116 research outputs found
Indusoidut pluripotentit kantasolut
Tiivistelmä. Indusoidut pluripotentit kantasolut eli iPS-solut ovat laboratoriossa keinotekoisesti valmistettuja pluripotentteja eli useakykyisiä kantasoluja. Niiden valmistuksessa käytetään tyypillisesti aikuiselta otettuja somaattisia soluja kuten veri- tai ihosoluja, mutta niitä voidaan valmistaa lähes kaikista somaattisista soluista, lukuunottamatta sukusoluja. iPS-solujen valmistusprosessin aikana somaattiset solut läpikäyvät uudelleenohjelmoinniksi kutsutun prosessin, jonka aikana ne menettävät alkuperäisen erilaistuneisuutensa ja saavat takaisin pluripotenteille soluille tyypilliset ominaisuudet: rajattoman uusiutumiskyvyn ja kyvyn erilaistua sekä kaikkien kolmen alkiokerroksen eli endodoermin, mesodermin ja ektodermin soluiksi että alkion sukusoluiksi.
Uudelleenohjelmointi toteutetaan tyypillisesti viemällä uudelleenohjelmoitaviin soluihin tietyt geeninsäätelyproteiineja koodaavat geenit esimerkiksi virusvektorin avulla. Käytetyimpiä siirtogeenejä ovat Yamanakan tekijöiksi kutsuttuja transkriptiotekijöitä koodaavat geenit: OCT4 (engl. octamer-binding transcription factor 4), KLF4 (engl. Kruppel-like factor 4), SOX2 (engl. SRY-box transcription factor 2) ja MYC (engl. MYC proto-oncogene, bHLH transcription factor).
Solujen uudelleenohjelmointi on monimutkainen prosessi joka voidaan jakaa kolmeen päävaiheeseen. Näitä ovat uudelleenohjelmoinnin aloittava epitelisoitumisvaihe jonka tärkeimpänä tapahtumana on mesenkymaali-epiteelinen siirtymä, maturaatio jossa pluripotenttisuuteen liittyvien geenien aktivoitumisen aiheuttavat vaikutukset alkavat näkyä soluissa ja stabilisaatio jonka aikana solut saavuttavat stabiilin pluripotentin tilan.
Uudelleenohjelmoinnin aikana muutoksia tapahtuu muun muassa solun epigeneettisessä tilaassa, erilaisten signalointireittien aktiivisuudessa ja transkriptioverkostoissa. Muutokset tapahtuvat kuitenkin hitaasti eivätkä kaikki uudelleenohjelmoitavista soluista ikinä saavuta täyttä pluripotenttisuutta. Valmistettujen iPS-solujen laatu ja pluripotenttisuus onkin siksi testattava ennen niiden jatkokäyttöä. Tähän on olemassa useita eri tekniikoita, kuten kimeerimääritys jossa iPS-solujen pluripotenttisuutta testataan injektoimalla niitä hiiren blastokystiin.
iPS-solut vastaavat ominaisuuksiltaan hyvin tarkasti alkion kantasoluja, mutta koska niiden valmistus ei vaadi alkion tuhoamista, pidetään niitä yleisesti alkion kantasoluja eettisempänä ja parempana vaihtoehtona. iPS-soluja voidaan hyödyntää monella tavalla esimerkiksi lääketieteessä ja tieteellisissä tutkimuksissa. Ne mahdollistavat esimerkiksi tarkkojen ja täysin potilaan genomin mukaisten tautimallien luomisen lääkekokeita ja muita tutkimuksia varten. Lisäksi niitä erilaistamalla voidaan valmistaa potilaan omia iPS-soluja käyttämällä erilaisia solu-, kudos- ja tulevaisuudessa ehkä jopa elinsiirteitä regeneratiivista lääketiedettä varten, mikä mahdollistaa uuden lähestymistavan useiden sairauksien hoitoon tarjoten samalla ratkaisun nykyisten siirteiden aiheuttamaan hylkimisongelmaan
Exploring early combination strategy in Latin American patients with newly diagnosed type 2 diabetes : a sub-analysis of the VERIFY study
Background Patients with type 2 diabetes mellitus (T2DM) from Latin American countries face challenges in access to healthcare, leading to under-diagnosis, under-achievement of glycemic target, and long-term complications. Early diagnosis and treatment initiation are of paramount importance in this population due to the high prevalence of risk factors such as obesity and metabolic syndrome. The VERIFY study in patients with newly diagnosed T2DM (across 34 countries), assessed the normoglycemic durability (5 years), with early combination (EC) therapy approach versus the traditional stepwise approach of initiating treatment with metformin monotherapy (MET). Here we present the results from the VERIFY study for participants from eight countries in Latin America. Methods Newly diagnosed adult patients with T2DM, HbA1c 6.5-7.5% and body-mass index (BMI) of 22-40 kg/m(2) were enrolled. The primary endpoint was time to initial treatment failure (TF; HbA1c >= 7.0% at two consecutive scheduled visits 13 weeks apart). Time to second TF was evaluated when patients in both groups were receiving and failing on the vildagliptin combination. Safety and tolerability were also assessed for both treatment approaches during the study. Results A total of 537 eligible patients (female, 58.8%) were randomly assigned to receive either EC (n = 266) or MET (n = 271). EC significantly reduced the relative risk of time to initial TF by 47% versus MET [HR (95% CI) 0.53 (0.4, 0.7) p < 0.0001]. Overall, 46.4% versus 66.3% of patients achieved the primary endpoint in the EC and MET groups, with a median [interquartile range (IQR)] time to TF of 59.8 (27.5, not evaluable) and 33.4 (12.2, 60.1) months, respectively. The risk for time to second TF was 31% lower with EC (p < 0.0092). A higher proportion of patients receiving EC maintained durable HbA1c < 7.0%, < 6.5%, and < 6.0%. Both treatment approaches were well tolerated, and only 3.2% of participants discontinued the study due to adverse events. All hypoglycemic events (EC: n = 7 and MET: n = 3) were single, mild episodes and did not lead to study discontinuation. Conclusion Similar to the global population, long-term clinical benefits were achieved more frequently and without tolerability issues with EC versus standard-of-care MET in this Latin American sub-population. This study is registered with ClinicalTrials.gov, NCT01528254.Peer reviewe
Time to do more
AbstractAimsClinical inertia, the tendency to maintain current treatment strategies despite results demanding escalation, is thought to substantially contribute to the disconnect between clinical aspirations for patients with diabetes and targets achieved. We wished to explore potential causes of clinical inertia among physicians and people with diabetes.MethodsA 20-min online survey of 652 adults with diabetes and 337 treating physicians in six countries explored opinions relating to clinical inertia from both perspectives, in order to correlate perceptions and expectations relating to diagnosis, treatment, diabetes complications and therapeutic escalation.ResultsPhysicians had low expectations for their patients, despite the belief that the importance of good glycaemic control through lifestyle and pharmacological interventions had been adequately conveyed. Conversely, people with diabetes had, at best, a rudimentary understanding of the risks of complications and the importance of good control; indeed, only a small proportion believed lifestyle changes were important and the majority did not intend to comply.ConclusionsThe principal findings of this survey suggest that impairments in communication are at the heart of clinical inertia. This manuscript lays out four key principles that we believe are achievable in all environments and can improve the lives of people with diabetes
A pre-specified statistical analysis plan for the VERIFY study : Vildagliptin efficacy in combination with metformin for early treatment of T2DM
Aims To ensure the integrity of the planned analyses and maximize the clinical utility of the VERIFY study results by describing the detailed concepts behind its statistical analysis plan (SAP) before completion of data collection and study database lock. The SAP will be adhered to for the final primary data analysis of the VERIFY trial. Materials and Methods Vildagliptin efficacy in combination with metformin for early treatment of T2DM (VERIFY) is an ongoing, multicentre, randomized controlled trial aiming to demonstrate the clinical benefits of glycaemic durability and glucose control achieved with an early combination therapy in newly-diagnosed type 2 diabetes (T2DM) patients. Results The SAP was initially designed at the study protocol conception phase and later modified, as reported here, in collaboration between the steering committee members, statisticians, and the VERIFY study leadership team. All authors were blinded to treatment allocation. An independent statistician has additionally retrieved and presented unblinded data to the independent data safety monitoring committee. An overview of the trial design with a focus on describing the fine-tuning of the analysis plan for the primary efficacy endpoint, risk of initial treatment failure, and secondary, exploratory and pre-specified subgroup analyses is provided here. Conclusion According to optimal trial practice, the details of the statistical analysis and data-handling plan prior to locking the database are reported here. The SAP accords with high-quality standards of internal validity to minimize analysis bias and will enhance the utility of the reported results for improved outcomes in the management of T2DM.Peer reviewe
Protein kinase C-activating isophthalate derivatives mitigate Alzheimer's disease-related cellular alterations
Abnormal protein kinase C (PKC) function contributes to many pathophysiological processes relevant for Alzheimer's disease (AD), such as amyloid precursor protein (APP) processing. Phorbol esters and other PKC activators have been demonstrated to enhance the secretion of soluble APP alpha (sAPP alpha), reduce the levels of beta-amyloid (A beta), induce synaptogenesis, and promote neuroprotection. We have previously described isophthalate derivatives as a structurally simple family of PKC activators. Here, we characterised the effects of isophthalate derivatives HMI-1a3 and HMI-1b11 on neuronal viability, neuroinflammatory response, processing of APP and dendritic spine density and morphology in in vitro. HMI-1a3 increased the viability of embryonic primary cortical neurons and decreased the production of the pro-inflammatory mediator TNF alpha, but not that of nitric oxide, in mouse neuron-BV2 microglia co-cultures upon LPS- and IFN-gamma-induced neuroinflammation. Furthermore, both HMI-1a3 and HMI-1b11 increased the levels of sAPPa relative to total sAPP and the ratio of A beta 42/A beta 40 in human SH-Sv5v neuroblastoma cells. Finally, bryostatin-1, but not HMI-1a3, increased the number of mushroom spines in proportion to total spine density in mature mouse hippocampal neuron cultures. These results suggest that the PKC activator HMI-1a3 exerts neuroprotective functions in the in vitro models relevant for AD by reducing the production of TNF alpha and increasing the secretion of neuroprotective sAPPa.Peer reviewe
Insights from VERIFY : Early Combination TherapyProvides Better Glycaemic Durability Than a StepwiseApproach in Newly Diagnosed Type2 Diabetes
Peer reviewe
Long-Term Glycaemic Durability of Early Combination Therapy Strategy versus Metformin Monotherapy in Korean Patients with Newly Diagnosed Type 2 Diabetes Mellitus
We assessed the glycaemic durability with early combination (EC; vildagliptin+metformin [MET], n=22) versus MET monotherapy (n=17), among newly-diagnosed type 2 diabetes mellitus (T2DM) enrolled (between 2012 and 2014) in the VERIFY study from Korea (n=39). Primary endpoint was time to initial treatment failure (TF) (glycosylated hemoglobin [HbA1c]>= 7.0% at two consecutive scheduled visits after randomization [end of period 1]). Time to second TF was assessed when both groups were receiving and failing on the combination (end of period 2). With EC the risk of initial TF significantly reduced by 78% compared to MET (n=3 [15%] vs. n=10 [58.7%], P=0.0228). No secondary TF occurred in EC group versus five patients (29.4%) in MET. Patients receiving EC treatment achieved consistently lower HbA1c levels. Both treatment approaches were well tolerated with no hypoglycaemic events. In Korean patients with newly diagnosed T2DM, EC treatment significantly and consistently improved the long-term glycaemic durability as compared with MET.Peer reviewe
Systematic Literature Review of DPP-4 Inhibitors in Patients with Type 2 Diabetes Mellitus and Renal Impairment
Dipeptidyl peptidase-4 (DPP-4) inhibitors are widely used in the management of patients with type 2 diabetes mellitus (T2DM) and renal impairment (RI). A systematic literature review was performed to compare the efficacy and safety of DPP-4 inhibitors in patients with T2DM and RI. We searched EMBASE, MEDLINE, and the Cochrane Central Register of Controlled Trials (cut-off, June 2015) to identify aeyen12-week, randomized, placebo-controlled trials on DPP-4 inhibitors in aeyen50 patients with T2DM and RI. Outcomes of interest included change in glycated hemoglobin (HbA1c), overall safety, and incidence of hypoglycemic events (HEs). Seven trials of aecurrency sign52-54 weeks duration were retrieved, which included one study each on vildagliptin, saxagliptin, and sitagliptin, two on linagliptin, and the remaining two were extension studies of vildagliptin and saxagliptin. Majority of patients were on insulin at baseline (53-86%), except in the sitagliptin study, where approximately 11% received insulin during the placebo-controlled phase. After 52 weeks, vildagliptin and saxagliptin reduced HbA1c levels by 0.6-0.7% (baseline 7.8-8.4%) versus placebo in the overall population. HbA1c reductions were similar at weeks 12 and 52. In the 12-week, placebo-controlled phase, sitagliptin and linagliptin reduced mean HbA1c by approximately 0.4% (baseline 7.7-8.1%) versus placebo. Rates of HEs with DPP-4 inhibitors were not significantly different versus placebo in any study. Rates of adverse events (AEs) and changes involving renal function were similar in the active- and placebo-treated groups. These results suggest that DPP-4 inhibitors have the potential to improve glycemic control in patients with RI without increasing the risk of HEs or overall AEs. Novartis Pharma AG.Peer reviewe
Presynaptic vesicle protein SEPTIN5 regulates the degradation of APP C-Terminal fragments and the levels of Aβ
© 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).Alzheimer's disease (AD) is a neurodegenerative disease characterized by aberrant amyloid-β (Aβ) and hyperphosphorylated tau aggregation. We have previously investigated the involvement of SEPTIN family members in AD-related cellular processes and discovered a role for SEPTIN8 in the sorting and accumulation of β-secretase. Here, we elucidated the potential role of SEPTIN5, an interaction partner of SEPTIN8, in the cellular processes relevant for AD, including amyloid precursor protein (APP) processing and the generation of Aβ. The in vitro and in vivo studies both revealed that the downregulation of SEPTIN5 reduced the levels of APP C-terminal fragments (APP CTFs) and Aβ in neuronal cells and in the cortex of Septin5 knockout mice. Mechanistic elucidation revealed that the downregulation of SEPTIN5 increased the degradation of APP CTFs, without affecting the secretory pathway-related trafficking or the endocytosis of APP. Furthermore, we found that the APP CTFs were degraded, to a large extent, via the autophagosomal pathway and that the downregulation of SEPTIN5 enhanced autophagosomal activity in neuronal cells as indicated by altered levels of key autophagosomal markers. Collectively, our data suggest that the downregulation of SEPTIN5 increases the autophagy-mediated degradation of APP CTFs, leading to reduced levels of Aβ in neuronal cells.This research was supported by the Academy of Finland (grant numbers 307866 and 315459), the Sigrid Jusélius Foundation, the Strategic Neuroscience Funding of the University of Eastern Finland, and the National Institute of Mental Health of the National Institutes of Health (grant numbers R01MH099660, R01DC015776, R21HD053114, and U54HD090260). Catarina B. Ferreira is a PhD Fellow (NeurULisboa - Integrated Neurosciences PhD program, supported by an individual grant from Fundação para a Ciência e Tecnologia (FCT), (PD/BD/128390/2017, SFRH/PD/BD/114441/2016, PD/BD/128091/2016). Work was also supported by Santa Casa da Misericórdia de Lisboa (MB37-2017) and SynaNet (LISBOA-01-0145-FEDER-0073919), under the grant agreement no. 692340, and the project was co-financed by FEDER, POR Lisboa 2020, Programa Operacional Regional de Lisboa, from PORTUGAL 2020 and by Fundação para a Ciência e a Tecnologia.info:eu-repo/semantics/publishedVersio
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