Orchestration of metabolism by macrophages

Metabolic adaptation is a key component of macrophage plasticity and polarization, instrumental to their function in homeostasis, immunity, and inflammation. Macrophage products also impact metabolism, as illustrated by obesity-associated pathologies. Defining the mechanisms regulating macrophage metabolic activity and orchestration of metabolism by macrophages is crucial to pathology and therapeutic intervention.     

Genetic analysis of 50-year old Brazilian pine (Araucaria angustifolia) plantations: implications for conservation planning

In order to determine the implications of including planted populations in conservation planning, we investigate the structure and genetic diversity, mating system, and effective population size within families in three planted and one natural Araucaria angustifolia populations. The study area is a Brazilian National Forest in southern Brazil, established in the 1950s. Genetic analysis was investigated using nine allozyme loci. Significant and positive fixation index was detected for the adults of all studied populations. Although we observed lower levels of genetic diversity and biparental inbreeding in some populations, their pattern of mating, similar to that expected in panmixia, indicates that all populations can be used in conservation planning. Furthermore, the presence of unique alleles and the significant genetic differentiation among all adult populations (F _ST = 0.404) reinforces that all populations are important conservation resources. The average paternity correlation was high in almost all populations, showing that open-pollinated families are composed of mixtures of half- and full-sibs. With regards to conservation strategies, our results suggest that seed collection from at least 133 seed trees is necessary to retain a reference effective population size of 500. Our results confirm that the planted Araucaria forests in southern Brazil can be useful as a genetic resource for conservation, breeding and reforestation strategies for this threatened species.     

Proposed local diagnostic reference levels in angiography and interventional neuroradiology and a preliminary analysis according to the complexity of the procedures

The aim of this study was to propose local diagnostic reference levels (DRL) for exposure to radiation during diagnostic procedures and neuroradiological interventions such as cerebral angiography and embolisation of cerebral aneurysms (intra-cranial aneurysms and arteriovenous malformations). Hospitals should adopt the national DRLs for use locally or establish their own DRLs based on local practice, if sufficient local data are available.For this purpose we studied a sample of 113 cerebral angiography procedures and 82 embolisations of cerebral aneurysms. The data recorded included the kerma-area product (KAP), the fluoroscopy time and the number of frames for each procedure: third quartiles from the total dosimetric databank were calculated and proposed as provisional local DRL. Since the complexity of a procedure must be taken into account when evaluating the radiation dose, in the case of embolisation of aneurysms (intra-cranial), in this initial phase we assessed whether the complexity of the embolisation procedure is related to the size of the aneurysm and/or its site. We, therefore, re-calculated the DRL for only intra-cranial aneurysms, leaving aside the arteriovenous malformations. Considering that the DRL calculated for all the therapeutic procedures are similar to those calculated considering only intra-cranial aneurysms, at the moment we propose, besides the DRL for cerebral angiography, a single DRL for all interventional procedures, even when the clinical pictures are very different. Local preliminary DRLs were proposed as follows: 180 Gy cm², 12 min and 317 frames for cerebral angiography and 487 Gy cm², 46 min and 717 frames for interventional procedures (intra-cranial aneurysms and arteriovenous malformations).     

Cryopreservation at −20 and −70 °C of Pleurotus ostreatus on Grains

Alternative substrates for cryopreservation at −20 °C have been little explored for basidiomycetes and could bring new possibilities of lower cost cryopreservation. Nevertheless, freezing temperatures between −15 and −60 °C are very challenging because they frequently result in cryoinjuries. The objective of this study was to evaluate substrates associated to cryoprotective agents for Pleurotus ostreatus cryopreservation at −20 or −70 °C in order to develop alternative techniques for basidiomycete cryopreservation. P. ostreatus was grown on potato dextrose agar or whole grains of oat, wheat, rice or millet and transferred to cryovials with cryoprotective solution with 1 % dimethyl sulfoxide, 5 % glycerol, 10 % saccharose, 4 % glucose, 6 % polyethylene glycol-6000 or 5 % malt extract. The mycelium in the cryovials were cryopreserved at −20 or −70 °C and recovered for evaluation of the mycelial growth viability after 1 and 3 years. Both substrates and cryoprotectants affect the viability of the mycelial growth cryopreserved at −20 or −70 °C; wheat grains combined with cryoprotectants such as saccharose or glucose are effective for keeping mycelium viable after cryopreservation at −20 °C for 1 or 3 years; for cryopreservation at −70 °C after 1 or 3 years, any substrate combined with any cryoprotectant is effective for preserving the mycelium viable, except for millet grains with polyethylene glycol after 3 years; semi-permeable cryoprotective agents such as saccharose and glucose are the most effective for cryopreservation at −20 or −70 °C for at least 3 years.     

Insulin-like growth factor binding protein-2 and neurotrophin 3 synergize together to promote the expansion of hematopoietic cells ex vivo

Co-culture of Umbilical Cord Blood (UCB) CD34+ cells with irradiated Mesenchymal Stem Cells (MSCs) without contact increase the expansion of Hematopoietic Progenitor Cells (HPC). Neurotrophin-3 (NT-3) and insulin-like growth factor binding protein-2 (IGFBP-2) are two factors whose expressions were significantly elevated in conditioned media derived from irradiated MSCs. To determine whether these factors are partly responsible for the growth promoting potential of MSCs, we investigated their impact on the growth and differentiation of UCB-CD34+ cells. Addition of either factor alone had little impact on cell growth, however both factors synergized together to increase the expansion of total nucleated cells, erythroids, megakaryocytes (Mk) and CD34+ cells. However, in contrast to MSCs they failed to significantly improve the expansion of hematopoietic progenitors. Consistent with the impact of these factors on hematopoietic cells, both synergized to activate ERK1/2 and AKT in primary human UCB cells. In conclusion, the study demonstrates for the first time that a neurotrophin factor can synergize with IGFBP-2 to promote hematopoietic cell expansion.     

Different expression of protein kinase A (PKA) regulatory subunits in cortisol-secreting adrenocortical tumors: relationship with cell proliferation

The four regulatory subunits (R1A, R1B, R2A, R2B) of protein kinase A (PKA) are differentially expressed in several cancer cell lines and exert distinct roles in growth control. Mutations of the R1A gene have been found in patients with Carney complex and in a minority of sporadic primary pigmented nodular adrenocortical disease (PPNAD). The aim of this study was to evaluate the expression of PKA regulatory subunits in non-PPNAD adrenocortical tumors causing ACTH-independent Cushing's syndrome and to test the impact of differential expression of these subunits on cell growth. Immunohistochemistry demonstrated a defective expression of R2B in all cortisol-secreting adenomas (n=16) compared with the normal counterpart, while both R1A and R2A were expressed at high levels in the same tissues. Conversely, carcinomas (n=5) showed high levels of all subunits. Sequencing of R1A and R2B genes revealed a wild type sequence in all tissues. The effect of R1/R2 ratio on proliferation was assessed in mouse adrenocortical Y-1 cells. The R2-selective cAMP analogue 8-Cl-cAMP dose-dependently inhibited Y-1 cell proliferation and induced apoptosis, while the R1-selective cAMP analogue 8-HA-cAMP stimulated cell proliferation. Finally, R2B gene silencing induced up-regulation of R1A protein, associated with an increase in cell proliferation. In conclusion, we propose that a high R1/R2 ratio favors the proliferation of well differentiated and hormone producing adrenocortical cells, while unbalanced expression of these subunits is not required for malignant transformation.     

Lack of Toll IL-1R8 exacerbates Th17 cell responses in fungal infection

TLRs contribute to the inflammatory response in fungal infections. Although inflammation is an essential component of the protective response to fungi, its dysregulation may significantly worsen fungal diseases. In this study, we tested the hypothesis that Toll IL-1R8 (TIR8)/single Ig IL-1-related receptor, a member of the IL-1R family acting as a negative regulator of TLR/IL-1R signaling, affects TLR responses in fungal infections. Genetically engineered Tir8(-/-) mice were assessed for inflammatory and adaptive Th cell responses to Candida albicans and Aspergillus fumigatus. Inflammatory pathology and susceptibility to infection were higher in Tir8(-/-) mice and were causally linked to the activation of the Th17 pathway. IL-1R signaling was involved in Th17 cell activation by IL-6 and TGF-beta in that limited inflammatory pathology and relative absence of Th17 cell activation were observed in IL-1RI(-/-) mice. These data demonstrate that TIR8 is required for host resistance to fungal infections and that it functions to negatively regulate IL-1-dependent activation of inflammatory Th17 responses. TIR8 may contribute toward fine-tuning the balance between protective immunity and immunopathology in infection.