ABSTRACT
Structural neuroimaging data have been used to compute an estimate of the biological age of the brain (brain-age) which has been associated with other biologically and behaviorally meaningful measures of brain development and aging. The ongoing research interest in brain-age has highlighted the need for robust and publicly available brain-age models pre-trained on data from large samples of healthy individuals. To address this need we have previously released a developmental brain-age model. Here we expand this work to develop, empirically validate, and disseminate a pre-trained brain-age model to cover most of the human lifespan. To achieve this, we selected the best-performing model after systematically examining the impact of seven site harmonization strategies, age range, and sample size on brain-age prediction in a discovery sample of brain morphometric measures from 35,683 healthy individuals (age range: 5-90 years; 53.59% female). The pre-trained models were tested for cross-dataset generalizability in an independent sample comprising 2101 healthy individuals (age range: 8-80 years; 55.35% female) and for longitudinal consistency in a further sample comprising 377 healthy individuals (age range: 9-25 years; 49.87% female). This empirical examination yielded the following findings: (1) the accuracy of age prediction from morphometry data was higher when no site harmonization was applied; (2) dividing the discovery sample into two age-bins (5-40 and 40-90 years) provided a better balance between model accuracy and explained age variance than other alternatives; (3) model accuracy for brain-age prediction plateaued at a sample size exceeding 1600 participants. These findings have been incorporated into CentileBrain (https://centilebrain.org/#/brainAGE2), an open-science, web-based platform for individualized neuroimaging metrics.
Subject(s)
Aging , Brain , Magnetic Resonance Imaging , Humans , Adolescent , Female , Aged , Adult , Child , Young Adult , Male , Brain/diagnostic imaging , Brain/anatomy & histology , Brain/growth & development , Aged, 80 and over , Child, Preschool , Middle Aged , Aging/physiology , Magnetic Resonance Imaging/methods , Neuroimaging/methods , Neuroimaging/standards , Sample SizeABSTRACT
Childhood maltreatment (CM) is associated with increased limbic activity, while social support is linked to decreased limbic activity towards negative stimuli. Our study aimed to explore the interaction of perceived social support with CM, and their combined impact on limbic activity in negative emotion processing. A total of 130 healthy individuals (HC) underwent a negative emotional face processing paradigm. They were divided into two groups based on the Childhood Trauma Questionnaire: n = 65 HC without CM matched with n = 65 HC with CM. In a region-of-interest approach of the bilateral amygdala-hippocampus-complex (AHC), regression analyses investigating the association of CM and perceived social support with limbic activity and a social support x CM ANCOVA were conducted. CM was associated with increased AHC activity, while perceived social support tended to be associated with decreased AHC activity during negative emotion processing. The ANCOVA showed a significant interaction in bilateral AHC activity (pFWE ≤ 0.024) driven by a negative association between perceived social support and bilateral AHC activity in HC without CM. No significant association was observed in HC with CM. Exploratory analyses using continuous CM scores support this finding. Our results suggest that CM moderates the link between perceived social support and limbic activity, with a protective effect of perceived social support only in HC without CM. The lack of this effect in HC with CM suggests that CM may alter the buffering effect of perceived social support on limbic functioning, highlighting the potential need for preventive interventions targeting social perception of HC with CM.
ABSTRACT
Climate change is predicted to narrow the prescriptive zone of dryland species, potentially leading to behavioural modifications with fitness consequences. This study explores the behavioural responses of three widespread African antelope species-springbok, kudu and eland-to extreme heat in a dryland savanna. We classified the behaviour of 29 individuals during the hot, dry season on the basis of accelerometer data using supervised machine learning and analysed the impact of afternoon heat on behaviour-specific time allocation and overall dynamic body acceleration (ODBA), a proxy for energy expenditure, along with compensatory changes over the 24-hour cycle. Extreme afternoon heat reduced feeding time in all three antelope species, increased ruminating and resting time, while only minimally affecting walking time. With rising heat, all three species reduced ODBA on feeding, while eland reduced and kudu increased ODBA on walking. Diel responses in behaviour differed between species, but were generally characterised by daytime reductions in feeding and increases in ruminating or resting on hot days compared to cool days. While antelope compensated for heat-driven behavioural change over the 24-hour cycle in some cases, significant differences persisted in others, including reduced feeding and increased rumination and resting. The impact of heat on antelope behaviour reveals trade-offs between feeding and thermoregulation, as well as between feeding and rumination, the latter suggesting a strategy to enhance nutrient uptake through increased digestive efficiency, while the walking response suggests narrow constraints between cost and necessity. Our findings suggest that heat influences both behaviour-specific time allocation and energy expenditure. Altered diel behaviour patterns and incomplete compensation over the 24-hour cycle point to fitness consequences. The need to prioritise thermoregulation over feeding is likely to narrow the prescriptive zone of these dryland antelope.
Subject(s)
Adaptation, Psychological , COVID-19 , Depression , Humans , COVID-19/psychology , COVID-19/epidemiology , COVID-19/prevention & control , Depression/psychology , Depression/epidemiology , Male , Female , Adult , Quarantine/psychology , Child Abuse/psychology , Child Abuse/statistics & numerical data , Middle Aged , Adult Survivors of Child Abuse/psychology , Adult Survivors of Child Abuse/statistics & numerical data , PandemicsABSTRACT
Background: The aim of this publication is to demonstrate similarities and differences in the association of risk factors with the prevalence of different manifestations of chronic venous disease (CVD), like varicose veins (VV), venous oedema (C3) and severe chronic venous insufficiency (CVI) in the population-based cross-sectional Bonn Vein Study 1 (BVS). Patients and methods: In the BVS 1 between 13.11.2000 and 15.3.2002, 3.072 participants, 1350 men and 1722 women, from a simple random sample of the general population of the city of Bonn and two rural townships aged 18-79 years were included. The overall response proportion was 59%. All participants answered a standardized questionnaire including information about socio-economic data, lifestyle, physical activity, medical history, and quality of life. Venous investigations were performed clinically and by a standardized duplex examination by trained investigators. The CEAP classification in the version of 1996 was used to classify the findings. Logistic regression models were performed for the association of possible risk factors with VV, venous edema (C3) and severe CVI (C4-C6). The predictive risk (PR) describes the association of the diseases and the possible influencing factors. Results: VV, venous oedema (C3) and severe CVI (C4-C6) have common risk factors like higher age, number of pregnancies, family history of VV and overweight or obesity. Female gender is significantly associated with VV and C3 but not with severe CVI (C4-C6). High blood pressure and urban living are only associated with C3 and C4-C6 disease whereas prolonged sitting is associated with C3 and lower social class with C4-C6 exclusively. Discussion: In many epidemiological studies risk factors were associated with chronic venous disorders in general. Our data show that VV, venous edema and severe CVI may have different risk profiles. Venous edema is more often associated with arterial hypertension and sedentary lifestyle whereas lower social class seems to be a risk factor for severe CVI including venous ulcers. Conclusions: The differences in the association of risk factors to VV, venous edema and severe CVI should be considered if prevention and treatment of chronic venous diseases are planned. As examples, compression stockings could be proposed in sitting profession to prevent oedema, VV patients with risk factors like obesity might benefit from early treatment for VV and obesity. More longitudinal evaluation of risk factors is necessary to evaluate the true risk profile of CVD.
Subject(s)
Hypertension , Varicose Veins , Venous Insufficiency , Male , Pregnancy , Humans , Female , Cross-Sectional Studies , Quality of Life , Varicose Veins/diagnostic imaging , Varicose Veins/epidemiology , Venous Insufficiency/diagnostic imaging , Venous Insufficiency/epidemiology , Chronic Disease , Obesity/complications , Edema/complicationsABSTRACT
Biased emotion processing has been suggested to underlie the etiology and maintenance of depression. Neuroimaging studies have shown mood-congruent alterations in amygdala activity in patients with acute depression, even during early, automatic stages of emotion processing. However, due to a lack of prospective studies over periods longer than 8 weeks, it is unclear whether these neurofunctional abnormalities represent a persistent correlate of depression even in remission. In this prospective case-control study, we aimed to examine brain functional correlates of automatic emotion processing in the long-term course of depression. In a naturalistic design, n = 57 patients with acute major depressive disorder (MDD) and n = 37 healthy controls (HC) were assessed with functional magnetic resonance imaging (fMRI) at baseline and after 2 years. Patients were divided into two subgroups according to their course of illness during the study period (n = 37 relapse, n = 20 no-relapse). During fMRI, participants underwent an affective priming task that assessed emotion processing of subliminally presented sad and happy compared to neutral face stimuli. A group × time × condition (3 × 2 × 2) ANOVA was performed for the amygdala as region-of-interest (ROI). At baseline, there was a significant group × condition interaction, resulting from amygdala hyperactivity to sad primes in patients with MDD compared to HC, whereas no difference between groups emerged for happy primes. In both patient subgroups, amygdala hyperactivity to sad primes persisted after 2 years, regardless of relapse or remission at follow-up. The results suggest that amygdala hyperactivity during automatic processing of negative stimuli persists during remission and represents a trait rather than a state marker of depression. Enduring neurofunctional abnormalities may reflect a consequence of or a vulnerability to depression.
Subject(s)
Amygdala , Depressive Disorder, Major , Emotions , Magnetic Resonance Imaging , Humans , Amygdala/physiopathology , Male , Female , Adult , Magnetic Resonance Imaging/methods , Depressive Disorder, Major/physiopathology , Emotions/physiology , Case-Control Studies , Middle Aged , Prospective Studies , Facial Expression , Depression/physiopathology , Brain Mapping/methods , Subliminal StimulationABSTRACT
BACKGROUND: Magnetic resonance imaging (MRI) studies on major depressive disorder (MDD) have predominantly found short-term electroconvulsive therapy (ECT)-related gray matter volume (GMV) increases, but research on the long-term stability of such changes is missing. Our aim was to investigate long-term GMV changes over a 2-year period after ECT administration and their associations with clinical outcome. METHODS: In this nonrandomized longitudinal study, patients with MDD undergoing ECT (n = 17) are assessed three times by structural MRI: Before ECT (t0), after ECT (t1) and 2 years later (t2). A healthy (n = 21) and MDD non-ECT (n = 33) control group are also measured three times within an equivalent time interval. A 3(group) × 3(time) ANOVA on whole-brain level and correlation analyses with clinical outcome variables is performed. RESULTS: Analyses yield a significant group × time interaction (pFWE < 0.001) resulting from significant volume increases from t0 to t1 and decreases from t1 to t2 in the ECT group, e.g., in limbic areas. There are no effects of time in both control groups. Volume increases from t0 to t1 correlate with immediate and delayed symptom increase, while volume decreases from t1 to t2 correlate with long-term depressive outcome (all p ⩽ 0.049). CONCLUSIONS: Volume increases induced by ECT appear to be a transient phenomenon as volume strongly decreased 2 years after ECT. Short-term volume increases are associated with less symptom improvement suggesting that the antidepressant effect of ECT is not due to volume changes. Larger volume decreases are associated with poorer long-term outcome highlighting the interplay between disease progression and structural changes.
Subject(s)
Depressive Disorder, Major , Electroconvulsive Therapy , Humans , Depressive Disorder, Major/diagnostic imaging , Depressive Disorder, Major/therapy , Depressive Disorder, Major/pathology , Electroconvulsive Therapy/methods , Depression , Longitudinal Studies , Brain/diagnostic imaging , Brain/pathology , Magnetic Resonance Imaging/methodsABSTRACT
Obesity is associated with alterations in brain structure and function, particularly in areas related to reward processing. Although brain structural investigations have demonstrated a continuous association between higher body weight and reduced gray matter in well-powered samples, functional neuroimaging studies have typically only contrasted individuals from the normal weight and obese body mass index (BMI) ranges with modest sample sizes. It remains unclear, whether the commonly found hyperresponsiveness of the reward circuit can (a) be replicated in well-powered studies and (b) be found as a function of higher body weight even below the threshold of clinical obesity. 383 adults across the weight spectrum underwent functional magnetic resonance imaging during a common card-guessing paradigm simulating monetary reward. Multiple regression was used to investigate the association of BMI and neural activation in the reward circuit. In addition, a one-way ANOVA model comparing three weight groups (normal weight, overweight, obese) was calculated. Higher BMI was associated with higher reward response in the bilateral insula. This association could no longer be found when participants with obesity were excluded from the analysis. The ANOVA revealed higher activation in obese vs. lean, but no difference between lean and overweight participants. The overactivation of reward-related brain areas in obesity is a consistent finding that can be replicated in large samples. In contrast to brain structural aberrations associated with higher body weight, the neurofunctional underpinnings of reward processing in the insula appear to be more pronounced in the higher body weight range.
Subject(s)
Magnetic Resonance Imaging , Overweight , Adult , Humans , Overweight/diagnostic imaging , Obesity/diagnostic imaging , Brain/physiology , Body Mass Index , RewardABSTRACT
BACKGROUND: The second-generation antipsychotic (SGA) quetiapine is an essential option for antidepressant augmentation therapy in major depressive disorder (MDD), yet neurobiological mechanisms behind its antidepressant properties remain unclear. As SGAs interfere with activity in reward-related brain areas, including the anterior cingulate cortex (ACC) - a key brain region in antidepressant interventions, this study examined whether quetiapine treatment affects ACC activity during reward processing in MDD patients. METHODS: Using the ACC as region of interest, an independent t-test comparing reward-related BOLD response of 51 quetiapine-taking and 51 antipsychotic-free MDD patients was conducted. Monetary reward outcome feedback was measured in a card-guessing paradigm using pseudorandom blocks. Participants were matched for age, sex, and depression severity and analyses were controlled for confounding variables, including total antidepressant medication load, illness chronicity and acute depression severity. Potential dosage effects were examined in a 3 × 1 ANOVA. Differences in ACC-related functional connectivity were assessed in psycho-physiological interaction (PPI) analyses. RESULTS: Left subgenual ACC activity was significantly higher in the quetiapine group compared to antipsychotic-free participants and dependent on high-dose quetiapine intake. Results remained significant after controlling for confounding variables. The PPI analysis did not yield significant group differences in ACC-related functional connectivity. LIMITATIONS: Causal interpretation is limited due to cross-sectional findings. CONCLUSION: Elevated subgenual ACC activity to rewarding stimuli may represent a neurobiological marker and potential key interface of quetiapine's antidepressant effects in MDD. These results underline ACC activity during reward processing as an investigative avenue for future research and therapeutic interventions to improve MDD treatment outcomes.
Subject(s)
Antipsychotic Agents , Depressive Disorder, Major , Humans , Antipsychotic Agents/adverse effects , Quetiapine Fumarate/therapeutic use , Gyrus Cinguli , Cross-Sectional Studies , Antidepressive Agents/therapeutic use , Antidepressive Agents/pharmacology , Reward , Magnetic Resonance ImagingABSTRACT
Context: Autoimmune polyglandular syndrome (APS-2: autoimmune Addison's disease or type 1 diabetes) is conferred by predisposing HLA molecules, vitamin D deficiency, and heritable susceptibility. Organ destruction is accompanied by cytokine alterations. We addressed the monocytic cytokines of two distinct APS-2 cohorts, effects of vitamin D and HLA DQ risk. Methods: APS-2 patients (n = 30) and healthy controls (n = 30) were genotyped for HLA DQA1/DQB1 and their CD14+ monocytes stimulated with IL1ß and/or 1,25(OH)2D3 for 24 h. Immune regulatory molecules (IL-6, IL-10, IL-23A, IL-15, CCL-2, PD-L1), vitamin D pathway gene transcripts (CYP24A1, CYP27B1, VDR), and CD14 were analyzed by enzyme-linked immunosorbent assay and RTqPCR. Results: Pro-inflammatory CCL-2 was higher in APS-2 patients than in controls (p = 0.001), whereas IL-6 showed a trend - (p = 0.1). In vitro treatment with 1,25(OH)2D3 reduced proinflammatory cytokines (IL-6, CCL-2, IL-23A, IL-15) whereas anti-inflammatory cytokines (IL-10 and PD-L1) rose both in APS-type 1 diabetes and APS-Addison´s disease. Patients with adrenal autoimmunity showed a stronger response to vitamin D. Expression of IL-23A and vitamin D pathway genes VDR and CYP27B1 varied by HLA genotype and was lower in healthy individuals with high-risk HLA (p = 0.0025; p = 0.04), while healthy controls with low-risk HLA showed a stronger IL-10 and CD14 expression (p = 0.01; p = 0.03). Conclusion: 1,25(OH)2D3 regulates the monocytic response in APS-2 disorders type 1 diabetes or Addison´s disease. The monocytic cytokine profile of individuals carrying HLA high-risk alleles is proinflammatory, enhances polyglandular autoimmunity and can be targeted by vitamin D.
Subject(s)
Cytokines/immunology , HLA-DQ Antigens/immunology , Monocytes/immunology , Polyendocrinopathies, Autoimmune/immunology , Vitamin D/immunology , Adult , Alleles , Case-Control Studies , Female , Genotype , Humans , Inflammation/immunology , Male , Middle Aged , Signal Transduction/immunologyABSTRACT
CONTEXT: Autoimmune endocrinopathies result from environmental triggers on the genetic background of risk alleles, especially HLA-DR and HLA-DQ with alanine (Ala) in HLA-DQB1 position 57 (Ala57), whereas amino acid Asp57 is protective. OBJECTIVES: Differentiate the effects of HLA-DQB1 amino acid variants at position 57 in adult patients with isolated endocrinopathies and autoimmune polyglandular syndrome type 2 (APS-2) compared with healthy controls in relation to gender. SETTING: University Hospital Frankfurt, Frankfurt, Germany. PARTICIPANTS: Two hundred seventy-eight patients with APS-2 and 1373 patients with isolated endocrinopathies: [type 1 diabetes (T1D), n = 867], Addison disease (AD, n = 185), autoimmune thyroiditis (AIT, n = 321) and 526 healthy controls. RESULTS: Homozygous HLA-DQB1 Ala57 was more frequent in polyglandular T1D/AIT (OR 11.7, Pc = 3 × 10-7) and AD/AIT (OR 4.0, Pc = 3 × 10-7), as well as in isolated T1D (OR 9.7, Pc = 3 × 10-7) and AD (OR 3.1, Pc = 3 × 10-7). Heterozygous HLA-DQB1 57 Ala/non-Ala was increased in women with isolated AD and polyglandular AD/AIT (both OR 1.7, Pc= 0.02) whereas the same amino acid variant was overrepresented in men with T1D compared with women (OR 1.6, Pc = 0.004). The amino acid Ala57 was more frequent (OR 2.0, Pc = 0.02) and the amino acid Asp57 was much more rare (OR 0.4, Pc = 0.007) in the APS-2 cohort T1D/AIT than in AD/AIT. CONCLUSION: HLA-DQB1 confers strong susceptibility by Ala57 homozygosity and protection by non-Ala57, both in adult isolated and polyglandular diseases. Frequencies of HLA-DQB1 amino acids differentiate between APS-2 T1D/AIT and AD/AIT. HLA-DQB1 Ala57 heterozygous women are at increased risk for AD or AIT, whereas men were found to have an increased susceptibility for T1D.
Subject(s)
Addison Disease/genetics , Diabetes Mellitus, Type 1/genetics , HLA-DQ beta-Chains/genetics , Polyendocrinopathies, Autoimmune/genetics , Thyroiditis, Autoimmune/genetics , Adult , Alanine/genetics , Amino Acid Substitution , Asparagine/genetics , Case-Control Studies , Female , Genetic Predisposition to Disease , Healthy Volunteers , Heterozygote , Homozygote , Humans , Male , Middle Aged , Retrospective StudiesSubject(s)
Coronary Occlusion/surgery , Exercise Tolerance/physiology , Percutaneous Coronary Intervention , Chronic Disease , Coronary Angiography , Coronary Occlusion/diagnosis , Coronary Occlusion/physiopathology , Exercise Test , Humans , Postoperative Period , Prospective Studies , Treatment OutcomeABSTRACT
DNAX accessory protein-1 (DNAM-1, CD226) is a co-stimulatory and adhesion molecule expressed mainly by natural killer cells and T cells. DNAM-1 and its two ligands CD112 and CD155 are important in graft-versus-host disease, but their role in solid organ transplantation is largely unknown. We investigated the relevance of this pathway in a mouse kidney transplantation model. CD112 and CD155 are constitutively expressed on renal tubular cells and strongly upregulated in acutely rejected renal allografts. In vitro DNAM-1 blockade during allogeneic priming reduced the allospecific T cell response but not the allospecific cytotoxicity against renal tubular epithelial cells. Accordingly, absence of DNAM-1 in recipient mice or absence of CD112 or CD155 in the kidney allograft did not significantly influence renal function and severity of rejection after transplantation, but led to a higher incidence of infarcts in CD112 and CD155 deficient kidney allografts. Thus, DNAM-1 blockade is not effective in preventing transplant rejection. Despite of being highly expressed, CD112 and CD155 do not appear to play a major immunogenic role in kidney transplantation. Considering the high incidence of renal infarcts in CD112 and CD155 deficient grafts, blocking these molecules might be detrimental.
Subject(s)
Antigens, Differentiation, T-Lymphocyte/metabolism , Kidney Transplantation , Lymphocyte Activation/immunology , T-Lymphocytes/immunology , T-Lymphocytes/metabolism , Allografts , Animals , Antigens, Differentiation, T-Lymphocyte/genetics , Cytotoxicity, Immunologic , Epithelial Cells/metabolism , Gene Expression , Graft Rejection/genetics , Graft Rejection/immunology , Interleukin-2 Receptor beta Subunit/genetics , Interleukin-2 Receptor beta Subunit/metabolism , Kidney Tubules/cytology , Kidney Tubules/metabolism , Ligands , Lymphocyte Activation/genetics , Mice , Mice, Knockout , Models, Animal , Receptors, Virus/genetics , Receptors, Virus/metabolism , Signal Transduction , Skin TransplantationABSTRACT
Mitochondrial demise is a key feature of progressive neuronal death contributing to acute and chronic neurological disorders. Recent studies identified a pivotal role for the BH3-only protein B-cell lymphoma-2 interacting domain death antagonist (Bid) for such mitochondrial damage and delayed neuronal death after oxygen-glucose deprivation, glutamate-induced excitotoxicity, or oxidative stress in vitro and after cerebral ischemia in vivo. Therefore, we developed new N-phenyl-substituted thiazolidine-2,4-dione derivatives as potent inhibitors of Bid-dependent neurotoxicity. The new compounds 6, 7, and 16 were identified as highly protective by extensive screening in a model of glutamate toxicity in immortalized mouse hippocampal neurons (HT-22 cells). These compounds significantly prevent truncated Bid-induced toxicity in the neuronal cell line, providing strong evidence that inhibition of Bid was the underlying mechanism of the observed protective effects. Furthermore, Bid-dependent hallmarks of mitochondrial dysfunction, such as loss of mitochondrial membrane potential, ATP depletion, as well as impairments in mitochondrial respiration, are significantly prevented by compounds 6, 7, and 16. Therefore, the present study identifies a class of N-phenyl thiazolidinediones as novel Bid-inhibiting neuroprotective agents that provide promising therapeutic perspectives for neurodegenerative diseases, in which Bid-mediated mitochondrial damage and associated intrinsic death pathways contribute to the underlying progressive loss of neurons.
Subject(s)
BH3 Interacting Domain Death Agonist Protein/toxicity , Glutamic Acid/toxicity , Neurons/drug effects , Neuroprotective Agents/pharmacology , Thiazolidinediones/pharmacology , Animals , Apoptosis/drug effects , Cells, Cultured , Humans , Membrane Potential, Mitochondrial/drug effects , Rats , Structure-Activity RelationshipABSTRACT
Induction of mixed hematopoietic chimerism results in donor-specific immunological tolerance by apoptosis-mediated deletion of donor-reactive lymphocytes. A broad clinical application of this approach is currently hampered by limited predictability and toxicity of the available conditioning protocols. We developed a new therapeutic approach to induce mixed chimerism and tolerance by a direct pharmacological modulation of the intrinsic apoptosis pathway in peripheral T cells. The proapoptotic small-molecule Bcl-2 inhibitor ABT-737 promoted mixed chimerism induction and reversed the antitolerogenic effect of calcineurin inhibitors by boosting the critical role of the proapoptotic Bcl-2 factor Bim. A short conditioning protocol with ABT-737 in combination with costimulation blockade and low-dose cyclosporine A resulted in a complete deletion of peripheral donor-reactive lymphocytes and was sufficient to induce mixed chimerism and robust systemic tolerance across full major histocompatibility complex barriers, without myelosuppression and by using moderate doses of bone marrow cells. Thus, immunological tolerance can be achieved by direct modulation of the intrinsic apoptosis pathway in peripheral lymphocytes-a new approach to translate immunological tolerance into clinically applicable protocols.
Subject(s)
Apoptosis/drug effects , Biphenyl Compounds/pharmacology , Graft Survival/drug effects , Hematopoiesis/drug effects , Molecular Targeted Therapy/methods , Nitrophenols/pharmacology , Sulfonamides/pharmacology , Transplantation Chimera , Animals , Apoptosis/immunology , Biphenyl Compounds/therapeutic use , Cells, Cultured , Graft Survival/physiology , Hematopoiesis/physiology , Immunosuppression Therapy , Mice , Mice, Inbred BALB C , Mice, Inbred C57BL , Mice, Inbred CBA , Mice, Knockout , Nitrophenols/therapeutic use , Piperazines/pharmacology , Piperazines/therapeutic use , Proto-Oncogene Proteins c-bcl-2/antagonists & inhibitors , Sulfonamides/therapeutic use , Transplantation Chimera/immunology , Transplantation Chimera/physiology , Transplantation Conditioning/methods , Transplantation Tolerance/drug effects , Up-Regulation/drug effects , Up-Regulation/immunologyABSTRACT
Blocking the CD40-CD154 pathway prevents allograft rejection and induces donor-specific tolerance in various experimental models. However, the translation to clinical studies has been hampered by unexpected thromboembolic complications of CD154-blocking antibodies. Thus, blocking CD40 instead is now considered as an alternative strategy. Here, we evaluated the role of donor CD40 in allospecific T-cell responses in vitro and in an in vivo model for renal transplantation. Fully MHC-mismatched allografts from CD40-deficient donors displayed better renal function than wild type. These functional data correlated with a lower level of apoptosis in renal tubular epithelial cells and higher expression of PD-L1, which is most probably because of a reduced Th17 response in recipients of a CD40-deficient donor. This hypothesis was supported in vitro, where donor CD40 expression was important for the induction of direct allospecific T-cell responses. Especially the induction of Th17 cells was critically dependent on donor CD40. IL-17A in conjunction with interferon-γ in turn rendered renal tubular epithelial cells to a more costimulatory state by upregulating CD40 and downregulating PD-L1 expression. In conclusion, CD40 blockade not only reduces the allospecific T-cell responses, but might also lead to protection of tubular epithelium from apoptosis and thereby preserve kidney allograft function.
Subject(s)
CD40 Antigens/deficiency , Kidney Transplantation , Tissue Donors , Animals , Apoptosis/immunology , CD40 Antigens/genetics , Dendritic Cells/immunology , Epithelium/immunology , Epithelium/pathology , Kidney/immunology , Kidney/pathology , Kidney/physiology , Mice , Mice, Inbred C57BL , Mice, Inbred CBA , Mice, Knockout , T-Lymphocytes, Cytotoxic/immunology , Th17 Cells/immunology , Transplantation, HomologousABSTRACT
Survival of lymphocytes and melanocyte stem cells critically depends on B cell lymphoma 2 (Bcl-2). In T lymphocytes, a basal calcineurin activity maintains Bcl-2 expression in naïve cells, and the activation of the calcineurin pathway orchestrates the regulation of the intrinsic apoptosis pathway after antigen recognition. Therefore, calcineurin inhibitors might potentiate the pro-apoptotic effect of pharmacological Bcl-2 inhibitors on lymphatic cells. In vitro, a reduced Bcl-2 expression in lymphocytes exposed to calcineurin inhibitors increased their sensitivity to the small molecule Bcl-2 inhibitor ABT-737. This correlated with an augmented pro-apoptotic activity of ABT-737 on lymphocytes in combination with cyclosporine A in naïve mice in vivo. Interestingly, similar processes were observed in melanocytes. ABT-737 induced a fur depigmentation at the site of injection, and this effect was expanded to a generalized depigmentation in combination with cyclosporine A. Thus, inhibiting calcineurin increases the pro-apoptotic potency of ABT-737 in cells depending on Bcl-2 for survival. The increased efficacy of Bcl-2 inhibitors in combination with cyclosporine A might be relevant to exploit their anti-neoplastic and immuno-modulatory properties.
Subject(s)
Biphenyl Compounds/pharmacology , Cyclosporine/pharmacology , Nitrophenols/pharmacology , Proto-Oncogene Proteins c-bcl-2/antagonists & inhibitors , Sulfonamides/pharmacology , Animals , Apoptosis/drug effects , Calcineurin Inhibitors , Drug Synergism , Hair Color/drug effects , Lymphocytes/drug effects , Lymphocytes/pathology , Melanocytes/drug effects , Mice , Piperazines/pharmacologyABSTRACT
OBJECTIVE: Propofol is not licensed for sedation in pediatric intensive care medicine mainly due to the risk of propofol infusion syndrome. Nevertheless, it is applied by many pediatric intensive care units. The aim of this national survey was to asses the current use of propofol in pediatric intensive care units in Germany. DESIGN: We performed a nationwide survey. The questionnaire assessed the intensive care unit type, patient numbers, dosing, duration, age and time limits, indications, side effects, and institutional protocols for propofol usage. SETTING: Pediatric intensive care units in Germany. SUBJECTS: Questionnaire about routine use of propofol sent to 214 pediatric departments. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: One hundred ninety-four questionnaires (90.7%) were returned, ten had to be censored. The final analysis comprised 184 questionnaires (134 pediatric/neonatal intensive care units, 28 pediatric intensive care units, 22 neonatal intensive care units). Seventy-nine percent of intensive care units (n = 145 of 184) used propofol in children under the age of 16 yrs. Of these, 98% were for bolus application (n = 142 of 145), 78% for infusion ≥3 hrs (n = 113 of 145), and 33% for infusion >3 hrs (n = 48 of 145). A lower age limit was applied by 52% (n = 75 of 145) and a dose limit by 51% (n = 74 of 145). The median dose limit was 4 mg/kg/hr; 48% (n = 70 of 145) used 3 mg/kg/hr or less. A time limit was applied by 98% (n = 46 of 47), 70% (n = 33 of 47) used it for ≤24 hrs, and 30% (n = 15 of 47) for >24 hrs. MAIN INDICATIONS FOR PROPOFOL APPLICATION WERE: difficult sedation (44%), postoperative ventilation (43%), and difficult extubation (30%). Seven cases of propofol infusion syndrome were reported by seven centers. CONCLUSIONS: This study shows that propofol is used off-license by many pediatric intensive care units in Ge. The majority of users has adopted tightly controlled regimens for propofol sedation, and limits the dose to ≤3-4 mg/kg/hr and the maximum application time to 24-48 hrs.
Subject(s)
Drug Utilization/statistics & numerical data , Hypnotics and Sedatives , Intensive Care Units, Pediatric/statistics & numerical data , Off-Label Use/statistics & numerical data , Propofol , Adolescent , Child , Child, Preschool , Germany , Health Care Surveys , Humans , Hypnotics and Sedatives/administration & dosage , Hypnotics and Sedatives/adverse effects , Infant , Infant, Newborn , Intensive Care Units, Neonatal/statistics & numerical data , Propofol/administration & dosage , Propofol/adverse effects , Surveys and QuestionnairesABSTRACT
Apoptosis controls the adaptive immune system through regulation of central and peripheral lymphocyte deletion. Therefore, substances that selectively interact with the intrinsic apoptosis pathway in lymphocytes offer unexplored opportunities to pharmacologically modulate the immune response. Here, we present evidence that the BH3-mimetic ABT-737 suppresses allogeneic immune responses. In vitro, ABT-737 prevented allogeneic T-cell activation, proliferation, and cytotoxicity by apoptosis induction, but without impairing the physiological functions of remaining viable T cells. In vivo, ABT-737 was highly selective for lymphoid cells and inhibited allogeneic T- and B-cell responses after skin transplantation. The immunosuppressive effect of ABT-737 was markedly increased in combination with low-dose cyclosporine A, as shown by the induction of long-term skin graft survival without significant inflammatory infiltrates in 50% of the recipients in an MHC class I single antigen mismatched model. Thus, pharmacological targeting of Bcl-2 proteins represents a novel immunosuppressive approach to prevent rejection of solid organ allografts.
Subject(s)
Apoptosis/drug effects , B-Lymphocytes/immunology , Biphenyl Compounds/pharmacology , Immunosuppressive Agents/pharmacology , Lymphocyte Activation/drug effects , Nitrophenols/pharmacology , Proto-Oncogene Proteins c-bcl-2/antagonists & inhibitors , Sulfonamides/pharmacology , T-Lymphocytes/immunology , Animals , B-Lymphocytes/drug effects , Cyclosporine/pharmacology , Graft Rejection/drug therapy , Graft Rejection/prevention & control , Lymphocyte Activation/immunology , Mice , Piperazines/pharmacology , Skin Transplantation/immunology , T-Lymphocytes/drug effectsABSTRACT
CXCR7 is an atypical receptor for the chemokines CXCL11 and CXCL12, which were found to be involved in animal models of allograft injury. We studied the expression of CXCR7 and its ligands in human kidneys by first quantifying the mRNA in 53 renal allograft biopsies. Receptor and ligand mRNAs were expressed in renal allografts, with a significant induction of CXCL11 and CXCL12 in biopsies showing borderline lesions and acute rejection. Immunohistochemical analysis for CXCR7 was performed in a series of 64 indication and 24 protocol biopsies. The indication biopsies included 46 acute rejections, 6 with interstitial fibrosis and tubular atrophy, and 12 pretransplant biopsies as controls. In control biopsies, CXCR7 protein was found on smooth muscle and on endothelial cells of a small number of peritubular vessels. The number of CXCR7-positive vessels was increased in acute rejection and, using double immunofluorescence labeling, a subset of these CXCR7-positive endothelial cells were identified as lymphatic vessels. Both CXCR7-positive blood and lymphatic vessels increased during allograft rejection. We found that CXCR7 is present in both blood and lymphatic endothelial cells in human renal allografts. Whether its presence modulates the formation of chemokine gradients and the recruitment of inflammatory cells will require further experimental studies.