P11 (S100A10) as a potential predictor of ketamine response in patients with SSRI-resistant depression

BACKGROUND

Ketamine can act as antidepressant in patients with major depressive disorder (MDD) who are treatment-resistant. P11 has been implicated in ketamine's mechanism of action and proposed as biomarker for treatment response to other antidepressants. This study explores the effect of ketamine on peripheral p11 and the potential role for p11 as response marker for ketamine treatment.

METHODS

Thirty Selective Serotonin Reuptake Inhibitor resistant MDD patients were randomized to either 0.5 mg/kg ketamine or placebo intravenous treatment. Using multicolor Flow Cytometry, peripheral p11 levels were measured before and 1-2 days after treatment.

RESULTS

P11 levels were decreased within the ketamine group in both cytotoxic T cell and T helper cells populations, although this did not significantly differ from changes seen in the placebo group. Baseline p11 levels in cytotoxic T cells were significantly correlated with antidepressant response to ketamine treatment.

LIMITATIONS

This study was part of a larger study examining the effect of ketamine on the serotonin system in MDD patients, therefore the number of study subjects was limited to that of the primary study.

CONCLUSIONS

High baseline p11 levels in cytotoxic T cells were associated with a stronger reduction of depressive symptoms in MDD patients after ketamine treatment. Future studies should confirm if peripheral p11 levels could be used as a predictor of ketamine treatment response.

Assessing the clinical and bacteriological outcomes of vaccination with recombinant Asp14 and OmpA against A. phagocytophilum in sheep

Anaplasma phagocytophilum is a tick borne bacterium, causing disease in sheep and other mammals, including humans. The bacterium has great economic and animal welfare implications for sheep husbandry in Northern Europe. With the prospect of a warmer and more humid climate, the vector availability will likely increase, resulting in a higher prevalence of A. phagocytophilum. The current preventive measures, as pyrethroids acting on ticks or long acting antibiotics controlling bacterial infection, are suboptimal for prevention of the disease in sheep. Recently, the increased awareness on antibiotic- and pyrethorid resistance, is driving the search for a new prophylactic approach in sheep against A. phagocytophilum. Previous studies have used an attenuated vaccine, which gave insufficient protection from challenge with live bacteria. Other studies have focused on bacterial membrane surface proteins like Asp14 and OmpA. An animal study using homologous proteins to Asp14 and OmpA of A. marginale, showed no protective effect in heifers. In the current study, recombinant proteins of Asp14 (rAsp14) and OmpA (rOmpA) of A. phagocytophilum were produced and prepared as a vaccine for sheep. Ten lambs were vaccinated twice with an adjuvant emulsified with rAsp14 or rOmpA, three weeks apart and challenged with a live strain of A. phagocytophilum (GenBank acc.nr M73220) on day 42. The control group consisted of five lambs injected twice with PBS and adjuvant. Hematology, real time qPCR, immunodiagnostics and flow cytometric analyses of peripheral blood mononuclear cells were performed. Vaccinated lambs responded with clinical signs of A.phagocytophilum infection after challenge and bacterial load in the vaccinated group was not reduced compared to the control group. rAsp14 vaccinated lambs generated an antibody response against the vaccine, but a clear specificity for rAsp14 could not be established. rOmpA-vaccinated lambs developed a strong specific antibody response on days 28 after vaccination and 14 days post-challenge. Immunofluorescent staining and flow cytometric analysis of peripheral blood mononuclear monocytes revealed no difference between the three groups, but the percentage of CD4⁺, CD8⁺, γδ TcR⁺, λ-Light chain⁺, CD11b⁺, CD14⁺ and MHC II⁺ cells, within the groups changed during the study, most likely due to the adjuvant or challenge with the bacterium. Although an antigen specific antibody response could be detected against rOmpA and possibly rAsp14, the vaccines seemed to be ineffective in reducing clinical signs and bacterial load caused by A. phagocytophilum. This is the first animal study with recombinant Asp14 and OmpA aimed at obtaining clinical protection against A. phagocytophilum in sheep.

Effects of Exercise on Gene Expression of Inflammatory Markers in Human Peripheral Blood Cells: A Systematic Review

Regular physical activity seems to be one of the most important contributors to prevent disease and promote health. Being physically active reduces the risk of developing chronic diseases such as cardiovascular disease, diabetes, and some types of cancers. The molecular mechanisms are however not fully elucidated. Depending on duration and intensity, exercise will cause disruption of muscle fibers triggering a temporary inflammatory response. This response may not only involve the muscle tissue, but also peripheral tissues such as white blood cells, which are important components of the immune system. The immune system plays a vital role in the development of atherosclerosis, thereby making white blood cells relevant to study when looking at molecular mechanisms induced by physical activity. In this review, we summarize the existing literature on exercise and gene expression in human white blood cells, and discuss these results in relation to inflammation and atherosclerosis.

Reduced expression of SP1 and SP4 transcription factors in peripheral blood mononuclear cells in first-episode psychosis

Alterations of transcription factor specificity protein 4 (SP4) and 1 (SP1) have been linked to different neuropsychiatric diseases. Reduced SP4 and SP1 protein levels in the prefrontal cortex have been associated with bipolar disorder and schizophrenia, respectively, suggesting that both factors could be involved in the pathogenesis of disorders with psychotic features. The aim of this study was to investigate whether the reduction of SP1, SP4 and SP3 protein and mRNA expression in peripheral blood mononuclear cells in the early stages of psychosis may act as a potential biomarker of these disorders. A cross-sectional study of first-episode psychosis patients (n = 14) compared to gender- and age-matched healthy controls (n = 14) was designed. Patients were recruited through the adult mental health services of Parc Sanitari Sant Joan de Déu. Protein and gene expression levels of SP1, SP4 and SP3 were assessed in peripheral blood mononuclear cells of patients with first-episode psychosis and healthy control subjects. We report that protein levels of SP1 and SP4, but not SP3, are significantly reduced in patients compared to controls. In contrast, we did not observe any differences in expression levels for SP1, SP4 or SP3 genes between patient and control groups. In patients, SP4 protein levels were significantly associated with SP1 protein levels. No association was found, however, between protein and gene expression levels for each factor. Our study shows reduced SP1 and SP4 protein levels in first-episode psychosis in lymphocytes, suggesting that these transcription factors are potential peripheral biomarkers of psychotic spectrum disorders in the early stages.