2/ M cell cycle arrest determines the level of autophagy following MMR processing of these nucleoside analogs.

Autophagy Enhances the Aggressiveness of Human Colorectal Cancer Cells and Their Ability to Adapt to Apoptotic Stimulus

Objective To investigate LC3B-Ⅱand active caspase-3 expression in human colorectal cancer to elucidate the role of autophagy and to explore the relationship of autophagy with apoptosis in human colorectal cancer. Methods LC3B expression was detected by immunohistochemistry in 53 human colorectal cancer tissues and 20 normal colon tissues.The protein levels of LC3B-Ⅱand active caspase-3 were also determined by Western blot analysis in 23 human colorectal cancer tissues and 10 normal colon tissues. Results LC3B was expressed both in cancer cells and normal epithelial cells.LC3B expression in the peripheral area of cancer tissues was correlated with several clinicopathological factors,including tumor differentiation(P=0.002),growth pattern of the tumor margin (P=0.028),pN(P=0.002),pStage(P=0.032),as well as vessel and nerve plexus invasion(P=0.002).The protein level of LC3B-Ⅱin cancer tissue was significantly higher than in normal tissue(P=0.038),but the expression of active forms of procaspase-3 in cancer tissue was lower(P=0.041).There was a statistically significant positive correlation between the expression levels of LC3B-Ⅱand the active forms of procaspase-3(r=0.537,P=0.008). Conclusions Autophagy has a prosurvival role in human colorectal cancer.Autophagy enhances the aggressiveness of colorectal cancer cells and their ability to adapt to apoptotic stimulus.

Interferon-alpha-2b induces autophagy in hepatocellular carcinoma cells through Beclin1 pathway

Objeαive： To determine whether Interferon-alpha-2b （IFN-α2b） can modulate the autophagic response in hepatocellular carcinoma cells. Methods： Hepatocellular carcinoma cells were treated with IFN-α2b. Autophagy was assessed by acridine orange staining, GFP-LC3 dotted assay, transmission eleαron microscopy and immunoblotting. Results： Acridine orange staining showed that IFN-α2b triggered the accumulation of acidic vesicular and autolysosomes in HepG2 cells. The acridine orange HepG2 cell ratios were （4.3±1.0）%, （6.9±1.4）%, and （13.1±2.3）%, respeαively, after treatment with 100, 1,000, and 10,000 IU/mL IFN-α2b for 48 h. A markedly punαate pattern was observed in HepG2 cells treated with 10,000 IU/mL [FN-α2b for 48 h, but only diffuse and weakly fluorescent GFP-LC3 punαa was observed in control cells. HepG2 cells treated with 10,000 IU/mL IFN-α2b for 48 h developed autophagosome-like charaαeristics, including single- or double-membrane vacuoles containing intaα and degraded cellular debris. The Beclinl and LC3-II protein expression was up-regulated by IFN-α2b treatment. Conclusion： Autophagy can be induced in a dose-dependent manner by treatment with IFN-α2b in HepG2 cells, and the Beclinl signaling pathway was stimulated by IFN-α2b.

Involvement of autophagy in alcoholic liver injury and hepatitis C pathogenesis

This review describes the principal pathways of macroautophagy (i.e. autophagy), microautophagy and chaperone-mediated autophagy as they are currently known to occur in mammalian cells. Because of its crucial role as an accessory digestive organ, the liver has a particularly robust autophagic activity that is sensitive to changes in plasma and dietary components. Ethanol consumption causes major changes in hepatic protein and lipid metabolism and both are regulated by autophagy, which is significantly affected by hepatic ethanol metabolism. Ethanol exposure enhances autophagosome formation in liver cells, but suppresses lysosome function. Excessive ethanol consumption synergizes with hepatitis C virus (HCV) to exacerbate liver injury, as alcohol-consuming HCV patients frequently have a longer course of infection and more severe manifestations of chronic hepatitis than abstinent HCV patients. Alcohol-elicited exacerbation of HCV infection pathogenesis is related to modulation by ethanol metabolism of HCV replication. Additionally, as part of this mechanism, autophagic proteins have been shown to regulate viral (HCV) replication and their intracel-lular accumulation. Because ethanol induces autophagosome expression, enhanced levels of autophagic proteins may enhance HCV infectivity in liver cells of alcoholics and heavy drinkers.

Hsp90 inhibition results in autophagy-mediated proteasome-independent degradation of IκB kinase(IKK)

Autophagic and proteasomal proteolysis are two major pathways for degradation of cellular constituents. Current models suggest that autophagy is responsible for the nonselective bulk degradation of long-lived proteins and organelles while the proteasome specifically degrades short-lived proteins including misfolded proteins caused by the absence of Hsp90 function. Here, we show that the IκB kinase （IKK）, an essential activator of NF-κB, is selectively degraded by autophagy when Hsp90 is inhibited by geldanamycin （GA）, a specific Hsp90 inhibitor showing highly effective anti-tumor activity. We find that in this case inactivation of ubiquitination or proteasome fails to block IKK degradation. However, inhibition of autophagy by an autophagy inhibitor or knockout of Atg5, a key component of the autophagy pathway, significantly rescues IKK from GA-induced degradation. These findings provide the first evidence that an Hsp90 client may be degraded by a mechanism different from the proteasome pathway and establish a molecular link among Hsp90, NF-κB and autophagy

Autophagy-related proteins Beclin-1 and LC3 predict cetuximab efficacy in advanced colorectal cancer

AIM:To investigate the utility of Beclin-1 and LC3,two autophagy-related proteins,in predicting the cetuximab efficacy in advanced colorectal cancer(ACRC) . METHODS:The data of 85 patients with ACRC treated at the Sun Yat-sen University Cancer Center from March 1,2005 to December 31,2008 were studied,including 45 cases treated with cetuximab-containing chemotherapy and 40 cases treated with non-cetuximab-containing chemotherapy.Beclin-1 and LC3 expression was evaluated by immunohistochemistry,and KRAS status was evaluated by polymerase chain reaction. RESULTS:Beclin-1 and LC3 expression in ACRC wassignificantly correlated(r=0.44,P<0.01);however,LC3 was more highly expressed in cancerous tissues than in normal tissues(Z=-2.63,P<0.01) .In the cetuximab-containing chemotherapy group,patients with low LC3 expression had higher objective response rates(ORRs) than those with high LC3 expression(52.9%vs 17.9%,P=0.01) ,and patients with low Beclin-1 expression had a longer median progressionfree survival(PFS) than their counterparts with higher Beclin-1 expression(9.0 mo vs 3.0 mo,P=0.01) . However,neither of these predictive relationships was detected in the group treated with non-cetuximabcontaining chemotherapy.Patients with wild-type KRAS had higher ORRs(42.3%vs 9.1%,P=0.049) and disease control rates(DCRs)(73.1%vs 36.4%,P= 0.035) ,and longer median PFS(5.5 mo vs 2.5 mo,P= 0.02) than those with mutant KRAS in the cetuximabcontaining chemotherapy group.Neither Beclin-1(P= 0.52) nor LC3(P=0.32) expression was significantly correlated with KRAS status. CONCLUSION:Patients with low Beclin-1 expression had a longer PFS than those with high Beclin-1 expression,and patients with low LC3 expression had a higher ORR in ACRC patients treated with cetuximab-containing chemotherapy.

Genetic regulation of programmed cell death in Drosophila

Programmed cell death plays an important role in maintaining homeostasis during animal development, and has been conserved in animals as different as nematodes and humans. Recent studies of Drosophila have provided valuable information toward our understanding of genetic regulation of death. Different signals trigger the novel death regulators rpr, hid, and grim, that utilize the evolutionarily conserved iap and ark genes to modulate caspase function. Subsequent removal of dying cells also appears to be accomplished by conserved mechanisms. The similarity between Drosophila and human in cell death signaling pathways illustrate the promise of fruit mes as a model system to elucidate the mechanisms underlying regulation of programmed cell death.

Inflammatory bowel disease:Genetic and epidemiologic considerations

Genome-wide association studies have firmly established that many genomic loci contribute to inflammatory bowel disease, especially in Crohn’s disease. These studies have newly-established the importance of the interleukin 23 and autophagy pathways in disease pathogenesis. Future challenges include: (1) the establishment of precisely causal alleles, (2) definition of altered functional outcomes of associated and causal alleles and (3) integration of genetic findings with environmental factors.

The therapeutic effect of Jiawei Danshen Decoction on myocardial ischemia-reperfusion injury by inhibiting H_(2)S-mediated autophagy signaling pathway

Objective To investigate the protective effects of Jiawei Danshen Decoction(加味丹参饮,JWDSD)on myocardial ischemia-reperfusion injury(MIRI)via the regulation of serum Hydrogen sulfide(H2S)and cardiac Beclin1,light Chain 3 A/B(LC3 A/B),p62,and autophagy protein5(ATG5).Methods Seventy specific pathogen free(SPF)Sprague-Dawley(SD)rats were randomly assigned to seven groups(n=10 in each group),including normal control,sham operation,MIRI model(model),ischemic preconditioning,Na HS,JWDSD,and JWDSD+CSE inhibitor(JWDSD+PPG)groups,and orally administered the indicated drugs for 14 d.Two hours after the last administration,the left anterior decreased branch of the coronary artery of each rat in model,Na HS,JWDSD,and JWDSD+PPG groups was ligated for 30 min and subsequently reperfused for 90 min to establish the MIRI model,and the rats in the sham operation group were only exposed to the thorax after surgery without coronary ligation.Blood samples were collected to detect H2S levels using an enzyme-linked immunosorbent assay(ELISA).Heart tissues were harvested for histopathological and immunohistochemical examination and quantitative reverse transcription polymerase chain reaction analysis of Beclin1 and ATG5 m RNA expression and Western blot analysis of Beclin1,LC3 A/B,and p62 protein expression.Results(1)The serum H2S content in model group rats was significantly reduced(P<0.01),JWDSD significantly increased the serum H2S content of model group rats(P<0.01),and the CSE inhibitor(PPG)significantly reduced H2S levels in the JWDSD group rats(P<0.01).(2)Compared with the normal control group,the myocardial tissue necrosis and cell destruction occurred in the MIRI model group,and JWDSD could alleviate the myocardial tissue necrosis of model rats,but the ameliorative effect of JWDSD could be reversed by PPG.(3)Beclin1,LC3 A/B,and p62 expression levels in the heart tissues of the model group were significantly increased(P<0.001),whereas decreased by JWDSD(P<0.05,P<0.01,and P<0.001,respectively),and the inhibitory effects of JWDSD on Beclin1,LC3 A/B,and p62 expression were partially reversed by PPG(P<0.01,P<0.05,and P<0.01,respectively).(4)The expression levels of autophagy-related genes Beclin1 and ATG5 were significantly increased in the model group(P<0.001).JWDSD clearly downregulated the expression levels of Beclin1 and ATG5(P<0.05 and P<0.001,respectively),which were reversed by PPG(P<0.001).Conclusion Our experimental data show that JWDSD can exhibit an anti-MIRI role by increasing endogenous H2S generation,and downregulating the expression of Beclin1,LC3 A/B,p62 and ATG5,which are related to inhibiting autophagy signaling.