AMPK-能量代谢感受器与可激活AMPK相关的药物研究进展

单磷酸腺苷活化蛋白激酶(AMPK)可以感受细胞能量代谢变化,调节细胞的葡萄糖、脂肪酸的代谢过程。AMPK与细胞生长、生存和多种代谢信号途径关系密切,研究发现AMPK信号途径涉及炎症、肿瘤和代谢疾病。本文综述AMPK的功能与炎症、肿瘤、代谢类疾病的关系和诸如水杨酸、二甲双胍等药物激活AMPK的研究进展。     

AMPK与糖尿病肾脏疾病

糖尿病肾脏疾病(DKD)的发病机制十分复杂,其发生、发展是在遗传背景基础上多因素综合作用的结果,目前认为高血糖是引起DKD进展的主要原因,炎性反应和氧化应激加速了DKD的病理过程.腺苷酸活化蛋白激酶(AMPK)是“细胞能量调节器”,在调节糖、脂代谢方面起重要作用.AMPK作为一个重要的信号通路,通过参与细胞蛋白质合成、机体炎性反应和氧化应激等过程,在延缓DKD的发生、发展中发挥了重要作用.     

AMP活化蛋白激酶的抗氧化作用

AMP活化蛋白激酶(AMPK)广泛参与细胞代谢,在调节细胞能量代谢过程中起重要作用.另外,AMPK还可以调节机体抗氧化能力,通过调节机体抗氧化防御系统蛋白的表达,如硫氧化还原蛋白(TRX)、NAD(P)H氧化酶、二氧化锰超氧化物歧化酶(MnSOD)、过氧化物酶体增殖物活化受体协同刺激因子(PGC)-1α等,减少机体活性...     

AMP活化蛋白激酶与脂肪细胞因子

腺苷酸活化蛋白激酶(AMPK)作为细胞重要的能量感受器,能通过增强分解代谢通路,抑制合成代谢通路,调节代谢和能量平衡.近年来研究显示AMPK同样参与了以瘦素、脂联素及抵抗素等为代表的脂肪细胞因子生理作用的发挥,同时AMPK激活亦可影响脂肪细胞因子的分泌,因此脂肪细胞因子与AMPK相关作用机制的研究将为治疗肥胖、糖尿病和代谢综合征提供新的途径.     

AMPK-能量代谢感受器与可激活AMPK相关的药物研究进展

单磷酸腺苷活化蛋白激酶（AMPK）可以感受细胞能量代谢变化,调节细胞的葡萄糖、脂肪酸的代谢过程。AMPK与细胞生长、生存和多种代谢信号途径关系密切,研究发现AMPK信号途径涉及炎症、肿瘤和代谢疾病。本文综述AMPK的功能与炎症、肿瘤、代谢类疾病的关系和诸如水杨酸、二甲双胍等药物激活AMPK的研究进展。     

AMPK与胰岛β细胞功能

腺苷酸活化蛋白激酶(AMPK)作为机体能量监测器,其活性主要受AMP/ATP比例调控。通过抑制能量合成,加速能量分解和ATP合成以保持机体能量平衡的同时,AMPK同样参与了胰岛β细胞胰岛素分泌的调节,并直接作用于β细胞的相关基因表达和胰岛素信号转导。以二甲双胍、罗格列酮、瘦素和脂联素为代表的AMPK激活剂对胰岛素分泌的直接影响尚有争议。本文就AMPK介导的胰岛β细胞功能作一简述。     

腺苷酸活化蛋白激酶与胰岛素抵抗

腺苷酸活化蛋白激酶（AMP-activated protein kinase, AMPK）是一类重要的蛋白激酶,通过改变细胞代谢和调节基因转录恢复细胞ATP水平。AMPK参与了肌肉收缩介导的葡萄糖转运和脂肪酸氧化,抑制肝脏葡萄糖、胆固醇和甘油三酯产生,并具有调节食物摄取和体重的作用。AMPK信号通路是目前具有吸引力的治疗肥胖、胰岛素抵抗、2型糖尿病和其它代谢病的药理靶点。     

基于RIPK1/PGAM5通路探讨二甲双胍干预治疗对高眼压青光眼大鼠视网膜神经节细胞退行性变的影响

目的 探讨单磷酸腺苷活化蛋白激酶(AMPK)激活抑制RIPK1及其下游信号通路参与挽救视网膜神经节细胞退行性变的机制.方法 清洁级大鼠72只,其中8只为假手术组(A组),其余构建高眼压(IOP)青光眼手术模型,随机分成B、C、D、E AMPK拮抗组、RIC组、RIPK1激动组.药物处理后检测IOP;染色比较各组视网膜形...     

曲格列酮对胰岛β细胞胰岛素分泌的影响及机制研究

研究曲格列酮对胰岛β细胞(MIN6细胞株)胰岛素分泌的影响,并探讨其机制.10μmol/L曲格列酮短期抑制大鼠胰岛和MIN6细胞的葡萄糖刺激的胰岛素分泌(GSIS,P<0.01),增加AMP活化的蛋白激酶(AMPK)、乙酰辅酶A羧化酶(ACC)的磷酸化水平(均P<0.01),而AMPK抑制剂复合物C可使其AMPK、ACC的磷酸化水平以及胰岛素分泌完全恢复.     

腺苷酸活化蛋白激酶信号通路变化与老年高脂患者关系的研究进展

<正>腺苷酸活化蛋白激酶(AMPK)是参与细胞生物调节及代谢的一种关键酶。早期研究发现AMPK可以磷酸化胆固醇合成通路中的限速酶羟甲基戊二酰辅酶A还原酶(HMG-CoA),导致胆固醇合成减缓;并磷酸化脂肪合成中的主要酶乙酰辅酶A羧化酶(ACC),最终导致脂肪酸合成减缓。此外,AMPK还可以磷酸化糖原合成通路中一个重要的调节因子糖原合成酶激酶(GSK),抑制糖原的生成。可以说AMPK是细胞能量代谢     

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.     

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.     

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.     

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.