Organelles Research Articles

The use of a fatty acidphospholipid complex in the cultivation of broiler chickens

Phospholipids make up the structure of cell membranes and organelles, influencing the activation of cellular enzymes. They are involved in the intercellular transport of fats, fatty acids, cholesterol and other substances in blood lipoproteins. These compounds, being natural metabolites, contribute to more efficient use of fat and prevent its excessive accumulation in tissues. Phospholipids have emulsifying properties, of particular interest are lecithins, which are phosphatides. Lecithin-based supplements in poultry feeding improve growth, reduce the risk of perosis, have a beneficial effect on skeletal formation and accumulation of vitamin A in the liver (lecithin has a synergistic effect). They also protect farm poultry from the development of liver obesity syndrome. The aim of the research was to study the effect of the phospholipid-fatty acid complex on the main zootechnical indicators in the cultivation of broiler chickens. Partial replacement of sunflower oil with fatty acids at various age periods by 0.69–1.48 % and phospholipids by 0.84–1.8 % (according to the experimental scheme) contributes to an increase in the safety of broiler chickens by 2.5 %. The inclusion of a phospholipid-fatty acid complex in broiler diets is advisable, which is confirmed by an increase in live weight by 1.95–7.42%; a decrease in conversion by 0.01–0.02 kg/ kg; preservation of safety indicators at the level of 97.5–100 %; an increase in income from the sale of chickens by 4.57–7.42 %; making a profit of 52.60–104.98 % more in comparison with the control; increasing the level of profitability by 1.01–2.19 %.

The Asgard archaeal origins of Arf family GTPases involved in eukaryotic organelle dynamics.

The evolution of eukaryotes is a fundamental event in the history of life. The closest prokaryotic lineage to eukaryotes, the Asgardarchaeota, encode proteins previously found only in eukaryotes, providing insight into their archaeal ancestor. Eukaryotic cells are characterized by endomembrane organelles, and the Arf family GTPases regulate organelle dynamics by recruiting effector proteins to membranes upon activation. The Arf family is ubiquitous among eukaryotes, but its origins remain elusive. Here we report a group of prokaryotic GTPases, the ArfRs, which are widely present in Asgardarchaeota. Phylogenetic analyses reveal that eukaryotic Arf family proteins arose from the ArfR group. Expression of representative Asgardarchaeota ArfR proteins in yeast and X-ray crystallographic studies show that ArfR GTPases possess the mechanism of membrane binding and structural features unique to Arf family proteins. Our results indicate that Arf family GTPases originated in the archaeal ancestor of eukaryotes, consistent with aspects of the endomembrane system evolving early in eukaryogenesis.

FABP4 as a therapeutic host target controlling SARS-CoV-2 infection.

Host metabolic fitness is a critical determinant of infectious disease outcomes. Obesity, aging, and other related metabolic disorders are recognized as high-risk disease modifiers for respiratory infections, including coronavirus infections, though the underlying mechanisms remain unknown. Our study highlights fatty acid-binding protein 4 (FABP4), a key regulator of metabolic dysfunction and inflammation, as a modulator of SARS-CoV-2 pathogenesis, correlating strongly with disease severity in COVID-19 patients. We demonstrate that loss of FABP4 function, by genetic or pharmacological means, reduces SARS-CoV-2 replication and disrupts the formation of viral replication organelles in adipocytes and airway epithelial cells. Importantly, FABP4 inhibitor treatment of infected hamsters diminished lung viral titers, alleviated lung damage and reduced collagen deposition. These findings highlight the therapeutic potential of targeting host metabolism in limiting coronavirus replication and mitigating the pathogenesis of infection.

A Golgi apparatus‑related subtype and risk signature predicts prognosis and evaluates immunotherapy response in gastric cancer

BackgroundGastric cancer (GC) remains a significant health burden, calling for the discovery of novel biomarkers. Golgi apparatus, a crucial cellular organelle involved in tumorigenesis, remains underexplored in GC research. A comprehensive understanding of its role and associated mechanisms is urgently needed.Materials and methodsUtilizing the TCGA-STAD dataset as the training cohort and GSE84433 as the validation cohort, we explored potential associations between Golgi apparatus-related genes (GARG) and GC clinical risk. We aimed to decipher the prognostic significance and underlying biological mechanisms of these genes via consistent clustering, differential expression analysis, enrichment analyses, and immune infiltration profiling. To assess the relationship between risk stratification and survival outcomes, drug sensitivity, and immune infiltration, we developed the Golgi Apparatus-Related Risk Signature (GARRS). The reliability of GARRS was further corroborated using immunohistochemical staining.ResultsConsensus clustering based on 17 GARG identified two patient subgroups, C1 and C2, exhibiting differential survival, immune scores, and immune cell infiltration. We developed a GARRS using Cox-Lasso regression analysis, accurately stratifying patients into high- and low-risk groups. GARRS’ validity was confirmed in the validation set and immunohistochemical staining. Our findings underline the Golgi apparatus' significance in the GC immune microenvironment and GARRS' utility in predicting GC survival outcomes.ConclusionThis study underscores the association between Golgi apparatus subtypes and GC immunotumor microenvironment. GARRS, validated for its prognostic, immune infiltration, and drug sensitivity predictive abilities, offers new insights into gastric cancer treatment strategies.

Mitochondria as a Therapeutic Target: Focusing on Traumatic Brain Injury.

Mitochondria are organelles of eukaryotic cells delimited by two membranes and cristae that consume oxygen to produce adenosine triphosphate (ATP), and are involved in the synthesis of vital metabolites, calcium homeostasis, and cell death mechanisms. Strikingly, normal mitochondria function as an integration center between multiple conditions that determine neural cell homeostasis, whereas lesions that lead to mitochondrial dysfunction can desynchronize cellular functions, thus contributing to the pathophysiology of traumatic brain injury (TBI). In addition, TBI leads to impaired coupling of the mitochondrial electron transport system with oxidative phosphorylation that provides most of the energy needed to maintain vital functions, ionic homeostasis, and membrane potentials. Furthermore, mitochondrial metabolism produces signaling molecules such as reactive oxygen species (ROS), regulating calcium levels and controlling the expression profile of intrinsic pro-apoptotic effectors influenced by TBI. Hence, the set of these functions is widely referred to as 'mitochondrial function', although the complexity of the relationship between such components limits such a definition. In this review, we present mitochondria as a therapeutic target, focus on TBI, and discuss aspects of mitochondrial structure and function.

Host factor DIAPH1 regulates pseudorabivirus replication by modulating the dynamics of cytoskeleton.

As obligate parasites, viruses exploit host cell organelles and molecular components to complete their life cycle. Among which, viruses firstly hijack the cytoskeleton of host cells to ensure their efficiently cell entry and replication. Although formin family members play a key role in both microfilament and microtubule cytoskeletal remodeling, few studies addressed the detailed function and mechanism of formins in the process of viral infection. Here, we showed that sus scrofa DIAPH1 was involved in the regulation of cytoskeletal dynamics during PRV replication. Firstly, we found that DIAPH1 showed significant changes in the expression level and intracellular localization during PRV infection of PK-15 cells. Next, inhibition of DIAPH1 by RNA interference or small molecular inhibitor SMIFH2 was found to diminish the outcome of PRV infection. Besides, DIAPH1 partially co-localized with actin and tubulin in PRV-infected cells. Cross-talk occurred between microfilaments and microfilaments, which also had an influence on the intracellular localization of DIAPH1. What's more, inhibition of DIAPH1 induced the reorganization of microfilament and the stability of microtubule. These results suggested that DIAPH1 regulated PRV infection by remodeling microfilament and microtubule cytoskeletal dynamics.

Selenium modulates bisphenol A-induced intestinal apoptosis, oxidative stress and autophagy in rats: A biochemical, histological and immunohistochemical study

Bisphenol A (BPA) is a hazardous endocrine disruptor released into the environment during the production of certain plastics used for covering of food and beverage cans. In this work, we examined the protective benefits of selenium (Se) against intestinal damage induced by BPA in male rats. Rats were distributed randomly into four groups. The first group received corn oil and served as the control. The second group was administered Se (1 mg/kg body weight; BW). The third group was given oral BPA (50 mg/kg BW). In the fourth group, Se (1 mg/kg BW) and BPA (50 mg/kg BW) were administered simultaneously. This experiment lasted for eight weeks. Specimens from the large intestine were subjected to biochemical analysis of antioxidants and oxidative stress biomarkers, histological observation under light and transmission electron microscopy and immunohistochemistry to autophagy and apoptosis markers. The BPA-exposed group showed significantly elevated oxidative stress markers associated with significant decline of antioxidants in intestinal tissues. BPA resulted in histological alterations such as severe mucosal necrosis with massive inflammatory cell infiltration. Ultra-structurally, the same group showed severe loss of the cell organelles, shrunken nuclei, and abundant autophagosomes. Immunohistochemistry results demonstrated a strong reactivity of caspase-3 and LC3 in the BPA group in contrast to the reaction to p62, which was markedly diminished. These effects were mitigated in the BPA+Se group. We concluded that BPA’s harmful effects on the large intestine are caused by apoptosis and autophagy. Se may protect intestinal cells from these effects and could be a useful and trustworthy approach for reducing BPA toxicity.

The Role of NLRP3 Inflammatory Bodies in Cerebral Hemorrhage and Progress in Targeted Therapy

The review aims to provide the basis for clinical treatment and prognosis improvement of cerebral hemorrhage. NLRP3 inflammatory bodies are localized to multiple fine cell organelles and transition to different intracellular sites during activation, The mechanism of NLRP3 activation in cerebral hemorrhage is becoming more and more clear. More and more studies tend to selectively inhibit NLRP3 inflammasome pathway to improve the prognosis of cerebral hemorrhage. Cerebral hemorrhage is a kind of devastating illness and a common form of cerebral apoplexy, which has a high disability and fatality rate. In this review, the role of NLRP3 inflammatory corpuscle in cerebral hemorrhage and the progress of targeted therapy are summarized.

Current and Emerging Therapies for Lysosomal Storage Disorders.

Lysosomal storage disorders (LSDs) are rare inherited metabolic disorders characterized by defects in the function of specific enzymes responsible for breaking down substrates within cellular organelles (lysosomes) essential for the processing of macromolecules. Undigested substrate accumulates within lysosomes, leading to cellular dysfunction, tissue damage, and clinical manifestations. Clinical features vary depending on the degree and type of enzyme deficiency, the type and extent of substrate accumulated, and the tissues affected. The heterogeneous nature of LSDs results in a variety of treatment approaches, which must be tailored to patient presentation and characteristics. The treatment landscape for LSDs is rapidly evolving. An up-to-date discussion of current evidence is required to provide clinicians with an appropriate overview of treatment options. Therefore, we aimed to review current and ongoing trials pertaining to the treatment of common LSDs.

The Role of Autophagy in Copper-Induced Apoptosis and Developmental Neurotoxicity in SH-SY5Y Cells.

Copper (Cu) is a global environmental pollutant that poses a serious threat to humans and ecosystems. Copper induces developmental neurotoxicity, but the underlying molecular mechanisms are unknown. Neurons are nonrenewable, and they are unable to mitigate the excessive accumulation of pathological proteins and organelles in cells, which can be ameliorated by autophagic degradation. In this study, we established an in vitro model of Cu2+-exposed (0, 15, 30, 60 and 120 μM) SH-SY5Y cells to explore the role of autophagy in copper-induced developmental neurotoxicity. The results showed that copper resulted in the reduction and shortening of neural synapses in differentiated cultured SH-SY5Y cells, a downregulated Wnt signaling pathway, and nuclear translocation of β-catenin. Exposure to Cu2+ increased autophagosome accumulation and autophagic flux blockage in terms of increased sequestosome 1 (p62/SQSTM1) and microtubule-associated protein 1 light chain 3B (LC3B) II/LC3BI expressions and inhibition of the phosphatidylinositol 3-kinase (PI3K)/Akt/mTOR pathway. Furthermore, copper induced apoptosis, characterized by increased expressions of Bcl2 X protein (Bax), caspase 3, and Poly (ADP-ribose) polymerase (PARP) and decreased expression of B-cell lymphoma 2 (Bcl2). Compared with the 120 μM Cu2+ exposure group alone, autophagy activator rapamycin pretreatment increased expression of Wnt and β-catenin nuclear translocation, decreased expression of LC3BII/LC3BI and p62, as well as upregulated expression of Bcl2 and downregulated expressions of caspase 3 and PARP. In contrast, after autophagy inhibitor chloroquine pretreatment, expressions of Wnt and β-catenin nuclear translocation were decreased, expression levels of LC3BII/LC3BI and p62 were upregulated, expression of Bcl2 was decreased, while expression levels of caspase 3, Bax, and PARP were increased. In conclusion, the study demonstrated that autophagosome accumulation and autophagic flux blockage were associated with copper-induced developmental neurotoxicity via the Wnt signaling pathway, which might deepen the understanding of the developmental neurotoxicity mechanism of environmental copper exposure.

Widespread occurrence and relevance of phosphate storage in foraminifera.

Foraminifera are ubiquitous marine protists that intracellularly accumulate phosphate1, an important macronutrient in marine ecosystems and in fertilizer potentially leaked into the ocean. Intracellular phosphate concentrations can be 100-1,000 times higher than in the surrounding water1. Here we show that phosphate storage in foraminifera is widespread, from tidal flats to the deep sea. The total amount of intracellular phosphate stored in the benthic foraminifer Ammonia confertitesta in the Wadden Sea during a bloom is as high as around 5% of the annual consumption of phosphorus (P) fertilizer in Germany. Budget calculations for the Southern North Sea and the Peruvian Oxygen Minimum Zone indicate that benthic foraminifera may buffer riverine P runoff for approximately 37 days at the Southern North Sea and for about 21 days at the Peruvian margin. This indicates that these organisms are probably relevant for marine P cycling-they potentially buffer anthropogenic eutrophication in coastal environments. Phosphate is stored as polyphosphate in cell organelles that are potentially acidocalcisomes. Their metabolic functions can range from regulation of osmotic pressure and intracellular pH to calcium and energy storage. In addition, storage of energetic P compounds, such as creatine phosphate and polyphosphate, is probably an adaptation of foraminifera to O2 depletion.

Diabetes mellitus and glymphatic dysfunction: Roles for oxidative stress, mitochondria, circadian rhythm, artificial intelligence, and imaging.

Diabetes mellitus (DM) is a debilitating disorder that impacts all systems of the body and has been increasing in prevalence throughout the globe. DM represents a significant clinical challenge to care for individuals and prevent the onset of chronic disability and ultimately death. Underlying cellular mechanisms for the onset and development of DM are multi-factorial in origin and involve pathways associated with the production of reactive oxygen species and the generation of oxidative stress as well as the dysfunction of mitochondrial cellular organelles, programmed cell death, and circadian rhythm impairments. These pathways can ultimately involve failure in the glymphatic pathway of the brain that is linked to circadian rhythms disorders during the loss of metabolic homeostasis. New studies incorporate a number of promising techniques to examine patients with metabolic disorders that can include machine learning and artificial intelligence pathways to potentially predict the onset of metabolic dysfunction.

Polarity‐selective Transfer of Lipophilic Cargoes From Lipid Droplets (Oleosomes) to Lipid Bilayers

AbstractLipid Droplets (LDs) or as also called oleosomes are lipid storage organelles in eukaryotic cells. Besides storing lipids, LDs can fuse their core into other intracellular organelles, but the mechanism remains unknown. In this work, this is aimed to understand the effect of cargo's polarity on the transportation of the cargo from LDs to lipid bilayers using liposomes. LDs are loaded with curcumin and Nile red, two lipophilic molecules with similar log P values. The loaded LDs are blended with liposomes, while curcumin and Nile red are tracked using confocal microscopy and spectroscopy. LDs remained intact, while curcumin was transferred in 5 min from LDs to liposomes. Nile red remained in LDs. The difference between curcumin and Nile red is attributed to the amphiphilicity of curcumin, which allowed its adsorption in the LD monolayer and the subsequent transportation to the liposome bilayer upon contact. The unique selectivity of LDs is shown as carriers since lipophilic cargo is transferred to the lipid bilayer only when participating in the LD membrane. The understanding of the transportation mechanism of molecules from LDs to bilayers helps the exploitation of LDs as natural lipid carriers.

Cryo-SEM and large volume FIB-SEM of Arabidopsis cotyledons: Degradation of lipid bodies, biogenesis of glyoxysomes and reorganisation of organelles during germination.

Until recently, the lack of three-dimensional visualisation of whole cells at the electron microscopic (EM) level has led to a significant gap in our understanding of the interaction of cellular organelles and their interconnection. This is particularly true with regard to the role of the endoplasmic reticulum (ER). In this study, we perform three-dimensional reconstructions of serial FIB/SEM stacks and anaglyphs derived from volume rendering, cryo-scanning electron microscopy (cryo-SEM) and state-of-the-art electron microscopy immobilisation and imaging techniques. The results show that glyoxysomes are formed de novo in large numbers and in characteristic clusters on the ER upon germination in mesophyll cells of Arabidopsis cotyledons. The degradation of lipid bodies during germination occurs not only via the ER, which enlarges by taking up polar lipids resulting from enzymatic degradation by lipases, but also via glyoxysomes, which engulf lipid bodies. Dictyosomal (Golgi-derived) vesicles, which fuse with glyoxysomes or their precursors, also appear to be involved in the differentiation of glyoxysomes from segments of the ER. The formation of the central vacuole is the result of the fusion of protein storage vacuoles (protein bodies), which become complex three-dimensional structures during germination. Our observations also suggest that the vacuole plays a role in the degradation of glyoxysomes. The evidence provided in three dimensions shows that the endoplasmic reticulum plays a central role in the biogenesis and degradation of lipid bodies, the ontogeny of glyoxysomes and the development of plastids in the mesophyll cells of Arabidopsis cotyledons.

Advances in Fluorescence Techniques for the Detection of Hydroxyl Radicals near DNA and Within Organelles and Membranes.

Hydroxyl radicals (•OH), the most potent oxidants among reactive oxygen species (ROS), are a major contributor to oxidative damage of biomacromolecules, including DNA, lipids, and proteins. The overproduction of •OH is implicated in the pathogenesis of numerous diseases such as cancer, neurodegenerative disorders, and some cardiovascular pathologies. Given the localized nature of •OH-induced damage, detecting •OH, specifically near DNA and within organelles, is crucial for understanding their pathological roles. The major challenge of •OH detection results from their short half-life, high reactivity, and low concentrations within biological systems. As a result, there is a growing need for the development of highly sensitive and selective probes that can detect •OH in specific cellular regions. This review focuses on the advances in fluorescence probes designed to detect •OH near DNA and within cellular organelles and membranes. The key designs of the probes are highlighted, with emphasis on their strengths, applications, and limitations. Recommendations for future research directions are given to further enhance probe development and characterization.

Emerging biomarkers in major depressive disorder: Diagnostic, prognostic, and therapeutic implications

Recent advancements in biomarker research for the diagnosis, prognosis, and treatment strategies of major depressive disorder (MDD) have yielded significant findings that warrant documentation. The clinical demand for biomarkers persists due to the limited accuracy and efficiency of subjective diagnostic approaches. This review scrutinized research papers related to MDD biomarkers published between January 2011 and till July 2024, focusing exclusively on human studies with statistically significant results. The compiled biomarkers encompass cellular membrane receptors, cytoplasmic organelles, and genomic and epigenomic intranuclear markers. Cell surface molecular receptors implicated in MDD pathogenesis include brain-derived neurotrophic factor (BDNF) receptors, N-methyl D-aspartate receptors (NMDAR), and interleukin (IL) receptors. Endogenous compounds with diagnostic and prognostic potential, such as L-carnitine and alpha-L-carnitine, have also been identified. Transcriptomic biomarkers, including mRNA expression levels of the BDNF, IL-1β, macrophage migration inhibitory factor, and tumor necrosis factor-alpha (TNF-α), have demonstrated utility in MDD management. MicroRNAs (miRNAs), the endogenous molecules that alter the structure of mRNA, show potential for diagnosis and treatment outcome prediction, with miR-221-3p, miR-129-5p, miR-134, and miR-184 emerging as key candidates for MDD monitoring. Long non-coding RNAs (lncRNAs), such as GSK3βAS1, GSK3βAS2, and GSK3βAS3 have been investigated for the evaluation of disease severity and treatment response. Most recently, the pathological role of circular (circRNA) and DNA methylation in MDD has also been documented. The rs155979 polymorphism in the lncRNA NOTHSAT102891 was significantly associated with depression and risk of suicide. The data compiled in this review aim to guide further research in the quest for biomarkers that will improve the management of MDD.

Omics Approaches to Study Perilipins and Their Significant Biological Role in Cardiometabolic Disorders.

Lipid droplets (LDs), highly dynamic cellular organelles specialized in lipid storage and maintenance of lipid homeostasis, contain several proteins on their surface, among which the perilipin (Plin) family stands out as the most abundant group of LD-binding proteins. They play a pivotal role in influencing the behavior and functionality of LDs, regulating lipase activity, and preserving a balance between lipid synthesis and degradation, which is crucial in the development of obesity and abnormal accumulation of fat in non-adipose tissues, causing negative adverse biological effects, such as insulin resistance, mitochondrial dysfunction, and inflammation. The expression levels of Plins are often associated with various diseases, such as hepatic steatosis and atherosclerotic plaque formation. Thus, it becomes of interest to investigate the Plin roles by using appropriate "omics" approaches that may provide additional insight into the mechanisms through which these proteins contribute to cellular and tissue homeostasis. This review is intended to give an overview of the most significant omics studies focused on the characterization of Plin proteins and the identification of their potential targets involved in the development and progression of cardiovascular and cardiometabolic complications, as well as their interactors that could be useful for more efficient therapeutic and preventive approaches for patients.

Apoptotic cell death of stomach cancer lines (AGS) induced by Co-NTB complex through cellular organelles and DNA damage.

Given that stomach cancer is the fourth leading cause of cancer-related death, there is a need to develop new drugs. Among various methods, metal-based coordination compounds are considered as an efficient strategy against this type of cancer. Similarly, the benzimidazole moiety plays a crucial role in biology; thus, various benzimidazole-based compounds have been found to be active as potential anticancer drugs and are currently used in clinical trials. In this study, we explored the benzimidazole-based cobalt(ii) complex as an anticancer agent against AGS stomach cancer cell lines. Interestingly, the MTT assay of the Co-NTB complex shows a lower IC50 value of 4.25 μg mL-1 compared to cisplatin, which has an IC50 of 7.5 μg mL-1 against AGS cell lines. Light microscopy and Hoechst/propidium iodide dye staining clearly indicate that the complex damages DNA, leading to cell death through an apoptotic pathway. The apoptotic cell death pathway was further complemented by Lysotracker and Mitotracker staining, as well as transmission electron microscopy (TEM) imaging. Overall, the Co-NTB complex acts as an effective anticancer agent against AGS stomach cancer cell lines, with apoptotic cell death induced by targeting cellular organelles and DNA.

A protein interaction map of the myosin Myo2 reveals a role of Alo1 in mitochondrial inheritance in yeast.

Budding yeast cells multiply by asymmetric cell division. During this process, the cell organelles are transported by myosin motors along the actin cytoskeleton into the growing bud, while at the same time some organelles must be retained in the mother cell. The ordered partitioning of organelles depends on highly regulated binding of motor proteins to cargo membranes. To search for novel components involved in this process, we performed a protein fragment complementation screen using the cargo binding domain of Myo2, the major organelle transporter in yeast, as a bait and a genome-wide strain collection expressing yeast proteins as prey. One robust hit was Alo1, a poorly characterized D-arabinono-1,4-lactone oxidase located in the mitochondrial outer membrane. We found that mutants lacking Alo1 exhibit defects in mitochondrial morphology and inheritance. During oxidative stress dysfunctional mitochondria are immobilized in the mother in wild type cells. Intriguingly, overexpression of ALO1 restores bud-directed transport of mitochondria under these conditions. We propose that Alo1 supports the recruitment of Myo2 to mitochondria and its activity is particularly important under oxidative stress.

Linear ubiquitination at damaged lysosomes induces local NFKB activation and controls cell survival

ABSTRACT Lysosomes are the major cellular organelles responsible for nutrient recycling and degradation of cellular material. Maintenance of lysosomal integrity is essential for cellular homeostasis and lysosomal membrane permeabilization (LMP) sensitizes toward cell death. Damaged lysosomes are repaired or degraded via lysophagy, during which glycans, exposed on ruptured lysosomal membranes, are recognized by galectins leading to K48- and K63-linked poly-ubiquitination (poly-Ub) of lysosomal proteins followed by recruitment of the macroautophagic/autophagic machinery and degradation. Linear (M1) poly-Ub, catalyzed by the linear ubiquitin chain assembly complex (LUBAC) E3 ligase and removed by OTULIN (OTU deubiquitinase with linear linkage specificity) exerts important functions in immune signaling and cell survival, but the role of M1 poly-Ub in lysosomal homeostasis remains unexplored. Here, we demonstrate that L-leucyl-leucine methyl ester (LLOMe)-damaged lysosomes accumulate M1 poly-Ub in an OTULIN- and K63 Ub-dependent manner. LMP-induced M1 poly-Ub at damaged lysosomes contributes to lysosome degradation, recruits the NFKB (nuclear factor kappa B) modulator IKBKG/NEMO and locally activates the inhibitor of NFKB kinase (IKK) complex to trigger NFKB activation. Inhibition of lysosomal degradation enhances LMP- and OTULIN-regulated cell death, indicating pro-survival functions of M1 poly-Ub during LMP and potentially lysophagy. Finally, we demonstrate that M1 poly-Ub also occurs at damaged lysosomes in primary mouse neurons and induced pluripotent stem cell-derived primary human dopaminergic neurons. Our results reveal novel functions of M1 poly-Ub during lysosomal homeostasis, LMP and degradation of damaged lysosomes, with important implications for NFKB signaling, inflammation and cell death. Abbreviation: ATG: autophagy related; BafA1: bafilomycin A1; CALCOCO2/NDP52: calcium binding and coiled-coil domain 2; CRISPR: clustered regularly interspaced short palindromic repeats; CHUK/IKKA: component of inhibitor of nuclear factor kappa B kinase complex; CUL4A-DDB1-WDFY1: cullin 4A-damage specific DNA binding protein 1-WD repeat and FYVE domain containing 1; DGCs: degradative compartments; DIV: days in vitro; DUB: deubiquitinase/deubiquitinating enzyme; ELDR: endo-lysosomal damage response; ESCRT: endosomal sorting complex required for transport; FBXO27: F-box protein 27; GBM: glioblastoma multiforme; IKBKB/IKKB: inhibitor of nuclear factor kappa B kinase subunit beta; IKBKG/NEMO: inhibitor of nuclear factor kappa B kinase regulatory subunit gamma; IKK: inhibitor of NFKB kinase; iPSC: induced pluripotent stem cell; KBTBD7: kelch repeat and BTB domain containing 7; KO: knockout; LAMP1: lysosomal associated membrane protein 1; LCD: lysosomal cell death; LGALS: galectin; LMP: lysosomal membrane permeabilization; LLOMe: L-leucyl-leucine methyl ester; LOP: loperamide; LUBAC: linear ubiquitin chain assembly complex; LRSAM1: leucine rich repeat and sterile alpha motif containing 1; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MTOR: mechanistic target of rapamycin kinase; MTORC1: MTOR complex 1; NBR1: NBR1 autophagy cargo receptor; NFKB/NF-κB: nuclear factor kappa B; NFKBIA/IĸBα: nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor alpha; OPTN: optineurin; ORAS: OTULIN-related autoinflammatory syndrome; OTULIN: OTU deubiquitinase with linear linkage specificity; RING: really interesting new gene; RBR: RING-in-between-RING; PLAA: phospholipase A2 activating protein; RBCK1/HOIL-1: RANBP2-type and C3HC4-type zinc finger containing 1; RNF31/HOIP: ring finger protein 31; SHARPIN: SHANK associated RH domain interactor; SQSTM1/p62: sequestosome 1; SR-SIM: super-resolution-structured illumination microscopy; TAX1BP1: Tax1 binding protein 1; TBK1: TANK binding kinase 1; TH: tyrosine hydroxylase; TNF/TNFα: tumor necrosis factor; TNFRSF1A/TNFR1-SC: TNF receptor superfamily member 1A signaling complex; TRIM16: tripartite motif containing 16; Ub: ubiquitin; UBE2QL1: ubiquitin conjugating enzyme E2 QL1; UBXN6/UBXD1: UBX domain protein 6; VCP/p97: valosin containing protein; WIPI2: WD repeat domain, phosphoinositide interacting 2; YOD1: YOD1 deubiquitinase.