CMV Late Phase-Induced mTOR Activation Is Essential for Efficient Virus Replication in Polarized Human Macrophages : Antiviral Effects of mTOR Inhibitors

Human cytomegalovirus (CMV) remains one of the most important pathogens following solid-organ transplantation. Mounting evidence indicates that mammalian target of rapamycin (mTOR) inhibitors may decrease the incidence of CMV infection in solid- organ recipients. Here we aimed at elucidating the molecular mechanisms of this effect by employing a human CMV (HCMV) infection model in human macrophages, since myeloid cells are the principal in vivo targets of HCMV. We demonstrate a highly di- vergent host cell permissiveness for HCMV with opti- mal infection susceptibility in M2 but not M1 polarized macrophages. Employing an ultrahigh purified HCMV stock we observed rapamycin-independent viral entry and induction of IFN-b transcripts, but no proinflam- matory cytokines or mitogen-activated protein kinases and mTOR activation early after infection. However, in the late infection phase, sustained mTOR activa- tion was observed in HCMV-infected cells and was required for efficient viral protein synthesis including the viral late phase proteins pUL-44 and pp65. Accord- ingly, rapamycin strongly suppressed CMV replication 3 and 5 days postinfection in macrophages. In conclu- sion, these data indicate that mTOR is essential for virus replication during late phases of the viral cycle in myeloid cells and might explain the potent anti-CMV effects of mTOR inhibitors after organ transplantatio

A randomized, placebo-controlled, double-blind, prospective trial to evaluate the effect of vildagliptin in new-onset diabetes mellitus after kidney transplantation

<p>Abstract</p> <p>Background</p> <p>New-onset diabetes mellitus after transplantation (NODAT), a frequent and serious complication after transplantation, is associated with decreased graft and patient survival. Currently, it is diagnosed and treated primarily according to existing guidelines for type II diabetes. To date, only a few trials have studied antidiabetic drugs in patients with NODAT. Vildagliptin is a novel dipeptidyl peptidase-4 (DPP-4) inhibitor that improves pancreatic islet function by enhancing both α- and β-cell responsiveness to increased blood glucose. Experimental data show potential protective effects of DPP-4 inhibitors on islet function after exogenous stress stimuli including immunosuppressants. Therefore, the therapy of NODAT with this class of compounds seems attractive. At present, vildagliptin is used to treat type II diabetes as monotherapy or in combination with other antidiabetic drugs, since that it efficiently decreases glycated hemoglobin (HbA1c) values. Additionally, vildagliptin has been shown to be safe in patients with moderately impaired kidney function. This study will evaluate the safety and efficacy of vildagliptin monotherapy in renal transplant recipients with recently diagnosed NODAT.</p> <p>Methods/Design</p> <p>This study is a randomized, placebo-controlled, double-blind, prospective phase II trial. Using the results of routinely performed oral glucose tolerance tests (OGTT) in stable renal transplant patients at our center, we will recruit patients without a history of diabetes and a 2 h glucose value surpassing 200 mg/dl (11.1 mmol/l). They are randomized to receive either 50 mg vildagliptin or placebo once daily. A total of 32 patients with newly diagnosed NODAT will be included. The primary endpoint is the difference in the 2 h glucose value between baseline and the repeated OGTT performed 3 months after treatment start, compared between the vildagliptin- and the placebo-group. Secondary endpoints include changes in HbA1c and fasting plasma glucose (FPG). The safety of vildagliptin in renal transplant patients will be assessed by the number of symptomatic hypoglycemic episodes (glucose <72 mg/dl or 4 mmol/l), the number of adverse events, and possible medication-associated side-effects.</p> <p>Discussion</p> <p>NODAT is a severe complication after kidney transplantation. Few trials have assessed the safety and efficacy of antidiabetic drugs for these patients. The purpose of this study is to assess the safety and efficacy of vildagliptin in renal transplant patients with NODAT.</p> <p>Trial Registration</p> <p>ClinicalTrials.gov NCT00980356</p

FDG uptake is a surrogate marker for defining the optimal biological dose of the mTOR inhibitor everolimus in vivo

This study aimed to test whether [18F]fluoro-D-glucose (FDG) uptake of tumours measured by positron emission tomography (PET) can be used as surrogate marker to define the optimal biological dose (OBD) of mTOR inhibitors in vivo. Everolimus at 0.05, 0.5, 5 and 15 mg kg−1 per day was administered to gastric cancer xenograft-bearing mice for 23 days and FDG uptake of tumours was measured using PET from day 1 to day 8. To provide standard comparators for FDG uptake, tumour volume, S6 protein phosphorylation, Ki-67 staining and everolimus blood levels were evaluated. Everolimus blood levels increased in a dose-dependent manner but antitumour activity of everolimus reached a plateau at doses ⩾5 mg kg−1 per day (tumour volume treated vs control (T/C): 51% for 5 mg kg−1 per day and 57% for 15 mg kg−1 per day). Correspondingly, doses ⩾5 mg kg−1 per day led to a significant reduction in FDG uptake of tumours. Dose escalation above 5 mg kg−1 per day did not reduce FDG uptake any further (FDG uptake T/C: 49% for 5 mg kg−1 per day and 52% for 15 mg kg−1 per day). Differences in S6 protein phosphorylation and Ki-67 index reflected tumour volume and changes in FDG uptake but did not reach statistical significance. In conclusion, FDG uptake might serve as a surrogate marker for dose finding studies for mTOR inhibitors in (pre)clinical trials

The mTOR Signalling Pathway in Human Cancer

The conserved serine/threonine kinase mTOR (the mammalian target of rapamycin), a downstream effector of the PI3K/AKT pathway, forms two distinct multiprotein complexes: mTORC1 and mTORC2. mTORC1 is sensitive to rapamycin, activates S6K1 and 4EBP1, which are involved in mRNA translation. It is activated by diverse stimuli, such as growth factors, nutrients, energy and stress signals, and essential signalling pathways, such as PI3K, MAPK and AMPK, in order to control cell growth, proliferation and survival. mTORC2 is considered resistant to rapamycin and is generally insensitive to nutrients and energy signals. It activates PKC-α and AKT and regulates the actin cytoskeleton. Deregulation of multiple elements of the mTOR pathway (PI3K amplification/mutation, PTEN loss of function, AKT overexpression, and S6K1, 4EBP1 and eIF4E overexpression) has been reported in many types of cancers, particularly in melanoma, where alterations in major components of the mTOR pathway were reported to have significant effects on tumour progression. Therefore, mTOR is an appealing therapeutic target and mTOR inhibitors, including the rapamycin analogues deforolimus, everolimus and temsirolimus, are submitted to clinical trials for treating multiple cancers, alone or in combination with inhibitors of other pathways. Importantly, temsirolimus and everolimus were recently approved by the FDA for the treatment of renal cell carcinoma, PNET and giant cell astrocytoma. Small molecules that inhibit mTOR kinase activity and dual PI3K-mTOR inhibitors are also being developed. In this review, we aim to survey relevant research, the molecular mechanisms of signalling, including upstream activation and downstream effectors, and the role of mTOR in cancer, mainly in melanoma

Benachrichtigungen mittels Vibrotaktiler Signale

Benachrichtigungen sind in der heutigen Zeit allgegenwärtig, wenn auch nicht gänzlich unproblematisch. In dieser Arbeit wird vorerst untersucht, welche Auswirkungen die für die heutige Zeit üblichen Benachrichtigungen auf uns haben. Studien sprechen von einer Informationsüberlastung, die zu negativen Auswirkungen führt. Es werden beispielsweise Zusammenhänge zwischen Unterbrechungen, verringerter Aufmerksamkeit und sogar geringerer Lebensqualität als Resultat genannt. Durch subtilere Mitteilungsmethoden, wie Vibration, können diese negativen Auswirkungen abgeschwächt werden. Der weitere Fokus dieser Arbeit liegt in der Erforschung von Vibration als Mittel, wichtige Information zu übermitteln. Es wird den folgenden Forschungsfragen nachgegangen: Welche Information kann mittels Vibration übertragen werden, ohne ein visuelles Display zu benötigen? Welche Parameter können verwendet werden, um Vibrationssignale zu erzeugen, die für Menschen gut unterscheidbar sind? Auf welche Weise kann ein vibrierendes Armband Kommunikation aufwerten? Als Methodik zur Beantwortung der Forschungsfragen wird ein gemixter Ansatz aus qualitativer und quantitativer Forschung betrieben. Zudem wird Prototyping und ein benutzerzentrierter Ansatz angewandt, um ein vibrierendes Armband zu entwickeln. Mittels Anwendertests wurde belegt, dass durch Vibration Nachrichten mit unterschiedlichen Dringlichkeitsstufen erzeugt werden können und dass diese von Testpersonen erkannt und unterschieden werden können. Weiters stellte sich heraus, dass ein vibrierendes Armband positiven Anklang findet, insbesondere wird es in lauten oder leisen Umgebungen als nützlich empfunden. Unerwartet waren Unterschiede in der Wahrnehmung der Intensität der Vibration zwischen weiblichen und männlichen Testpersonen. Zudem wurde festgestellt, dass bei den ältesten Testpersonen eine signifikant schlechtere Wiedererkennungsrate von Vibrationsmustern vorlag.These days notifications are part of our everyday lives, although they are not without problems. First off, there will be an examination of the effects lying in the most common types of notification of our current times. Studies mention attention overload leading to negative effects influencing us daily. There have been found to be correlations between interruption caused by notifications, leading to inattention and further, even decreased satisfaction in life. By using more subtle forms of notification, such as vibration, these negative effects can be lessened in severity. The further focus of this thesis explores vibration as a means to transmit information. The following research questions will be examined: Which information can be conveyed via vibration without relying on a visual display? Which parameters can be used to produce vibration signals that are easily distinguishable for humans? In which way does a vibrating bracelet enhance communication? To answer these research questions, a mixed-methods approach consisting of both qualitative and quantitative research has been utilized. Additionally, prototyping and a user-centered approach have been used to develop a vibrating bracelet. User tests showed that vibration notifications with different urgency levels could be produced and that test persons were able to reliably identify and distinguish them. Test users showed a positive response towards a vibrating bracelet, and consider it especially useful in noisy or quiet environments. Some unexpected findings included a difference in the perceived intensity of the vibration between female and male test persons. In addition, there was a significant difference in recognizing vibration patterns connected to the test persons' ages.12