scholarly journals Increased Susceptibility of  Thymocytes to Apoptosis in Mice Lacking AIM, a Novel Murine Macrophage-derived Soluble Factor Belonging to the Scavenger Receptor Cysteine-rich Domain Superfamily

1999 ◽  
Vol 189 (2) ◽  
pp. 413-422 ◽  
Author(s):  
Toru Miyazaki ◽  
Yumiko Hirokami ◽  
Nobuyuki Matsuhashi ◽  
Hisakazu Takatsuka ◽  
Makoto Naito

Apoptosis of cells must be regulated both positively and negatively in response to a variety of stimuli in the body. Various environmental stresses are known to initiate apoptosis via differential signal transduction cascades. However, induction of signals that may inhibit apoptosis is poorly understood, although a number of intracellular molecules that mediate inhibition of apoptosis have been identified. Here we present a novel murine macrophage-specific 54-kD secreted protein which inhibits apoptosis (termed AIM, for apoptosis inhibitor expressed by macrophages). AIM belongs to the macrophage scavenger receptor cysteine-rich domain superfamily (SRCR-SF), members of which share a highly homologous conserved cysteine-rich domain. In AIM-deficient mice, the thymocyte numbers were diminished to half those in wild-type mice, and CD4/CD8 double-positive (DP) thymocytes were strikingly more susceptible to apoptosis induced by both dexamethasone and irradiation in vivo. Recombinant AIM protein significantly inhibited cell death of DP thymocytes in response to a variety of stimuli in vitro. These results indicate that in the thymus, AIM functions in trans to induce resistance to apoptosis within DP cells, and thus supports the viability of DP thymocytes before thymic selection.

2005 ◽  
Vol 170 (7) ◽  
pp. 1091-1099 ◽  
Author(s):  
Jessica E. Smotrys ◽  
Marissa J. Schoenfish ◽  
Monica A. Stutz ◽  
Maurine E. Linder

Palmitoylation of the vacuolar membrane protein Vac8p is essential for vacuole fusion in yeast (Veit, M., R. Laage, L. Dietrich, L. Wang, and C. Ungermann. 2001. EMBO J. 20:3145–3155; Wang, Y.X., E.J. Kauffman, J.E. Duex, and L.S. Weisman. 2001. J. Biol. Chem. 276:35133–35140). Proteins that contain an Asp-His-His-Cys (DHHC)–cysteine rich domain (CRD) are emerging as a family of protein acyltransferases, and are therefore candidates for mediators of Vac8p palmitoylation. Here we demonstrate that the DHHC-CRD proteins Pfa3p (protein fatty acyltransferase 3, encoded by YNL326c) and Swf1p are important for vacuole fusion. Cells lacking Pfa3p had fragmented vacuoles when stressed, and cells lacking both Pfa3p and Swf1p had fragmented vacuoles under normal growth conditions. Pfa3p promoted Vac8p membrane association and palmitoylation in vivo and partially purified Pfa3p palmitoylated Vac8p in vitro, establishing Vac8p as a substrate for palmitoylation by Pfa3p. Vac8p is the first N-myristoylated, palmitoylated protein identified as a substrate for a DHHC-CRD protein.


2018 ◽  
Vol 1 (1) ◽  
pp. 1-5

The inaugural issue is introduced by several editorials: "The Story of Precision Nanomedicine-the Journal", "Balancing Interests of Science, Scientists, and the Publishing Business", and "Improving Innovation in Nano-Healthcare Funding". The Clinical Editor's comments on research papers: Prec. Nanomed. 2018, Apr; 1(1):18-42. Extracellular vesicles (EVs) are involved in various biological processes such as cargo trafficking, cell-cell communication, and signal transduction. The advances in nanotechnology have enabled researchers to utilize EVs for potential use in clinical applications, within the so-called precision medicine approach. In this review article, the authors discuss the techniques used in EV isolation in length, together with their applications in clinical diagnosis and therapeutics. Prec. Nanomed. 2018 Apr;1(1):63-75. Due to potential hypersensitivity reactions to nanodrugs, thorough testing is required before these drugs can be used in the clinical setting. Here the authors provide a succinct review on the use of pigs as a reliable in-vivo model for pre-clinical drug testing. Prec. Nanomed. 2018 Apr;1(1):76-85. One of the ways that nanoparticles are cleared in the body is via Kupffer cells. The authors of the next paper tested the role of scavenger receptor SR-AI/II in the clearance of dextran superparamagnetic iron oxide (SPIO) Feridex-IV® and dextran-coated SPIO nanoworms (SPIO NWs). Results here show that multiple pathways and mechanisms exist in nanoparticle clearance. Thus, further understanding of nanoparticle clearance would be required to prolong in vivo half-life. Prec. Nanomed. 2018 Apr;1(1):43-62. Liposomes have been used in clinical practice for some years, this delivery system often result in significant systemic effects due to hypersensitivity reactions, via the activation of the complement system. The authors here show good biocompatibility of Rad-PC-Rad liposomes in terms of complement activation and pro-inflammatory cytokines production in-vitro.


2018 ◽  
Vol 1 (1) ◽  
pp. 76-84 ◽  
Author(s):  
Guankui Wang ◽  
Ernest Groman ◽  
Dmitri Simberg

Nanoparticles are recognized and cleared by Kupffer cells (KCs) in the liver. This process complicates the development of targeted nanoparticles because of significant reduction of number of nanoparticles that can reach target tissues. Macrophage scavenger receptor SR type AI/II is the central phagocytic receptor that has been shown to promote in vitro uptake of many nanoparticle types. In this paper, the authors set out to clarify the role of SR-AI/II in the in vivo liver clearance of 10kDa dextran superparamagnetic iron oxide (SPIO) Feridex-IV® and 20kDa dextran-coated SPIO nanoworms (SPIO NWs). Feridex showed efficient SR-AI/II-dependent uptake by isolated KCs in vitro, whereas SPIO NWs showed no uptake by KCs. Both Feridex and SPIO NWs showed a very short and nearly identical circulation half-life and efficient uptake by KCs in vivo. The SR-AI/II inhibitor, polyinosinic acid, prolonged the circulation half-life of both Feridex and SPIO NWs, but did not reduce the KC uptake. The circulation half-life and KC uptake of Feridex and SPIO NWs were identical in SR-AI/II-deficient mice and wild-type mice. These data suggest: (1) there is a limited correlation between in vitro and in vivo uptake mechanisms of nanoparticles in KCs; and (2) redundant, SR-AI/II independent mechanisms play a significant role in the nanoparticle recognition by KCs in vivo. Understanding the complexity of nanoparticle clearance assays and mechanisms is an important step to improving the design of “stealthy” nanoparticles.


2002 ◽  
Vol 159 (1) ◽  
pp. 23-28 ◽  
Author(s):  
Amy F. Roth ◽  
Ying Feng ◽  
Linyi Chen ◽  
Nicholas G. Davis

Protein palmitoylation has been long appreciated for its role in tethering proteins to membranes, yet the enzymes responsible for this modification have eluded identification. Here, experiments in vivo and in vitro demonstrate that Akr1p, a polytopic membrane protein containing a DHHC cysteine-rich domain (CRD), is a palmitoyl transferase (PTase). In vivo, we find that the casein kinase Yck2p is palmitoylated and that Akr1p function is required for this modification. Akr1p, purified to near homogeneity from yeast membranes, catalyzes Yck2p palmitoylation in vitro, indicating that Akr1p is itself a PTase. Palmitoylation is stimulated by added ATP. Furthermore, during the reaction, Akr1p is itself palmitoylated, suggesting a role for a palmitoyl-Akr1p intermediate in the overall reaction mechanism. Mutations introduced into the Akr1p DHHC-CRD eliminate both the trans- and autopalmitoylation activities, indicating a central participation of this conserved sequence in the enzymatic reaction. Finally, our results indicate that palmitoylation within the yeast cell is controlled by multiple PTase specificities. The conserved DHHC-CRD sequence, we propose, is the signature feature of an evolutionarily widespread PTase family.


1997 ◽  
Vol 57 (1-3) ◽  
pp. 203-208 ◽  
Author(s):  
Luc J.W van der Laan ◽  
Maarit Kangas ◽  
Ed A Döpp ◽  
Ellen Broug-Holub ◽  
Outi Elomaa ◽  
...  

2012 ◽  
Vol 82 (3) ◽  
pp. 228-232 ◽  
Author(s):  
Mauro Serafini ◽  
Giuseppa Morabito

Dietary polyphenols have been shown to scavenge free radicals, modulating cellular redox transcription factors in different in vitro and ex vivo models. Dietary intervention studies have shown that consumption of plant foods modulates plasma Non-Enzymatic Antioxidant Capacity (NEAC), a biomarker of the endogenous antioxidant network, in human subjects. However, the identification of the molecules responsible for this effect are yet to be obtained and evidences of an antioxidant in vivo action of polyphenols are conflicting. There is a clear discrepancy between polyphenols (PP) concentration in body fluids and the extent of increase of plasma NEAC. The low degree of absorption and the extensive metabolism of PP within the body have raised questions about their contribution to the endogenous antioxidant network. This work will discuss the role of polyphenols from galenic preparation, food extracts, and selected dietary sources as modulators of plasma NEAC in humans.


Author(s):  
А.А. Раецкая ◽  
С.В. Калиш ◽  
С.В. Лямина ◽  
Е.В. Малышева ◽  
О.П. Буданова ◽  
...  

Цель исследования. Доказательство гипотезы, что репрограммированные in vitro на М3 фенотип макрофаги при введении в организм будут существенно ограничивать развитие солидной карциномы in vivo . Методика. Рост солидной опухоли инициировали у мышей in vivo путем подкожной инъекции клеток карциномы Эрлиха (КЭ). Инъекцию макрофагов с нативным М0 фенотипом и с репрограммированным M3 фенотипом проводили в область формирования солидной КЭ. Репрограммирование проводили с помощью низких доз сыворотки, блокаторов факторов транскрипции STAT3/6 и SMAD3 и липополисахарида. Использовали две схемы введения макрофагов: раннее и позднее. При раннем введении макрофаги вводили на 1-е, 5-е, 10-е и 15-е сут. после инъекции клеток КЭ путем обкалывания макрофагами с четырех сторон область развития опухоли. При позднем введении, макрофаги вводили на 10-е, 15-е, 20-е и 25-е сут. Через 15 и 30 сут. после введения клеток КЭ солидную опухоль иссекали и измеряли ее объем. Эффект введения макрофагов оценивали качественно по визуальной и пальпаторной характеристикам солидной опухоли и количественно по изменению ее объема по сравнению с группой без введения макрофагов (контроль). Результаты. Установлено, что M3 макрофаги при раннем введении от начала развития опухоли оказывают выраженный антиопухолевый эффект in vivo , который был существенно более выражен, чем при позднем введении макрофагов. Заключение. Установлено, что введение репрограммированных макрофагов M3 ограничивает развитие солидной карциномы в экспериментах in vivo . Противоопухолевый эффект более выражен при раннем введении М3 макрофагов. Обнаруженные в работе факты делают перспективным разработку клинической версии биотехнологии ограничения роста опухоли, путем предварительного программирования антиопухолевого врожденного иммунного ответа «в пробирке». Aim. To verify a hypothesis that macrophages reprogrammed in vitro to the M3 phenotype and injected into the body substantially restrict the development of solid carcinoma in vivo . Methods. Growth of a solid tumor was initiated in mice in vivo with a subcutaneous injection of Ehrlich carcinoma (EC) cells. Macrophages with a native M0 phenotype or reprogrammed towards the M3 phenotype were injected into the region of developing solid EC. Reprogramming was performed using low doses of serum, STAT3/6 and SMAD3 transcription factor blockers, and lipopolysaccharide. Two schemes of macrophage administration were used: early and late. With the early administration, macrophages were injected on days 1, 5, 10, and 15 following the injection of EC cells at four sides of the tumor development area. With the late administration, macrophages were injected on days 10, 15, 20, and 25. At 15 and 30 days after the EC cell injection, the solid tumor was excised and its volume was measured. The effect of macrophage administration was assessed both qualitatively by visual and palpation characteristics of solid tumor and quantitatively by changes in the tumor volume compared with the group without the macrophage treatment. Results. M3 macrophages administered early after the onset of tumor development exerted a pronounced antitumor effect in vivo , which was significantly greater than the antitumor effect of the late administration of M3 macrophages. Conclusion. The observed significant inhibition of in vivo growth of solid carcinoma by M3 macrophages makes promising the development of a clinical version of the biotechnology for restriction of tumor growth by in vitro pre-programming of the antitumor, innate immune response.


2020 ◽  
Vol 26 (45) ◽  
pp. 5783-5792
Author(s):  
Kholood Abid Janjua ◽  
Adeeb Shehzad ◽  
Raheem Shahzad ◽  
Salman Ul Islam ◽  
Mazhar Ul Islam

There is compelling evidence that drug molecules isolated from natural sources are hindered by low systemic bioavailability, poor absorption, and rapid elimination from the human body. Novel approaches are urgently needed that could enhance the retention time as well as the efficacy of natural products in the body. Among the various adopted approaches to meet this ever-increasing demand, nanoformulations show the most fascinating way of improving the bioavailability of dietary phytochemicals through modifying their pharmacokinetics and pharmacodynamics. Curcumin, a yellowish pigment isolated from dried ground rhizomes of turmeric, exhibits tremendous pharmacological effects, including anticancer activities. Several in vitro and in vivo studies have shown that curcumin mediates anticancer effects through the modulation (upregulation and/or downregulations) of several intracellular signaling pathways both at protein and mRNA levels. Scientists have introduced multiple modern techniques and novel dosage forms for enhancing the delivery, bioavailability, and efficacy of curcumin in the treatment of various malignancies. These novel dosage forms include nanoparticles, liposomes, micelles, phospholipids, and curcumin-encapsulated polymer nanoparticles. Nanocurcumin has shown improved anticancer effects compared to conventional curcumin formulations. This review discusses the underlying molecular mechanism of various nanoformulations of curcumin for the treatment of different cancers. We hope that this study will make a road map for preclinical and clinical investigations of cancer and recommend nano curcumin as a drug of choice for cancer therapy.


2021 ◽  
Vol 22 (5) ◽  
pp. 2530
Author(s):  
Bijean D. Ford ◽  
Diego Moncada Giraldo ◽  
Camilla Margaroli ◽  
Vincent D. Giacalone ◽  
Milton R. Brown ◽  
...  

Cystic fibrosis (CF) lung disease is dominated by the recruitment of myeloid cells (neutrophils and monocytes) from the blood which fail to clear the lung of colonizing microbes. In prior in vitro studies, we showed that blood neutrophils migrated through the well-differentiated lung epithelium into the CF airway fluid supernatant (ASN) mimic the dysfunction of CF airway neutrophils in vivo, including decreased bactericidal activity despite an increased metabolism. Here, we hypothesized that, in a similar manner to neutrophils, blood monocytes undergo significant adaptations upon recruitment to CFASN. To test this hypothesis, primary human blood monocytes were transmigrated in our in vitro model into the ASN from healthy control (HC) or CF subjects to mimic in vivo recruitment to normal or CF airways, respectively. Surface phenotype, metabolic and bacterial killing activities, and transcriptomic profile by RNA sequencing were quantified post-transmigration. Unlike neutrophils, monocytes were not metabolically activated, nor did they show broad differences in activation and scavenger receptor expression upon recruitment to the CFASN compared to HCASN. However, monocytes recruited to CFASN showed decreased bactericidal activity. RNASeq analysis showed strong effects of transmigration on monocyte RNA profile, with differences between CFASN and HCASN conditions, notably in immune signaling, including lower expression in the former of the antimicrobial factor ISG15, defensin-like chemokine CXCL11, and nitric oxide-producing enzyme NOS3. While monocytes undergo qualitatively different adaptations from those seen in neutrophils upon recruitment to the CF airway microenvironment, their bactericidal activity is also dysregulated, which could explain why they also fail to protect CF airways from infection.


Sign in / Sign up

Export Citation Format

Share Document