Search

The synthesis of carborane-1,8-naphthalimide conjugates and evaluation of their DNA-binding ability and anticancer activity were performed. A series of 4-carboranyl-3-nitro-1,8-naphthalimide derivatives, mitonafide and pinafide analogs, were synthesised via amidation and reductive amination reactions, and their calf thymus DNA (ct-DNA)-binding properties were investigated using circular dichroism, UV–vis spectroscopy, and thermal denaturation. Results showed that conjugates 34–37 interacted very strongly with ct-DNA (ΔTm = 10.00–13.00 °C), indicating their ability to intercalate with DNA, but did not inhibit the activity of topoisomerase II. The conjugates inhibited the cell growth of the HepG2 cancer cell line in vitro. The same compounds caused the G2M phase arrest. Cell lines treated with these conjugates showed an increase in reactive oxygen species, glutathione, and Fe2+ levels, lipid peroxidation, and mitochondrial membrane potential relative to controls, indicating the involvement of ferroptosis. Furthermore, these conjugates caused lysosomal membrane permeabilization in HepG2 cells but not in MRC-5 cells. [ABSTRACT FROM AUTHOR]

Engineered nanomaterials (ENMs), or small anthropogenic particles approximately < 100 nm in size and of various shapes and compositions, are increasingly incorporated into commercial products and used for industrial and medical purposes. There is an exposure risk to both the population at large and individuals in the workplace with inhalation exposures to ENMs being a primary concern. Further, there is increasing evidence to suggest that certain ENMs may represent a significant health risk, and many of these ENMs exhibit distinct similarities with other particles and fibers that are known to induce adverse health effects, such as asbestos, silica, and particulate matter (PM). Evidence regarding the importance of lysosomal membrane permeabilization (LMP) and release of cathepsins in ENM toxicity has been accumulating. The aim of this review was to describe our current understanding of the mechanisms leading to ENM-associated pathologies, including LMP and the role of cathepsins with a focus on inflammation. In addition, anti-cathepsin agents, some of which have been tested in clinical trials and may prove useful for ameliorating the harmful effects of ENM exposure, are examined. [ABSTRACT FROM AUTHOR]

Elemene is a broad-spectrum antitumor agent. In the present study, lysosomal membrane permeabilization (LMP) was detected after short elemene emulsion - exposure (12 h) that preceded a decrease of the mitochondrial membrane potential and DNA damage (24 h) in A549 cells. At later time points (36 h) elemene emulsion caused the appearance of A549 cells with apoptotic features, including apoptotic morphology, phosphatidylserine exposure, and caspase-3 activation. A significant increase in protein expression for cathepsin D was also observed utilizing Western blot analysis after exposure to elemene emulsion for 12 h. The present study showed that elemene emulsion induced the increased levels of reactive oxygen species (ROS) and depletion of glutathione (GSH) in A549 cells. Cells treated with pepstatin A, an inhibitor for cathepsin D, showed a significant inhibition in DNA damage, mitochondrial membrane permeabilization, caspase-3 activation, and phosphatidylserine exposure. These results demonstrated that apoptosis induced by elemene emulsion in A549 cells is mediated in part through LMP and lysosomal protease cathepsin D. [ABSTRACT FROM AUTHOR]

Porcine reproductive and respiratory syndrome virus (PRRSV) is a major swine pathogen, which can survive host antiviral immunity with various mechanisms. PRRSV infection induces macroautophagy/autophagy, facilitating virus replication. MALT1, a central immune regulator, was manipulated by PRRSV to optimize viral infection at different stages of the virus cycle. In this study, the key role of MALT1 in autophagy regulation during PRRSV infection was characterized, enlightening the role of autophagy flux in favor of virus spread and persistent infection. PRRSV-induced autophagy was confirmed to facilitate virus proliferation. Furthermore, autophagic fusion was dynamically regulated during PRRSV infection. Importantly, PRRSV-induced MALT1 facilitated autophagosome-lysosome fusion and autolysosome formation, thus contributing to autophagy flux and virus proliferation. Mechanically, MALT1 regulated autophagy via mediating MTOR-ULK1 and -TFEB signaling and affecting lysosomal homeostasis. MALT1 inhibition by inhibitor Mi-2 or RNAi induced lysosomal membrane permeabilization (LMP), leading to the block of autophagic fusion. Further, MALT1 overexpression alleviated PRRSV-induced LMP via inhibiting ROS generation. In addition, blocking autophagy flux suppressed virus release significantly, indicating that MALT1-maintained complete autophagy flux during PRRSV infection favors successful virus spread and its proliferation. In contrast, autophagosome accumulation upon MALT1 inhibition promoted PRRSV reserve for future virus proliferation once the autophagy flux recovers. Taken together, for the first time, these findings elucidate that MALT1 was utilized by PRRSV to regulate host autophagy flux, to determine the fate of virus for either proliferation or reserve.Abbreviations: 3-MA: 3-methyladenine; BafA1: bafilomycin A1; BFP/mBFP: monomeric blue fluorescent protein; CQ: chloroquine; DMSO: dimethyl sulfoxide; dsRNA: double-stranded RNA; GFP: green fluorescent protein; hpi: hours post infection; IFA: indirect immunofluorescence assay; LAMP1: lysosomal associated membrane protein 1; LGALS3: galectin 3; LLOMe: L-leucyl-L-leucine-methyl ester; LMP: lysosomal membrane permeabilization; mAb: monoclonal antibody; MALT1: MALT1 paracaspase; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MOI: multiplicity of infection; MTOR: mechanistic target of rapamycin kinase; NFKB/NF-κB: nuclear factor kappa B; nsp: nonstructural protein; ORF: open reading frame; pAb: polyclonal antibody; PRRSV: porcine reproductive and respiratory syndrome virus; PRRSV-N: PRRSV nucleocapsid protein; Rapa: rapamycin; RFP: red fluorescent protein; ROS: reactive oxygen species; SBI: SBI-0206965; siRNA: small interfering RNA; SQSTM1/p62: sequestosome 1; TCID50: 50% tissue culture infective dose; TFEB: transcription factor EB; ULK1: unc-51 like autophagy activating kinase 1. [ABSTRACT FROM AUTHOR]

Lysosomal dysfunction is a pathogenic link that may explain the causal relationship between diabetes and Alzheimer disease; however, there is no information about the regulation of hyperglycemia in neuronal lysophagy modulating lysosomal function. We examined the effect and related mechanisms of action of high glucose on lysophagy impairment and subsequent Aβ accumulation in human induced pluripotent stem cell (hiPSC)-derived neurons, mouse hippocampal neurons, and streptozotocin (STZ)-induced diabetic mice. High-glucose induced neuronal lysosomal dysfunction through reactive oxygen species-mediated lysosomal membrane permeabilization and lysophagy impairment. Among lysophagy-related factors, the expression of TRIM16 (tripartite motif containing 16) was reduced in high-glucose-treated neuronal cells and the diabetic hippocampus through MTOR (mechanistic target of rapamycin kinase) complex 1 (MTORC1)-mediated inhibition of TFEB (transcription factor EB) activity. TRIM16 overexpression recovered lysophagy through the recruitment of MAP1LC3/LC3 (microtubule associated protein 1 light chain 3), SQSTM1/p62, and ubiquitin to damaged lysosomes, which inhibited the high-glucose-induced accumulation of Aβ and p-MAPT/tau. In the diabetic mice model, TFEB enhancer recovered lysophagy in the hippocampus, resulting in the amelioration of cognitive impairment. In conclusion, TRIM16-mediated lysophagy is a promising candidate for the inhibition of diabetes-associated Alzheimer disease pathogenesis. Aβ: amyloid β; AD: Alzheimer disease; AMPK: 5' adenosine monophosphate-activated protein kinase; CTSB: cathepsin B; CTSD: cathepsin D; DM: diabetes mellitus; ESCRT: endosomal sorting complex required for transport; FBXO27: F-box protein 27; iPSC-NDs: induced pluripotent stem cell-derived neuronal differentiated cells; LAMP1: lysosomal-associated membrane protein 1; LMP: lysosomal membrane permeabilization; LRSAM1: leucine rich repeat and sterile alpha motif containing 1; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MTORC1: mechanistic target of rapamycin kinase complex 1; p-MAPT/tau: phosphorylated microtubule associated protein tau; ROS: reactive oxygen species; STZ: streptozotocin; TFE3: transcription factor E3; TFEB: transcription factor EB; TRIM16: tripartite motif containing 16; UBE2QL1: ubiquitin conjugating enzyme E2 Q family like 1; VCP: valosin containing protein. [ABSTRACT FROM AUTHOR]

Dysregulated macroautophagy/autophagy is one of the hallmarks of aging and has also been linked to higher incidence of several age-associated diseases such as age-related macular degeneration (AMD). The main cell type affected in AMD is the retinal pigment epithelium (RPE), and this disease can lead to central vision loss. Despite affecting around 8.7% of the population between 45–85 years, its etiopathogenesis remains unknown. In our recent manuscript using the pharmacological sodium iodate (SI) model of AMD we identified severe lysosomal membrane permeabilization (LMP) in the RPE, that leads to autophagy flux blockage and proteostasis defects. Treatment with the natural compound urolithin A (UA) reduces RPE cell death and alleviates vision loss, concurrent with full autophagy restoration. While UA was initially described as a specific mitophagy inducer, we now show that it is also able to promote SQSTM1/p62-dependent lysophagy in the context of lysosomal damage and LMP. Genetic downregulation of SQSTM1/p62 fully abolishes the effect of UA on lysophagy while mitophagy stimulation remains unaffected. In summary, these findings highlight the wide range of pathways modulated by UA and its potential implementation in the management of AMD and other diseases involving lysosomal damage. [ABSTRACT FROM AUTHOR]

Hepatocellular carcinoma is the most frequent primary liver cancer. Macroautophagy/autophagy inhibitors have been extensively studied in cancer but, to date, none has reached efficacy in clinical trials. In this study, we demonstrated that GNS561, a new autophagy inhibitor, whose anticancer activity was previously linked to lysosomal cell death, displayed high liver tropism and potent antitumor activity against a panel of human cancer cell lines and in two hepatocellular carcinoma in vivo models. We showed that due to its lysosomotropic properties, GNS561 could reach and specifically inhibited its enzyme target, PPT1 (palmitoyl-protein thioesterase 1), resulting in lysosomal unbound Zn2+ accumulation, impairment of cathepsin activity, blockage of autophagic flux, altered location of MTOR (mechanistic target of rapamycin kinase), lysosomal membrane permeabilization, caspase activation and cell death. Accordingly, GNS561, for which a global phase 1b clinical trial in liver cancers was just successfully achieved, represents a promising new drug candidate and a hopeful therapeutic strategy in cancer treatment. Abbreviations: ANXA5:annexin A5; ATCC: American type culture collection; BafA1: bafilomycin A1; BSA: bovine serum albumin; CASP3: caspase 3; CASP7: caspase 7; CASP8: caspase 8; CCND1: cyclin D1; CTSB: cathepsin B; CTSD: cathepsin D; CTSL: cathepsin L; CQ: chloroquine; iCCA: intrahepatic cholangiocarcinoma; DEN: diethylnitrosamine; DMEM: Dulbelcco's modified Eagle medium; FBS: fetal bovine serum; FITC: fluorescein isothiocyanate; GAPDH: glyceraldehyde-3-phosphate dehydrogenase; HCC: hepatocellular carcinoma; HCQ: hydroxychloroquine; HDSF: hexadecylsulfonylfluoride; IC50: mean half-maximal inhibitory concentration; LAMP: lysosomal associated membrane protein; LC3-II: phosphatidylethanolamine-conjugated form of MAP1LC3; LMP: lysosomal membrane permeabilization; MALDI: matrix assisted laser desorption ionization; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MKI67: marker of proliferation Ki-67; MTOR: mechanistic target of rapamycin kinase; MRI: magnetic resonance imaging; NH4Cl: ammonium chloride; NtBuHA: N-tert-butylhydroxylamine; PARP: poly(ADP-ribose) polymerase; PBS: phosphate-buffered saline; PPT1: palmitoyl-protein thioesterase 1; SD: standard deviation; SEM: standard error mean; vs, versus; Zn2+: zinc ion; Z-Phe: Z-Phe-Tyt(tBu)-diazomethylketone; Z-VAD-FMK: carbobenzoxy-valyl-alanyl-aspartyl-[O-methyl]- fluoromethylketone. [ABSTRACT FROM AUTHOR]

In this study, we studied the mechanism of the cytotoxicity of malabaricone C (mal C) against human breast cancer MCF-7 cell line. Mal C dose-dependently increased the sub G1 cell population, associated with cytoplasmic oligonucleosome formation and chromatin condensation. The mal C-induced apoptosis led to mitochondrial damage as revealed by fluorescence microscopy and flow cytometry of the JC-1-stained cells as well as from the release of mitochondrion-specific nuclease proteins AIF and endo G. Mal C also released intracellular Ca2+ from the MCF-7 cells, but the Ca2+-modulators BAPTA-AM and Ru360 only partially abrogated the apoptosis. The calpain activation by mal C did not have any effect on its cytotoxicity. On the other hand, after mal C treatment significant lysosomal membrane permeabilization (LMP), along with release of cathepsin B, as well as Bid-cleavage and its translocation to mitochondria were observed much earlier than the mitochondrial damage. This suggested that cytotoxicity of mal C against human MCF-7 human breast cancer cell line may proceed through LMP as the initial event that triggered a caspase-independent, but cathepsin B and t-Bid-dependent intrinsic mitochondrial apoptotic pathway. A significant accumulation of cells in the S or G2-M phases along with upregulation of the cyclins E and A due to mal C exposure promises it to be a potential anti-cancer agent. [ABSTRACT FROM AUTHOR]

Podocyte injury leading to albuminuria is a characteristic feature of diabetic nephropathy (DN). Hyperglycemia and advanced glycation end products (AGEs) are major determinants of DN. However, the underlying mechanisms of podocyte injury remain poorly understood. The cytosolic protein TNFAIP2/M-Sec is required for tunneling nanotubes (TNTs) formation, which are membrane channels that transiently connect cells, allowing organelle transfer. Podocytes express TNFAIP2 and form TNTs, but the potential relevance of the TNFAIP2-TNT system in DN is unknown. We studied TNFAIP2 expression in both human and experimental DN and the renal effect of tnfaip2 deletion in streptozotocin-induced DN. Moreover, we explored the role of the TNFAIP2-TNT system in podocytes exposed to diabetes-related insults. TNFAIP2 was overexpressed by podocytes in both human and experimental DN and exposre of podocytes to high glucose and AGEs induced the TNFAIP2-TNT system. In diabetic mice, tnfaip2 deletion exacerbated albuminuria, renal function loss, podocyte injury, and mesangial expansion. Moreover, blockade of the autophagic flux due to lysosomal dysfunction was observed in diabetes-injured podocytes both in vitro and in vivo and exacerbated by tnfaip2 deletion. TNTs allowed autophagosome and lysosome exchange between podocytes, thereby ameliorating AGE-induced lysosomal dysfunction and apoptosis. This protective effect was abolished by tnfaip2 deletion, TNT inhibition, and donor cell lysosome damage. By contrast, Tnfaip2 overexpression enhanced TNT-mediated transfer and prevented AGE-induced autophagy and lysosome dysfunction and apoptosis. In conclusion, TNFAIP2 plays an important protective role in podocytes in the context of DN by allowing TNT-mediated autophagosome and lysosome exchange and may represent a novel druggable target. Abbreviations: AGEs: advanced glycation end products; AKT1: AKT serine/threonine kinase 1; AO: acridine orange; ALs: autolysosomes; APs: autophagosomes; BM: bone marrow; BSA: bovine serum albumin; CTSD: cathepsin D; DIC: differential interference contrast; DN: diabetic nephropathy; FSGS: focal segmental glomerulosclerosis; HG: high glucose; KO: knockout; LAMP1: lysosomal-associated membrane protein 1; LMP: lysosomal membrane permeabilization; MAP1LC3/LC3: microtubule-associated protein 1 light chain 3; PI3K: phosphoinositide 3-kinase; STZ: streptozotocin; TNF: tumor necrosis factor; TNFAIP2: tumor necrosis factor, alpha-induced protein 2; TNTs: tunneling nanotubes; WT: wild type. [ABSTRACT FROM AUTHOR]

Aging is associated with a gradual decline of cellular proteostasis, giving rise to devastating protein misfolding diseases, such as Alzheimer disease (AD) or Parkinson disease (PD). These diseases often exhibit a complex pathology involving non-cell autonomous proteotoxic effects, which are still poorly understood. Using Caenorhabditis elegans we investigated how local protein misfolding is affecting neighboring cells and tissues showing that misfolded PD-associated SNCA/α-synuclein is accumulating in highly dynamic endo-lysosomal vesicles. Irrespective of whether being expressed in muscle cells or dopaminergic neurons, accumulated proteins were transmitted into the hypodermis with increasing age, indicating that epithelial cells might play a role in remote degradation when the local endo-lysosomal degradation capacity is overloaded. Cell biological and genetic approaches revealed that inter-tissue dissemination of SNCA was regulated by endo- and exocytosis (neuron/muscle to hypodermis) and basement membrane remodeling (muscle to hypodermis). Transferred SNCA conformers were, however, inefficiently cleared and induced endo-lysosomal membrane permeabilization. Remarkably, reducing INS (insulin)-IGF1 (insulin-like growth factor 1) signaling provided protection by maintaining endo-lysosomal integrity. This study suggests that the degradation of lysosomal substrates is coordinated across different tissues in metazoan organisms. Because the chronic dissemination of poorly degradable disease proteins into neighboring tissues exerts a non-cell autonomous toxicity, this implies that restoring endo-lysosomal function not only in cells with pathological inclusions, but also in apparently unaffected cell types might help to halt disease progression. Abbreviations: AD: Alzheimer disease; BM: basement membrane; BWM: body wall muscle; CEP: cephalic sensilla; CLEM: correlative light and electron microscopy; CTNS-1: cystinosin (lysosomal protein) homolog; DA: dopaminergic; DAF-2: abnormal dauer formation; ECM: extracellular matrix; FLIM: fluorescence lifetime imaging microscopy; fps: frames per second; GFP: green fluorescent protein; HPF: high pressure freezing; IGF1: insulin-like growth factor 1; INS: insulin; KD: knockdown; LMP: lysosomal membrane permeabilization; MVB: multivesicular body; NOC: nocodazole; PD: Parkinson disease; RFP: red fluorescent protein; RNAi: RNA interference; sfGFP: superfolder GFP; SNCA: synuclein alpha; TEM: transmission electron microscopy; TNTs: tunneling nanotubes; TCSPC: time correlated single photon counting; YFP: yellow fluorescent protein. [ABSTRACT FROM AUTHOR]

Lysosomal membrane permeabilization (LMP) is observed under many pathological conditions, leading to cellular dysfunction and death. However, the mechanisms by which lysosomal membranes become leaky in vivo are not clear. Our data demonstrate that LMP occurs in neurons following controlled cortical impact induced (CCI) traumatic brain injury (TBI) in mice, leading to impaired macroautophagy (autophagy) and neuronal cell death. Comparison of LC-MS/MS lysosomal membrane lipid profiles from TBI and sham animals suggested a role for PLA2G4A/cPLA2 (phospholipase A2, group IVA [cytosolic, calcium-dependent]) in TBI-induced LMP. Activation of PLA2G4A caused LMP and inhibition of autophagy flux in cell lines and primary neurons. In vivo pharmacological inhibition of PLA2G4A attenuated TBI-induced LMP, as well as subsequent impairment of autophagy and neuronal loss, and was associated with improved neurological outcomes. Inhibition of PLA2G4A in vitro limited amyloid-β-induced LMP and inhibition of autophagy. Together, our data indicate that PLA2G4A -mediated lysosomal membrane damage is involved in neuronal cell death following CCI-induced TBI and potentially in other neurodegenerative disorders. Abbreviations: AACOCF3, arachidonyl trifluoromethyl ketone; ACTB/β-actin, actin, beta; AD, Alzheimer disease; ATG5, autophagy related 5; ATG7, autophagy related 7; ATG12, autophagy related 12; BECN1, beclin 1, autophagy related; C1P, ceramide-1-phosphate; CCI, controlled cortical impact; CTSD, cathepsin D; CTSL, cathepsin L; GFP, green fluorescent protein; IF, immunofluorescence; LAMP1, lysosomal-associated membrane protein 1; LAMP2, lysosomal-associated membrane protein 2; LC-MS/MS, liquid chromatography-tandem mass spectrometry; LMP, Lysosomal membrane permeabilization; LPC, lysophosphatidylcholine; LPE, lysophosphatidylethanolamine; MAP1LC3/LC3, microtuble-associated protein 1 light chain 3; NAGLU, alpha-N-acetylglucosaminidase (Sanfilippo disease IIIB); PC, diacyl glycerophosphatidylcholine; PE, diacyl glycerophosphatidylethanolamine; PE-O, plasmanyl glycerophosphatidylethanolamine; PE-P, plasmenyl glycerophosphatidylethanolamine; PLA2G4A/cPLA2, phospholipase A2, group IVA (cytosolic, calcium-dependent); RBFOX3, RNA binding protein, fox-1 homolog (C. elegans) 3; RFP, red fluorescent protein; ROS, reactive oxygen species; SQSTM1, sequestosome 1; TUBA1/α-tubulin, tubulin, alpha; TBI, traumatic brain injury; TFEB, transcription factor EB; ULK1, unc-51 like kinase 1. [ABSTRACT FROM AUTHOR]

Lysosomal ion channels are proposed therapeutic targets for a number of diseases, including those driven by NLRP3 inflammasome-mediated inflammation. Here, the specific role of the lysosomal big conductance Ca2+-activated K+ (BK) channel was evaluated in a silica model of inflammation in murine macrophages. A specific-inhibitor of BK channel function, paxilline (PAX), and activators NS11021 and NS1619 were utilized to evaluate the role of lysosomal BK channel activity in silica-induced lysosomal membrane permeabilization (LMP) and NLRP3 inflammasome activation resulting in IL-1β release. Murine macrophages were exposed in vitro to crystalline silica following pretreatment with BK channel inhibitors or activators and LMP, cell death, and IL-1β release were assessed. In addition, the effect of PAX treatment on silica-induced cytosolic K+ decrease was measured. Finally, the effects of BK channel modifiers on lysosomal pH, proteolytic activity, and cholesterol transport were also evaluated. PAX pretreatment significantly attenuated silica-induced cell death and IL-1β release. PAX caused an increase in lysosomal pH and decrease in lysosomal proteolytic activity. PAX also caused a significant accumulation of lysosomal cholesterol. BK channel activators NS11021 and NS1619 increased silica-induced cell death and IL-1β release. BK channel activation also caused a decrease in lysosomal pH and increase in lysosomal proteolytic function as well as a decrease in cholesterol accumulation. Taken together, these results demonstrate that inhibiting lysosomal BK channel activity with PAX effectively reduced silica-induced cell death and IL-1β release. Blocking cytosolic K+ entry into the lysosome prevented LMP through the decrease of lysosomal acidification and proteolytic function and increase in lysosomal cholesterol. [ABSTRACT FROM AUTHOR]

Colorectal cancer (CRC) is one of the most common malignancies worldwide and remains a major clinical challenge. Periplocin, a major bioactive component of the traditional Chinese herb Cortex periplocae, has recently been reported to be a potential anticancer drug. However, the mechanism of action is poorly understood. Here, we show that periplocin exhibits promising anticancer activity against CRC both in vitro and in vivo. Mechanistically, periplocin promotes lysosomal damage and induces apoptosis in CRC cells. Notably, periplocin upregulates LGALS3 (galectin 3) by binding and preventing LGALS3 from Lys210 ubiquitination-mediated proteasomal degradation, leading to the induction of excessive lysophagy and resultant exacerbation of lysosomal damage. Inhibition of LGALS3-mediated lysophagy attenuates periplocin-induced lysosomal damage and growth inhibition in CRC cells, suggesting a critical role of lysophagy in the anticancer effects of periplocin. Taken together, our results reveal a novel link between periplocin and the lysophagy machinery, and indicate periplocin as a potential therapeutic option for the treatment of CRC. Abbreviations: 3-MA: 3-methyladenine; ACACA/ACC1: acetyl-CoA carboxylase alpha; AMPK: adenosine monophosphate-activated protein kinase; AO: Acridine orange; ATG5: autophagy related 5; ATG7: autophagy related 7; CALM: calmodulin; CHX: cycloheximide; CRC: colorectal cancer; CQ: chloroquine; CTSB: cathepsin B; CTSD: cathepsin D; ESCRT: endosomal sorting complex required for transport; LAMP1: lysosomal associated membrane protein 1; LMP: lysosomal membrane permeabilization; MAP1LC3B/LC3B: microtubule associated protein 1 light chain 3 beta; MCOLN1/TRPML1: mucolipin TRP cation channel 1; MKI67/Ki-67: marker of proliferation Ki-67; MTOR: mechanistic target of rapamycin kinase; P2RX4/P2X4: purinergic receptor P2X 4; PARP1/PARP: poly(ADP-ribose) polymerase 1; PRKAA/AMPKα: protein kinase AMP-activated catalytic subunit alpha; SQSTM1/p62: sequestosome 1; TFEB: transcription factor EB; TRIM16: tripartite motif containing 16. [ABSTRACT FROM AUTHOR]

Differentiated tissue is particularly vulnerable to alterations in protein and organelle homeostasis. The essential protein VCP, mutated in hereditary inclusion body myopathy, amyotrophic lateral sclerosis and frontotemporal dementia, is critical for efficient clearance of misfolded proteins and damaged organelles in dividing cells, but its role in terminally differentiated tissue affected by disease mutations is less clear. To understand the relevance of VCP in differentiated tissue, we inactivated it in skeletal muscle of adult mice. Surprisingly, knockout muscle demonstrated a necrotic myopathy with increased macroautophagic/autophagic proteins and damaged lysosomes. This was not solely due to a defect in autophagic degradation because age-matched mice with muscle inactivation of the autophagy essential protein, ATG5, did not demonstrate a myopathy. Notably, myofiber necrosis was preceded by upregulation of LGALS3/Galectin-3, a marker of damaged lysosomes, and TFEB activation, suggesting early defects in the lysosomal system. Consistent with that, myofiber necrosis was recapitulated by chemical induction of lysosomal membrane permeabilization (LMP) in skeletal muscle. Moreover, TFEB was activated after LMP in cells, but activation and nuclear localization of TFEB persisted upon VCP inactivation or disease mutant expression. Our data identifies VCP as central mediator of both lysosomal clearance and biogenesis in skeletal muscle. Abbreviations: AAA: ATPases Associated with diverse cellular Activities; TUBA1A/α-tubulin: tubulin alpha 1a; ATG5: autophagy related 5; ATG7: autophagy related 7; ACTA1: actin alpha 1, skeletal muscle; CLEAR: coordinated lysosomal expression and regulation; CTSB/D: cathepsin B/D; Ctrl: control; DAPI: diamidino-2-phenylindole; EBSS: Earle's balanced salt solution; ELDR: endolysosomal damage response; ESCRT: endosomal sorting complexes required for transport; Gastroc/G: gastrocnemius; H&E: hematoxylin and eosin; HSPA5/GRP78: heat shock protein family A (Hsp70) member 5; IBMPFD/ALS: inclusion body myopathy associated with Paget disease of the bone, frontotemporal dementia and amyotrophic lateral sclerosis; i.p.: intraperitoneal; LAMP1/2: lysosomal-associated membrane protein 1/2; LLOMe: Leu-Leu methyl ester hydrobromide; LGALS3/Gal3: galectin 3; LMP: lysosomal membrane permeabilization; MTOR: mechanistic target of rapamycin kinase; MYL1: myosin light chain 1; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MSP: multisystem proteinopathy; PBS: phosphate-buffered saline; PCR: polymerase chain reaction; Quad/Q: quadriceps; RHEB: Ras homolog, mTORC1 binding; SQSTM1: sequestosome 1; TFEB: transcription factor EB; TA: tibialis anterior; siRNA: small interfering RNA; SQSTM1/p62, sequestosome 1; TARDBP/TDP-43: TAR DNA binding protein; TBS: Tris-buffered saline; TXFN, tamoxifen; UBXN6/UBXD1: UBX domain protein 6; VCP: valosin containing protein; WT: wild-type. [ABSTRACT FROM AUTHOR]

Mutations in the PKD1 gene result in autosomal dominant polycystic kidney disease (ADPKD), the most common monogenetic cause of end-stage renal disease (ESRD) in humans. Previous reports suggested that PKD1, together with PKD2/polycystin-2, may function as a receptor-cation channel complex at cilia and on intracellular membranes and participate in various signaling pathways to regulate cell survival, proliferation and macroautophagy/autophagy. However, the exact molecular function of PKD1 and PKD2 has remained enigmatic. Here we used Pkd1-deficient mouse inner medullary collecting duct cells (mIMCD3) genetically deleted for Pkd1, and tubular epithelial cells isolated from nephrons of doxycycline-inducible conditional pkd1fl/fl;Pax8rtTA;TetOCre+ knockout mice to show that the lack of Pkd1 caused diminished lysosomal acidification, LAMP degradation and reduced CTSB/cathepsin B processing and activity. This led to an impairment of autophagosomal-lysosomal fusion, a lower delivery of ubiquitinated cargo from multivesicular bodies (MVB)/exosomes to lysosomes and an enhanced secretion of unprocessed CTSB into the extracellular space. The TFEB-dependent lysosomal biogenesis pathway was however unaffected. Pkd1-deficient cells exhibited increased activity of the calcium-dependent CAPN (calpain) proteases, probably due to a higher calcium influx. Consistent with this notion CAPN inhibitors restored lysosomal function, CTSB processing/activity and autophagosomal-lysosomal fusion, and blocked CTSB secretion and LAMP degradation in pkd1 knockout cells. Our data reveal for the first time a lysosomal function of PKD1 which keeps CAPN activity in check and ensures lysosomal integrity and a correct autophagic flux. Abbreviations: acCal: acetyl-calpastatin peptide; ADPKD: autosomal dominant polycystic kidney disease; CI-1: calpain inhibitor-1; CQ: chloroquine; Dox: doxycycline; EV: extracellular vesicles; EXO: exosomes; LAMP1/2: lysosomal-associated membrane protein 1/2; LGALS1/GAL1/galectin-1: lectin, galactose binding, soluble 1; LMP: lysosomal membrane permeabilization; mIMCD3: mouse inner medullary collecting duct cells; MV: microvesicles; MVB: multivesicular bodies; PAX8: paired box 8; PKD1/polycystin-1: polycystin 1, transient receptor potential channel interacting; PKD2/polycystin-2: polycystin 2, transient receptor potential cation channel; Tet: tetracycline; TFEB: transcription factor EB; VFM: vesicle-free medium; WT: wild-type. [ABSTRACT FROM AUTHOR]

Background: While the role of lysosomal membrane permeabilization (LMP) in NP-induced inflammatory responses has been recognized, the underlying mechanism of LMP is still unclear. The assumption has been that zinc oxide (ZnO)-induced LMP is due to Zn2+; however, little is known about the role of ZnO nanoparticles (NP) in toxicity. Methods: We examined the contribution of intact ZnO NP on membrane permeability using red blood cells (RBC) and undifferentiated THP-1 cells as models of particle-membrane interactions to simulate ZnO NP-lysosomal membrane interaction. The integrity of plasma membranes was evaluated by transmission electron microscopy (TEM) and confocal microscopy. ZnO NP dissolution was determined using ZnAF-2F, Zn2+ specific probe. The stability of ZnO NP inside the phagolysosomes of phagocytic cells, differentiated THP-1, alveolar macrophages, and bone marrow-derived macrophages, was determined. Results: ZnO NP caused significant hemolysis and cytotoxicity under conditions of negligible dissolution. Fully ionized Zn2SO4 caused slight hemolysis, while partially ionized ZnO induced significant hemolysis. Confocal microscopy and TEM images did not reveal membrane disruption in RBC and THP-1 cells, respectively. ZnO NP remained intact inside the phagolysosomes after a 4 h incubation with phagocytic cells. Conclusions: These studies demonstrate the ability of intact ZnO NP to induce membrane permeability and cytotoxicity without the contribution of dissolved Zn2+, suggesting that ZnO NP toxicity does not necessarily depend upon Zn2+. The stability of ZnO NP inside the phagolysosomes suggests that LMP is the result of the toxic effect of intact ZnO NP on phagolysosomal membranes. [ABSTRACT FROM AUTHOR]

Macroautophagy/autophagy, a defense mechanism against aberrant stresses, in neurons counteracts aggregate-prone misfolded protein toxicity. Autophagy induction might be beneficial in neurodegenerative diseases (NDs). The natural compound trehalose promotes autophagy via TFEB (transcription factor EB), ameliorating disease phenotype in multiple ND models, but its mechanism is still obscure. We demonstrated that trehalose regulates autophagy by inducing rapid and transient lysosomal enlargement and membrane permeabilization (LMP). This effect correlated with the calcium-dependent phosphatase PPP3/calcineurin activation, TFEB dephosphorylation and nuclear translocation. Trehalose upregulated genes for the TFEB target and regulator Ppargc1a, lysosomal hydrolases and membrane proteins (Ctsb, Gla, Lamp2a, Mcoln1, Tpp1) and several autophagy-related components (Becn1, Atg10, Atg12, Sqstm1/p62, Map1lc3b, Hspb8 and Bag3) mostly in a PPP3- and TFEB-dependent manner. TFEB silencing counteracted the trehalose pro-degradative activity on misfolded protein causative of motoneuron diseases. Similar effects were exerted by trehalase-resistant trehalose analogs, melibiose and lactulose. Thus, limited lysosomal damage might induce autophagy, perhaps as a compensatory mechanism, a process that is beneficial to counteract neurodegeneration. Abbreviations: ALS: amyotrophic lateral sclerosis; AR: androgen receptor; ATG: autophagy related; AV: autophagic vacuole; BAG3: BCL2-associated athanogene 3; BECN1: beclin 1, autophagy related; CASA: chaperone-assisted selective autophagy; CTSB: cathepsin b; DAPI: 4ʹ,6-diamidino-2-phenylindole; DMEM: Dulbecco's modified Eagle's medium; EGFP: enhanced green fluorescent protein; fALS, familial amyotrophic lateral sclerosis; FRA: filter retardation assay; GAPDH: glyceraldehyde-3-phosphate dehydrogenase; GLA: galactosidase, alpha; HD: Huntington disease; hIPSCs: human induced pluripotent stem cells; HSPA8: heat shock protein A8; HSPB8: heat shock protein B8; IF: immunofluorescence analysis; LAMP1: lysosomal-associated membrane protein 1; LAMP2A: lysosomal-associated membrane protein 2A; LGALS3: lectin, galactose binding, soluble 3; LLOMe: L-leucyl-L-leucine methyl ester; LMP: lysosomal membrane permeabilization; Lys: lysosomes; MAP1LC3B: microtubule-associated protein 1 light chain 3 beta; MCOLN1: mucolipin 1; mRNA: messenger RNA; MTOR: mechanistic target of rapamycin kinase; NDs: neurodegenerative diseases; NSC34: neuroblastoma x spinal cord 34; PBS: phosphate-buffered saline; PD: Parkinson disease; polyQ: polyglutamine; PPARGC1A: peroxisome proliferative activated receptor, gamma, coactivator 1 alpha; PPP3CB: protein phosphatase 3, catalytic subunit, beta isoform; RT-qPCR: real-time quantitative polymerase chain reaction; SBMA: spinal and bulbar muscular atrophy; SCAs: spinocerebellar ataxias; siRNA: small interfering RNA; SLC2A8: solute carrier family 2, (facilitated glucose transporter), member 8; smNPCs: small molecules neural progenitors cells; SOD1: superoxide dismutase 1; SQSTM1/p62: sequestosome 1; STED: stimulated emission depletion; STUB1: STIP1 homology and U-box containing protein 1; TARDBP/TDP-43: TAR DNA binding protein; TFEB: transcription factor EB; TPP1: tripeptidyl peptidase I; TREH: trehalase (brush-border membrane glycoprotein); WB: western blotting; ZKSCAN3: zinc finger with KRAB and SCAN domains 3 [ABSTRACT FROM AUTHOR]

Cells challenged by photosensitized oxidations face strong redox stresses and rely on autophagy to either survive or die. However, the use of macroautophagy/autophagy to improve the efficiency of photosensitizers, in terms of inducing cell death, remains unexplored. Here, we addressed the concept that a parallel damage in the membranes of mitochondria and lysosomes leads to a scenario of autophagy malfunction that can greatly improve the efficiency of the photosensitizer to cause cell death. Specific damage to these organelles was induced by irradiation of cells pretreated with 2 phenothiazinium salts, methylene blue (MB) and 1,9-dimethyl methylene blue (DMMB). At a low concentration level (10 nM), only DMMB could induce mitochondrial damage, leading to mitophagy activation, which did not progress to completion because of the parallel damage in lysosome, triggering cell death. MB-induced photodamage was perceived almost instantaneously after irradiation, in response to a massive and nonspecific oxidative stress at a higher concentration range (2 µM). We showed that the parallel damage in mitochondria and lysosomes activates and inhibits mitophagy, leading to a late and more efficient cell death, offering significant advantage (2 orders of magnitude) over photosensitizers that cause unspecific oxidative stress. We are confident that this concept can be used to develop better light-activated drugs. Abbreviations: ΔΨm: mitochondrial transmembrane inner potential; AAU: autophagy arbitrary units; ATG5, autophagy related 5; ATG7: autophagy related 7; BAF: bafilomycin A1; BSA: bovine serum albumin; CASP3: caspase 3; CF: carboxyfluorescein; CTSB: cathepsin B; CVS: crystal violet staining; DCF: dichlorofluorescein; DCFH2: 2ʹ,7ʹ-dichlorodihydrofluorescein; DMMB: 1,9-dimethyl methylene blue; ER: endoplasmic reticulum; HaCaT: non-malignant immortal keratinocyte cell line from adult human skin; HP: hydrogen peroxide; LC3B-II: microtubule associated protein 1 light chain 3 beta-II; LMP: lysosomal membrane permeabilization; LTG: LysoTracker™ Green DND-26; LTR: LysoTracker™ Red DND-99; 3-MA: 3-methyladenine; MB: methylene blue; mtDNA: mitochondrial DNA; MitoSOX™: red mitochondrial superoxide probe; MTDR: MitoTracker™ Deep Red FM; MTO: MitoTracker™ Orange CMTMRos; MT-ND1: mitochondrially encoded NADH:ubiquinone oxidoreductase core subunit 1; MTT: methylthiazolyldiphenyl-tetrazolium bromide; 1O2: singlet oxygen; OH. hydroxil radical; PRKN/parkin: parkin RBR E3 ubiquitin protein ligase; PBS: phosphate-buffered saline; PI: propidium iodide; PDT: photodynamic therapy; PS: photosensitizer; QPCR: gene-specific quantitative PCR-based; Rh123: rhodamine 123; ROS: reactive oxygen species RTN: rotenone; SQSTM1/p62: sequestosome 1; SUVs: small unilamellar vesicles; TBS: Tris-buffered saline [ABSTRACT FROM AUTHOR]

Sepsis-associated acute kidney injury (S-AKI) is a common disease in pediatric intensive care units (ICU) with high morbidity and mortality. The newly discovered results indicate that microRNAs (miRNAs) play an important role in the diagnosis and treatment of S-AKI and can be used as markers for early diagnosis. In this study, the expression level of miR-16-5p was found to be significantly upregulated about 20-fold in S-AKI patients, and it also increased by 1.9 times in the renal tissue of S-AKI mice. Receiver operating characteristic (ROC) curve analysis showed that miR-16-5p had the highest predictive accuracy in the diagnosis of S-AKI (AUC = 0.9188). In vitro, the expression level of miR-16-5p in HK-2 cells treated with 10 μg/mL lipopolysaccharide (LPS) increased by more than 2 times. In addition, LPS-exposed renal tissue and HK-2 cells lead to upregulation of inflammatory cytokines IL-6, IL-1β, TNF-a, and kidney damage molecules kidney injury molecule-1 (KIM-1), neutrophil gelatinase-associated lipocalin (NGAL). However, inhibition of miR-16-5p significantly mitigated LPS expose-mediated kidney injury and inflammation. Furthermore, LPS-exposed HK-2 cells increased more than 1.7-fold the expression levels of Bax and caspase-3, decreased 3.2-fold the expression level of B-cell lymphoma-2 (Bcl-2), and significantly promoted the occurrence of apoptosis. MiR-16-5p mimic further increased LPS-induced apoptosis in HK-2 cells. Nevertheless, inhibition of miR-16-5p significantly attenuated this effect. In summary, up-regulation of miR-16-5p expression can significantly aggravate renal injury and apoptosis in S-AKI, which also proves that miR-16-5p can be used as a potential biomarker to promote early identification of S-AKI. [ABSTRACT FROM AUTHOR]

Liposomes are versatile platforms to carry anticancer drugs in targeted drug delivery; they can be surface modified by different strategies and, when coupled with targeting ligands, are able to increase cellular internalisation and organelle-specific drug delivery. An interesting strategy of antitumoral therapy could involve the use of lysosomotropic ligand-targeted liposomes loaded with molecules, which can induce lysosomal membrane permeabilization (LMP), leakage of cathepsins into the cytoplasm and subsequent apoptosis. We have previously demonstrated the ability of liposomes functionalised with a mannose-6-phosphate to reach lysosomes; in this research we compare the behaviour of M6P-modified and non-functionalised liposomes in MCF7 tumour cell and in HDF normal cells. With this aim, we first demonstrated by Western blotting the overexpression of mannose-6-phosphate/insulin-like growth factor (M6P/IGF-II) receptor in MCF7. Then, we prepared calcein-loaded liposomes and we revealed the increased uptake of M6P-functionalised liposomes in MCF7 cells respect to HDF cells by flow cytometry analysis. Finally, we loaded functionalised and not functionalised liposomes with N-hexanoyl-d-erythro-sphingosine (C6Cer), able to initiate LMP-induced apoptosis; after having studied the stability of both vesicles in the presence of serum by Dynamic Light Scattering and Spectrophotometric turbidity measurements, we showed that ceramide-loaded M6P-liposomes significantly increased apoptosis in MCF7 with respect to HDF cells. [ABSTRACT FROM AUTHOR]

Lysosomal membrane permeabilization or full rupture of lysosomes is a common and severe stress condition that is relevant for degenerative disease, infection and cancer. Cells respond with extensive ubiquitination of damaged lysosomes, which triggers selective macroautophagy/autophagy of the whole organelle, termed lysophagy. We screened an siRNA library targeting human E2-conjugating enzymes and identified UBE2QL1 as critical for efficient lysosome ubiquitination after chemically-induced lysosomal damage. UBE2QL1 translocates to lysosomes upon damage and associates with autophagy regulators. Loss of UBE2QL1-mediated ubiquitination reduces association of the autophagy receptor SQSTM1/p62 and the LC3-decorated phagophore, and prevents recruitment of the ubiquitin-targeted AAA-ATPase VCP/p97 that facilitates lysophagy. Even in unchallenged cells, UBE2QL1 depletion leads to MTOR dissociation and TFEB activation, and mutation of the homolog UBC-25 destabilizes lysosomes in C. elegans, indicating that UBE2QL1 is critical for maintaining lysosome integrity in addition to lysophagy. [ABSTRACT FROM AUTHOR]

Sepsis-associated acute kidney injury (S-AKI) is a common disease in pediatric intensive care units (ICU) with high morbidity and mortality. The newly discovered results indicate that microRNAs (miRNAs) play an important role in the diagnosis and treatment of S-AKI and can be used as markers for early diagnosis. In this study, the expression level of miR-16-5p was found to be significantly upregulated about 20-fold in S-AKI patients, and it also increased by 1.9 times in the renal tissue of S-AKI mice. Receiver operating characteristic (ROC) curve analysis showed that miR-16-5p had the highest predictive accuracy in the diagnosis of S-AKI (AUC = 0.9188). In vitro, the expression level of miR-16-5p in HK-2 cells treated with 10μg/mL lipopolysaccharide (LPS) increased by more than 2 times. In addition, LPS-exposed renal tissue and HK-2 cells lead to upregulation of inflammatory cytokines IL-6, IL-1β, TNF-a, and kidney damage molecules kidney injury molecule-1 (KIM-1), neutrophil gelatinase-associated lipocalin (NGAL). However, inhibition of miR-16-5p significantly mitigated LPS expose-mediated kidney injury and inflammation. Furthermore, LPS-exposed HK-2 cells increased more than 1.7-fold the expression levels of Bax and caspase-3, decreased 3.2-fold the expression level of B-cell lymphoma-2 (Bcl-2), and significantly promoted the occurrence of apoptosis. MiR-16-5p mimic further increased LPS-induced apoptosis in HK-2 cells. Nevertheless, inhibition of miR-16-5p significantly attenuated this effect. In summary, up-regulation of miR-16-5p expression can significantly aggravate renal injury and apoptosis in S-AKI, which also proves that miR-16-5p can be used as a potential biomarker to promote early identification of S-AKI. [ABSTRACT FROM AUTHOR]

Brain tumor accounts for about 1.6% of incidence and 2.5% of mortality of all tumors, and the median survival for brain tumor patients is only about 20 months. The treatment for brain tumor still faces many challenges, such as the blood-brain barrier (BBB), blood-brain tumor barrier (BBTB), the overexpressed efflux pumps, the infiltration, invasion, high heterogeneity of tumor cells, drug resistance and immune escape caused by tumor microenvironment (TME) and cancer stem cells (CSC). This review attempts to clarify the challenges for multi-functional nano drug delivery systems (NDDS) to cross the BBB and target the cancer cells or organelles, and also provides a brief description of the different types of targeted multi-functional NDDS that have shown potential for success in delivering drugs to the brain. Further, this review also summarizes the research progress of multi-functional NDDS in the combination therapy of brain tumors from the following sections, the combination of chemotherapy drugs, chemotherapy-chemodynamic combination therapy, chemotherapy-immunization combination therapy, and chemotherapy-gene combination therapy. We also provide an insight into the recent advances in designing multi-functional NDDS for combination therapy. [ABSTRACT FROM AUTHOR]

Ferroptosis is an emerging and novel type of iron-dependent programmed cell death which is mainly caused by the excessive deposition of free intracellular iron in the brain cells. This deposited free iron exerts a ferroptosis pathway, resulting in lipid peroxidation (LiPr). There are mainly three ferroptosis pathways viz. iron metabolism-mediated cysteine/glutamate, and LiPr-mediated. Iron is required by the brain as a redox metal for several physiological activities. Due to the iron homeostasis balance disruption, the brain gets adversely affected which further causes neurodegenerative diseases (NDDs) like Parkinson's and Alzheimer's disease, strokes, and brain tumors like glioblastoma (GBS), and glioma. Nanotechnology has played an important role in the prevention and treatment of these NDDs. A synergistic effect of nanomaterials and ferroptosis could prove to be an effective and efficient approach in the field of nanomedicine. In the current review, the authors have highlighted all the latest research in the field of ferroptosis, specifically emphasizing on the role of major molecular key players and various mechanisms involved in the ferroptosis pathway. Moreover, here the authors have also addressed the correlation of ferroptosis with the pathophysiology of NDDs and theragnostic effect of ferroptosis and nanomaterials for the prevention and treatment of NDDs. [ABSTRACT FROM AUTHOR]

Inter-organelle contacts enable crosstalk among organelles, facilitating the exchange of materials and coordination of cellular events. In this study, we demonstrated that, upon starvation, autolysosomes recruit Pi4KIIα (Phosphatidylinositol 4-kinase II α) to generate phosphatidylinositol−4-phosphate (PtdIns4P) on their surface and establish endoplasmic reticulum (ER)-autolysosome contacts through PtdIns4P binding proteins Osbp (Oxysterol binding protein) and cert (ceramide transfer protein). We found that the Sac1 (Sac1 phosphatase), Osbp, and cert proteins are required for the reduction of PtdIns4P on autolysosomes. Loss of any of these proteins leads to defective macroautophagy/autophagy and neurodegeneration. Osbp, cert, and Sac1 are required for ER-Golgi contacts in fed cells. Our data establishes a new mode of organelle contact formation – the ER-Golgi contact machinery can be reused by ER-autolysosome contacts by re-locating PtdIns4P from the Golgi apparatus to autolysosomes when faced with starvation. Abbreviations: Atg1: Autophagy-related 1; Atg8: Autophagy-related 8; Atg9: Autophagy-related 9; Atg12: Autophagy-related 12; cert: ceramide transfer protein; Cp1/CathL: cysteine proteinase−1; CTL: control; ER: endoplasmic reticulum; ERMCS: ER-mitochondria contact site; fwd: four wheel drive; GM130: Golgi matrix protein 130 kD; Osbp: Oxysterol binding protein; PG: phagophore; PtdIns4K: phosphatidylinositol 4-kinase; Pi4KIIα: Phosphatidylinositol 4-kinase II α; Pi4KIIIα: Phosphatidylinositol 4-kinase III α; PtdIns4P: phosphatidylinositol−4-phosphate; PR: photoreceptor cell; RT: room temperature; Sac1: Sac1 phosphatase; Stv: starvation; Syx17: Syntaxin 17; TEM: transmission electron microscopy; VAP: VAMP-associated protein. [ABSTRACT FROM AUTHOR]

Nearly fifty million older people suffer from neurodegenerative diseases, including Alzheimer (AD) and Parkinson (PD) disease, a global burden expected to triple by 2050. Such an imminent "neurological pandemic" urges the identification of environmental risk factors that are hopefully avoided to fight the disease. In 2022, strong evidence in mouse models incriminated defective lysosomal acidification and impairment of the autophagy pathway as modifiable risk factors for dementia. To date, the most prescribed lysosomotropic drugs are proton pump inhibitors (PPIs), chloroquine (CQ), and the related hydroxychloroquine (HCQ), which belong to the group of disease-modifying antirheumatic drugs (DMARDs). This commentary aims to open the discussion on the possible mechanisms connecting the long-term prescribing of these drugs to the elderly and the incidence of neurodegenerative diseases. Abbreviations: AD: Alzheimer disease; APP-βCTF: amyloid beta precursor protein-C-terminal fragment; BACE1: beta-secretase 1; BBB: brain blood barrier; CHX: Ca2+/H+ exchanger; CMI: cognitive mild impairment; CQ: chloroquine; DMARD: disease-modifying antirheumatic drugs; GBA1: glucosylceramidase beta 1; HCQ: hydroxychloroquine; HPLC: high-performance liquid chromatography; LAMP: lysosomal associated membrane protein; MAPK/JNK: mitogen-activated protein kinase; MAPT: microtubule associated protein tau; MCOLN1/TRPML1: mucolipin TRP cation channel 1; NFE2L2/NRF2: NFE2 like bZIP transcription factor 2; NRBF2: nuclear receptor binding factor 2; PANTHOS: poisonous flower; PD: Parkinson disease; PIK3C3: phosphatIdylinositol 3-kinase catalytic subunit type 3; PPI: proton pump inhibitor; PSEN1: presenilin 1, RUBCN: rubicon autophagy regulator; RUBCNL: rubicon like autophagy enhancer; SQSTM1: sequestosome 1; TMEM175: transmembrane protein 175; TPCN2: two pore segment channel 2; VATPase: vacuolar-type H+-translocating ATPase; VPS13C: vacuolar protein sorting ortholog 13 homolog C; VPS35: VPS35 retromer complex component; WDFY3: WD repeat and FYVE domain containing 3; ZFYVE1: zinc finger FYVE-type containing 1. [ABSTRACT FROM AUTHOR]

Copper is an essential trace element in biological systems, maintaining the activity of enzymes and the function of transcription factors. However, at high concentrations, copper ions show increased toxicity by inducing regulated cell death, such as apoptosis, paraptosis, pyroptosis, ferroptosis, and cuproptosis. Furthermore, copper ions can trigger macroautophagy/autophagy, a lysosome-dependent degradation pathway that plays a dual role in regulating the survival or death fate of cells under various stress conditions. Pathologically, impaired copper metabolism due to environmental or genetic causes is implicated in a variety of human diseases, such as rare Wilson disease and common cancers. Therapeutically, copper-based compounds are potential chemotherapeutic agents that can be used alone or in combination with other drugs or approaches to treat cancer. Here, we review the progress made in understanding copper metabolic processes and their impact on the regulation of cell death and autophagy. This knowledge may help in the design of future clinical tools to improve cancer diagnosis and treatment. Abbreviations: ACSL4, acyl-CoA synthetase long chain family member 4; AIFM1/AIF, apoptosis inducing factor mitochondria associated 1; AIFM2, apoptosis inducing factor mitochondria associated 2; ALDH, aldehyde dehydrogenase; ALOX, arachidonate lipoxygenase; AMPK, AMP-activated protein kinase; APAF1, apoptotic peptidase activating factor 1; ATF4, activating transcription factor 4; ATG, autophagy related; ATG13, autophagy related 13; ATG5, autophagy related 5; ATOX1, antioxidant 1 copper chaperone; ATP, adenosine triphosphate; ATP7A, ATPase copper transporting alpha; ATP7B, ATPase copper transporting beta; BAK1, BCL2 antagonist/killer 1; BAX, BCL2 associated X apoptosis regulator; BBC3/PUMA, BCL2 binding component 3; BCS, bathocuproinedisulfonic acid; BECN1, beclin 1; BID, BH3 interacting domain death agonist; BRCA1, BRCA1 DNA repair associated; BSO, buthionine sulphoximine; CASP1, caspase 1; CASP3, caspase 3; CASP4/CASP11, caspase 4; CASP5, caspase 5; CASP8, caspase 8; CASP9, caspase 9; CCS, copper chaperone for superoxide dismutase; CD274/PD-L1, CD274 molecule; CDH2, cadherin 2; CDKN1A/p21, cyclin dependent kinase inhibitor 1A; CDKN1B/p27, cyclin-dependent kinase inhibitor 1B; COMMD10, COMM domain containing 10; CoQ10, coenzyme Q 10; CoQ10H2, reduced coenzyme Q 10; COX11, cytochrome c oxidase copper chaperone COX11; COX17, cytochrome c oxidase copper chaperone COX17; CP, ceruloplasmin; CYCS, cytochrome c, somatic; DBH, dopamine beta-hydroxylase; DDIT3/CHOP, DNA damage inducible transcript 3; DLAT, dihydrolipoamide S-acetyltransferase; DTC, diethyldithiocarbamate; EIF2A, eukaryotic translation initiation factor 2A; EIF2AK3/PERK, eukaryotic translation initiation factor 2 alpha kinase 3; ER, endoplasmic reticulum; ESCRT-III, endosomal sorting complex required for transport-III; ETC, electron transport chain; FABP3, fatty acid binding protein 3; FABP7, fatty acid binding protein 7; FADD, Fas associated via death domain; FAS, Fas cell surface death receptor; FASL, Fas ligand; FDX1, ferredoxin 1; GNAQ/11, G protein subunit alpha q/11; GPX4, glutathione peroxidase 4; GSDMD, gasdermin D; GSH, glutathione; HDAC, histone deacetylase; HIF1, hypoxia inducible factor 1; HIF1A, hypoxia inducible factor 1 subunit alpha; HMGB1, high mobility group box 1; IL1B, interleukin 1 beta; IL17, interleukin 17; KRAS, KRAS proto-oncogene, GTPase; LOX, lysyl oxidase; LPCAT3, lysophosphatidylcholine acyltransferase 3; MAP1LC3, microtubule associated protein 1 light chain 3; MAP2K1, mitogen-activated protein kinase kinase 1; MAP2K2, mitogen-activated protein kinase kinase 2; MAPK, mitogen-activated protein kinases; MAPK14/p38, mitogen-activated protein kinase 14; MEMO1, mediator of cell motility 1; MT-CO1/COX1, mitochondrially encoded cytochrome c oxidase I; MT-CO2/COX2, mitochondrially encoded cytochrome c oxidase II; MTOR, mechanistic target of rapamycin kinase; MTs, metallothioneins; NAC, N-acetylcysteine; NFKB/NF-Κb, nuclear factor kappa B; NLRP3, NLR family pyrin domain containing 3; NPLOC4/NPL4, NPL4 homolog ubiquitin recognition factor; PDE3B, phosphodiesterase 3B; PDK1, phosphoinositide dependent protein kinase 1; PHD, prolyl-4-hydroxylase domain; PIK3C3/VPS34, phosphatidylinositol 3-kinase catalytic subunit type 3; PMAIP1/NOXA, phorbol-12-myristate-13-acetate-induced protein 1; POR, cytochrome P450 oxidoreductase; PUFA-PL, PUFA of phospholipids; PUFAs, polyunsaturated fatty acids; ROS, reactive oxygen species; SCO1, synthesis of cytochrome C oxidase 1; SCO2, synthesis of cytochrome C oxidase 2; SLC7A11, solute carrier family 7 member 11; SLC11A2/DMT1, solute carrier family 11 member 2; SLC31A1/CTR1, solute carrier family 31 member 1; SLC47A1, solute carrier family 47 member 1; SOD1, superoxide dismutase; SP1, Sp1 transcription factor; SQSTM1/p62, sequestosome 1; STEAP4, STEAP4 metalloreductase; TAX1BP1, Tax1 binding protein 1; TEPA, tetraethylenepentamine; TFEB, transcription factor EB; TM, tetrathiomolybdate; TP53/p53, tumor protein p53; TXNRD1, thioredoxin reductase 1; UCHL5, ubiquitin C-terminal hydrolase L5; ULK1, Unc-51 like autophagy activating kinase 1; ULK1, unc-51 like autophagy activating kinase 1; ULK2, unc-51 like autophagy activating kinase 2; USP14, ubiquitin specific peptidase 14; VEGF, vascular endothelial gro wth factor; XIAP, X-linked inhibitor of apoptosis [ABSTRACT FROM AUTHOR]

Impaired activities and abnormally enlarged structures of endolysosomes are frequently observed in Alzheimer disease (AD) brains. However, little is known about whether and how endolysosomal dysregulation is triggered and associated with AD. Here, we show that vacuolar ATPase (V-ATPase) is a hub that mediates proteopathy of oligomeric amyloid beta (Aβ) and hyperphosphorylated MAPT/Tau (p-MAPT/Tau). Endolysosomal integrity was largely destroyed in Aβ-overloaded or p-MAPT/Tau-positive neurons in culture and AD brains, which was a necessary step for triggering neurotoxicity, and treatments with acidic nanoparticles or endocytosis inhibitors rescued the endolysosomal impairment and neurotoxicity. Interestingly, we found that the lumenal ATP6V0C and cytosolic ATP6V1B2 subunits of the V-ATPase complex bound to the internalized Aβ and cytosolic PHF-1-reactive MAPT/Tau, respectively. Their interactions disrupted V-ATPase activity and accompanying endolysosomal activity in vitro and induced neurodegeneration. Using a genome-wide functional screen, we isolated a suppressor, HYAL (hyaluronidase), which reversed the endolysosomal dysfunction and proteopathy and alleviated the memory impairment in 3xTg-AD mice. Further, we found that its metabolite hyaluronic acid (HA) and HA receptor CD44 attenuated neurotoxicity in affected neurons via V-ATPase. We propose that endolysosomal V-ATPase is a bona fide proteotoxic receptor that binds to pathogenic proteins and deteriorates endolysosomal function in AD, leading to neurodegeneration in proteopathy. Abbreviations: AAV, adeno-associated virus; Aβ, amyloid beta; AD, Alzheimer disease; APP, amyloid beta precursor protein; ATP6V0C, ATPase H+ transporting V0 subunit c; ATP6V1A, ATPase H+ transporting V1 subunit A; ATP6V1B2, ATPase H+ transporting V1 subunit B2; CD44.Fc, CD44-mouse immunoglobulin Fc fusion construct; Co-IP, co-immunoprecipitation; CTSD, cathepsin D; HA, hyaluronic acid; HMWHA, high-molecular-weight hyaluronic acid; HYAL, hyaluronidase; i.c.v, intracerebroventricular; LMWHA, low-molecular-weight hyaluronic acid; NPs, nanoparticles; p-MAPT/Tau, hyperphosphorylated microtubule associated protein tau; PI3K, phosphoinositide 3-kinase; V-ATPase, vacuolar-type H+-translocating ATPase; WT, wild-type [ABSTRACT FROM AUTHOR]

Guanine-quadruplex structures (G4) are unusual nucleic acid conformations formed by guanine-rich DNA and RNA sequences and known to control gene expression mechanisms, from transcription to protein synthesis. So far, a number of molecules that recognize G4 have been developed for potential therapeutic applications in human pathologies, including cancer and infectious diseases. These molecules are called G4 ligands. When the biological effects of G4 ligands are studied, the analysis is often limited to nucleic acid targets. However, recent evidence indicates that G4 ligands may target other cellular components and compartments such as lysosomes and mitochondria. Here, we summarize our current knowledge of the regulation of lysosome by G4 ligands, underlying their potential functional impact on lysosome biology and autophagic flux, as well as on the transcriptional regulation of lysosomal genes. We outline the consequences of these effects on cell fate decisions and we systematically analyzed G4-prone sequences within the promoter of 435 lysosome-related genes. Finally, we propose some hypotheses about the mechanisms involved in the regulation of lysosomes by G4 ligands. [ABSTRACT FROM AUTHOR]

Overexpression of PTP4A phosphatases are associated with advanced cancers, but their biological functions are far from fully understood due to limited knowledge about their physiological substrates. VCP is implicated in lysophagy via collaboration with specific cofactors in the ELDR complex. However, how the ELDR complex assembly is regulated has not been determined. Moreover, the functional significance of the penultimate and conserved Tyr805 phosphorylation in VCP has not been established. Here, we use an unbiased substrate trapping and mass spectrometry approach and identify VCP/p97 as a bona fide substrate of PTP4A2. Biochemical studies show that PTP4A2 dephosphorylates VCP at Tyr805, enabling the association of VCP with its C-terminal cofactors UBXN6/UBXD1 and PLAA, which are components of the ELDR complex responsible for lysophagy, the autophagic clearance of damaged lysosomes. Functionally, PTP4A2 is required for cellular homeostasis by promoting lysophagy through facilitating ELDR-mediated K48-linked ubiquitin conjugate removal and autophagosome formation on the damaged lysosomes. Deletion of Ptp4a2 in vivo compromises the recovery of glycerol-injection induced acute kidney injury due to impaired lysophagy and sustained lysosomal damage. Taken together, our data establish PTP4A2 as a critical regulator of VCP and uncover an important role for PTP4A2 in maintaining lysosomal homeostasis through dephosphorylation of VCP at Tyr805. Our study suggests that PTP4A2 targeting could be a potential therapeutic approach to treat cancers and other degenerative diseases by modulating lysosomal homeostasis and macroautophagy/autophagy. Abbreviations: AAA+: ATPases associated with diverse cellular activities; AKI: acute kidney injury; CBB: Coomassie Brilliant Blue; CRISPR: clustered regularly interspaced short palindromic repeats; ELDR: endo-lysosomal damage response; GFP: green fluorescent protein; GST: ‎glutathione S-transferase; IHC: immunohistochemistry; IP: immunoprecipitation; LAMP1: lysosomal-associated membrane protein 1; LC-MS: liquid chromatography-mass spectrometry; LGALS3/Gal3: galectin 3; LLOMe: L-leucyl-L-leucine methyl ester; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MEF: mouse embryonic fibroblast; PLAA: phospholipase A2, activating protein; PTP4A2: protein tyrosine phosphatase 4a2; PUB: NGLY1/PNGase/UBA- or UBX-containing protein; PUL: PLAP, Ufd3, and Lub1; TFEB: transcription factor EB; UBXN6/UBXD1: UBX domain protein 6; UPS: ubiquitin-proteasome system; VCP/p97: valosin containing protein; VCPIP1: valosin containing protein interacting protein 1; YOD1: YOD1 deubiquitinase. [ABSTRACT FROM AUTHOR]

This review provides a description of the historical background of the development of biological applications of low-temperature plasmas. The generation of plasma, methods and devices, plasma sources, and measurements of plasma properties, such as electron dynamics and chemical species generation in both gaseous and aqueous phases, were assessed. Currently, direct irradiation methods for plasma discharges contacting biological surfaces, such as the skin and teeth, are related to plasma biological interactions. Indirect methods using plasma-treated liquids are based on plasma–liquid interactions. The use of these two methods is rapidly increasing in preclinical studies and cancer therapy. The authors address the prospects for further developments in cancer therapeutic applications by understanding the interactions between the plasma and living organisms. [ABSTRACT FROM AUTHOR]

Age-related macular degeneration (AMD) is the leading cause of visual impairment in the aging population with limited understanding of its pathogenesis and a lack of effective treatment. The progression of AMD is initially characterized by atrophic alterations in the retinal pigment epithelium, as well as the formation of lysosomal lipofuscin and extracellular drusen deposits. Damage caused by chronic oxidative stress, protein aggregation and inflammatory processes may lead to geographic atrophy and/or choroidal neovascularization and fibrosis. The role of macroautophagy/autophagy in AMD pathology is steadily emerging. This review describes selective and secretory autophagy and their role in drusen biogenesis, senescence-associated secretory phenotype, inflammation and epithelial-mesenchymal transition in the pathogenesis of AMD. Abbreviations: Aβ: amyloid-beta; AMBRA1: autophagy and beclin 1 regulator 1; AMD: age-related macular degeneration; ATF6: activating transcription factor 6; ATG: autophagy related; BACE1: beta-secretase 1; BHLHE40: basic helix-loop-helix family member e40; BNIP3: BCL2 interacting protein 3; BNIP3L/NIX: BCL2 interacting protein 3 like; C: complement; CALCOCO2/NDP52: calcium binding and coiled-coil domain 2; CARD: caspase recruitment domain; CDKN2A/p16: cyclin dependent kinase inhibitor 2A; CFB: complement factor B; DELEC1/Dec1; deleted in esophageal cancer 1; EIF2AK3/PERK: eukaryotic translation initiation factor 2 alpha kinase 3; EMT: epithelial-mesenchymal transition; ER: endoplasmic reticulum; ERN1/IRE1: endoplasmic reticulum to nucleus signaling 1; FUNDC1: FUN14 domain containing 1; GABARAP: GABA type A receptor-associated protein; HMGB1: high mobility group box 1; IL: interleukin; KEAP1: kelch like ECH associated protein 1; LAP: LC3-associated phagocytosis; LAMP2: lysosomal associated membrane protein 2; LIR: LC3-interacting region; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MTOR: mechanistic target of rapamycin kinase; NFE2L2: NFE2 like bZIP transcription factor 2; NLRP3; NLR family pyrin domain containing 3; NFKB/NFκB: nuclear factor kappa B; OPTN: optineurin; PARL: presenilin associated rhomboid like; PGAM5: PGAM family member 5, mitochondrial serine/threonine protein phosphatase; PINK1: PTEN induced kinase 1; POS: photoreceptor outer segment; PPARGC1A: PPARG coactivator 1 alpha; PRKN: parkin RBR E3 ubiquitin protein ligase; PYCARD/ASC: PYD and CARD domain containing; ROS: reactive oxygen species; RPE: retinal pigment epithelium; SA: secretory autophagy; SASP: senescence-associated secretory phenotype; SEC22B: SEC22 homolog B, vesicle trafficking protein; SNAP: synaptosome associated protein; SNARE: soluble N-ethylmaleimide-sensitive factor attachment protein receptor; SQSTM1/p62: sequestosome 1; STX: syntaxin; TGFB2: transforming growth factor beta 2; TRIM16: tripartite motif containing 16; TWIST: twist family bHLH transcription factor; Ub: ubiquitin; ULK: unc-51 like autophagy activating kinase; UPR: unfolded protein response; UPS: ubiquitin-proteasome system; V-ATPase: vacuolar-type H+-translocating ATPase; VIM: vimentin [ABSTRACT FROM AUTHOR]

Extracellular vesicles (EVs) are identified as a non-classical way to mediate iron efflux except ferroportin. Interestingly, recent studies indicated that EVs pathway is a novel way involved in iron efflux. Mitochondria-derived vesicles (MDVs) are the potential mediator to load mitochondrial iron into EVs. Additionally, iron-replete cells resist excess iron-induced damage by secreting iron-loaded EVs, and the uptake of these EVs induces oxidative damage in the recipient cell. Importantly, iron-loaded EVs play a key role in aberrant iron distribution, which drives the progress of diseases like nonalcoholic fatty liver disease (NAFLD) and neurodegenerative diseases. Herein, we summarize extant research on intracellular iron export with an emphasis on EVs and put our eyes on the relationship between iron-loaded EVs with both parent and target cells. Iron-loaded EVs will be an important avenue for later research on their vital role in iron redistribution. [ABSTRACT FROM AUTHOR]

We rely on vision more than on any other sense to obtain information about our environment. Hence, the loss or even impairment of vision profoundly affects our quality of life. Diet or food components have already demonstrated beneficial effects on the development of retinal diseases. Recently, there has been a growing interest in resources from marine animals and plants for the prevention of retinal diseases through nutrition. Especially fish intake and omega-3 fatty acids have already led to promising results, including associations with a reduced incidence of retinal diseases. However, the underlying molecular mechanisms are insufficiently explained. The aim of this review was to summarize the known mechanistic effects of marine resources on the pathophysiological processes in retinal diseases. We performed a systematic literature review following the PRISMA guidelines and identified 107 studies investigating marine resources in the context of retinal diseases. Of these, 46 studies described the underlying mechanisms including anti-inflammatory, antioxidant, antiangiogenic/vasoprotective, cytoprotective, metabolic, and retinal function effects, which we critically summarize. We further discuss perspectives on the use of marine resources for human nutrition to prevent retinal diseases with a particular focus on regulatory aspects, health claims, safety, and bioavailability. [ABSTRACT FROM AUTHOR]

The vacuoles in Saccharomyces cerevisiae are the key players digesting the waste within the cell. This functional organelle corresponding to the lysosome of mammalians contains acidic hydrolases and specific membrane proteins. Vacuoles have more than 60 hydrolytic enzymes and can easily be modified by genetic engineering. In previous study, we optimised the encapsulation condition with appropriate time and concentration and confirmed the use of vacuole as drug delivery carrier for acute myeloid leukaemia treatment. In this study, recombinant vacuole that could target the acute myeloid leukaemia cell line was constructed. The vacuoles derived from genetic engineered yeast were decorated with targeting peptide that has specific affinity with TLR2 on AML cell membrane. The anti-cancer efficacy of AML targeting vacuoles carriers with encapsulated daunorubicin was shown to be higher than normal vacuole carriers and the crude daunorubicin. The results confirmed that target selective chemotherapy using the vacuole drug delivery system is effective and offers potential for cancer therapy. [ABSTRACT FROM AUTHOR]

Necroptosis is a tightly adjusted inflammatory necrotizing cell death signaling pathway that participates in pathogenesis of discrete diseases as rheumatoid arthritis (RA). Irisin is a myokine with immuno-modulatory effect. Evaluation of irisin efficiency as a novel therapeutic agent in experimentally induced RA via modulating immuno-inflammatory, necroptotic molecular and biochemical signaling pathways. RA was induced in 30 female Wister albino rats by a single subcutaneous injection of collagen-II with incomplete Freund's adjuvant (CII-IFA) followed by booster immunization dose 10 days later. After 14 days of the injection, arthritis chronic phase was precipitated. 15 rats were treated by S.C irisin injection daily for 4 weeks. Joint tissue homogenate RIPK-3, MLKL, HMGB1, MCP1, IL-6, CHIT1, MDA, and PN levels were assessed calorimetrically. However, TNF-α mRNA expression level was evaluated by the qrt-PCR technique. The results showed that irisin significantly decreases the level of all assessed biochemical parameters, except MDA, which was significantly increased in comparison with the correspondent values in the arthritic group with no treatment (ttt). Irisin exhibits therapeutic anti-inflammatory and antioxidant effects via modulating immuno-inflammatory, necroptotic molecular, and biochemical signaling pathways in experimentally induced RA in rats. RA: rheumatoid arthritis; RIPK3: receptor-interacting protein kinase 1; MLKL: mixed lineage kinase domain-like protein; HMGB1: High-mobility group protein box 1; MCP1: Monocyte chemoattractant protein 1; IL-6: Interleukin 6; CHIT1: Chitotriosidase; MDA: Malondialdehyde; PN: Peroxynitrite; TNF-α: Tumor Necrosis Factor; qrt-PCR: quantitative real-time reverse transcription PCR; CII-IFA: collagen-II with incomplete Freund's adjuvant; ttt: treatment Note: TNF-α gene (NCBI GenBank Nucleotide accession # NM_012675.3); The housekeeping gene GAPDH (NCBI GenBank Nucleotide accession # NM_017008.4) [ABSTRACT FROM AUTHOR]

Mucopolysaccharidosis Type I (MPS I) is an autosomal recessive lysosomal storage disorder characterized by a defect in the enzyme alpha-L-iduronidase. Glycosaminoglycan accumulation causes ocular involvement such as corneal clouding or pigmentary retinopathy. Here we report bilateral macular cysts in mucopolysaccharidosis type I (MPS I) that responds to nepafenac treatment. Retrospective case report. A 27-year-old woman with MPS I (Scheie phenotype) was complaining of slightly blurred vision. She had been on alpha-L-iduronidase enzyme replacement therapy for ten years. Best-corrected visual acuity was 20/25 in both eyes. Biomicroscopy was normal. Dilated fundus examination revealed pigmentary retinopathy. Optical coherence tomography (OCT) detected macular cysts in inner and outer nuclear layers, with preservation of ellipsoid zone and IS/OS line. There was no dye leakage on fluorescein angiography. Macular cysts regressed partially after one month with topical nepafenac 0.1% four times a day. BCVA improved to 20/20 in both eyes. This is the first report of bilateral macular cysts that was demonstrated with OCT and treated with topical nepafenac in a patient with MPS I. Because the symptoms of our patient were mild, large-scaled cohort studies are required to ascertain the real prevalence of macular cysts in MPS I. It may also be beneficial to do more research on the possible benefits of nepafenac on the retinal manifestations of MPS. [ABSTRACT FROM AUTHOR]

Extensive toxicology studies of synthetic vitreous fibers (SVFs) demonstrated that fiber dimension, durability/dissolution, and biopersistence are critical factors for risk of fibrogenesis and carcinogenesis. Lessons learned from the SVF experience provide useful context for predicting hazards and risk of nano-enabled advanced materials. This review provides (1) a historical toxicological overview of animal and in vitro toxicology studies of SVFs, (2) key findings that long durable fibers pose a risk of fibrogenic and tumorigenic responses and not short fibers or long soluble fibers, (3) in vitro and in vivo test methods for biodurability and biopersistence and associated predictive thresholds for fibrosis or tumors, and (4) recommendations for testing of advanced materials. Generally, SVFs (fiber lengths >20 µm) with in vitro fiber dissolution rates greater than 100 ng/cm2/hr (glass fibers in pH 7 and stone fibers in pH 4.5) and in vivo fiber clearance less than WT1/2 40 or 50 days were not associated with fibrosis or tumors. Long biodurable and biopersistent fibers exceeding these fiber dissolution and clearance thresholds may pose a risk of fibrosis and cancer. Fiber length-, durability-, and biopersistent-dependent factors that influence pathogenicity of mineral fibers are also expected to affect the biological effects of high aspect ratio nanomaterials (HARN). Only with studies aimed to correlate in vitro durability, in vivo biopersistence, and biological outcomes will it be determined whether similar or different in vitro fiber dissolution and in vivo half-life thresholds, which exempt carcinogenicity classification of SVFs, can also apply to HARNs. [ABSTRACT FROM AUTHOR]

Tuberculosis (TB) is a global health problem with the major brunt of disease occurring in developing countries. The cornerstone of treatment of TB is anti-tubercular therapy (ATT), which includes rifampicin, isoniazid, pyrazinamide and ethambutol. Because of emerging drug resistance, treatment failures, defaulters and increasing incidence of disseminated and extrapulmonary TB, the guidelines have been modified in some countries. Ethambutol is prescribed for longer times (in some cases >8 months) and hence the incidence of ethambutol-induced optic neuropathy (EtON) is expected to rise. The fundamental question which needs explanation is why only a small subset of patients on ethambutol are prone to develop loss of vision. This review focuses on available genetic studies which provide evidence that mitochondria are the likely substrates involved in the final pathway of reactive oxidative damage of the papillo-macular bundle. Genetic analysis of mitochondrial mutations encoding genes involved in oxidative phosphorylation pathways may help in isolating the subset of patients who are genetically susceptible. If the groups having high risk of developing EtON are recognised then prolonged duration of ethambutol treatment can be avoided in these susceptible individuals. A better understanding of the pathophysiology will also pave the way for the development of management strategies in this condition. [ABSTRACT FROM AUTHOR]