Problematic rise of vitamin B6 supplementation overuse and potential risk to bariatric surgery patients.

OBJECTIVES: Due to the increased prevalence of obesity in the world, bariatric surgeries are on the rise and necessitate life-long surveillance for deficiencies; hence the recommended vitamin supplementation in these patients. However, inadequate multivitamin supplementation may induce vitamin B6 overload. METHODS: We reviewed all vitamin B6 dosages at the university hospitals of Poitiers, Tours, Bordeaux, and Limoges for the past 5 to 8 years. Analyses were performed by high-performance liquid chromatography, coupled with a fluorescence detector on whole blood samples. RESULTS: During the study period, there was an increase in the number of vitamin B6 dosages. Deficiencies were detected early in Poitiers and Limoges, but were negligible by 2020. However, during the same time period, the number of overdoses increased, reaching close to 40% of dosages at all centers. CONCLUSIONS: Pyridoxin overload is not possible through food-derived pyridoxin; hence, combined with the fact that most vitamin supplements contain vitamin B6, inadequate vitamin supplementation is likely the cause of the observed increase in overdoses. High doses of vitamin B6 can induce polyneuropathy, particularly targeting motor neurons; thus, the increase of overdoses is worrying. In light of the possible risks and the ease with which these could be averted (better formulation of supplements), the precaution principle requires a definition of clear guidelines for vitamin supplementation, especially in patients undergoing bariatric surgery.

Rho GTPases in kidney physiology and diseases.

Rho family GTPases are molecular switches best known for their pivotal role in dynamic regulation of the actin cytoskeleton, but also of cellular morphology, motility, adhesion and proliferation. The prototypic members of this family (RhoA, Rac1 and Cdc42) also contribute to the normal kidney function and play important roles in the structure and function of various kidney cells including tubular epithelial cells, mesangial cells and podocytes. The kidney's vital filtration function depends on the structural integrity of the glomerulus, the proximal portion of the nephron. Within the glomerulus, the architecturally actin-based cytoskeleton podocyte forms the final cellular barrier to filtration. The glomerulus appears as a highly dynamic signalling hub that is capable of integrating intracellular cues from its individual structural components. Dynamic regulation of the podocyte cytoskeleton is required for efficient barrier function of the kidney. As master regulators of actin cytoskeletal dynamics, Rho GTPases are therefore of critical importance for sustained kidney barrier function. Dysregulated activities of the Rho GTPases and of their effectors are implicated in the pathogenesis of both hereditary and idiopathic forms of kidney diseases. Diabetic nephropathy is a progressive kidney disease that is caused by injury to kidney glomeruli. High glucose activates RhoA/Rho-kinase in mesangial cells, leading to excessive extracellular matrix production (glomerulosclerosis). This RhoA/Rho-kinase pathway also seems involved in the post-transplant hypertension frequently observed during treatment with calcineurin inhibitors, whereas Rac1 activation was observed in post-transplant ischaemic acute kidney injury.

Myelinosome Organelles in the Retina of R6/1 Huntington Disease (HD) Mice: Ubiquitous Distribution and Possible Role in Disease Spreading.

Visual deficit is one of the complications of Huntington disease (HD), a fatal neurological disorder caused by CAG trinucleotide expansions in the Huntingtin gene, leading to the production of mutant Huntingtin (mHTT) protein. Transgenic HD R6/1 mice expressing human HTT exon1 with 115 CAG repeats recapitulate major features of the human pathology and exhibit a degeneration of the retina. Our aim was to gain insight into the ultrastructure of the pathological HD R6/1 retina by electron microscopy (EM). We show that the HD R6/1 retina is enriched with unusual organelles myelinosomes, produced by retinal neurons and glia. Myelinosomes are present in all nuclear and plexiform layers, in the synaptic terminals of photoreceptors, in the processes of retinal neurons and glial cells, and in the subretinal space. In vitro study shows that myelinosomes secreted by human retinal glial Müller MIO-M1 cells transfected with EGFP-mHTT-exon1 carry EGFP-mHTT-exon1 protein, as revealed by immuno-EM and Western-blotting. Myelinosomes loaded with mHTT-exon1 are incorporated by naive neuronal/neuroblastoma SH-SY5Y cells. This results in the emergence of mHTT-exon1 in recipient cells. This process is blocked by membrane fusion inhibitor MDL 28170. Conclusion: Incorporation of myelinosomes carrying mHTT-exon1 in recipient cells may contribute to HD spreading in the retina. Exploring ocular fluids for myelinosome presence could bring an additional biomarker for HD diagnostics.

MERTK-Mediated LC3-Associated Phagocytosis (LAP) of Apoptotic Substrates in Blood-Separated Tissues: Retina, Testis, Ovarian Follicles.

Timely and efficient elimination of apoptotic substrates, continuously produced during one's lifespan, is a vital need for all tissues of the body. This task is achieved by cells endowed with phagocytic activity. In blood-separated tissues such as the retina, the testis and the ovaries, the resident cells of epithelial origin as retinal pigmented epithelial cells (RPE), testis Sertoli cells and ovarian granulosa cells (GC) provide phagocytic cleaning of apoptotic cells and cell membranes. Disruption of this process leads to functional ablation as blindness in the retina and compromised fertility in males and females. To ensure the efficient elimination of apoptotic substrates, RPE, Sertoli cells and GC combine various mechanisms allowing maintenance of tissue homeostasis and avoiding acute inflammation, tissue disorganization and functional ablation. In tight cooperation with other phagocytosis receptors, MERTK-a member of the TAM family of receptor tyrosine kinases (RTK)-plays a pivotal role in apoptotic substrate cleaning from the retina, the testis and the ovaries through unconventional autophagy-assisted phagocytosis process LAP (LC3-associated phagocytosis). In this review, we focus on the interplay between TAM RTKs, autophagy-related proteins, LAP, and Toll-like receptors (TLR), as well as the regulatory mechanisms allowing these components to sustain tissue homeostasis and prevent functional ablation of the retina, the testis and the ovaries.

High Throughput Proteomic Exploration of Hypothermic Preservation Reveals Active Processes within the Cell Associated with Cold Ischemia Kinetic.

The demand for organs to be transplanted increases pressure on procurement centers, to the detriment of organ quality, increasing complications. New preservation protocols are urgently needed, requiring an in-depth understanding of ischemia-reperfusion mechanisms. We performed a proteomic analysis using LC-MS/MS-TOF data analyzed through R software and Cytoscape's ClueGO application, comparing the proteome of kidney endothelial cells, key cell type, subjected to 3, 6, 12, 19, and 24 h of cold ischemia and 6 h reperfusion. Critical pathways such as energy metabolism, cytoskeleton structure/transport system, and gene transcription/translation were modulated. Important time windows were revealed: a-during the first 3 h, central proteins were upregulated within these pathways; b-the majority of these upregulations were maintained until 12 h cold ischemia time (CIT); c-after that time, the overall decrease in protein expression was observed; d-at reperfusion, proteins expressed in response to cold ischemia were all downregulated. This shows that cold ischemia is not a simple slowing down of metabolism, as deep changes take place within the proteome on major pathways. Time-sensitive expression of key protein reveals possible quality biomarkers as well as potential targets for new strategies to maintain or optimize organ quality.

[Myelinosomes: A new pathway of protein quality control]. / Les myélinosomes : une nouvelle voie du contrôle de qualité des protéines.

Maintenance of cell proteostasis relies on two degradation pathways: proteasome and autophagy. Here we describe a new proteostasis pathway avoiding degradation of abnormal proteins yet carrying them outside the cell using nanovesicles called myelinosomes. These myelinosomes are produced in pathological or stress situations in relation with genetic or environmental factors. Myelinosome vesicles are nano-sized multi-stacked membrane structures, resembling myelin sheath. It has recently been shown in two models of genetic diseases (Huntington's disease and cystic fibrosis) that myelinosomes are important for eliminating mutant proteins in an unusual secretory process, thus preventing their accumulation and aggregation in cells.

Title: Les myélinosomes : une nouvelle voie du contrôle de qualité des protéines. Abstract: Deux voies de dégradation des protéines mal repliées sont classiquement décrites : la voie du protéasome et la voie de l'autophagie. Nous décrivons ici une nouvelle voie de protéostase cellulaire ne dégradant pas la protéine anormale mais l'expulsant hors de la cellule grâce à des nanovésicules appelées myélinosomes. Ces myélinosomes sont produits par la cellule dans des situations pathologiques ou de stress en lien avec des facteurs génétiques ou environnementaux. Sur le plan morphologique, les myélinosomes sont caractérisés par des membranes osmiophiles denses aux électrons dont l'arrangement empilé est semblable à celui de la myéline et présente jusqu'à 30 feuillets selon le type de cellule. Dans deux modèles, au moins, de maladies génétiques (la maladie de Huntington et la mucoviscidose), les myélinosomes sont importants pour éliminer les protéines mutées par un processus sécrétoire inhabituel, évitant ainsi leur agrégation dans les cellules.

Cx43 Present at the Leading Edge Membrane Governs Promigratory Effects of Osteoblast-Conditioned Medium on Human Prostate Cancer Cells in the Context of Bone Metastasis.

Among the different interacting molecules implicated in bone metastases, connexin43 (Cx43) may increase sensitivity of prostate cancer (PCa) cells to bone microenvironment, as suggested by our in silico and human tissue samples analyses that revealed increased level of Cx43 expression with PCa progression and a Cx43 specific expression in bone secondary sites. The goal of the present study was to understand how Cx43 influences PCa cells sensitivity and aggressiveness to bone microenvironment. By means of Cx43-overexpressing PCa cell lines, we revealed a Cx43-dependent promigratory effect of osteoblastic conditioned media (ObCM). This effect on directional migration relied on the presence of Cx43 at the plasma membrane and not on gap junctional intercellular communication and hemichannel functions. ObCM stimulation induced Rac1 activation and Cx43 interaction with cortactin in protrusions of migrating PCa cells. Finally, by transfecting two different truncated forms of Cx43 in LNCaP cells, we determined that the carboxy terminal (CT) part of Cx43 is crucial for the responsiveness of PCa cells to ObCM. Our study demonstrates that Cx43 level and its membrane localization modulate the phenotypic response of PCa cells to osteoblastic microenvironment and that its CT domain plays a pivotal role.

[Autophagy and spermatozoa]. / Autophagie et spermatozoïde.

Spermiogenesis, the ultimate stage of spermatogenesis, is a process involving autophagy. At this stage, the acrosome is generated by vesicular fusion and most of the cytoplasm disappears. Autophagy, literally "eating oneself", allowing the elimination and replacement of proteins and nonfunctional organelles, ensures the recycling of cellular constituents and is a highly conserved cellular mechanism within eukaryotic cells. The machinery of autophagy is present in the spermatozoon, regulating the vitality and mobility of the cells. The environmental and behavioral impact on autophagy and the consequences on spermatogenesis are beginning to be studied. The purpose of this review is to synthesize current knowledge about autophagy in the mature male gamete.

TITLE: Autophagie et spermatozoïde. ABSTRACT: La spermiogenèse, étape ultime de la spermatogenèse, est un processus qui fait intervenir des acteurs qui participe à l'autophagie. C'est en effet lors de cette étape que se forme l'acrosome par fusion vésiculaire et que disparaît la majeure partie du cytoplasme du spermatozoïde. L'autophagie (littéralement « se manger soi-même ¼), en permettant l'élimination et le remplacement continuel des protéines et des organites non fonctionnels, assure le recyclage des constituants de la cellule. C'est un mécanisme cellulaire très conservé au sein des cellules eucaryotes. La machinerie de l'autophagie est également présente dans les spermatozoïdes. Elle régule la vitalité de ces cellules et leur mobilité. Les conséquences environnementales et comportementales sur l'autophagie et sur la spermatogenèse commencent à être étudiées. Le but de cette revue est de synthétiser les connaissances actuelles concernant les processus d'autophagie dans le gamète mâle mature.

Autophagy is increased in cryptorchid testis resulting in abnormal spermatozoa.

Autophagy is involved in spermatogenesis by regulating germ cell maturation. This catabolic process increases with hyperthermic conditions to prevent the accumulation of damaged organelles. Cryptorchidism is associated with impairment of germ cell maturation revealed by the presence of immature forms of sperm cells in ejaculates. The aim of the present study was to evaluate the status of autophagy in sperm cells from cryptorchid patients. Semen samples of cryptorchid patients and normozoospermic controls were analyzed by immunocytochemistry and electron microscopy. Autophagy proteins, autophagy-related protein 9 (ATG9) and microtubule-associated protein, 1A/1B-light chain 3 (LC3) were localized by immunocytochemistry on the acrosome and on the equatorial segment of sperm cells. LC3 was also detected in the midpiece of cryptorchid sperm tail. Autophagy substrate p62 protein was present in the acrosome and in the postequatorial segment of sperm in control samples, but not in the cryptorchid ones. Transmission electron microscopy revealed double-membrane-limited autophagosomes in postequatorial part of spermatozoa head and midpiece in cryptorchid samples. Partly degraded mitochondria were frequently discerned in autophagic vacuoles. In conclusion, autophagy is increased in sperm cells from patients with cryptorchid history comparatively to control. Our work provides insights into the role of autophagy in the maturation and survival of human male gametes in pathological conditions. Thus, regulating autophagy could represent a potential way to improve sperm quality in cryptorchid men.

Mathematical Modeling of Substrates Fluxes and Tumor Growth in the Brain.

The aim of this article is to show how a tumor can modify energy substrates fluxes in the brain to support its own growth. To address this question we use a modeling approach to explain brain nutrient kinetics. In particular we set up a system of 17 equations for oxygen, lactate, glucose concentrations and cells number in the brain. We prove the existence and uniqueness of nonnegative solutions and give bounds on the solutions. We also provide numerical simulations.

Deregulation of calcium homeostasis in Bcr-Abl-dependent chronic myeloid leukemia.

BACKGROUND: Chronic myeloid leukemia (CML) results from hematopoietic stem cell transformation by the bcr-abl chimeric oncogene, encoding a 210 kDa protein with constitutive tyrosine kinase activity. In spite of the efficiency of tyrosine kinase inhibitors (TKI; Imatinib), other strategies are explored to eliminate CML leukemia stem cells, such as calcium pathways. RESULTS: In this work, we showed that Store-Operated Calcium Entry (SOCE) and thrombin induced calcium influx were decreased in Bcr-Abl expressing 32d cells (32d-p210). The 32d-p210 cells showed modified Orai1/STIM1 ratio and reduced TRPC1 expression that could explain SOCE reduction. Decrease in SOCE and thrombin induced calcium entry was associated to reduced Nuclear Factor of Activated T cells (NFAT) nucleus translocation in 32d-p210 cells. We demonstrated that SOCE blockers enhanced cell mobility of 32d-p210 cells and reduced the proliferation rate in both 32d cell lines. TKI treatment slightly reduced the thrombin-induced response, but imatinib restored SOCE to the wild type level. Bcr-Abl is also known to deregulate Protein Kinase C (PKC), which was described to modulate calcium entries. We showed that PKC enhances SOCE and thrombin induced calcium entries in control cells while this effect is lost in Bcr-Abl-expressing cells. CONCLUSION: The tyrosine kinase activity seems to regulate calcium entries probably not directly but through a global cellular reorganization involving a PKC pathway. Altogether, calcium entries are deregulated in Bcr-Abl-expressing cells and could represent an interesting therapeutic target in combination with TKI.

Phagocytosis by Sertoli Cells: Analysis of Main Phagocytosis Steps by Confocal and Electron Microscopy.

Sertoli cells were discovered in the seminiferous tubules by Enrico Sertoli in 1865 (Morgagni 7:31-33, 1865). Intense phagocytosis is, in the context of spermatogenesis cycle, morphologically the most noticeable function of Sertoli cells. In this chapter the major principles of phagocytosis machinery and its specificities in the seminiferous tubules will be briefly reviewed, guidelines of analysis of main phagocytosis steps by confocal and transmission electron microscopy will be described, and a simplified method to assess phagocytosis rate in routine experiments will be given.

Myelinosomes act as natural secretory organelles in Sertoli cells to prevent accumulation of aggregate-prone mutant Huntingtin and CFTR.

Inappropriate deposition of insoluble aggregates of proteins with abnormal structures is a hallmark of affected organs in protein aggregation disease. Very rare, affected organs avoid aggregation naturally. This concerns atrophic testis in Huntington disease (HD). We aimed to understand how HD testis avoids aggregation. Using HD model R6/1 mice, we demonstrate that affected testis contain rare organelles myelinosomes. Myelinosomes secreted from testis somatic TM4 Sertoli cells provide the release of aggregate-prone mutant, but not normal Huntingtin (Htt) exon1. Myelinosomes also support the release of other aggregate-prone mutant protein responsible for cystic fibrosis (CF), F508delCFTR. The traffic and discharge of myelinosomes is facilitated by multivesicular bodies (MVB)s. Inhibition of MVB excretion induced reversible retention of both misfolded proteins inside TM4 Sertoli cells. We propose that myelinosome-mediated elimination of mutant proteins is an unusual secretory process allowing Sertoli cells getting rid of misfolded proteins to avoid aggregation and to maintain cell proteostasis.

The Rho-ROCK pathway as a new pathological mechanism of innate immune subversion in chronic myeloid leukaemia.

CD1d-restricted invariant natural killer T (iNKT) cells are believed to play a key role in cancer immune surveillance, and are functionally deficient in patients with chronic myeloid leukaemia (CML). Herein, we have hypothesized that this defect might originate from BCR-ABL-dependent dysfunctions in myeloid dendritic cells (mDCs). Indeed, flow cytometry and confocal microscopy revealed that cell surface expression of CD1d was downregulated in CML mDCs, relative to healthy donor (HD) controls. The decreased cell surface display of CD1d could not be ascribed to defective mDC differentiation, as attested by normal expression of HLA-DR and the CD86 maturation marker. On the other hand, reduced membrane expression was not associated with decreased intracytoplasmic levels of CD1d or its mRNA transcripts, consistent with intracellular retention. In vitro treatment of CML mDCs with the Rho-associated protein kinase (ROCK) inhibitor Y-27632 partially restored both cell surface CD1d expression and CD1d-mediated antigen presentation, whereas it had no effect on HD mDCs. An inhibitor of BCR-ABL tyrosine kinase (TK), imatinib mesylate (IM), had no such activity. Similar recovery of CD1d expression occurred with fasudil, another ROCK inhibitor that is commonly used in clinical trials. Our data support the conclusion that BCR-ABL-dependent ROCK, but not TK, is involved in CD1d downregulation. We propose that ROCK, which is most likely activated by the DH/PH domain of BCR-ABL, mediates iNKT-cell immune subversion in CML patients by downregulating CD1d expression on CML mDCs. Our study reveals the ROCK-mDC axis as a new potential target to restore immune surveillance in patients with CML, offering new therapeutic perspectives for CML treatment. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

SK3/TRPC1/Orai1 complex regulates SOCE-dependent colon cancer cell migration: a novel opportunity to modulate anti-EGFR mAb action by the alkyl-lipid Ohmline.

BACKGROUND: Barely 10-20% of patients with metastatic colorectal cancer (mCRC) receive a clinical benefit from the use of anti-EGFR monoclonal antibodies (mAbs). We hypothesized that this could depends on their efficiency to reduce Store Operated Calcium Entry (SOCE) that are known to enhance cancer cells. RESULTS: In the present study, we demonstrate that SOCE promotes migration of colon cancer cell following the formation of a lipid raft ion channel complex composed of TRPC1/Orai1 and SK3 channels. Formation of this complex is stimulated by the phosphorylation of the reticular protein STIM1 by EGF and activation of the Akt pathway. Our data show that, in a positive feedback loop SOCE activates both Akt pathway and SK3 channel activity which lead to SOCE amplification. This amplification occurs through the activation of Rac1/Calpain mediated by Akt. We also show that Anti-EGFR mAbs can modulate SOCE and cancer cell migration through the Akt pathway. Interestingly, the alkyl-lipid Ohmline, which we previously showed to be an inhibitor of SK3 channel, can dissociated the lipid raft ion channel complex through decreased phosphorylation of Akt and modulation of mAbs action. CONCLUSIONS: This study demonstrates that the inhibition of the SOCE-dependent colon cancer cell migration trough SK3/TRPC1/Orai1 channel complex by the alkyl-lipid Ohmline may be a novel strategy to modulate Anti-EGFR mAb action in mCRC.

Nav1.5 channels can reach the plasma membrane through distinct N-glycosylation states.

BACKGROUND: Like many voltage-gated sodium channels, the cardiac isoform Nav1.5 is well known as a glycoprotein which necessarily undergoes N-glycosylation processing during its transit to the plasma membrane. In some cardiac disorders, especially the Brugada syndrome (BrS), mutations in Nav1.5 encoding gene lead to intracellular retention and consequently trafficking defect of these proteins. We used two BrS mutants as tools to clarify both Nav1.5 glycosylation states and associated secretory behaviors. METHODS: Patch-clamp recordings and surface biotinylation assays of HEK293T cells expressing wild-type (WT) and/or mutant Nav1.5 proteins were performed to assess the impact of mutant co-expression on the membrane activity and localization of WT channels. Enzymatic deglycosylation assays and brefeldin A (BFA) treatments were also employed to further characterize recombinant and native Nav1.5 maturation. RESULTS: The present data demonstrate that Nav1.5 channels mainly exist as two differentially glycosylated forms. We reveal that dominant negative effects induced by BrS mutants upon WT channel current result from the abnormal surface expression of the fully-glycosylated forms exclusively. Furthermore, we show that core-glycosylated channels can be found at the surface membrane of BFA-treated or untreated cells, but obviously without generating any sodium current. CONCLUSIONS: Our findings provide evidence that native and recombinant Nav1.5 subunits are expressed as two distinct matured forms. Fully-glycosylated state of Nav1.5 seems to determine its functionality whereas core-glycosylated forms might be transported to the plasma membrane through an unconventional Golgi-independent secretory route. GENERAL SIGNIFICANCE: This work highlights that N-linked glycosylation processing would be critical for Nav1.5 membrane trafficking and function.

Influence of the scaffolding protein Zonula Occludens (ZOs) on membrane channels.

Zonula Occludens (ZO) proteins are ubiquitous scaffolding proteins providing the structural basis for the assembly of multiprotein complexes at the cytoplasmic surface of the plasma membrane and linking transmembrane proteins to the filamentous cytoskeleton. They belong to the large family of membrane-associated guanylate kinase (MAGUK)-like proteins comprising a number of subfamilies based on domain content and sequence similarity. ZO proteins were originally described to localize specifically to tight junctions, or Zonulae Occludentes, but this notion was rapidly reconsidered since ZO proteins were found to associate with adherens junctions as well as with gap junctions, particularly with connexin-made intercellular channels, and also with a few other membrane channels. Accumulating evidence reveals that in addition to having passive scaffolding functions in organizing gap junction complexes, including connexins and cytoskeletals, ZO proteins (particularly ZO-1) also actively take part in the dynamic function as well as in the remodeling of junctional complexes in a number of cellular systems. This article is part of a Special Issue entitled: Reciprocal influences between cell cytoskeleton and membrane channels, receptors and transporters. Guest Editor: Jean Claude Hervé.

A chimerical phagocytosis model reveals the recruitment by Sertoli cells of autophagy for the degradation of ingested illegitimate substrates.

Phagocytosis and autophagy are typically dedicated to degradation of substrates of extrinsic and intrinsic origins respectively. Although overlaps between phagocytosis and autophagy were reported, the use of autophagy for ingested substrate degradation by nonprofessional phagocytes has not been described. Blood-separated tissues use their tissue-specific nonprofessional phagocytes for homeostatic phagocytosis. In the testis, Sertoli cells phagocytose spermatid residual bodies produced during germ cell differentiation. In the retina, pigmented epithelium phagocytoses shed photoreceptor tips produced during photoreceptor renewal. Spermatid residual bodies and shed photoreceptor tips are phosphatidylserine-exposing substrates. Activation of the tyrosine kinase receptor MERTK, which is implicated in phagocytosis of phosphatidylserine-exposing substrates, is a common feature of Sertoli and retinal pigmented epithelial cell phagocytosis. The major aim of our study was to investigate to what extent phagocytosis by Sertoli cells may be tissue specific. We analyzed in Sertoli cell cultures that were exposed to either spermatid residual bodies (legitimate substrates) or retina photoreceptor outer segments (illegitimate substrates) the course of the main phagocytosis stages. We show that whereas substrate binding and ingestion stages occur similarly for legitimate or illegitimate substrates, the degradation of illegitimate but not of legitimate substrates triggers autophagy as evidenced by the formation of double-membrane wrapping, MAP1LC3A-II/LC3-II clustering, SQSTM1/p62 degradation, and by marked changes in ATG5, ATG9 and BECN1/Beclin 1 protein expression profiles. The recruitment by nonprofessional phagocytes of autophagy for the degradation of ingested cell-derived substrates is a novel feature that may be of major importance for fundamentals of both apoptotic substrate clearance and tissue homeostasis.