自噬在胆管癌中的相关研究进展

自噬是细胞利用溶酶体降解细胞质异常蛋白质及受损细胞器等以重新利用胞内的降解物质、降解胞内有害物质的过程,以维持细胞内环境稳定.正常情况下,自噬维持在较低水平,但当细胞处在不利因素条件下时,自身自噬也会被激活应对不利因素.自噬参与许多生理和病理过程,如细胞老化、细菌入侵、神经退行性疾病、细胞凋亡以及肿瘤的发生发展.自噬与包括胆管癌在内的多种肿瘤的发生、发展、转移、复发、耐药等方面有着重要作用,但自噬在这些方面的详细机制仍不清楚.探讨分析自噬在胆管癌中的发生、发展中的作用机制和调控途径,具有重要的意义和应用价值.本文对自噬在胆管癌中的研究进展进行综述.     

核因子-kB信号通路与自噬在动脉粥样硬化发生发展中的相互调节作用

动脉粥样硬化(atherosclerosis,AS)是一种复杂的慢性血管炎症疾病,由多种AS相关细胞与其表达的促炎因子相互作用促进其发生发展。核因子-k B(NF-kB)信号通路是由多种细胞因子介导的经典信号通路,不仅参与炎症反应,也调控细胞损伤、氧化应激、细胞凋亡等过程。而自噬是细胞稳态的溶酶体降解过程,在一定范围内的自噬激活可调节炎症反应。AS多伴有炎症反应并与自噬密切相关,NF-kB的激活可介导自噬,而自噬的过度激活抑制NF-kB活性。本研究主要对NF-kB与自噬在AS中的相互关系做一综述。     

自噬与肝再生关系的研究进展

自噬是细胞内的一种降解途径,通过形成自噬泡将细胞内生物大分子和受损细胞器运送至溶酶体进行降解,在维持肝脏功能的动态平衡中发挥着重要作用,肝脏通过自噬可消除异常肝细胞。回顾了自噬和肝细胞、非实质肝细胞以及肝干细胞增殖的密切关系,分析表明自噬可通过促进肝细胞、肝干细胞的增殖从而恢复肝脏的体积和功能,并能够适时终止,防止肿瘤的发生;而功能失调时,自噬可能通过增强非实质肝细胞的活化,进而抑制肝细胞再生,同时导致纤维化的发生和发展;肿瘤形成阶段,自噬在正常细胞向癌细胞转化的过程中发挥重要作用,肝细胞恶性再生被激活但不能适时终止。     

自噬在天然药物活性成分抗心血管衰老中的作用

心血管系统维持着机体正常的生命活动,心血管系统衰老可引发高血压、动脉粥样硬化、心力衰竭、心肌梗死等疾病。自噬是一种溶酶体依赖性降解途径,其水平随着年龄增加而逐渐降低,一方面提高机体自噬可延缓细胞和组织衰老,另一方面自噬水平的过度激活可诱导细胞自噬性死亡、加速衰老。某些天然药物活性成分能调节自噬,并改善心血管系统衰老。它们可能是通过调节细胞自噬发挥对心血管系统衰老的保护作用。因此,文章就自噬在天然药物活性成分延缓心血管系统衰老中的作用及研究进展进行综述。     

Beclin 1与mTOR对心肌缺血/再灌注损伤中自噬的交互调控机制

自噬是一个进化上高度保守的受损或功能障碍的蛋白质聚集体或细胞器降解的过程。在心肌缺血/再灌注(I/R)过程中,可以通过多种因素诱导细胞的自噬活动,而且越来越多的证据表明,自噬在心肌缺血/再灌注损伤(MIRI)中可能起“双刃剑”的作用,适度自噬可促进细胞存活;而不适当的激活自噬可能会加速细胞死亡。Beclin 1介导的自噬/凋亡互反馈信号通路和哺乳动物雷帕霉素靶蛋白(mTOR)介导的自噬与mTOR的互反馈信号通路,是两条经典的自噬激活信号途径,也可能是调控自噬“双刃剑”转向促进细胞存活的重要调控机制。本文将重点综述上述两条信号通路对自噬的交互式调控作用。速发挥作用。因此,Z盘部位实质上成为心肌细胞中的信号转导中心。     

细胞自噬在急性肝损伤中的变化及作用

正近年来,细胞自噬已成为热点研究领域,而细胞自噬在肝脏疾病中的作用也越来越受到重视,抑制或促进自噬可能成为一个新的治疗靶点,本文就细胞自噬在急性肝损伤中的变化及作用作一综述。1细胞自噬的概述细胞自噬(autophagy)是存在于真核细胞内的一种溶酶体依赖的降解途径,形成过程包括膜状结构包裹部分胞质和细胞内需降解的长寿蛋白质、受损的细胞器等形成     

自噬在心肌缺血再灌注中作用的研究进展

自噬是指细胞内的自身物质被溶酶体所降解的过程,为普遍存在的生命现象,是细胞处于饥饿状态时的一种自我保护机制。既往研究表明,在心肌缺血再灌注过程中,自噬被诱导激活,自噬体明显增多。自噬在缺血再灌注中的作用表现出双面性,缺血期主要发挥保护作用,但再灌注时期自噬过度激活则表现出损伤作用,可导致自噬性细胞死亡。自噬具体是如何被激活,怎样发挥其影响作用,至今尚无清楚的答案。本文就自噬在心肌缺血再灌注中作用的研究进展进行综述。     

信息快递

自噬抑制剂可抑制肝星状细胞激活【据J Hepatol 2011年12月报道】题:自噬在肝星状细胞激活中的作用(作者Thoen LFR等)细胞自我吞噬是一个降解和再循环细胞器和蛋白的过程,与人类的疾病和生理具有多种联系。为了研究自噬在肝星状     

自噬在HBV及相关肝脏疾病中的双重作用

自噬是一种溶酶体降解过程,其在疾病的发生发展中具有双重作用,即自噬促进细胞存活,又可诱导细胞死亡。简述了自噬在HBV、慢性乙型肝炎、肝纤维化及肝细胞癌中的双重作用,以及自噬在相关肝脏疾病中的作用机制。提出了细胞自噬可能是未来HBV相关肝病治疗的研究方向,为肝纤维化和肝细胞癌的治疗提供了新思路。     

细胞自噬在肝纤维化中的作用

细胞自噬是细胞内的一种代谢过程,通过细胞内的膜结构包裹部分胞质和细胞内需降解的细胞器、蛋白质等形成自噬小体,然后与溶酶体融合降解其所包裹内容物,其降解产物氨基酸、游离脂肪酸等可供细胞物质能量循环,细胞自噬在肝脏疾病的发生发展中有重要的作用,最近研究表明,细胞自噬可以通过降解脂滴为肝星状细胞的活化提供能量从而促进肝纤维化的发生。     

The immunoneuroendocrine role of melatonin

Abstract: A tight, physiological link between the pineal gland and the immune system is emerging from a series of experimental studies. This link might reflect the evolutionary connection between self-recognition and reproduction. Pinealectomy or other experimental methods which inhibit melatonin synthesis and secretion induce a state of immunodepression which is counteracted by melatonin. In general, melatonin seems to have an immunoenhancing effect that is particularly apparent in immunodepressive states. The negative effect of acute stress or immunosuppressive pharmacological treatments on various immune parameters are counteracted by melatonin. It seems important to note that one of the main targets of melatonin is the thymus, i.e., the central organ of the immune system. The clinical use of melatonin as an immunotherapeutic agent seems promising in primary and secondary immunodeficiencies as well as in cancer immunotherapy. The immunoenhancing action of melatonin seems to be mediated by T-helper cell-derived opioid peptides as well as by lymphokines and, perhaps, by pituitary hormones. Melatonin-induced-immuno-opioids (MHO) and lymphokines imply the presence of specific binding sites or melatonin receptors on cells of the immune system. On the other hand, lymphokines such as -γ-interferon and interleukin-2 as well as thymic hormones can modulate the synthesis of melatonin in the pineal gland. The pineal gland might thus be viewed as the crux of a sophisticated immunoneuroendocrine network which functions as an unconscious, diffuse sensory organ.     

Changes in connexin43, the gap junction protein of astrocytes, during development of the rat pineal gland

Abstract: The abundance of gap junctions between rat pineal astrocytes formed by connexin43 (Cx43) was studied during development. Levels and distribution of Cx43 were measured by immunoblotting and indirect immunofluorescence, respectively. The amount of Cx43 in cells located within the gland was low until about the 7th postnatal day and increased to adult values between the 14th and 21st days postpartum. Although astrocytes, recognized by their vimentin immunoreactivity, were scarce before birth, they were abundant by the 7th postnatal day suggesting that the low levels of Cx43 found at this age corresponded to a low expression of this protein. Localization of the immunoreactivity to Cx43 and vimentin showed a close correlation, indicating that mature or immature pineal astrocytes form gap junctions made of Cx43. Since Cx43 levels attained their adult values at about the time the innervation and the functional state of the gland reached maturity (2–3 weeks after birth), it is proposed that astrocyte gap junctions are involved in the function of the adult rat pineal gland.     

Conservative management of perforated duodenal diverticulum： A case report and review of the literature

Duodenal diverticula are a relatively common condition. They are asymptomatic, unless they become complicated, with perforation being the rarest but most severe complication. Surgical treatment is the most frequently performed approach. We report the case of a patient with a perforated duodenal diverticulum, which was diagnosed early and treated conservatively with antibiotics and percutaneous drainage of secondary retroperitoneal abscesses. We suggest this method could be an acceptable option for the management of similar cases, provided that the patient is in good general condition and without septic signs.     

Response of rat pineal melatonin to calcium, magnesium, and lithium is circadian stage dependent

Abstract: Herein we documented the response of pineal melatonin production to electrolytes known to be effective on pineal function in view of a possible circadian stage dependence. We studied the release of melatonin by perifused rat pineal glands at 2 different circadian stages corresponding to the middle of the light and dark periods, i.e., respectively, 7 and 19 HALO (Hours After Light Onset, L:D = 12:12). The initial efflux rates were, as expected, much higher in the perifusates of glands removed from rats sacrificed during the dark phase than of those removed during the light phase. After 3 hr of perifusion, melatonin release reached similar levels which were found constant up to the 8th hr of perifusion, whatever the circadian stage. Perifusion of the glands with physiological concentrations for the rat of calcium (5.2 mmol/1) and magnesium (1.34 mmol/1) resulted in a stimulatory effect on the pineal glands removed from rats sacrificed in the middle of the dark period (19 HALO), whereas no effects were observed on the pineal glands removed from rats sacrificed during the light (7 HALO). Lithium (0.28 and 0.55 mmol/1) was ineffective on melatonin release in pineal glands removed 7 and 19 HALO. Our results show differences in the initial efflux rates of melatonin and in the response of perifused pineal glands to calcium and magnesium according to the circadian stage.     

Presence of immunoreactive growth hormone and prolactin in the ovine pineal gland

Abstract: The use of antisera raised against bovine growth hormone (GH) and ovine prolactin (PRL) enabled the detection of related immunoreactive (ir) sequences of proteins in ovine pineal tissue. The isolation of PRL-like ir-material was accomplished using a 0.25 M ammonium sulphate (pH 5.5) extraction followed by ethanol precipitation, whereas the resulting 2.0 M ammonium sulphate (pH 7.0) precipitate contained a GH-like immunoreactivity. Gel chromatography of the GH-like immunoreactivity (Sephadex G-100) indicated the presence of several GH-like fragments ranging in the M_r range of 7,000 to 55,000. Analyses of the PRL-like ir-material found in pineal tissue on HPLC using a TSK 545-DEAE column led to the resolution into a single peak of immunoreactivity. A single peak of activity was also observed following chromatofocusing and hydrophobic interaction chromatography of the ir-peak from the TSK 545-DEAE column. The PRL-like ir-material inhibited the binding of [¹²⁵I]ovine PRL-S14 to anti-ovine PRL antibodies without showing an affinity for binding to anti-rat PRL or anti-bovine GH antibodies. Scatchard analysis of the binding of pineal PRL-like ir-material and pituitary ovine PRL-S14 to liver membranes from day-20 pregnant rats revealed similar affinity constants (K_a of 4.7 ± 0.2 × 10⁹ M^-1). In addition, the replication of Nb 2 Node rat lymphoma cells was stimulated by pineal PRL-like ir-material, an effect known to be specific for lactogenic hormones. The pineal PRL-like immunoreactivity appeared on sodium dodecyl sulfate polyacrylamide gels as a single major band of M_r 24,000. The functional status of PRL-and GH-like ir-material in the ovine pineal remains to be determined, but evidence is presented that the overall protein synthesis rate of the rat pineal responded to circulating concentrations of PRL.     

Microbiology of human immunodeficiency virus anorectal disease

PURPOSE: Individuals who are seropositive for the human immunodeficiency virus are at high risk for opportunistic infection and anorectal disorders. Little prospective information is available regarding anorectal pathogens in these patients. METHODS: One hundred sixty-three HIV-seropositive patients presented to the colorectal clinic between 1989 and 1992. Forty-seven (29 percent) patients were thought to have an infectious process and were prospectively studied using a standardized multiculture protocol. RESULTS: Mean age was 33 (range, 19–59) years. All were male; high-risk behavior accounted for 87 percent of HIV transmissions. Presenting complaints included anorectal pain (79 percent), pus per anum (28 percent), and blood per anum (26 percent). Examination revealed perianal tenderness (60 percent), condyloma (38 percent), perianal ulcers (38 percent), and anal fissures (34 percent). Sixty-six sets of cultures were performed; 28 patients had one set, 15 had two sets, and 4 had three sets. Thirty-two of these 47 patients (68 percent) had positive cultures including herpes (50 percent), cytomegalovirus (25 percent),Neisseria gonorrhoeae (16 percent), chlamydia (16 percent), acidfast bacilli (2 percent), and others (9 percent). Six of 32 patients with positive cultures had more than one organism cultured. Sixteen (50 percent) patients with positive cultures were treated medically, 8 (25 percent) were treated surgically and 8 (25 percent) were treated with both modalities. Sixty-one procedures were performed on 17 patients for condylomata. Eighteen patients had 20 procedures for abscesses, 50 percent of whom had positive cultures for other than common bowel flora; all improved. Fourteen patients underwent 33 procedures for perianal fistulas.Mycobacterium fortuitum was cultured from one patient who required 13 procedures for abscesses and fistulas. Forty-five (96 percent) patients were followed for an average of 12.5 months ±2.9 SEM (range, 1–94 months). Symptoms were improved or resolved in 22 of 32 (69 percent) patients with positive cultures and in 11 of 13 (84 percent) with negative cultures. CONCLUSIONS: Specific pathogens may often be identified in human immunodeficiency virus-seropositive patients with anorectal disorders if aggressively sought. Although patients without specific pathogens identified may be expected to improve with planned empiric treatment, positive identification allows more directed therapy.