bims-drudre 2022-11-13 papers

bims-drudre

Biomed News

on Targeted drug delivery and programmed release mechanisms

Issue of 2022–11–13
fiveteen papers selected by
Ceren Kimna, Technical University of Munich

Switchable targeting of solid tumors by BsCAR T cells.
Enhanced Sensitivity of Tumor Cells to Autophagy Inhibitors Using Fasting-Mimicking Diet and Targeted Lysosomal Delivery Nanoplatform.
Non-lysosomal Route of mRNA delivery and Combining with Epigenetic Regulation Optimized Antitumor Immunoprophylactic Efficacy.
DNA-Tetrahedra Corona-Modified Hydrogel Microcapsules: "Smart" ATP- or microRNA-Responsive Drug Carriers.
Probiotic-inspired nanomedicine restores intestinal homeostasis in colitis by regulating redox balance, immune responses, and the gut microbiome.
Platelet-Covered Nanocarriers for Targeted Delivery of Hirudin to Eliminate Thrombotic Complication in Tumor Therapy.
Near infrared-activatable biomimetic nanogels enabling deep tumor drug penetration inhibit orthotopic glioblastoma.
Neuronal Cellular Nanosponges for Effective Detoxification of Neurotoxins.
Extracellular matrix degrading enzyme with stroma-targeting peptides enhance the penetration of liposomes into tumors.
Boronate Building Blocks for Intracellular Protein Delivery.
Active tissue adhesive activates mechanosensors and prevents muscle atrophy.
Magnetically Induced Brownian Motion of Iron Oxide Nanocages in Alternating Magnetic Fields and Their Application for Efficient siRNA Delivery.
On the Influence of Nucleic Acid Backbone Modifications on Lipid Nanoparticle Morphology.
Surface Engineering of Protein Nanoparticles Modulates Transport, Adsorption, and Uptake in Mucus.
Mitochondrial membrane proteins and VPS35 orchestrate selective removal of mtDNA.

Proc Natl Acad Sci U S A. 2022 11 16. 119(46): e2210562119

Switchable targeting of solid tumors by BsCAR T cells.

Alexey V Stepanov, Roman S Kalinin, Victoria O Shipunova, Ding Zhang, Jia Xie, Yuri P Rubtsov, Valeria M Ukrainskaya, Alexey Schulga, Elena V Konovalova, Dmitry V Volkov, Igor A Yaroshevich, Anastasiia M Moysenovich, Alexey A Belogurov, Hongkai Zhang, Georgij B Telegin, Alexandr S Chernov, Mikhail A Maschan, Stanislav S Terekhov, Peng Wu, Sergey M Deyev, Richard A Lerner, Alexander G Gabibov, Sidney Altman.

  The development of chimeric antigen receptor (CAR) T cell therapy has become a critical milestone in modern oncotherapy. Despite the remarkable in vitro effectiveness, the problem of safety and efficacy of CAR T cell therapy against solid tumors is challenged by the lack of tumor-specific antigens required to avoid on-target off-tumor effects. Spatially separating the cytotoxic function of CAR T cells from tumor antigen recognition provided by protein mediators allows for the precise control of CAR T cell cytotoxicity. Here, the high affinity and capability of the bacterial toxin-antitoxin barnase-barstar system were adopted to guide CAR T cells to solid tumors. The complementary modules based on (1) ankyrin repeat (DARPin)-barnase proteins and (2) barstar-based CAR (BsCAR) were designed to provide switchable targeting to tumor cells. The alteration of the DARPin-barnase switches enabled the targeting of different tumor antigens with a single BsCAR. A gradual increase in cytokine release and tunable BsCAR T cell cytotoxicity was achieved by varying DARPin-barnase loads. Switchable BsCAR T cell therapy was able to eradicate the HER2<sup>+</sup> ductal carcinoma in vivo. Guiding BsCAR T cells by DARPin-barnase switches provides a universal approach for a controlled multitargeted adoptive immunotherapy.

Keywords:  CAR T cells; DARPins; barnase–barstar interaction; solid tumors; switchable adoptive immunotherapy (SAI)

DOI:  https://doi.org/10.1073/pnas.2210562119
Nano Lett. 2022 Nov 07.

Enhanced Sensitivity of Tumor Cells to Autophagy Inhibitors Using Fasting-Mimicking Diet and Targeted Lysosomal Delivery Nanoplatform.

Ruihao Qian, Guoliang Cao, Wen Su, Jie Zhang, Yue Jiang, Haohao Song, Fuhao Jia, Hai Wang.

  Autophagy is one of the key pathways for tumor cell survival and proliferation. Therefore, inhibition of autophagy has been extensively studied for cancer therapy. However, current autophagy inhibitors lack specificity and are ineffective in limiting tumor progression. Herein, we report a nanoplatform for tumor-site-targeted delivery of hydroxychloroquine (HCQ) using insulin-like growth factors 2 receptor (IGF2R)-targeted liposomes (iLipo-H). A fasting-mimicking diet (FMD) is used to increase the autophagy levels in tumor cells, thereby increasing the sensitivity of tumor cells to HCQ. In addition, FMD treatment upregulates the expression of IGF2R in tumor cells, but not normal cells. Consequently, iLipo-H nanoparticles efficiently accumulate at the tumor site under FMD condition. In vivo studies demonstrate that iLipo-H nanoparticles efficiently inhibit 4T1 tumor growth without obvious side effects, especially under FMD condition. This study provides a promising strategy to increase the sensitivity of tumor cells to autophagy inhibitors for effective cancer therapy.

Keywords:  autophagy; hydroxychloroquine; insulin-like growth factors 2 receptor; targeted delivery

DOI:  https://doi.org/10.1021/acs.nanolett.2c03890
Adv Healthc Mater. 2022 Nov 11. e2202460

Non-lysosomal Route of mRNA delivery and Combining with Epigenetic Regulation Optimized Antitumor Immunoprophylactic Efficacy.

Yu Liu, Xu Liu, Jiaxin Huang, Yingying Shi, Zhenyu Luo, Junlei Zhang, Xuemeng Guo, Mengshi Jiang, Xiang Li, Hang Yin, Bing Qin, Guannan Guan, Lihua Luo, Yun Zhou, Jian You.

  Currently, mRNA-based tumor therapies are in full flow because in vitro-transcribed (IVT) mRNA has the potential to express tumor antigens to initiate the adaptive immune responses. However, the efficacy of such therapy relies heavily on the delivery system. Here, a Pardaxin-modified liposome loaded with tumor antigen-encoding mRNA and adjuvant (2',3'-cGAMP, (cyclic [G(2',5')pA(3',5')p])), termed P-Lipoplex-CDN is reported. Due to an non-lysosomal delivery route, the transfection efficiency on DCs is improved by reducing the lysosome disruption of cargos. The mRNA modified DCs efficiently induced tumor antigen-specific immune responses both in vitro and in vivo. As prophylactic vaccines, mRNA transfected DCs significantly delay the occurrence and development of tumors, and several immunized mice are even completely resistant to tumors. Interestingly, the efficacy depends on the major histocompatibility complex class I (MHC-I) expression level on tumor cells. Furthermore, epigenetic modification (decitabine, DAC) is applied as a combination strategy to deal with malignant tumor progression caused by deficient tumor MHC-I expression. This study highlighted the close relationship between mRNA-DCs vaccine efficacy and the expression level of tumor cell MHC-I molecules. Moreover, a feasible strategy for tumor MHC-I expression deficiency is proposed, which may provide clinical guidance for the design and application of mRNA-based tumor therapies. This article is protected by copyright. All rights reserved.

Keywords:  MHC-I-restricted immunity; cancer therapy; cationic liposomes; epigenetic modification; mRNA-DCs

DOI:  https://doi.org/10.1002/adhm.202202460
Small. 2022 Nov 09. e2204108

DNA-Tetrahedra Corona-Modified Hydrogel Microcapsules: "Smart" ATP- or microRNA-Responsive Drug Carriers.

Amit Fischer, Pu Zhang, Yu Ouyang, Yang Sung Sohn, Ola Karmi, Rachel Nechushtai, Eli Pikarsky, Itamar Willner.

  The assembly of adenosine triphosphate (ATP)-responsive and miRNA-responsive DNA tetrahedra-functionalized carboxymethyl cellulose hydrogel microcapsules is presented. The microcapsules are loaded with the doxorubicin-dextran drug or with CdSe/ZnS quantum dots as a drug model. Selective unlocking of the respective microcapsules and the release of the loads in the presence of ATP or miRNA-141 are demonstrated. Functionalization of the hydrogel microcapsules a with corona of DNA tetrahedra nanostructures yields microcarriers that revealed superior permeation into cells. This is demonstrated by the effective permeation of the DNA tetrahedra-functionalized microcapsules into MDA-MB-231 breast cancer cells, as compared to epithelial MCF-10A nonmalignant breast cells. The superior permeation of the tetrahedra-functionalized microcapsules into MDA-MB-231 breast cancer cells, as compared to analog control hydrogel microcapsules modified with a corona of nucleic acid duplexes. The effective permeation of the stimuli-responsive, drug-loaded, DNA tetrahedra-modified microcapsules yields drug carriers of superior and selective cytotoxicity toward cancer cells.

Keywords:  cancer; controlled release; doxorubicin; drug delivery; quantum dots

DOI:  https://doi.org/10.1002/smll.202204108
Adv Mater. 2022 Nov 07. e2207890

Probiotic-inspired nanomedicine restores intestinal homeostasis in colitis by regulating redox balance, immune responses, and the gut microbiome.

Jiaqi Xu, Junchao Xu, Tongfei Shi, Yinlong Zhang, Fangman Chen, Chao Yang, Xinjing Guo, Guangna Liu, Dan Shao, Kam W Leong, Guangjun Nie.

  Microbiota-based therapeutics offer innovative strategies to treat inflammatory bowel diseases (IBDs). However, the poor clinical outcome so far and the limited flexibility of the bacterial approach call for improvement. Inspired by the health benefits of probiotics in alleviating symptoms of bowel diseases, we designed bioartificial probiotics to restore the intestinal microenvironment in colitis by regulating redox balance, immune responses, and the gut microbiome. The bioartificial probiotic comprises two components: an E. coli Nissle 1917-derived membrane (EM) as the surface and the biodegradable diselenide-bridged mesoporous silica nanoparticles (SeM) as the core. When orally administered, the probiotic-inspired nanomedicine (SeM@EM) adhered strongly to the mucus layer and restored intestinal redox balance and immune regulation homeostasis in a murine model of acute colitis induced by dextran sodium sulfate. In addition, the respective properties of the EM and SeM synergistically altered the gut microbiome to a favorable state by increasing the bacterial diversity and shifting the microbiome profile to an anti-inflammatory phenotype. This work suggests a safe and effective nanomedicine that can restore intestinal homeostasis for IBDs therapy. This article is protected by copyright. All rights reserved.

Keywords:  Colitis; Diselenide-bridged mesoporous silica nanoparticles; EcN membrane; Intestinal homeostasis; Microbiota-based therapeutics

DOI:  https://doi.org/10.1002/adma.202207890
ACS Nano. 2022 Nov 09.

Platelet-Covered Nanocarriers for Targeted Delivery of Hirudin to Eliminate Thrombotic Complication in Tumor Therapy.

Kai Zhang, Zhaoyu Ma, Shuting Li, Weiyun Zhang, Mohamed Frahat Foda, Yanli Zhao, Heyou Han.

  Most patients are at high risk of thrombosis during cancer treatment. However, the major discrepancy in the therapeutic mechanisms and microenvironment between tumors and thrombosis makes it challenging for a panacea to treat cancer while being able to eliminate the risk of thrombosis. Herein, we developed a biomimetic MnOx/Ag2S nanoflower platform with platelet membrane modification (MnOx@Ag2S@hirudin@platelet membrane: MAHP) for the long-term release of anticoagulant drugs to treat thrombosis together with tumor therapy. This MAHP platform could achieve the targeted delivery of hirudin to the thrombus site and perform the controlled release under the irradiation of near-infrared light, demonstrating effective removal of the thrombus. Moreover, MAHP could inhibit tumor progression and prolong the survival time of mice with thromboembolic complications.

Keywords:  hirudin; platelet membrane; thrombotic complication; thrombus therapy; tumor therapy

DOI:  https://doi.org/10.1021/acsnano.2c06666
Nat Commun. 2022 Nov 11. 13(1): 6835

Near infrared-activatable biomimetic nanogels enabling deep tumor drug penetration inhibit orthotopic glioblastoma.

Dongya Zhang, Sidan Tian, Yanjie Liu, Meng Zheng, Xiangliang Yang, Yan Zou, Bingyang Shi, Liang Luo.

Glioblastoma multiforme (GBM) is one of the most fatal malignancies due to the existence of blood-brain barrier (BBB) and the difficulty to maintain an effective drug accumulation in deep GBM lesions. Here we present a biomimetic nanogel system that can be precisely activated by near infrared (NIR) irradiation to achieve BBB crossing and deep tumor penetration of drugs. Synthesized by crosslinking pullulan and poly(deca-4,6-diynedioic acid) (PDDA) and loaded with temozolomide and indocyanine green (ICG), the nanogels are inert to endogenous oxidative conditions but can be selectively disintegrated by ICG-generated reactive oxygen species upon NIR irradiation. Camouflaging the nanogels with apolipoprotein E peptide-decorated erythrocyte membrane further allows prolonged blood circulation and active tumor targeting. The precisely controlled NIR irradiation on tumor lesions excites ICG and deforms the cumulated nanogels to trigger burst drug release for facilitated BBB permeation and infiltration into distal tumor cells. These NIR-activatable biomimetic nanogels suppress the tumor growth in orthotopic GBM and GBM stem cells-bearing mouse models with significantly extended survival.

DOI: https://doi.org/10.1038/s41467-022-34462-8
ACS Nano. 2022 Nov 10.

Neuronal Cellular Nanosponges for Effective Detoxification of Neurotoxins.

Dan Wang, Xiangzhao Ai, Yaou Duan, Nianfei Xian, Ronnie H Fang, Weiwei Gao, Liangfang Zhang.

  Neurotoxins attack and destruct the nervous system, which can cause serious health problems and security threats. Existing detoxification approaches, such as antibodies and small molecule antidotes, rely on neurotoxin's molecular structure as design cues and require toxin-specific development for each type of toxins. However, the enormous diversity of neurotoxins makes such structure-based development of antitoxin particularly challenging and inefficient. Here, we report on the development and use of neuronal membrane-coated nanosponges (denoted "Neuron-NS") as an effective approach to detoxifying neurotoxins. Specifically, Neuron-NS act as neuron decoys to lure neurotoxins, bind with and neutralize the toxins, and thus block them from attacking the host neuron cells. These nanosponges detoxify neurotoxins regardless of their molecular structures and therefore can overcome the challenge posed by toxin structural diversity. In the study, we fabricate Neuron-NS by coating the membrane of Neuro-2a cells onto polymeric cores. Meanwhile, we select tetrodotoxin (TTX) as a model neurotoxin and demonstrate the detoxification efficacy of the Neuron-NS in a cytotoxicity assay, a calcium flux assay, and a cell osmotic swelling assay in vitro. Additionally, in mouse models of TTX intoxication, the Neuron-NS significantly enhance mouse survival in therapeutic and prophylactic regimens without showing acute toxicity. Overall, the Neuron-NS contribute to the current detoxification arsenal with the potential to treat various injuries and diseases caused by neurotoxins.

Keywords:  cell membrane coating; detoxification; nanomedicine; nanoparticle; neurotoxin

DOI:  https://doi.org/10.1021/acsnano.2c08319
J Control Release. 2022 Nov 06. pii: S0168-3659(22)00748-9. [Epub ahead of print]

Extracellular matrix degrading enzyme with stroma-targeting peptides enhance the penetration of liposomes into tumors.

Mayumi Ikeda-Imafuku, Yongsheng Gao, Suyog Shaha, Lily Li-Wen Wang, Kyung Soo Park, Mayuka Nakajima, Omokolade Adebowale, Samir Mitragotri.

  Various anti-tumor nanomedicines have been developed based on the enhanced permeability and retention effect. However, the dense extracellular matrix (ECM) in tumors remains a major barrier for the delivery and accumulation of nanoparticles into tumors. While ECM-degrading enzymes, such as collagenase, hyaluronidase, and bromelain, have been used to facilitate the accumulation of nanoparticles, serious side effects arising from the current non-tumor-specific delivery methods limit their clinical applications. Here, we report targeted delivery of bromelain into tumor tissues through its covalent attachment to a hyaluronic acid (HA)-peptide conjugate with tumor ECM targeting ability. The ECM targeting peptide, collagen type IV-binding peptide (C4BP), was chosen from six candidate-peptides based on their ability to bind to frozen sections of triple-negative breast cancer, 4 T1 tumor ex vivo. The HA- C4BP conjugate showed a significant increase in tumor accumulation in 4 T1-bearing mice after intravenous administration compared to unmodified HA. We further demonstrated that the systemic administration of bromelain conjugated C4BP-HA (C4BP-HA-Bro) potentiates the anti-tumor efficacy of liposomal doxorubicin. C4BP-HA-Bro decreased the number and length of collagen fibers and improved the distribution of doxorubicin within the tumor. No infusion reaction was noted after delivery of C4BP-HA-Bro. C4BP-HA thus offers a potential for effective and safe delivery of bromelain for improved intratumoral delivery of therapeutics.

Keywords:  Bromelain; Cancer stroma; Collagen type IV; EPR effect; Extracellular matrix; Triple-negative breast cancer

DOI:  https://doi.org/10.1016/j.jconrel.2022.11.007
Adv Healthc Mater. 2022 Nov 11. e2202049

Boronate Building Blocks for Intracellular Protein Delivery.

Qianyi Ren, Yiyun Cheng, Jia Lv.

  Intracellular protein delivery plays a critical role in the development of biotherapeutics and biotechnologies, yet it is hampered by a number of factors, including protein binding, cellular uptake, endosomal escape, and protein release. Boronate building blocks, which are frequently employed to create effective protein delivery systems, have shown significant promise in overcoming these limitations thanks to their versatile reactivities and stimuli-responsive property. Boronate ligands transport conjugated proteins into the cytosol via receptor-mediated endocytosis by forming reversible boronate disaster bonds with carbohydrates like sialic acid on the surface cell membrane. Additionally, boronate modification gives cargo proteins extra binding sites for forming complexes with nanocarriers. After internalization, boronate-tagged proteins are released from their carriers in response to endolysosomal acidity, reactive oxygen species, and adenosine triphosphate, and sometimes transport into nucleus via the importin α/β pathway. Besides, boronate ligands are directly decorated on nanocarriers to enhance their binding affinity to native proteins via nitrogen-boron coordination. Owing to these promising features, various supramolecular and dynamic nanoassemblies were constructed based on boronate building blocks for efficient intracellular protein delivery. This article is protected by copyright. All rights reserved.

Keywords:  boronate building blocks; dynamic covalent bond; intracellular protein delivery; polymer; stimuli-responsive

DOI:  https://doi.org/10.1002/adhm.202202049
Nat Mater. 2022 Nov 10.

Active tissue adhesive activates mechanosensors and prevents muscle atrophy.

Sungmin Nam, Bo Ri Seo, Alexander J Najibi, Stephanie L McNamara, David J Mooney.

While mechanical stimulation is known to regulate a wide range of biological processes at the cellular and tissue levels, its medical use for tissue regeneration and rehabilitation has been limited by the availability of suitable devices. Here we present a mechanically active gel-elastomer-nitinol tissue adhesive (MAGENTA) that generates and delivers muscle-contraction-mimicking stimulation to a target tissue with programmed strength and frequency. MAGENTA consists of a shape memory alloy spring that enables actuation up to 40% strain, and an adhesive that efficiently transmits the actuation to the underlying tissue. MAGENTA activates mechanosensing pathways involving yes-associated protein and myocardin-related transcription factor A, and increases the rate of muscle protein synthesis. Disuse muscles treated with MAGENTA exhibit greater size and weight, and generate higher forces compared to untreated muscles, demonstrating the prevention of atrophy. MAGENTA thus has promising applications in the treatment of muscle atrophy and regenerative medicine.

DOI: https://doi.org/10.1038/s41563-022-01396-x
Nano Lett. 2022 Nov 08.

Magnetically Induced Brownian Motion of Iron Oxide Nanocages in Alternating Magnetic Fields and Their Application for Efficient siRNA Delivery.

Min A Kang, Justin Fang, Aloka Paragodaarachchi, Keita Kodama, Daniela Yakobashvili, Yuko Ichiyanagi, Hiroshi Matsui.

  Hyperthermia of superparamagnetic nanoparticles driven by Néel relaxation in an alternating magnetic field (AMF) has been studied in biomedical areas; however, Brownian motion, induced by another magnetic relaxation mechanism, has not been explored extensively despite its potential in intracellular mechanoresponsive applications. We investigated whether superparamagnetic cage-shaped iron oxide nanoparticles (IO-nanocages), previously demonstrated to carry payloads inside their cavities for drug delivery, can generate Brownian motion by tuning the nanoparticle size at 335 kHz AMF frequency. The motivation of this work is to examine the magnetically driven Brownian motion for the delivery of nanoparticles allowing escape from endosomes before digestion in lysosomes and efficient delivery of siRNA cargoes to the cytoplasm. Superconducting quantum interference device (SQUID) measurements reveal the nanocage size dependence of Brownian relaxation, and a magnetic Brownian motion of 20 nm IO-nanocages improved the efficiency of siRNA delivery while endosomal membranes were observed to be compromised to release IO-nanocages in AMFs during the delivery process.

Keywords:  Brownian motion; RNA delivery; alternating magnetic field; drug delivery; endosomal escape; superparamagnetic iron oxide nanoparticle

DOI:  https://doi.org/10.1021/acs.nanolett.2c02691
Langmuir. 2022 Nov 11.

On the Influence of Nucleic Acid Backbone Modifications on Lipid Nanoparticle Morphology.

Kevin An, Daniel Kurek, Mark Mahadeo, Yao Zhang, Jenifer L Thewalt, Pieter R Cullis, Jayesh A Kulkarni.

Nucleic acid therapeutics represent a major advance toward treating diseases at their root cause. However, nucleic acids are prone to degradation by serum endonucleases, clearance through the immune system, and rapid degradation in complex medium. To overcome these barriers, nucleic acids frequently include chemical modifications to improve stability or decrease immune responses. Lipid nanoparticles (LNPs) have enabled a dramatic reduction in the dose required to achieve a therapeutic effect by protecting these nucleic acids and improving their intracellular delivery. It has been assumed thus far that nonspecific ionic interactions drive LNP formation and chemical modifications to the nucleic acid backbone to confer improved stability do not impact LNP delivery in any way. Here, we demonstrate that these chemical modifications do impact LNP morphology substantially, and phosphorothioate modifications produce stronger interactions with ionizable amino lipids, resulting in enhanced entrapment. This work represents a major first step toward greater understanding of the interaction between the lipid components and nucleic acids within an LNP.

DOI: https://doi.org/10.1021/acs.langmuir.2c01492
ACS Appl Mater Interfaces. 2022 Nov 10.

Surface Engineering of Protein Nanoparticles Modulates Transport, Adsorption, and Uptake in Mucus.

Thomas Pho, Julie A Champion.

  Protein nanoparticles have been demonstrated as effective carriers for protein antigens and therapeutics due to properties endowed by their protein composition. They exhibit high protein to carrier yields, biocompatibility, and heterogeneous surface properties. While protein nanoparticles have been delivered via multiple routes, including intranasal, their interactions with mucosal barriers have not been well studied or modified. Biological barriers associated with intranasal delivery consist of viscoelastic mucus that hinders material transport through surface interactions and the underlying epithelium. Herein, we altered protein nanoparticle surface properties and characterized interactions with nasal mucus and the subsequent effects on diffusion, cellular uptake, and immune cell maturation. Ovalbumin protein nanoparticles were used, serving as a model vaccine nanoparticle. Unmodified ovalbumin protein nanoparticles were compared to cationic ovalbumin particles functionalized with amine groups, neutral particles functionalized with polyethylene glycol, and zwitterionic particles coated layer-by-layer (LBL) with chitosan and oligonucleotides. Transport analysis indicated rapid diffusion of polyethylene glycol and LBL-modified ovalbumin nanoparticles in porcine nasal mucus, while cationic particles were mucoadhesive. Cellular uptake in the presence of mucus by epithelial and dendritic cells was highest for particles containing positive charges, both LBL and amine-functionalized. These particles also exhibited the most diverse adsorbed protein corona from nasal fluids. The corona impacted both dendritic cell uptake and maturation, with polyethylene glycol and LBL modifications improving CD86 expression. Altogether, surface modifications on protein-based nanocarriers are shown to facilitate distinctive physical and cellular behavior associated with mucosal delivery.

Keywords:  cell uptake; diffusion; mucus; nanoparticles; protein corona

DOI:  https://doi.org/10.1021/acsami.2c14670
Nat Commun. 2022 Nov 07. 13(1): 6704

Mitochondrial membrane proteins and VPS35 orchestrate selective removal of mtDNA.

Ayesha Sen, Sebastian Kallabis, Felix Gaedke, Christian Jüngst, Julia Boix, Julian Nüchel, Kanjanamas Maliphol, Julia Hofmann, Astrid C Schauss, Marcus Krüger, Rudolf J Wiesner, David Pla-Martín.

Understanding the mechanisms governing selective turnover of mutation-bearing mtDNA is fundamental to design therapeutic strategies against mtDNA diseases. Here, we show that specific mtDNA damage leads to an exacerbated mtDNA turnover, independent of canonical macroautophagy, but relying on lysosomal function and ATG5. Using proximity labeling and Twinkle as a nucleoid marker, we demonstrate that mtDNA damage induces membrane remodeling and endosomal recruitment in close proximity to mitochondrial nucleoid sub-compartments. Targeting of mitochondrial nucleoids is controlled by the ATAD3-SAMM50 axis, which is disrupted upon mtDNA damage. SAMM50 acts as a gatekeeper, influencing BAK clustering, controlling nucleoid release and facilitating transfer to endosomes. Here, VPS35 mediates maturation of early endosomes to late autophagy vesicles where degradation occurs. In addition, using a mouse model where mtDNA alterations cause impairment of muscle regeneration, we show that stimulation of lysosomal activity by rapamycin, selectively removes mtDNA deletions without affecting mtDNA copy number, ameliorating mitochondrial dysfunction. Taken together, our data demonstrates that upon mtDNA damage, mitochondrial nucleoids are eliminated outside the mitochondrial network through an endosomal-mitophagy pathway. With these results, we unveil the molecular players of a complex mechanism with multiple potential benefits to understand mtDNA related diseases, inherited, acquired or due to normal ageing.

DOI: https://doi.org/10.1038/s41467-022-34205-9