Ex Vivo Lung Perfusion:Scientific Research and Clinical Application

刘明耀教授是多伦多大学临床医学研究生院院长、外科教授、资深科学家,主要从事肺移植的临床与科研工作。主持科研课题27项,主要参与课题10项,曾荣获伊丽莎白二世女王钻石禧年奖章。其所在的多伦多大学总医院于1983年和1986年分别完成了世界首例成功的单肺及双肺移植,肺移植的相关临床及科研水平处于世界第一位。近年来成功研发了体外肺灌注装置(ex-vivo lung perfusion,EVLP),200多例经临床鉴定不可使用的肺脏经过此装置修复后已经成功用于移植,效果甚佳,引起全球轰动。EVLP是一种新型的肺脏体外灌注技术,可以在体外为供肺提供通气和血供,并可在灌注期间对供肺进行快速的功能评估和干预治疗。因此,EVLP技术可在移植前有效延长供肺保存时间,提高供肺质量,为受损伤供肺,尤其是边缘性供肺提供了体外修复的可能,可显著增加适合移植的供肺数量,提高边缘供肺的利用率,有效缓解供肺短缺的现状。刘明耀教授团队已协助全球包括我国在内的多家医疗中心开展肺移植的临床及科研工作,其中EVLP装置的深入研发及多中心临床试验也是刘教授团队与天津市第一中心医院沈中阳教授团队合作承担的国家国际科技合作专项项目的主要研究内容之一,无锡人民医院陈静瑜教授团队也参与了研究,将对我国肺移植的发展起到积极的促进作用。

Applications and safety of gold nanoparticles as therapeutic devices in clinical trials

Use of gold nanoparticles(GNPs)in medicine is an emerging field of translational research with vast clinical implications and exciting therapeutic potential.However,the safety of using GNPs in human subjects is an important question that remains unanswered.This study reviews over 20 clinical trials focused on GNP safety and aims to summarize all the clinical studies,completed and ongoing,to identify whether GNPs are safe to use in humans as a therapeutic platform.In these studies,GNPs were implemented as drug delivery devices,for photothermal therapy,and utilized for their intrinsic therapeutic effects by various routes of delivery.These studies revealed no major safety concerns with the use of GNPs;however,the number of trials and total patient number remains limited.Multi-dose,multicenter blinded trials are required to deepen our understanding of the use of GNPs in clinical settings to facilitate translation of this novel,multifaceted therapeutic device.Expanding clinical trials will require collaboration between clinicians,scientists,and biotechnology companies.

HepG2、Hep3B细胞中肿瘤干细胞相关标志分子的表达

目的富集培养肝癌干细胞,研究肝癌干细胞相关标志物CD90、CD133、八聚体4(Oct4)和ATP结合盒转运蛋白ABCG2在肝癌细胞HepG2、Hep3B中的表达,并初步分析其意义。方法使用流式细胞仪从肝癌细胞(检测HepG2、Hep3B两种细胞系)中分选肝癌干细胞并行无血清成球培养。设肝癌细胞组为对照组。单细胞克隆形成实验检测细胞增殖能力。分别给予肝癌细胞及肝癌干细胞阿霉素处理,MTT法测阿霉素处理后各组细胞的存活率,Real-time PCR及Western blot分别检测各组细胞CD90、CD133、Oct4和ABCG2 mRNA及蛋白水平的表达。结果肝癌干细胞单个细胞增殖能力强于肝癌细胞,克隆形成分析显示培养第14天克隆形成率Hep3B细胞组低于Hep3B CSCs组[8/27(30%)vs 12/23(52%),P<0.05];HepG2细胞组克隆形成率也低于HepG2 CSCs组[7/38(18%)vs 9/26(35%),P<0.05]。用阿霉素处理肝癌细胞及肝癌干细胞48 h后,MTT法测定结果显示肝癌干细胞组细胞活性显著高于对照组(P<0.05):HepG2细胞组细胞活性为(38.17±6.92)%、HepG2 CSCs组为(69.88±5.43)%;Hep3B细胞组(50.16±4.89)%,Hep3B CSCs组为(78.53±7.86)%。Real-time PCR结果显示肝癌干细胞组中CD90、CD133、Oct4及ABCG2基因mRNA表达较亲代细胞组显著上调(P<0.05)。Western blot结果显示肝癌干细胞组Oct4及ABCG2蛋白水平显著上调,与亲代细胞组间表达差异有显著性(P<0.05)。结论肝癌干细胞相关标志CD90、CD133、Oct4及ABCG2均高表达于肝癌干细胞,并且Oct4及ABCG2基因的高表达有可能与肝癌干细胞耐药性相关。

肝癌干细胞样细胞的分离及其耐药性受PI3K/Akt通路调节

目的分离肝癌干细胞样细胞,初步探讨PI3K/Akt通路调节其对化疗药物阿霉素的敏感性。方法将人肝癌细胞株PLC、HepG2、Hep3B置于无血清条件培养基中培养,形成细胞球,选用PLC细胞株进行后续实验。采用流式细胞仪、克隆形成实验、SCID小鼠体内成瘤实验鉴定PLC细胞球(肝癌干细胞样细胞)的肿瘤干细胞特性。MTT法、流式细胞仪测定PLC细胞球对化疗药物阿霉素的敏感性。流式细胞仪分析加入PI3K/Akt通路特异性抑制剂LY294002、阿霉素共同孵育细胞球后,其凋亡率的变化。Western blot法比较PLC细胞球、PLC贴壁细胞中p-Akt1(Ser473)蛋白分子表达量及加入抑制剂LY294002作用于细胞球后,p-Akt1(Ser473)、Akt1蛋白分子表达量的变化。结果肝癌干细胞标志物CD90在细胞球中的表达较贴壁细胞显著升高(P<0.01)。细胞球的克隆形成数目(123.00±28.48)为贴壁细胞(56.33±7.37)的2.18倍(P<0.05)。同样细胞数接种于SCID小鼠皮下7周后,细胞球的致瘤率明显大于贴壁细胞。以5μg/mL的阿霉素分别处理细胞球和贴壁细胞48 h后,细胞球的增殖率明显高于贴壁细胞[(71.83±12.30)%vs(45.68±5.95)%,P<0.05],凋亡率显著低于贴壁细胞[(11.73±3.77)%vs(41.22±6.73)%,P<0.01],而以阿霉素5μg/mL和LY294002共同孵育细胞球后,其凋亡率[(35.44±6.65)%]显著增加(P<0.01)。Western blot检测到细胞球的p-Akt1(Ser473)蛋白分子表达量显著高于贴壁细胞(P<0.01),加入抑制剂LY294002处理细胞球后,p-Akt1(Ser473)蛋白表达量明显降低(P<0.05),Akt1的表达量无明显变化(P>0.05)。结论肝癌干细胞样细胞对化疗药物阿霉素具有耐药性,其耐药机制与Akt信号通路第473位点磷酸化Akt1分子有关。

Insulin-like growth factor binding protein related protein 1 knockdown attenuates hepatic ?brosis via the regulation of MMPs/TIMPs in mice

Background: Previous research suggested that insulin-like growth factor binding protein related protein 1(IGFBPrP1), as a novel mediator, contributes to hepatic fibrogenesis. Matrix metalloproteinases(MMP) and tissue inhibitors of metalloproteinases(TIMP) play an essential role in hepatic fibrogenesis by regulating homeostasis and remodeling of the extracellular matrix(ECM). However, the interaction between IGFBPrP1 and MMP/TIMP is not clear. The present study was to knockdown IGFBPrP1 to investigate the correlation between IGFBPrP1 and MMP/TIMP in hepatic fibrosis. Methods: Hepatic fibrosis was induced by thioacetamide(TAA) in mice. Knockdown of IGFBPrP1 expression by ultrasound-targeted microbubble destruction-mediated CMB-shRNA-IGFBPrP1 delivery, or inhibition of the Hedgehog(Hh) pathway by cyclopamine treatment, was performed in TAA-induced liver fibrosis mice. Hepatic fibrosis was determined by hematoxylin and eosin and Sirius red staining. Hepatic expression of IGFBPrP1, α-smooth muscle actin( α-SMA), transforming growth factor β 1(TGF β1), collagen I, MMPs/TIMPs, Sonic Hedgehog(Shh), and glioblastoma family transcription factors(Gli1) were investigated by immunohistochemical staining and Western blotting analysis. Results: We found that hepatic expression of IGFBPrP1, TGF β1, α-SMA, and collagen I were increased longitudinally in mice with TAA-induced hepatic fibrosis, concomitant with MMP2/TIMP2 and MMP9/TIMP1 imbalance and Hh pathway activation. Knockdown of IGFBPrP1 expression, or inhibition of the Hh pathway, reduced the hepatic expression of IGFBPrP1, TGF β1, α-SMA, and collagen I and re-established MMP2/TIMP2 and MMP9/TIMP1 balance. Conclusions: Our findings suggest that IGFBPrP1 knockdown attenuates liver fibrosis by re-establishing MMP2/TIMP2 and MMP9/TIMP1 balance, concomitant with the inhibition of hepatic stellate cell activation, down-regulation of TGF β1 expression, and degradation of the ECM. Furthermore, the Hh pathway mediates IGFBPrP1 knockdown-induced attenuation of hepatic fibrosis through the regulation of MMPs/TIMPs balance.

Claudin 1 mediates tumor necrosis factor alpha-induced cell migration in human gastric cancer cells

AIM:To investigate the role of claudin 1 in the regulation of genes involved in cell migration and tumor necrosis factor alpha(TNF-α)-induced gene expression in human gastric adenocarcinoma cells.METHODS:Knockdown experiments were conducted with claudin 1 small interfering RNA(si RNA),and theeffects on the cell cycle,apoptosis,migration and invasion were analyzed in human gastric adenocarcinoma MKN28 cells.The gene expression profiles of cells were analyzed by microarray and bioinformatics.RESULTS:The knockdown of claudin 1 significantly inhibited cell proliferation,migration and invasion,and increased apoptosis.Microarray analysis identified 245genes whose expression levels were altered by the knockdown of claudin 1.Pathway analysis showed that the top-ranked molecular and cellular function was the cellular movement related pathway,which involved MMP7,TNF-SF10,TGFBR1,and CCL2.Furthermore,TNFand nuclear frctor-κB were the top-ranked upstream regulators related to claudin 1.TNF-αtreatment increased claudin 1 expression and cell migration in MKN28 cells.Microarray analysis indicated that the depletion of claudin1 inhibited 80%of the TNF-α-induced m RNA expression changes.Further,TNF-αdid not enhance cell migration in the claudin 1 si RNA transfected cells.CONCLUSION:These results suggest that claudin 1 is an important messenger that regulates TNF-α-induced gene expression and migration in gastric cancer cells.A deeper understanding of these cellular processes may be helpful in establishing new therapeutic strategies for gastric cancer.

胰高血糖素样肽1和肠道菌群（英文）

胃肠道生产20多种肽类激素。其中,胰高血糖素样肽1(GLP-1)在过去的30年里受到最多关注。人们对GLP-1以及另一肠道激素葡萄糖依赖性促胰岛素肽(GIP)功能的研究已导致了两类新的糖尿病治疗药物的开发,分别称为GLP-1R激动剂和DPP-Ⅳ抑制剂。肠道的这些内分泌细胞不是聚集在内分泌腺体中,而是广泛分布在整个胃肠道中,从而与"外部"环境包括食物以及肠道菌群充分接触。本文简要介绍了GLP-1以及营养成分如何调节其分泌,并重点讨论了肠道环境如何影响GLP-1的产生和分泌,包括肠道菌群的贡献。

Nkx6.2 synergizes with Cdx-2 in stimulating proglucagon gene expression

AIM: To investigate whether the transactivator of the proglucagon gene (Gcg), Cdx-2, synergizes with other transcription factors in stimulating Gcg expression and the trans-differentiation of Gcg-expressing cells. METHODS: We conducted affinity chromatography to identify proteins that interact with Cdx-2, using GST-tagged Cdx-2 against cell lysates from pancreatic InR1-G9 and intestinal GLUTag cell lines. This was followed by a mass-spectrometry analysis. From a potential Cdx-2 interaction protein identified, we examined its expression in pancreatic and gut endocrine cells, confirmed its interaction with Cdx-2 by GST-pull down and determined its effect in provoking Gcg expression in cell lines that do not express endogenous Gcg.RESULTS: We identified 18 potential Cdx-2 interacting proteins. One of them is Nkx6.2. This homeodomain (HD) protein is expressed in pancreatic α and intestinal endocrine L cells but not in insulin producing cell lines, inclu ding In111. Nkx6.2, but not Nkx6.1, was shown to intera ct with Cdx-2, detected by GST-pull down. Furthermore, Nkx6.2 was found to synergize with Cdx-2 in provoking Gcg expression when they were ectopically expressed in the In111 cell line. Finally, when Cdx-2 and Nkx6.2 were co-transfected into the undifferentiated rat intestinal IEC-6 cell line, it produced detectable amount of Gcg mRNA. CONCLUSION: Cdx-2 recruits Nkx6.2 in exerting its ef fect in stimulating Gcg expression. Our observations fur ther support the notion that multiple HD proteins, including Cdx-2 and Nkx6.2, are involved in the regulation of Gcg expression and the genesis of Gcg-producing cells.

Nr2e1 Downregulation Is Involved in Excess Retinoic Acid-induced Developmental Abnormality in the Mouse Brain

Objective This study aimed to investigate the expression pattern and function of Nuclear receptor subfamily 2 group E member 1(Nr2e1) in retinoic acid(RA)-induced brain abnormality. Methods The mouse model of brain abnormality was established by administering 28 mg/kg RA, and neural stem cells(NSCs) were isolated from the mouse embryo and cultured in vitro. Nr2e1 expression was detected by whole mount in situ hybridization, RT-PCR, and Western blotting. Nr2e1 function was determined by transducing Nr2e1 shRNA into NSCs, and the effect on the sonic hedgehog(Shh) signaling pathway was assessed in the cells. In addition, the regulation of Nr2e1 expression by RA was also determined in vitro. Results Nr2e1 expression was significantly downregulated in the brain and NSCs of RA-treated mouse embryos, and knockdown of Nr2e1 affected the proliferation of NSCs in vitro. In addition, a similar expression pattern of Nr2e1 and RA receptor(RAR) α was observed after treatment of NSCs with different concentrations of RA. Conclusion Our study demonstrated that Nr2e1 could be regulated by RA, which would aid a better understanding of the mechanism underlying RA-induced brain abnormality.

生物材料在心脏修复和再生中的应用

心血管疾病是全世界主要致死原因之一。人们对新的干预性治疗手段的需求与日俱增。虽然药物和手术治疗极大地改善了心血管疾病患者的生活质量,但人们还是需要价格更便宜、副作用更小的治疗手段。天然和合成生物材料无论是作为给药载体,还是替代支架的细胞外基质,在心脏修复和再生中都展现出巨大的潜力。本文探讨了目前治疗心血管疾病的几种方式和应用于上述疾病干预性治疗的生物材料;着重研究了导电聚合物在纠正局部缺血性心脏病引发的传导异常及其在心脏起搏器中应用的可能性,以改善心肌梗死状态下的传导路径。

Tissue Engineering to Restore Cardiac Function

1. Introduction The purpose of cardiac surgery is to restore the injured heart to full function. For many congenital cardiac defects, appropriate repair is able to establish nearly normal cardiac function. One example of such repair is closing abnormal holes between cardiac chambers in young children, which usually restores normal function that persists for the lifetime of the child. However, the advent of surgery for ischemic heart disease has resulted in new challenges for cardiac surgeons.

生物材料在心脏修复和再生中的应用

心血管疾病是全世界主要致死原因之一。人们对新的干预性治疗手段的需求与日俱增。虽然药物和手术治疗极大地改善了心血管疾病患者的生活质量,但人们还是需要价格更便宜、副作用更小的治疗手段。天然和合成生物材料无论是作为给药载体,还是替代支架的细胞外基质,在心脏修复和再生中都展现出巨大的潜力。本文探讨了目前治疗心血管疾病的几种方式和应用于上述疾病干预性治疗的生物材料;着重研究了导电聚合物在纠正局部缺血性心脏病引发的传导异常及其在心脏起搏器中应用的可能性,以改善心肌梗死状态下的传导路径。

Novel Cytocidal Substituted Phenyl 4-(2-Oxoimidazolidin-1-yl) Benzenesulfonates and Benzenesulfonamides with Affinity to the Colchicine-Binding Site: Is the Phenyl 2-Imidazolidinone Moiety a New Haptophore for the Design of New Antimitotics?

Phenyl 4-(2-oxoimidazolidin-1-yl)benzenesulfonates (PIB-SOs) and phenyl 4-(2-oxoimidazolidin- 1-yl)benzenesulfonamides (PIB-SAs) are new, potent combretastatin A-4 (CA-4) analogs designed on the basis of their common phenyl 2-imidazolidone moiety. This phenyl 2-imidazolidone group is a bioisosteric equivalent of the trimethoxyphenyl group also found in colchicine, podophyllotoxin and several other ligands of the colchicine-binding site (C-BS). In this study, we investigate the interactions involved in the binding of PIB-SO and PIB-SA into the C-BS. We describe three distinct pockets (I, II, and III) as key structural elements involved in the interactions between the C-BS and PIB-SOs as well as PIB-SAs. We show that PIB-SOs and PIB-SAs adopt 4 and 3 distinct binding conformations, respectively, within the C-BS. The binding conformations I and IV are common to most PIB-SOs and PIB-SAs exhibiting high affinity for the C-BS and high cytocidal potency. In addition, binding conformation I is the main conformation adopted by PIB-SOs, PIB-SAs, T138067, ABT-751, colchicine and CA-4. We also observe that the sulfonate and the sulfonamide moieties of PIB-SOs and PIB-SAs are bioisosteric equivalents. Interestingly, we further find that a large portion of the phenyl 2-imidazolidinone moiety in these analogs does not bind to pocket I unlike the trimethoxyphenyl moiety found in several antimicrotubule agents such as colchicine, CA-4 and podophyllotoxin, suggesting that the phenyl 2-imidazolidinone group may represent a new haptophoric moiety useful for the design of new C-BS inhibitors mimicking the tropolone and the methoxylated phenolic moieties of colchicine and CA-4, respectively.

Unusual outcome of in utero infection and subsequent postnatal super-infection with different PCV2b strains

VC2002, isolated from postweaning multisystemic wasting syndrome(PMWS)-affected pig, is a mixture of two porcine circovirus genotype 2b(PCV2b) viruses, K2 and K39. Preliminary experiments disclosed short-term adverse effects of K39, but not K2, on porcine foetuses. These findings led to the hypothesis that infection of immuno-incompetent foetuses with K2 confers a status of immunotolerance, and postnatal super-infection with K39 triggers PMWS. To explore this hypothesis, nine 55-day-old foetuses were inoculated in utero(three with K2-104.3TCID50, three with K39-104.3TCID50 and three with medium), and foeto-pathogenicity examined. At 21 days post-inoculation(dpi), K2 did not induce pathology, whereas pathological effects of K39 were evident. Twenty-four 45-day-old foetuses were subsequently inoculated to examine the long-term effect of K2, including six with K2-high dose-104.3TCID50, six with K2-low dose-102.3TCID50 and 12 mock-inoculated controls. Both doses resulted in five mummified foetuses and one live-born piglet each(69dpi). K2 was recovered from all mummies. K2 and K2-specific antibodies were not detected in serum of the two live-born piglets at birth, indicating full control of K2 infection. The K2-low dose-infected piglet was immunostimulated at day 2, but not the K2-high dose-infected piglet. Both non-stimulated and stimulated K2-infected piglets were super-inoculated with K39 at day 6 or 8(taken as 0 days post super-inoculation). Low viral replication was observed in the non-stimulated K2-K39 piglet(up to 103.3 TCID50/g; identified as K39). In contrast, viral replication was extremely high in the stimulated K2-K39 piglet(up to 105.6TCID50/g) and identified as K2, indicating that K2 infection is controlled during foetal life, but emerges after birth upon immunostimulation. However, none of the piglets showed any signs of PMWS.

IN VIVO NEAR-INFRAREDFLUORESCENCEIMAGING OF HUMANCOLONADENOCARCINOMABY SPECIFIC IMMUNOTARGETINGOFA TUMOR-ASSOCIATEDMUCIN

Background and Aims: Accurate endoscopic detection of premalignant lesions and earlycancers in the colon is essential for cure, since prognosis is closely related to lesion size andstage. Although it has great clinical potential, autofluorescence endoscopy has limited tumorto-normal tissue image contrast for detecting small preneoplastic lesions. We have developed amolecularly specific, near-infrared fluorescent monoclonal antibody (CC49) bioconjugate whichtargets tumor-associated glycoprotein 72 (TAG72), as a contrast agent to improve fluorescencebased endoscopy of colon cancer. Methods: The fluorescent anti-TAG72 conjugate was evaluated in vitro and in vivo in athymic nude mice bearing human colon adenocarcinoma (LS174T)subcutaneous tumors. Autofluorescence, a fluorescent but irrelevant antibody and the free fluorescent dye served as controls. Fluorescent agents were injected intravenously, and in vivowhole body fluorescence imaging was performed at various time points to determine pharmacokinetics, followed by ex vivo tissue analysis by confocal fluorescence microscopy and histology Results: Fluorescence microscopy and histology confirmed specific LS174T cell membrane targeting of labeled CC49 in vitro and ex vivo. In vivo fluorescence imaging demonstrated significant tumor-to-normal tissue contrast enhancement with labeled-CC49 at three hours postinjection, with maximum contrast after 48 h. Accumulation of tumor fluorescence demonstratedthat modification of CC49 antibodies did not alter their specific tumor-localizing properties, andwas antibody-dependent since controls did not produce detectable tumor fluorescence. Conclusions: These results show proof-of-principle that our near-infrared fluorescent-antibody probetargeting a tumor-associated mucin detects colonic tumors at the molecular level in real time,and offer a basis for future improvement of image contrast during clinical fluorescence endoscopy.

Commentary:Can FXR serve as a potential target for COVID-19 prevention?

A research article has been accepted by Nature very recently entitled:FXR inhibition may protect from SARS-CoV-2 infection by reducing ACE2.This is a multiple-author study by 80 scientists from 40 different research units in UK,Germany,Greece,USA,Austria,Sweden,and Norway,with Teresa Brevini as the 1st author and one of the senior authors^(1).The pre-print of this study was posted online back to June 7,2021(bioRxiv).

Toll样受体参与小鼠肝脏缺血再灌注损伤

目的 探讨Toll样受体是否参与小鼠肝脏缺血再灌注损伤及其机制。方法 用Toll样受体缺损小鼠(C3H/Hej,Hej组)和野生型(C3H/Heouj,Heouj组)小鼠复制部分肝脏缺血再灌注损伤模型,于缺血45min,再灌注1h和3h处死动物,检测血清天门冬氨酸氨基转移酶(AST)和血清肿瘤坏死因子α(TNFα)的含量;并以northern blot及髓过氧化物酶(MPO)试验分别检测缺血肝组织TNFα mRNA的表达和MPO的含量。结果(1)再灌注1、3h,与假手术组相比,小鼠血浆AST明显升高,但Hej组明显低于Heouj组(661.83U/L±106.09U/L和1215.5U/L±174.03U/L,t=-6.65,P<0.01;1145.17U/L±132.43U/L和2958.17U/L±186.81U/L,t=-5.57,P<0.01);(2)再灌注3h时,与假手术组相比,Hej组和Heouj组小鼠血清TNFα浓度明显升高,且前者明显低于后者(152.39pg/ml±43.3pg/ml和249.12pg/ml±51.89pg/ml,t=-3.13,P<0.05);(3)再灌注1h,除假手术组外,Hej组和Heouj组小鼠缺血肝组织内可见TNFα mRNA的表达,但前者的表达水平明显低于后者,杂交带密度分析显示两者之间差异有显著性(80.3±28.8与189.4±24.6,t=-3.25,P<0.05);(4)再灌注3h,与假手术组相比,Hej组和Heouj组小鼠缺血肝组织内MPO含量明显升高,且前者含量明显低于后者(0.059±0.004和0.173±0.025,F=33.49,P<0.01)。结?

胰高糖素样肽-1基因荧光真核表达载体的构建及鉴定

目的：克隆大鼠胰高糖素样肽-1（GLP-1）的编码基因，构建荧光真核表达载体，为研究GLP-1与糖尿病的相关性奠定实验基础。方法：用RT-PCR方法从大鼠胰腺组织中扩增GLP-1的编码基因，克隆至PMD18-T载体并测序，结果正确后亚克隆至荧光真核表达载体pEYFP-N1中。结果：测序证实从胰腺中扩增出的GLP-1编码基因的序列及读框全部正确，重组质粒pEYFP-GLP-1经酶切后产生与理论预期长度相符的片段。结论：克隆了大鼠GLP-1的编码基因，成功构建了荧光真核表达载体pEYFP-GLP-1。