Agroecology has been criticized for being more labor-intensive than other more industrialized forms of agriculture. We challenge the assertion that labor input in agriculture has to be generally ...minimized and argue that besides quantity of work one should also consider the quality of work involved in farming. Early assessments on work quality condemned the deskilling of the rural workforce, whereas later criticisms have concentrated around issues related to fair trade and food sovereignty. We bring into the discussion the concept of contributive justice to welcome the added labor-intensity of agroecological farming. Contributive justice demands a work environment where people are stimulated to develop skills and learn to be productive. It also suggests a fairer distribution of meaningful work and tedious tasks. Building on the notion of contributive justice we explore which capabilities and types of social relationships are sustainably promoted and reinforced by agroecological farming practices. We argue that agroecological principles encourage a reconceptualization of farm work. Farmers are continuously stimulated to develop skills and acquire valuable experiential knowledge on local ecosystems and agricultural techniques. Further, generalized ecological studies recognize the significance of the farmer’s observations on natural resources management. This contributes to the development of a number of capabilities and leads to more bargaining power, facilitating self-determination. Hereby farm work is made more attractive to a younger generation, which is an essential factor for safeguarding the continuity of family farms.
Long-term potentiation (LTP) of excitatory synaptic transmission has long been considered a cellular correlate for learning and memory. Early LTP (less than 1 h) had initially been explained either ...by presynaptic increases in glutamate release or by direct modification of postsynaptic AMPA (α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid) receptor function. Compelling models have more recently proposed that synaptic potentiation can occur by the recruitment of additional postsynaptic AMPA receptors (AMPARs), sourced either from an intracellular reserve pool by exocytosis or from nearby extra-synaptic receptors pre-existing on the neuronal surface. However, the exact mechanism through which synapses can rapidly recruit new AMPARs during early LTP remains unknown. In particular, direct evidence for a pivotal role of AMPAR surface diffusion as a trafficking mechanism in synaptic plasticity is still lacking. Here, using AMPAR immobilization approaches, we show that interfering with AMPAR surface diffusion markedly impairs synaptic potentiation of Schaffer collaterals and commissural inputs to the CA1 area of the mouse hippocampus in cultured slices, acute slices and in vivo. Our data also identify distinct contributions of various AMPAR trafficking routes to the temporal profile of synaptic potentiation. In addition, AMPAR immobilization in vivo in the dorsal hippocampus inhibited fear conditioning, indicating that AMPAR diffusion is important for the early phase of contextual learning. Therefore, our results provide a direct demonstration that the recruitment of new receptors to synapses by surface diffusion is a critical mechanism for the expression of LTP and hippocampal learning. Since AMPAR surface diffusion is dictated by weak Brownian forces that are readily perturbed by protein-protein interactions, we anticipate that this fundamental trafficking mechanism will be a key target for modulating synaptic potentiation and learning.
Bone remodeling is a tightly controlled mechanism in which osteoblasts (OB), the cells responsible for bone formation, osteoclasts (OC), the cells specialized for bone resorption, and osteocytes, the ...multifunctional mechanosensing cells embedded in the bone matrix, are the main actors. Increased oxidative stress in OB, the cells producing and mineralizing bone matrix, has been associated with osteoporosis development but the role of autophagy in OB has not yet been addressed. This is the goal of the present study. We first show that the autophagic process is induced in OB during mineralization. Then, using knockdown of autophagy-essential genes and OB-specific autophagy-deficient mice, we demonstrate that autophagy deficiency reduces mineralization capacity. Moreover, our data suggest that autophagic vacuoles could be used as vehicles in OB to secrete apatite crystals. In addition, autophagy-deficient OB exhibit increased oxidative stress and secretion of the receptor activator of NFKB1 (TNFSF11/RANKL), favoring generation of OC, the cells specialized in bone resorption. In vivo, we observed a 50% reduction in trabecular bone mass in OB-specific autophagy-deficient mice. Taken together, our results show for the first time that autophagy in OB is involved both in the mineralization process and in bone homeostasis. These findings are of importance for mineralized tissues which extend from corals to vertebrates and uncover new therapeutic targets for calcified tissue-related metabolic pathologies.
Autophagy is the major catabolic process in eukaryotic cells for the degradation and recycling of damaged macromolecules and organelles. It plays a crucial role in cell quality control and nutrient ...supply under stress conditions. Although autophagy is classically described as a degradative mechanism, it can also be involved in some secretion pathways, leading to the extracellular release of proteins, aggregates, or organelles.
The role of autophagy in cancer is complex and depends on tumor development stage. While autophagy limits cancer development in the early stages of tumorigenesis, it can also have a protumoral role in more advanced cancers, promoting primary tumor growth and metastatic spread. In addition to its pro-survival role in established tumors, autophagy recently emerged as an active player in the crosstalk between tumor and stromal cells. The aim of this review is to analyze the impact of tumoral autophagy on the microenvironment and conversely the effect of stromal cell autophagy on tumor cells.
•Autophagy is an intracellular degradative process which can be involved in some secretion processes.•Tumor autophagy affects microenvironment resulting in reduced immune cell recruitement and interaction.•Stromal autophagy supports tumor development by providing protumoral factors and promoting immunosuppression.•Autophagy emerges as an active player in the crosstalk between tumor and stromal cells.
Autophagy in bone: Self-eating to stay in balance Pierrefite-Carle, Valérie; Santucci-Darmanin, Sabine; Breuil, Véronique ...
Ageing research reviews,
11/2015, Letnik:
24, Številka:
Pt B
Journal Article
Recenzirano
Highlights • Impaired autophagy in osteoblasts leads to low bone mass phenotype. • Suppression of autophagy in osteocytes mimics skeletal aging. • Autophagy proteins are required for osteoclast bone ...resorption. • Autophagy was reported to undergo age-related decline in various tissues.
Lysosomes are single membrane bounded group of acidic organelles that can be involved in a process called lysosomal exocytosis which leads to the extracellular release of their content. Lysosomal ...exocytosis is required for plasma membrane repair or remodeling events such as bone resorption, antigen presentation or mitosis, and for protection against toxic agents such as heavy metals. Recently, it has been showed that to fulfill this protective role, lysosomal exocytosis needs some autophagic proteins, in an autophagy-independent manner. In addition to these crucial physiological roles, lysosomal exocytosis plays a major protumoral role in various cancers. This effect is exerted through tumor microenvironment modifications, including extracellular matrix remodeling, acidosis, oncogenic and profibrogenic signals. This review provides a comprehensive overview of the different elements released in the microenvironment during lysosomal exocytosis, i.e. proteases, exosomes, and protons, and their effects in the context of tumor development and treatment.
•Lysosomal exocytosis plays crucial roles in different physiological processes.•Lysosomal exocytosis and autophagy proteins cooperate for cell protection.•Lysosomal exocytosis promotes tumor progression through various mechanisms.•Cancer treatment resistance involves increased lysosomal exocytosis.
Agriculture in Europe results in the production of food for both the European population and for the export sector. Significant environmental and social problems have emerged with the intensification ...of European agriculture. These include the loss of biodiversity, the contamination of soils, water, and food with pesticides, and the eutrophication of water bodies. Industrialized agricultural and food systems are also a major contributing factor in the decline of farm numbers, and the high use of antibiotics has led to serious human health problems. In this respect, agroecology can provide insights into important pathways and guide the design, development, and promotion of the transition towards sustainable farming and food systems. An analysis of the major challenges for the amplification of agroecology in Europe was carried out by 310 stakeholders in a World Café exercise and 23 sessions and workshops during the Agroecology Europe Forum 2017. The different challenges that were identified can be grouped into seven categories: (1) definition and concepts; (2) education, training, and knowledge sharing; (3) research approach and funding; (4) policies; (5) productivity and practices; (5) food systems and consumer awareness; and (6) co-optation. To address these challenges, the following key actions are recommended: (1) to develop a common understanding of agroecology; (2) to enhance education in agroecology and knowledge exchange; (3) to invest in agroecological research; (4) to develop policies enhancing agroecology; (5) to support new and existing agroecological practices; (6) to transform food systems; and (7) to strengthen communication and alliances. In this paper we present and discuss these recommendations for pathways and actions to develop sustainable agro-food systems in Europe through agroecology.
Role of autophagy in osteosarcoma Camuzard, Olivier; Santucci-Darmanin, Sabine; Carle, Georges F. ...
Journal of bone oncology,
06/2019, Letnik:
16
Journal Article
Recenzirano
Odprti dostop
Osteosarcoma (OS) is the most common primary bone tumour in children and adolescents. It is a highly aggressive tumor with a tendency to spread to the lungs, which are the most common site of ...metastasis. Advanced osteosarcoma patients with metastasis share a poor prognosis. Despite the use of chemotherapy to treat OS, the 5-year overall survival rate for patients has remained unchanged at 65–70% for the past 20 years. In addition, the 5-year survival of patients with a metastatic disease is around 20%, highlighting the need for novel therapeutic targets.
Autophagy is an intracellular degradation process which eliminates and recycles damaged proteins and organelles to improve cell lifespan. In the context of cancer, numerous studies have demonstrated that autophagy is used by tumor cells to repress initial steps of carcinogenesis and/or support the survival and growth of established tumors. In osteosarcoma, autophagy appears to be deregulated and could also act both as a pro or anti-tumoral process. In this manuscript, we aim to review these major findings regarding the role of autophagy in osteosarcoma.
Autophagy and bone diseases Trojani, Marie-Charlotte; Santucci-Darmanin, Sabine; Breuil, Véronique ...
Joint, bone, spine : revue du rhumatisme,
20/May , Letnik:
89, Številka:
3
Journal Article
Recenzirano
Odprti dostop
Display omitted
•Autophagy is a mechanism of elimination and recycling of cellular components allowing quality control in the cell.•Autophagy can be increased under stress for survival ...purposes.•Autophagy is an essential process for bone cell differentiation and function.•A defective autophagy in bone cells is involved in the development of pathologies such as osteoporosis, osteopetrosis, or Paget's disease of bone.•Autophagy modulation appears as a promising avenue for the development of new therapeutic strategies in bone pathologies.
Autophagy is a ubiquitous cellular process, allowing the removal and recycling of damaged proteins and organelles. At the basal level, this process plays a role in quality control, thus participating in cellular homeostasis. Autophagy can also be induced by various stresses, such as nutrient deprivation or hypoxia, to allow the cell to survive until conditions improve. In recent years, the role of this process has been widely studied in many pathologies such as neurodegenerative diseases or cancers. In bone tissue, various studies have shown that autophagy is involved in the survival, differentiation and activity of osteoblasts, osteocytes and osteoclasts. The evolution of this knowledge has led to the identification of new molecular pathophysiological mechanisms in bone pathologies. This review reports the current state of knowledge on the role of autophagy in 4 bone diseases: osteoporosis, which seems to be associated with a decrease in autophagy, osteopetrosis and Paget's disease where the course of the autophagic process is disturbed, and finally osteosarcoma where autophagy seems to play a protumoral role. A better understanding of the involvement of autophagy in these pathologies should eventually lead to the identification of new potential therapeutic targets.
In most experimental protocols, false starts are produced on dry bones obtained through a maceration process for anthropological analyses, for the sake of reproducibility. Although this allows for ...controlled experimental conditions, the absence of soft parts when experimentally creating false starts does not correspond to the real conditions of criminal dismemberment. The main objective of this study was to determine if the results of experimental work on the characteristics of false starts were valid under medico-legal conditions. In this experimental study, a hand saw (rip saw, wavy set, TPI 32) was used. 240 false starts were produced on human and pig bones. Randomly, the false starts were either produced on a dry bone or on a flesh bone. The criteria for microscopic analysis included the shape of the walls, the shape and visibility of striae on the floor, the shape of the profile, and the minimum width of the false start. On human bone, 100% of the false starts produced on a bone that had previously undergone a maceration process for anthropological analyses (dry bone) allowed the definition of all the blade characteristics. This was the case for 78.3% on bone in the presence of soft tissue (flesh bone). The striae on the floor of the false start are in some cases less visible with flesh bones, implying that it may be more difficult to conclude on the characteristics of a saw under medico-legal conditions.
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