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1.
BMC Anesthesiol ; 24(1): 34, 2024 Jan 22.
Article in English | MEDLINE | ID: mdl-38254013

ABSTRACT

BACKGROUND: Dyclonine hydrochloride mucilage is a topical anaesthetic formulated for mucosal surfaces. It is employed frequently for topical anaesthesia of the pharynx prior to endoscopic examinations such as electronic gastroscopy, and few adverse reactions have been reported. This article describes a patient who experienced a transient but severe disturbance of consciousness following oral dyclonine hydrochloride mucilage administration. CASE PRESENTATION: A 75-year-old female presenting with gastrointestinal bleeding was examined by electronic gastroscopy. Six minutes after oral dyclonine hydrochloride mucilage administration, the patient entered a comatose-like state accompanied by loss of limb muscle tone and profuse perspiration. This response was not accompanied by changes in cardiac rhythm, blood pressure, or respiration rate, suggesting an effect on higher brain centres. After ten minutes, the patient's symptoms were alleviated. CONCLUSION: We suggest that sites of dyclonine hydrochloride mucilage use be equipped with appropriate rescue devices for these rare events.


Subject(s)
Brain , Consciousness , Propiophenones , Female , Humans , Aged , Administration, Oral , Anesthesia, Local
4.
Lupus ; 32(9): 1084-1092, 2023 Aug.
Article in English | MEDLINE | ID: mdl-37480363

ABSTRACT

BACKGROUND: This study aimed to explore risk factors for lupus nephritis (LN) in systemic lupus erythematosus (SLE) patients and establish a Nomogram prediction model based on LASSO-logistic regression. METHODS: The clinical and laboratory data of SLE patients in Meishan People's Hospital from July 2012 to December 2021 were analyzed retrospectively. All SLE patients were divided into two groups with or without LN. Risk factors were screened based on LASSO-logistic regression analysis, and a Nomogram prediction model was established. The receiver operating characteristic curve, calibration curves, and decision curve analysis were adopted to evaluate the performance of the Nomogram model. RESULTS: A total of 555 SLE patients were enrolled, including 303 SLE patients with LN and 252 SLE patients without LN. LASSO regression and multivariate logistic regression analyses showed that ESR, mucosal ulcer, proteinuria, and hematuria were independent risk factors for LN in SLE patients. The four clinical features were incorporated into the Nomogram prediction model. Results showed that calibration curve was basically close to the diagonal dotted line with slope 1 (ideal prediction case), which proved that the prediction ability of the model was acceptable. In addition, the decision curve analysis showed that the Nomogram prediction model could bring net clinical benefits to patients when the threshold probability was 0.12-0.54. CONCLUSION: Four clinical indicators of ESR, mucosal ulcer, proteinuria, and hematuria were independent risk factors for LN in SLE patients. The predictive power of the Nomogram model based on LASSO-logistic regression was acceptable and could be used to guide clinical work.


Subject(s)
Lupus Erythematosus, Systemic , Lupus Nephritis , Humans , Lupus Nephritis/complications , Lupus Erythematosus, Systemic/complications , Retrospective Studies , Nomograms , Hematuria/complications , Ulcer , Biomarkers , Proteinuria/complications , Risk Factors
5.
World J Clin Cases ; 11(11): 2576-2581, 2023 Apr 16.
Article in English | MEDLINE | ID: mdl-37123311

ABSTRACT

BACKGROUND: Primary cancer of the appendix is rare and often difficult to diagnose preoperatively due to the lack of specific clinical symptoms. Autoimmune encephalitis (AIE) is the most common cause of non-infectious encephalitis. The etiologies of AIE include tumors (paraneoplastic), infections (parainfections), or recessive infections. The tumors that have been reported to cause AIE include thymomas, ovarian teratomas, lung cancers, and breast cancers. However, there are no reports of AIE occurring after surgery for appendiceal cancer. This report describes the diagnosis and treatment of a patient with an appendiceal cancer and postoperative AIE. CASE SUMMARY: We report the case of a 47-year-old man who was transferred to our hospital due to a recurrent low intestinal obstruction. Abdominal enhanced computed tomography was used to consider the possibility of a terminal ileal tumor with serous infiltration and lymph node metastasis. A right hemi-colectomy was performed under general anesthesia with an ileo-transcolon anastomosis and laparoscopic exploration. The postoperative pathologic evaluation revealed a high-grade goblet cell carcinoma of the appendix, accompanied by mesangial and abdominal lymph node metastases, and neural tube and vascular infiltration. The operation was completed without complication. The patient developed restlessness on postoperative day 4, and gradually developed a disturbance of consciousness on postoperative day 6. He was transferred to West China Hospital of Sichuan University and diagnosed with AIE. CONCLUSION: Albeit rare, the occurrence of neurologic and psychiatric symptoms in patients with an appendiceal cancer postoperatively suggests the possibility of AIE.

6.
Environ Res ; 219: 115097, 2023 02 15.
Article in English | MEDLINE | ID: mdl-36566965

ABSTRACT

As one of the key stable crops to feed half of the world's population, how rice cropping system affects honey bee health regarding pesticide exposure and forage availability is under investigated. We predicted honey bees were stressed by high pesticide exposure and forage dearth in monoculture rice systems. Providing access to natural habitats is a typical approach to mitigate the negative impact of intensive agriculture on honey bees. We aimed to determine if bee colonies located in landscapes with more cover of forest habitat would collect more forage and be exposed to less pesticides. We selected beekeeping locations in rice dominated landscapes (as control), mosaic landscapes of rice and medium woodland (MW) cover, and landscapes of high woodland (HW) cover, respectively, in July when rice starts bloom and pesticides are commonly used. Colonies were inspected at a biweekly frequency from July to October with population growth and forage (nectar and pollen) availability estimated. Pollen and bees were collected in middle August for pesticide exposure analysis. We did not observe enhancement in forage availability and reduction in pesticide exposure in landscapes with increased forest habitat (i.e., MW or HW cover), and all colonies failed in the end. Other natural habitats that can supplement flower shortage periods in forest can be considered for supporting bee health. Our results suggest that forest should be carefully assessed for being incorporated into beekeeping management or pollinator conservation when forest phenology can be a factor to affect its impact as a natural habitat.


Subject(s)
Oryza , Pesticides , Bees , Animals , Agriculture , Beekeeping , Plant Nectar
7.
Gastrointest Endosc ; 97(5): 952-961.e1, 2023 05.
Article in English | MEDLINE | ID: mdl-36572127

ABSTRACT

BACKGROUND AND AIMS: The single dose of 2 L polyethylene glycol (PEG) has shown high cleaning efficacy and tolerability in low-risk patients. However, the dosage of this regimen is still challenging for many patients. We investigated the efficacy and tolerability of a novel ultra-low-volume regimen using 1 L PEG and linaclotide (1 L PEG+L) versus a single dose of 2 L PEG in low-risk patients. METHODS: In this prospective, randomized, observer-blinded, multicenter study, low-risk adult patients scheduled for colonoscopy were enrolled and randomized (1:1) to receive the 1 L PEG+L regimen or the 2 L PEG regimen. The primary outcome was the effectiveness of bowel cleansing according to the Boston Bowel Preparation Scale. Secondary outcomes included cecal intubation rate, cecal insertion time, withdrawal time, polyp detection rate and adenoma detection rate, tolerability, adverse events, and willingness to repeat bowel preparation. The full analysis set (FAS) and per-protocol set (PPS) were used for statistical analyses. RESULTS: A total of 548 patients comprised the FAS, and 522 patients comprised the PPS. Noninferiority on adequate bowel cleansing of 1 L PEG+L vs 2 L PEG was established both in FAS (90.5% vs 91.6%, P = .644) and PPS (90.3% vs 92.4%, P = .390). There were no significant differences regarding the total score and each segment scores of the Boston Bowel Preparation Scale, cecal intubation rate, cecal insertion time, withdrawal time, polyp detection rate, and adenoma detection rate (all, P > .05). However, patients in the 1 L PEG+L group reported less nausea (7.7% vs 17.1%, P < .01) and vomiting (4.0% vs 10.9%, P < .01) and had a higher willingness to repeat bowel preparation (95.2% vs 82.2%, P < .01). CONCLUSIONS: The regimen of 1 L PEG+L was not inferior to 2 L PEG on colon cleansing, with better tolerability and higher willingness to repeat the bowel preparation in a low-risk population. (Clinical trial registration number: ChiCTR2100053273.).


Subject(s)
Adenoma , Polyethylene Glycols , Adult , Humans , Colonoscopy/methods , Cathartics , Cecum , Prospective Studies
8.
Molecules ; 27(18)2022 Sep 13.
Article in English | MEDLINE | ID: mdl-36144674

ABSTRACT

Due to the body's systemic distribution of photothermal agents (PTAs), and to the imprecise exposure of lasers, photothermal therapy (PTT) is challenging to use in treating tumor sites selectively. Striving for PTT with high selectivity and precise treatment is nevertheless important, in order to raise the survival rate of cancer patients and lower the likelihood of adverse effects on other body sections. Here, we studied cold atmospheric plasma (CAP) as a supplementary procedure to enhance selectivity of PTT for cancer, using the classical photothermic agent's gold nanostars (AuNSs). In in vitro experiments, CAP decreases the effective power of PTT: the combination of PTT with CAP at lower power has similar cytotoxicity to that using higher power irradiation alone. In in vivo experiments, combination therapy can achieve rapid tumor suppression in the early stages of treatment and reduce side effects to surrounding normal tissues, compared to applying PTT alone. This research provides a strategy for the use of selective PTT for cancer, and promotes the clinical transformation of CAP.


Subject(s)
Neoplasms , Photochemotherapy , Plasma Gases , Cell Line, Tumor , Gold/therapeutic use , Humans , Neoplasms/drug therapy , Photochemotherapy/methods , Phototherapy , Photothermal Therapy , Plasma Gases/pharmacology , Plasma Gases/therapeutic use
9.
J Colloid Interface Sci ; 624: 734-746, 2022 Oct 15.
Article in English | MEDLINE | ID: mdl-35696791

ABSTRACT

Studies have shown that disulfiram (DSF) can combine with Cu2+ to form bis(N, N-diethyldithiocarbamate) copper(II) complex (CuET) as antitumor drugs. However, there is insufficient endogenous Cu2+ dose to eradicate cancer cells selectively. Inspired by the buffet, we use Cu2+ doped hollow zeolitic imidazolate framework nanoparticles (HZIFCu) as the carrier and equipped with DSF and indocyanine green (ICG) and targeted by folic acid (FA) (D&I@HZIFCu-FA) to enhance DSF-based cancer therapy. D&I@HZIFCu-FA could effectively supply Cu2+ by a buffet-style, assisting the "DSF-to-CuET" transformation in the tumor. Additionally, self-supply Cu2+ could convert H2O2 into ·OH by triggering a Fenton-like reaction for chemo-dynamic therapy, and ICG achieves photothermal therapy for tumors under laser irradiation. This work provides a buffet-style for Cu2+ to make DSF a strong candidate for cancer treatment by combining chemotherapy, chemo-dynamic therapy, and photothermal therapy and inspires more research about its applications in tumor therapy.


Subject(s)
Antineoplastic Agents , Neoplasms , Antineoplastic Agents/pharmacology , Cell Line, Tumor , Copper , Disulfiram/pharmacology , Hydrogen Peroxide , Neoplasms/drug therapy
10.
Ying Yong Sheng Tai Xue Bao ; 32(7): 2433-2439, 2021 Jul.
Article in English | MEDLINE | ID: mdl-34313061

ABSTRACT

Grazing is the dominant land use way for natural grasslands. Different grazing intensities could affect soil stoichiometry in grasslands by influencing the selective feeding by livestock, litter input, and microbial community structure. In this study, a grazing experiment was carried out in a grassland of agro-pastoral ecotone in Northern China for three years (2017-2019). The concentrations of total carbon (TC), total nitrogen (TN), dissolved organic carbon (DOC), dissolved nitrogen (DN), microbial biomass carbon (MBC), and microbial biomass nitrogen (MBN) in soils were measured. We analyzed the stoichiometric characteristics of those parameters. The results showed that different grazing intensities (1, 2, 4 sheep·0.2 hm-2) had no significant effect on soil TC after three years. The moderate grazing intensity significantly reduced soil TN in 10-20 cm layer in 2019. The light, moderate, and heavy grazing intensities significantly increased soil C/N at 10-20 cm layer, while grazing intensities did not affect soil DOC, DN and DOC/DN. The soil DOC and DN content showed a decreasing trend with the increase of grazing intensity in 2019. It indicated that continuous high intensity grazing might reduce soil dissolved nutrients. The light grazing inten-sity increased soil MBC, while heavy grazing intensity reduced soil MBC significantly, with the increase of grazing year. Different grazing intensities did not affect soil MBN and MBC/MBN.


Subject(s)
Grassland , Soil , Animals , Biomass , Carbon/analysis , China , Nitrogen/analysis , Sheep
11.
Cell Calcium ; 87: 102171, 2020 05.
Article in English | MEDLINE | ID: mdl-32062191

ABSTRACT

B-cell activating factor (BAFF) is a crucial survival factor for B cells, and excess BAFF contributes to development of autoimmune diseases. Recent studies have shown that rapamycin can prevent BAFF-induced B-cell proliferation and survival, but the underlying mechanism remains to be elucidated. Here we found that rapamycin inhibited human soluble BAFF (hsBAFF)-stimulated cell proliferation by inducing G1-cell cycle arrest, which was through downregulating the protein levels of CDK2, CDK4, CDK6, cyclin A, cyclin D1, and cyclin E. Rapamycin reduced hsBAFF-stimulated cell survival by downregulating the levels of anti-apoptotic proteins (Mcl-1, Bcl-2, Bcl-xL and survivin) and meanwhile upregulating the levels of pro-apoptotic proteins (BAK and BAX). The cytostatic and cytotoxic effects of rapamycin linked to its attenuation of hsBAFF-elevated intracellular free Ca2+ ([Ca2+]i). In addition, rapamycin blocked hsBAFF-stimulated B-cell proliferation and survival by preventing hsBAFF from inactivating PTEN and activating the Akt-Erk1/2 pathway. Overexpression of wild type PTEN or ectopic expression of dominant negative Akt potentiated rapamycin's suppression of hsBAFF-induced Erk1/2 activation and proliferation/viability in Raji cells. Interestingly, PP242 (mTORC1/2 inhibitor) or Akt inhibitor X, like rapamycin (mTORC1 inhibitor), reduced the basal or hsBAFF-induced [Ca2+]i elevations. Chelating [Ca2+]i with BAPTA/AM, preventing [Ca2+]i elevation using EGTA, 2-APB or verapamil, inhibiting CaMKII with KN93, or silencing CaMKII strengthened rapamycin's inhibitory effects. The results indicate that rapamycin inhibits BAFF-stimulated B-cell proliferation and survival by blunting mTORC1/2-mediated [Ca2+]i elevations and suppressing Ca2+-CaMKII-dependent PTEN/Akt-Erk1/2 signaling pathway. Our finding underscores that rapamycin may be exploited for prevention of excessive BAFF-induced aggressive B-cell malignancies and autoimmune diseases.


Subject(s)
B-Cell Activating Factor/metabolism , B-Lymphocytes/metabolism , Calcium-Calmodulin-Dependent Protein Kinase Type 2/metabolism , Calcium/metabolism , Lymphoma, B-Cell/pathology , PTEN Phosphohydrolase/metabolism , Proto-Oncogene Proteins c-akt/metabolism , Sirolimus/pharmacology , Animals , Apoptosis/drug effects , B-Lymphocytes/drug effects , B-Lymphocytes/pathology , Cell Cycle/drug effects , Cell Line, Tumor , Cell Proliferation/drug effects , Cell Survival/drug effects , Cyclin-Dependent Kinases/metabolism , Down-Regulation/drug effects , Humans , Lymphoma, B-Cell/metabolism , MAP Kinase Signaling System , Mice , Models, Biological
12.
Cell Signal ; 53: 68-79, 2019 01.
Article in English | MEDLINE | ID: mdl-30244168

ABSTRACT

B cell activating factor from the TNF family (BAFF) is implicated in not only the physiology of normal B cells, but also the pathophysiology of aggressive B cells related to malignant and autoimmune diseases. Autophagy plays a crucial role in balancing the beneficial and detrimental effects of immunity and inflammation. However, little is known about whether and how excessive BAFF mediates autophagy contributing to B-cell proliferation and survival. Here, we show that excessive human soluble BAFF (hsBAFF) inhibited autophagy with a concomitant reduction of LC3-II in normal and B-lymphoid (Raji) cells. Knockdown of LC3 not only potentiated hsBAFF inhibition of autophagy, but also attenuated hsBAFF activation of Akt/mTOR pathway, thereby diminishing hsBAFF-induced B-cell proliferation/viability. Further, we found that hsBAFF inhibition of autophagy was Akt/mTOR-dependent. This is supported by the findings that hsBAFF increased mTORC1-mediated phosphorylation of ULK1 (Ser757); Akt inhibitor X, mTORC1 inhibitor rapamycin, mTORC1/2 inhibitor PP242, expression of dominant negative Akt, or knockdown of mTOR attenuated hsBAFF-induced phosphorylation of ULK1, decrease of LC3-II level, and increase of cell proliferation/viability. Chelating intracellular free Ca2+ ([Ca2+]i) with BAPTA/AM or preventing [Ca2+]i elevation using EGTA or 2-APB profoundly blocked hsBAFF-induced activation of Akt/mTOR, phosphorylation of ULK1 and decrease of LC3-II, as well as increase of cell proliferation/viability. Similar effects were observed in the cells where CaMKII was inhibited by KN93 or knocked down by CaMKII shRNA. Collectively, these results indicate that hsBAFF inhibits autophagy promoting cell proliferation and survival through activating Ca2+-CaMKII-dependent Akt/mTOR signaling pathway in normal and neoplastic B-lymphoid cells. Our findings suggest that manipulation of intracellular Ca2+ level or CaMKII, Akt, or mTOR activity to promote autophagy may be exploited for prevention of excessive BAFF-induced aggressive B lymphocyte disorders and autoimmune diseases.


Subject(s)
Autophagy , B-Cell Activating Factor/metabolism , B-Lymphocytes/pathology , Calcium-Calmodulin-Dependent Protein Kinase Type 2/metabolism , B-Lymphocytes/cytology , B-Lymphocytes/metabolism , Calcium/metabolism , Cell Line , Cell Line, Tumor , Cell Proliferation , Cell Survival , Humans , Lymphoma, B-Cell/metabolism , Lymphoma, B-Cell/pathology , Proto-Oncogene Proteins c-akt/metabolism , Signal Transduction , TOR Serine-Threonine Kinases/metabolism
13.
J Cell Physiol ; 233(1): 516-529, 2018 Jan.
Article in English | MEDLINE | ID: mdl-28300280

ABSTRACT

B cell activating factor from the TNF family (BAFF) stimulates B-cell proliferation and survival, but excessive BAFF promotes the development of aggressive B cells leading to malignant and autoimmune diseases. Recently, we have reported that rapamycin, a macrocyclic lactone, attenuates human soluble BAFF (hsBAFF)-stimulated B-cell proliferation/survival by suppressing mTOR-mediated PP2A-Erk1/2 signaling pathway. Here, we show that the inhibitory effect of rapamycin on hsBAFF-promoted B cell proliferation/survival is also related to blocking hsBAFF-stimulated phosphorylation of Akt, S6K1, and 4E-BP1, as well as expression of survivin in normal and B-lymphoid (Raji and Daudi) cells. It appeared that both mTORC1 and mTORC2 were involved in the inhibitory activity of rapamycin, as silencing raptor or rictor enhanced rapamycin's suppression of hsBAFF-induced survivin expression and proliferation/viability in B cells. Also, PP242, an mTORC1/2 kinase inhibitor, repressed survivin expression, and cell proliferation/viability more potently than rapamycin (mTORC1 inhibitor) in B cells in response to hsBAFF. Of interest, ectopic expression of constitutively active Akt (myr-Akt) or constitutively active S6K1 (S6K1-ca), or downregulation of 4E-BP1 conferred resistance to rapamycin's attenuation of hsBAFF-induced survivin expression and B-cell proliferation/viability, whereas overexpression of dominant negative Akt (dn-Akt) or constitutively hypophosphorylated 4E-BP1 (4EBP1-5A), or downregulation of S6K1, or co-treatment with Akt inhibitor potentiated the inhibitory effects of rapamycin. The findings indicate that rapamycin attenuates excessive hsBAFF-induced cell proliferation/survival via blocking mTORC1/2 signaling in normal and neoplastic B-lymphoid cells. Our data underscore that rapamycin may be a potential agent for preventing excessive BAFF-evoked aggressive B-cell malignancies and autoimmune diseases.


Subject(s)
Antineoplastic Agents/pharmacology , B-Cell Activating Factor/metabolism , B-Lymphocytes/drug effects , Cell Proliferation/drug effects , Lymphoma, B-Cell/drug therapy , Multiprotein Complexes/metabolism , Signal Transduction/drug effects , Sirolimus/pharmacology , TOR Serine-Threonine Kinases/metabolism , Adaptor Proteins, Signal Transducing/genetics , Adaptor Proteins, Signal Transducing/metabolism , B-Lymphocytes/enzymology , B-Lymphocytes/pathology , Cell Cycle Proteins , Cell Line, Tumor , Cell Survival/drug effects , Dose-Response Relationship, Drug , Gene Expression Regulation, Neoplastic , Humans , Lymphoma, B-Cell/genetics , Lymphoma, B-Cell/pathology , Mechanistic Target of Rapamycin Complex 1 , Mechanistic Target of Rapamycin Complex 2 , Phosphoproteins/genetics , Phosphoproteins/metabolism , Phosphorylation , Proto-Oncogene Proteins c-akt/genetics , Proto-Oncogene Proteins c-akt/metabolism , RNA Interference , Ribosomal Protein S6 Kinases, 70-kDa/genetics , Ribosomal Protein S6 Kinases, 70-kDa/metabolism , Transfection
14.
Cell Physiol Biochem ; 39(2): 481-90, 2016.
Article in English | MEDLINE | ID: mdl-27383277

ABSTRACT

BACKGROUND/AIMS: Paclitaxel (PTX) is one of the most effective anti-cancer drugs. However, multiple drug resistance is still the main factor that hinders the effective treatment of cancer with PTX. Several factors including YAP over-expression can cause PTX resistance. In this study, we aimed to verify the role YAP plays in PTX resistance, explore the reversal of PTX resistance by verteporfin (VP) and investigate the effect of combination therapy of PTX and VP on the PTX resistant colon cancer cells (HCT-8/T). METHODS: To study the relationship between YAP and PTX resistance, a stable YAP-over-expression or YAP silencing cell line was generated by transfected with YAP-plasmids or siYAP-RNA. WST-1 assay was performed to detect the cytotoxicity of PTX on HCT-8 and HCT-8/T cells. Clone formation assay and Transwell assay was preformed to determine the cell proliferation and invasion ability respectively. Immunofluorescence and Western blot analysis was performed for protein detection. RESULTS: YAP was stronger expressed in HCT-8/T than in HCT-8, and PTX resistance was positively correlated with the level of YAP expression. VP, a strongly YAP inhibitor, could reduce the PTX resistance on HCT-8/T cells without light activation by inhibiting YAP. Beside, VP and PTX combination therapy showed synergism on inhibition of YAP and cytotoxicity to HCT-8/T. Moreover, verteporfin and PTX combination therapy affect the invasion and colony formation ability and induce apoptosis of HCT-8/T cells. CONCLUSIONS: VP can reverse the PTX resistance induced by YAP over-expression in HCT-8/T cells without photoactivation through inhibiting YAP expression.


Subject(s)
Adaptor Proteins, Signal Transducing/metabolism , Drug Resistance, Neoplasm/drug effects , Paclitaxel/pharmacology , Phosphoproteins/metabolism , Porphyrins/pharmacology , Adaptor Proteins, Signal Transducing/antagonists & inhibitors , Adaptor Proteins, Signal Transducing/genetics , Antineoplastic Agents, Phytogenic/pharmacology , Apoptosis/drug effects , Apoptosis/genetics , Blotting, Western , Cell Line, Tumor , Cell Proliferation/drug effects , Cell Proliferation/genetics , Cell Survival/drug effects , Cell Survival/genetics , Colonic Neoplasms/genetics , Colonic Neoplasms/metabolism , Colonic Neoplasms/pathology , Drug Resistance, Neoplasm/genetics , Drug Synergism , Humans , Inhibitory Concentration 50 , Microscopy, Confocal , Phosphoproteins/antagonists & inhibitors , Phosphoproteins/genetics , Photosensitizing Agents/pharmacology , RNA Interference , Transcription Factors , Verteporfin , YAP-Signaling Proteins
15.
Cell Mol Life Sci ; 72(24): 4867-84, 2015 Dec.
Article in English | MEDLINE | ID: mdl-26118661

ABSTRACT

B-cell activating factor (BAFF) is involved in not only physiology of normal B cells, but also pathophysiology of aggressive B cells related to malignant and autoimmune diseases. Rapamycin, a lipophilic macrolide antibiotic, has recently shown to be effective in the treatment of human lupus erythematosus. However, how rapamycin inhibits BAFF-stimulated B-cell proliferation and survival has not been fully elucidated. Here, we show that rapamycin inhibited human soluble BAFF (hsBAFF)-induced cell proliferation and survival in normal and B-lymphoid (Raji and Daudi) cells by activation of PP2A and inactivation of Erk1/2. Pretreatment with PD98059, down-regulation of Erk1/2, expression of dominant negative MKK1, or overexpression of wild-type PP2A potentiated rapamycin's suppression of hsBAFF-activated Erk1/2 and B-cell proliferation/viability, whereas expression of constitutively active MKK1, inhibition of PP2A by okadaic acid, or expression of dominant negative PP2A attenuated the inhibitory effects of rapamycin. Furthermore, expression of a rapamycin-resistant and kinase-active mTOR (mTOR-T), but not a rapamycin-resistant and kinase-dead mTOR-T (mTOR-TE), conferred resistance to rapamycin's effects on PP2A, Erk1/2 and B-cell proliferation/viability, implying mTOR-dependent mechanism involved. The findings indicate that rapamycin inhibits BAFF-stimulated cell proliferation/survival by targeting mTOR-mediated PP2A-Erk1/2 signaling pathway in normal and neoplastic B-lymphoid cells. Our data highlight that rapamycin may be exploited for preventing excessive BAFF-induced aggressive B-cell malignancies and autoimmune diseases.


Subject(s)
B-Cell Activating Factor/physiology , B-Lymphocytes/drug effects , MAP Kinase Signaling System/drug effects , Sirolimus/pharmacology , TOR Serine-Threonine Kinases/physiology , Animals , B-Cell Activating Factor/metabolism , B-Lymphocytes/metabolism , Cell Proliferation/drug effects , Cell Survival/drug effects , Down-Regulation , Humans , Mice , Signal Transduction , TOR Serine-Threonine Kinases/metabolism , Tumor Cells, Cultured
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