Interleukin-1beta and tumor necrosis factor-alpha are expressed by different subsets of microglia and macrophages after ischemic stroke in mice

<p>Abstract</p> <p>Background</p> <p>Interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) are expressed by microglia and infiltrating macrophages following ischemic stroke. Whereas IL-1β is primarily neurotoxic in ischemic stroke, TNF-α may have neurotoxic and/or neuroprotective effects. We investigated whether IL-1β and TNF-α are synthesized by overlapping or segregated populations of cells after ischemic stroke in mice.</p> <p>Methods</p> <p>We used flow cytometry and immunohistochemistry to examine cellular co-expression of IL-1β and TNF-α at 6, 12 and 24 hours after permanent middle cerebral artery occlusion in mice, validating the results by the use of bone marrow chimeric mice.</p> <p>Results</p> <p>We found that IL-1β and TNF-α were expressed in largely segregated populations of CD11b⁺CD45^dimmicroglia and CD11b⁺CD45^highmacrophages, with cells expressing both cytokines only rarely. The number of Gr1⁺granulocytes producing IL-1β or TNF-α was very low, and we observed no IL-1β- or TNF-α-expressing T cells or astrocytes.</p> <p>Conclusion</p> <p>Taken together, the results show that IL-1β and TNF-α are produced by largely segregated populations of microglia and macrophages after ischemic stroke in mice. Our findings provide evidence of a functional diversity among different subsets of microglia and macrophages that is potentially relevant to future design of anti-inflammatory therapies in stroke.</p

Spontaneous ischaemic stroke lesions in a dog brain: neuropathological characterisation and comparison to human ischaemic stroke

Abstract Background Dogs develop spontaneous ischaemic stroke with a clinical picture closely resembling human ischaemic stroke patients. Animal stroke models have been developed, but it has proved difficult to translate results obtained from such models into successful therapeutic strategies in human stroke patients. In order to face this apparent translational gap within stroke research, dogs with ischaemic stroke constitute an opportunity to study the neuropathology of ischaemic stroke in an animal species. Case presentation A 7\ua0years and 8\ua0months old female neutered Rottweiler dog suffered a middle cerebral artery infarct and was euthanized 3\ua0days after onset of neurological signs. The brain was subjected to histopathology and immunohistochemistry. Neuropathological changes were characterised by a pan-necrotic infarct surrounded by peri-infarct injured neurons and reactive microglia/macrophages and astrocytes. Conclusions The neuropathological changes reported in the present study were similar to findings in human patients with ischaemic stroke. The dog with spontaneous ischaemic stroke is of interest as a complementary spontaneous animal model for further neuropathological studies

No effect of ablation of surfactant protein-D on acute cerebral infarction in mice

BACKGROUND: Crosstalk between the immune system in the brain and the periphery may contribute to the long-term outcome both in experimental and clinical stroke. Although, the immune defense collectin surfactant protein-D (SP-D) is best known for its role in pulmonary innate immunity, SP-D is also known to be involved in extrapulmonary modulation of inflammation in mice. We investigated whether SP-D affected cerebral ischemic infarction and ischemia-induced inflammatory responses in mice. METHODS: The effect of SP-D was studied by comparing the size of ischemic infarction and the inflammatory and astroglial responses in SP-D knock out (KO) and wild type (WT) mice subjected to permanent middle cerebral artery occlusion. SP-D mRNA production was assessed in isolated cerebral arteries and in the whole brain by PCR, and SP-D protein in normal appearing and ischemic human brain by immunohistochemistry. Changes in plasma SP-D and TNF were assessed by ELISA and proximity ligation assay, respectively. RESULTS: Infarct volumetric analysis showed that ablation of SP-D had no effect on ischemic infarction one and five days after induction of ischemia. Further, ablation of SP-D had no effect on the ischemia-induced increase in TNF mRNA production one day after induction of ischemia; however the TNF response to the ischemic insult was affected at five days. SP-D mRNA was not detected in parenchymal brain cells in either naïve mice or in mice subjected to focal cerebral ischemia. However, SP-D mRNA was detected in middle cerebral artery cells in WT mice and SP-D protein in vascular cells both in normal appearing and ischemic human brain tissue. Measurements of the levels of SP-D and TNF in plasma in mice suggested that levels were unaffected by the ischemic insult. Microglial-leukocyte and astroglial responses were comparable in SP-D KO and WT mice. CONCLUSIONS: SP-D synthesis in middle cerebral artery cells is consistent with SP-D conceivably leaking into the infarcted area and affecting local cytokine production. However, there was no SP-D synthesis in parenchymal brain cells and ablation of SP-D had no effect on ischemic cerebral infarction

Efeito de um imunomodulador na qualidade do colostro e na incidência de doenças no pós-parto de vacas leiteiras

Dissertação de Mestrado Integrado em Medicina VeterináriaEste estudo analisou a eficácia do pegbovigrastim (ImrestorTM) na incidência de doenças no pós-parto de vacas leiteiras e o seu efeito na qualidade do colostro. Às vacas do grupo experimental foi administrado pegbovigrastim e às vacas do grupo controlo soro fisiológico. Não se observaram diferenças significativas no número de neutrófilos e macrófagos nos esfregaços de colostro. Contudo, os seus valores máximos foram superiores no colostro de vacas do grupo ImrestorTM. Verificou-se que no colostro não centrifugado das vacas tratadas com ImrestorTM o número de linfócitos foi tendencialmente superior (p=0,08). O colostro de vacas que receberam as duas doses de ImrestorTM teve uma média de 300 mil células/ml superior ao colostro do grupo controlo. A incidência de mastites, metrites e RP foi inferior no grupo experimental, comparativamente ao grupo controlo, contudo esta redução não foi estatisticamente significativa. O valor Brix foi semelhante entre os dois grupos em estudo. Não se observaram diferenças significativas entre os dois grupos na produção leiteira acumulada no primeiro mês após o parto. A percentagem de vacas com hipercetonémia foi 5,3% no grupo experimental e 8,2% no grupo controlo. É de todo o interesse que futuramente se desenvolvam mais estudos de modo a obter conclusões mais consolidadas.ABSTRACT - EFFECT OF AN IMMUNOMODULATOR IN THE QUALITY OF COLOSTRUM AND THE INCIDENCE OF DISEASES IN THE POSTPARTUM OF DAIRY COWS - This study examined the efficacy of pegbovigrastim (ImrestorTM) on the incidence of postpartum diseases in dairy cows and its effect on the quality of colostrum. Cows in the experimental group received pegbovigrastim and cows in the control group saline solution. No significant differences were observed in the number of neutrophils and macrophages in the colostrum. However, its maximum values were higher in colostrum of the ImrestorTM group. It was found that in the non-centrifuged colostrum of cows treated with ImrestorTM the number of lymphocytes was tendentially higher (p=0,08). The colostrum of cows that received the two doses of ImrestorTM was an average of 300,000 cells/ml higher than colostrum in the control group. The incidence of mastitis, metritis and RP was lower in the experimental group, compared to the control group, but this reduction was not statistically significant. The Brix value was similar between the two groups under study. There were no significant differences between the two groups in milk production accumulated in the first month after calving. The percentage of cows with hyperketonemia was 5.3% in the experimental group and 8.2% in the control group. It is of great interest that more studies are carried out in the future in order to obtain more consolidated conclusions.Fonte de Leite Exploração Agrícola e Pecuária, S.A.N/

Lack of Chemokine Signaling through CXCR5 Causes Increased Mortality, Ventricular Dilatation and Deranged Matrix during Cardiac Pressure Overload

RATIONALE: Inflammatory mechanisms have been suggested to play a role in the development of heart failure (HF), but a role for chemokines is largely unknown. Based on their role in inflammation and matrix remodeling in other tissues, we hypothesized that CXCL13 and CXCR5 could be involved in cardiac remodeling during HF. OBJECTIVE: We sought to analyze the role of the chemokine CXCL13 and its receptor CXCR5 in cardiac pathophysiology leading to HF. METHODS AND RESULTS: Mice harboring a systemic knockout of the CXCR5 (CXCR5(-/-)) displayed increased mortality during a follow-up of 80 days after aortic banding (AB). Following three weeks of AB, CXCR5(-/-) developed significant left ventricular (LV) dilatation compared to wild type (WT) mice. Microarray analysis revealed altered expression of several small leucine-rich proteoglycans (SLRPs) that bind to collagen and modulate fibril assembly. Protein levels of fibromodulin, decorin and lumican (all SLRPs) were significantly reduced in AB CXCR5(-/-) compared to AB WT mice. Electron microscopy revealed loosely packed extracellular matrix with individual collagen fibers and small networks of proteoglycans in AB CXCR5(-/-) mice. Addition of CXCL13 to cultured cardiac fibroblasts enhanced the expression of SLRPs. In patients with HF, we observed increased myocardial levels of CXCR5 and SLRPs, which was reversed following LV assist device treatment. CONCLUSIONS: Lack of CXCR5 leads to LV dilatation and increased mortality during pressure overload, possibly via lack of an increase in SLRPs. This study demonstrates a critical role of the chemokine CXCL13 and CXCR5 in survival and maintaining of cardiac structure upon pressure overload, by regulating proteoglycans essential for correct collagen assembly