MMP-8 is only a minor gene product of human adult articular chondrocytes of the knee

OBJECTIVE: The initial degradation of collagen fibrils during osteoarthritic cartilage destruction depends on the cleavage at the collagenase site, for which there exist three major candidate enzymes: collagenase 1 (MMP-1), collagenase 2 (MMP-8), and collagense 3 (MMP-13). The objective of this study was to determine the quantitative expression as well as distribution levels in normal and osteoarthritic cartilage and synovium and in cultured articular chondrocytes with and without stimulation by Il-1 beta. METHODS: Conventional and online PCR technology and immunohistochemistry were used to determine MMP-8 expression levels on the mRNA and protein level. RESULTS: Whereas conventional PCR analysis could demonstrate the presence of MMP-8 mRNA in normal and osteoarthritic chondrocytes, online quantitative PCR showed that only very minor amounts of MMP-8 mRNA expression is found in articular chondrocytes in vivo (and in vitro) and that there is no significant upregulation in osteoarthritic cartilage in vivo nor by Il-1 beta in vitro. The in vivo results were confirmed by the absence of significant protein staining with monoclonal antibodies for MMP-8 in normal and osteoarthritic chondrocytes. CONCLUSIONS: The presented results confirm the presence of a very minor MMP-8 expression by articular chondrocytes, but clearly question the hypothesis that MMP-8 is a major cartilage matrix degrading protease and is involved in enhanced cartilage matrix breakdown in osteoarthritic cartilage degeneration or by Il-1 beta stimulation in vitro.     

Self-Compassion as a Resource in the Self-Stigma Process of Overweight and Obese Individuals

ObjectiveSelf-stigma in overweight and obese individuals has strong associations with impairment in mental and global health. This study sought to explore self-compassion as a psychological resource in the self-stigma process.MethodsIn a 2012 representative German population survey of N = 1,158 overweight and obese individuals, self-compassion was examined as a mediator between self-stigma and mental and physical health outcomes, including BMI (kg/m²), using structural equation modeling and controlling for sociodemographic factors.ResultsPsychological variables were assessed using validated self-report questionnaires. Self-compassion partially mediated the relationships between self-stigma and depression, somatic symptoms, and health status / quality of life, lowering the predictive effect of self-stigma on the outcomes by approximately one-third. In contrast, self-compassion, because it was unrelated to BMI, did not mediate the association between self-stigma and BMI.ConclusionSelf-compassion has the potential to act as a buffer against the mental and global health detriments of self-stigma in overweight and obesity and could thus represent a target for interventions to reduce self-stigma and prevent these health impairments. In order to influence the association between self-stigma and BMI, self-compassion should conceptually be linked to weight management.Key Words: Stigma, Weight bias, Self-compassion, Depression, Somatic symptoms, Health, Quality of life     

The future of autoimmune liver diseases – Understanding pathogenesis and improving morbidity and mortality

Autoimmune liver diseases (AILD), namely autoimmune hepatitis (AIH), primary biliary cholangitis (PBC) and primary sclerosing cholangitis (PSC), are rare diseases. These days, patients with PBC almost never require liver transplantation. When treated early with ursodeoxycholic acid patients have a normal life expectancy if the disease is diagnosed at an early stage and the patients respond to treatment. Patients with AIH often go into remission with first‐line therapy including corticosteroids alone or in combination with azathioprine. Nevertheless, about one quarter of patients already developed cirrhosis at diagnosis. Those who do not respond to first line standard of care (SOC) have significant liver‐related morbidity and mortality. No approved second‐ or third‐line treatments are available and the drugs are selected based on limited case series and personal experience. Larger trials are needed to develop efficient therapies for difficult‐to‐treat AIH patients. No treatment has been found to alter the natural course of disease in patients with PSC except for liver transplantation. Identifying PSC patients at risk of developing cholangiocarcinoma (CCA) is another unmet need. Current research in all AILD including AIH, PBC and PSC, focuses on improving our understanding of the underlying disease process and identifying new therapeutic targets to decrease morbidity and mortality.     

Phosphorylation-regulated axonal dependent transport of syntaxin 1 is mediated by a Kinesin-1 adapter

Presynaptic nerve terminals are formed from preassembled vesicles that are delivered to the prospective synapse by kinesin-mediated axonal transport. However, precisely how the various cargoes are linked to the motor proteins remains unclear. Here, we report a transport complex linking syntaxin 1a (Stx) and Munc18, two proteins functioning in synaptic vesicle exocytosis at the presynaptic plasma membrane, to the motor protein Kinesin-1 via the kinesin adaptor FEZ1. Mutation of the FEZ1 ortholog UNC-76 in Caenorhabditis elegans causes defects in the axonal transport of Stx. We also show that binding of FEZ1 to Kinesin-1 and Munc18 is regulated by phosphorylation, with a conserved site (serine 58) being essential for binding. When expressed in C. elegans, wild-type but not phosphorylation-deficient FEZ1 (S58A) restored axonal transport of Stx. We conclude that FEZ1 operates as a kinesin adaptor for the transport of Stx, with cargo loading and unloading being regulated by protein kinases.     

Mutated regions of nucleophosmin 1 elicit both CD4(+) and CD8(+) T-cell responses in patients with acute myeloid leukemia

Mutations in the nucleophosmin gene (NPM1(mut)) are one of the most frequent molecular alterations in acute myeloid leukemia (AML), and immune responses may contribute to the favorable prognosis of AML patients with NPM1(mut). In the present study, we were able to demonstrate both CD4(+) and CD8(+) T-cell responses against NPM1(mut). Ten peptides derived from wild-type NPM1 and NPM1(mut) were subjected to ELISPOT analysis in 33 healthy volunteers and 27 AML patients. Tetramer assays against the most interesting epitopes were performed and Cr(51)-release assays were used to show the cytotoxicity of peptide-specific T cells. Moreover, HLA-DR-binding epitopes were used to test the role of CD4(+) T cells in NPM1 immunogenicity. Two epitopes (epitopes #1 and #3) derived from NPM1(mut) induced CD8(+) T-cell responses. A total of 33% of the NPM1(mut) AML patients showed immune responses against epitope #1 and 44% against epitope #3. Specific lysis of leukemic blasts was detected. To obtain robust immune responses against tumor cells, the activation of CD4(+) T cells is crucial. Therefore, overlapping (OL) peptides were analyzed in ELISPOT assays and OL8 was able to activate both CD8(+) and CD4(+) T cells. The results of the present study show that NPM1(mut) induces specific T-cell responses of CD4(+) and CD8(+) T cells and therefore is a promising target for specific immunotherapies in AML.     

Attitudes of Health Care Professionals towards Female Obese Patients

ObjectiveThe health care setting has been reported to be one main source of weight stigma repeatedly; however, studies comparing different professions have been lacking.Methods682 health care professionals (HCP) of a large German university hospital were asked to fill out a questionnaire on stigmatizing attitudes, perceived causes of obesity, and work-related impact of obesity. Stigmatizing attitudes were assessed on the Fat Phobia Scale (FPS) based on a vignette describing a female obese patient.ResultsOnly 25% graded current health care of obese patients to be ‘good’ or ‘very good’. 63% of all HCPs ‘somewhat’ or ‘strongly’ agreed that it was often difficult to get the resources needed in order to care for obese patients. The mean FPS score was comparable to that in the general public (M = 3.59), while nursing staff showed slightly more positive attitudes compared to physicians and therapists. Higher age, higher BMI, and ascribing personal responsibility for obesity to the individual were associated with a higher level of stigmatizing attitudes. The nursing staff agreed on obesity as an illness to a greater extent while physicians attributed obesity to the individual.ConclusionsIn summary, by making complex models on the causes of obesity known among health care professionals, stigmatizing attitudes might be reduced. Ongoing further education for health care professionals ought to be part of anti-stigma campaigns in the medical field.Key Words: Health care professionals, Obesity, Care, Stigma