Presence of functionally active protease-activated receptors 1 and 2 in myenteric glia

Protease-activated receptors (PARs) belong to the family of membrane receptors coupled to G-proteins; their presence is reported in a wide variety of cells. The object of this study was to demonstrate the presence of PAR-1 and PAR-2 in myenteric glia of the guinea pig, and to elucidate the cellular mechanisms that are triggered upon receptor activation. Thrombin and PAR-1 agonist peptide (PARP-1) activate PAR-1 with a maximum mean ± SEM change in intracellular calcium concentration with respect to basal level (δ[Ca 2+ ] i ) of 183 ± 18 nm and 169 ± 6 nm, respectively. Trypsin and PAR-2 agonist peptide (PARP-2) activate PAR-2 with a maximum δ[Ca 2+ ] i of 364 ± 28 nm and 239 ± 19 nm, respectively. Inhibition of phospholipase C by U73312 (1 µm) decreased the δ[Ca 2+ ] i due to PAR-1 activation from 167 ± 10 nm to 87 ± 6 nm. The PAR-2-mediated δ[Ca 2+ ] i decreased from 193 ± 10 nm to 124 ± 8 nm when phospholipase C activity was inhibited. Blockade of sphingosine kinase with dimethylsphingosine (1 µm) decreased the δ[Ca 2+ ] i due to PAR-2 activation from 149 ± 19 nm to 67 ± 1 nm, but did not influence the PAR-1-mediated δ[Ca 2+ ] i . PAR-1 and PAR-2 were localized in myenteric glia by immunolabeling. Our results indicate that PAR-1 and PAR-2 are present in myenteric glia of the guinea pig, and their activation leads to increases in intracellular calcium via different signal transduction mechanisms that involve activation of phospholipase C and sphingosine kinase.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66037/1/j.1471-4159.2002.01119.x.pd

Inhibition of CLIC4 Enhances Autophagy and Triggers Mitochondrial and ER Stress-Induced Apoptosis in Human Glioma U251 Cells under Starvation

CLIC4/mtCLIC, a chloride intracellular channel protein, localizes to mitochondria, endoplasmic reticulum (ER), nucleus and cytoplasm, and participates in the apoptotic response to stress. Apoptosis and autophagy, the main types of the programmed cell death, seem interconnected under certain stress conditions. However, the role of CLIC4 in autophagy regulation has yet to be determined. In this study, we demonstrate upregulation and nuclear translocation of the CLIC4 protein following starvation in U251 cells. CLIC4 siRNA transfection enhanced autophagy with increased LC3-II protein and puncta accumulation in U251 cells under starvation conditions. In that condition, the interaction of the 14-3-3 epsilon isoform with CLIC4 was abolished and resulted in Beclin 1 overactivation, which further activated autophagy. Moreover, inhibiting the expression of CLIC4 triggered both mitochondrial apoptosis involved in Bax/Bcl-2 and cytochrome c release under starvation and endoplasmic reticulum stress-induced apoptosis with CHOP and caspase-4 upregulation. These results demonstrate that CLIC4 nuclear translocation is an integral part of the cellular response to starvation. Inhibiting the expression of CLIC4 enhances autophagy and contributes to mitochondrial and ER stress-induced apoptosis under starvation

METACOHORTS for the study of vascular disease and its contribution to cognitive decline and neurodegeneration: an initiative of the Joint Programme for Neurodegenerative Disease Research

Dementia is a global problem and major target for health care providers. Although up to 45% of cases are primarily or partly due to cerebrovascular disease, little is known of these mechanisms or treatments because most dementia research still focuses on pure Alzheimer's disease. An improved understanding of the vascular contributions to neurodegeneration and dementia, particularly by small vessel disease, is hampered by imprecise data, including the incidence and prevalence of symptomatic and clinically “silent” cerebrovascular disease, long-term outcomes (cognitive, stroke, or functional), and risk factors. New large collaborative studies with long follow-up are expensive and time consuming, yet substantial data to advance the field are available. In an initiative funded by the Joint Programme for Neurodegenerative Disease Research, 55 international experts surveyed and assessed available data, starting with European cohorts, to promote data sharing to advance understanding of how vascular disease affects brain structure and function, optimize methods for cerebrovascular disease in neurodegeneration research, and focus future research on gaps in knowledge. Here, we summarize the results and recommendations from this initiative. We identified data from over 90 studies, including over 660,000 participants, many being additional to neurodegeneration data initiatives. The enthusiastic response means that cohorts from North America, Australasia, and the Asia Pacific Region are included, creating a truly global, collaborative, data sharing platform, linked to major national dementia initiatives. Furthermore, the revised World Health Organization International Classification of Diseases version 11 should facilitate recognition of vascular-related brain damage by creating one category for all cerebrovascular disease presentations and thus accelerate identification of targets for dementia prevention

New insights into the genetic etiology of Alzheimer's disease and related dementias

Characterization of the genetic landscape of Alzheimer's disease (AD) and related dementias (ADD) provides a unique opportunity for a better understanding of the associated pathophysiological processes. We performed a two-stage genome-wide association study totaling 111,326 clinically diagnosed/'proxy' AD cases and 677,663 controls. We found 75 risk loci, of which 42 were new at the time of analysis. Pathway enrichment analyses confirmed the involvement of amyloid/tau pathways and highlighted microglia implication. Gene prioritization in the new loci identified 31 genes that were suggestive of new genetically associated processes, including the tumor necrosis factor alpha pathway through the linear ubiquitin chain assembly complex. We also built a new genetic risk score associated with the risk of future AD/dementia or progression from mild cognitive impairment to AD/dementia. The improvement in prediction led to a 1.6- to 1.9-fold increase in AD risk from the lowest to the highest decile, in addition to effects of age and the APOE ε4 allele

Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)1.

In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field

Multiancestry analysis of the HLA locus in Alzheimer’s and Parkinson’s diseases uncovers a shared adaptive immune response mediated by HLA-DRB1*04 subtypes

Across multiancestry groups, we analyzed Human Leukocyte Antigen (HLA) associations in over 176,000 individuals with Parkinson’s disease (PD) and Alzheimer’s disease (AD) versus controls. We demonstrate that the two diseases share the same protective association at the HLA locus. HLA-specific fine-mapping showed that hierarchical protective effects of HLA-DRB1*04 subtypes best accounted for the association, strongest with HLA-DRB1*04:04 and HLA-DRB1*04:07, and intermediary with HLA-DRB1*04:01 and HLA-DRB1*04:03. The same signal was associated with decreased neurofibrillary tangles in postmortem brains and was associated with reduced tau levels in cerebrospinal fluid and to a lower extent with increased Aβ42. Protective HLA-DRB1*04 subtypes strongly bound the aggregation-prone tau PHF6 sequence, however only when acetylated at a lysine (K311), a common posttranslational modification central to tau aggregation. An HLA-DRB1*04-mediated adaptive immune response decreases PD and AD risks, potentially by acting against tau, offering the possibility of therapeutic avenues

Anatomic healing after non-operative treatment of a large, displaced anterior glenoid rim fracture after primary traumatic anterior shoulder dislocation - a case report

BACKGROUND Large, displaced anterior glenoid rim fractures after primary traumatic anterior shoulder dislocation are usually managed by surgical stabilization. Although there is little evidence supporting surgical management, it is often preferred over non-operative treatment. This case report describes non-operative management of such large, displaced anterior glenoid rim fracture with CT- and MRI-based documentation of anatomical healing of the fracture fragment, a finding that has not been described previously. CASE PRESENTATION This case report describes a 49-year-old male, right-hand dominant, carpenter, who had a left-sided primary anterior shoulder dislocation after a fall while skiing. Initial plain radiographs showed a reduced glenohumeral joint with a large, displaced anterior glenoid rim fracture. CT-evaluation showed a centered humeral head, and as per our institutional protocol, non-operative management was initiated. Longitudinal radiographic assessment at 2 weeks, 4.5 months and 12 months showed reduction of the initially severely displaced fracture fragment. MRI- and CT-evaluation after 12 months confirmed anatomical healing of the fragment. At final follow-up, the patient was highly satisfied, although the healing process was complicated by posttraumatic frozen shoulder, which has had almost fully resolved after 12 months. CONCLUSIONS Given that the glenohumeral joint is concentrically reduced, large (displaced) anterior glenoid rim fractures after traumatic primary shoulder dislocation can be successfully treated non-operatively, with the potential of anatomical fracture fragment healing. Therefore, it remains subject to conservative treatment at our institution and surgical stabilization is reserved for patients with a decentered humeral head or persistent glenohumeral instability

Transkriptomweite Auswirkungen der pulsierenden Magnetfeldtherapie auf proinflammatorisch stimulierte 3D-Sehnenzellkonstrukte

Die pulsierende Elektromagnetfeldtherapie „PEMF“ stellt in der Behandlung muskuloskeletaler Erkrankungen eine Möglichkeit zur konservativen und perioperativen Therapie dar. In Hinblick auf das Sehnengewebe konnten präklinische Studien eine günstige Beeinflussung inflammatorischer und tenogener Marker, sowie eine schnellere Sehnenheilung in Tiermodellen zeigen. Klinische Studien weißen ebenfalls auf einen regenerationsfördernden Effekt auf Sehnen und zudem auf eine Schmerzverringerung hin. Auf zellulärer Ebene ist jedoch das Verständnis der biologischen Reaktionen der Tenozyten auf einen externen, physikalischen Reiz durch ein Elektromagnetfeld sehr begrenzt. Daher war das Ziel dieser Arbeit, einen für dreidimensionale, sehnenähnliche Konstrukte geeignetes Behandlungsregime der PEMF-Therapie zu entwerfen, um sowohl die vitale Funktion als auch die transkriptomweiten Reaktionen von Sehnenstamm/-vorläuferzellen (Tendon-Derived Stem/Progenitor Cells) auf eine hochenergetische PEMF-Behandlung unter proinflammatorischer Stimulation mit Interleukin-1b zu untersuchen. Die bisherigen in der Literatur verwendeten PEMF-Geräte beschränkten sich meist auf Intensitäten bis 10 Millitesla. Nachdem sich das in dieser Studie verwendete PEMF-Gerät mit einer Intensität von 82 Millitesla als sicher für die in den Sehnenkonstrukten eingebetteten Sehnenstamm/-vorläuferzellen erwies, konnte anschließend die PEMF-Therapieeinstellungen optimiert werden. Somit konnte ein optimiertes Behandlungsregime für die PEMF-Behandlung pro-inflammatorisch stimulierter Sehnenstamm/-vorläuferzellen in dreidimensionaler Zellkultur mit zweifach repetitiver Behandlungszeit von 60 Minuten mit 82 Millitesla bei jeweils anschließenden 90 Minuten Ruhepause ermittelt werden. Nach anschließender Transkriptom-Analyse konnte dabei ein anti-apoptotischer, anti-inflammatorischer und ein regenerationsfördernder Effekt der PEMF-Therapie auf Interleukin-1b-behandelte Sehnenstamm/-vorläuferzellen festgestellt werden. Zusammengenommen deuten die Ergebnisse der vorliegenden Studie darauf hin, dass die hochenergetische PEMF die katabolischen Effekte eines pro-inflammatorschen Stimulus durch Interleukin-1β begrenzt, indem sie die Expression von zellschützenden Molekülen induziert und die Apoptose dämpft, wodurch ein degeneratives, entzündliches Milieu in einen eher geweberegenerativen Zustand versetzt wird. Die ermittelten in vitro Ergebnisse legen nahe, dass es sich bei der PEMF um ein erfolgversprechendes Therapieverfahren zur perioperativen und konservativen Therapie von sowohl akuten als auch chronischen Sehnenpathologien handeln könnte. Um die Ergebnisse dieser Arbeit zu festigen, sollten weitere präklinische als auch klinische Studien mit dem in dieser Studie verwendeten PEMF-Gerät folgen, um die In-vitro-Ergebnisse zu bestätigen