bims-scepro 2024-12-15 papers

bims-scepro

Biomed News

on Stem cell proteostasis

Issue of 2024–12–15
nineteen papers selected by
William Grey, University of York

Platelet Factor 4 (PF4) Regulates Hematopoietic Stem Cell Aging.
Elevated hematopoietic stem cell frequency in mouse alveolar bone marrow.
Self-organization of the hematopoietic vascular niche and emergent innate immunity on a chip.
Making blood from iPSCs: Reaching for the most sought-after prize.
An Injectable Solution for Preservation of Hematopoietic Stem and Progenitors Cells in Hypothermic Condition.
Autophagy inhibition induces AML cell death and enhances the efficacy of chemotherapy under hypoxia.
Gene editing without ex vivo culture evades genotoxicity in human hematopoietic stem cells.
Single-cell epigenetic and clonal analysis decodes disease progression in pediatric acute myeloid leukemia.
ADAR1-regulated cytoplasmic dsRNA-sensing pathway is a novel mechanism of lenalidomide resistance in multiple myeloma.
M2 macrophages secrete CCL20 to regulate iron metabolism and promote daunorubicin resistance in AML cells.
PRMT1 Promotes the Self-renewal of Leukemia Stem Cells by Regulating Protein Synthesis.
Bone marrow stromal cells protect myeloma cells from ferroptosis through GPX4 deSUMOylation.
BCL11A +58/+55 enhancer-editing facilitates HSPC engraftment and HbF induction in rhesus macaques conditioned with a CD45 antibody-drug conjugate.
Reactive oxygen species control protein degradation at the mitochondrial import gate.
Pseudokinase TRIB3 stabilizes SSRP1 via USP10-mediated deubiquitination to promote multiple myeloma progression.
PNPO-Mediated Oxidation of DVL3 Promotes Multiple Myeloma Malignancy and Osteoclastogenesis by Activating the Wnt/β-Catenin Pathway.
The crossroads of clonal evolution, differentiation hierarchy and ontogeny in leukemia development.
Advancements in Umbilical Cord Biobanking: A Comprehensive Review of Current Trends and Future Prospects.
MLL/WDR5 complex recruits centriolar satellite protein Cep72 to regulate microtubule nucleation and spindle formation.

bioRxiv. 2024 Nov 27. pii: 2024.11.25.625252. [Epub ahead of print]

Platelet Factor 4 (PF4) Regulates Hematopoietic Stem Cell Aging.

Sen Zhang, Charles E Ayemoba, Anna M Di Staulo, Kenneth Joves, Chandani M Patel, Eva Hin Wa Leung, Sang-Ging Ong, Claus Nerlov, Maria Maryanovich, Constantinos Chronis, Sandra Pinho.

Hematopoietic stem cells (HSCs) responsible for blood cell production and their bone marrow regulatory niches undergo age-related changes, impacting immune responses and predisposing individuals to hematologic malignancies. Here, we show that the age-related alterations of the megakaryocytic niche and associated downregulation of Platelet Factor 4 (PF4) are pivotal mechanisms driving HSC aging. PF4-deficient mice display several phenotypes reminiscent of accelerated HSC aging, including lymphopenia, increased myeloid output, and DNA damage, mimicking physiologically aged HSCs. Remarkably, recombinant PF4 administration restored old HSCs to youthful functional phenotypes characterized by improved cell polarity, reduced DNA damage, enhanced in vivo reconstitution capacity, and balanced lineage output. Mechanistically, we identified LDLR and CXCR3 as the HSC receptors transmitting the PF4 signal, with double knockout mice showing exacerbated HSC aging phenotypes similar to PF4-deficient mice. Furthermore, human HSCs across various age groups also respond to the youthful PF4 signaling, highlighting its potential for rejuvenating aged hematopoietic systems. These findings pave the way for targeted therapies aimed at reversing age-related HSC decline with potential implications in the prevention or improvement of the course of age-related hematopoietic diseases.
Key Points: Age-related attrition of the megakaryocytic niche and associated PF4 downregulation is a central mechanism in HSC aging.PF4 supplementation, acting on LDLR and CXCR3 receptors, rejuvenates the function of aged HSCs.

DOI: https://doi.org/10.1101/2024.11.25.625252
Stem Cell Reports. 2024 Dec 11. pii: S2213-6711(24)00318-7. [Epub ahead of print] 102374

Elevated hematopoietic stem cell frequency in mouse alveolar bone marrow.

Kouta Niizuma, Satoru Morikawa, Eric Gars, Jinyi Xiang, Tomoko Matsubara-Takahashi, Rei Saito, Eri Takematsu, Yuting Wang, Haojun Xu, Arata Wakimoto, Tze Kai Tan, Yoshiaki Kubota, Charles K F Chan, Irving L Weissman, Taneaki Nakagawa, Adam C Wilkinson, Hiromitsu Nakauchi, Ryo Yamamoto.

  Hematopoietic stem cells (HSCs) are crucial for maintaining hematopoietic homeostasis and are localized within distinct bone marrow (BM) niches. While BM niches are often considered similar across different skeletal sites, we discovered that the alveolar BM (al-BM) in the mandible harbors the highest frequency of immunophenotypic HSCs in nine different skeletal sites. Transplantation assays revealed significantly increased engraftment from al-BM compared to femur, tibia, or pelvis BM, likely due to a higher proportion of alveolar HSCs. Moreover, hematopoietic progenitor cells (c-Kit+ Sca-1+ Lin-) in al-BM exhibited increased quiescence and reduced apoptosis, indicating superior maintenance and survival characteristics. We also observed an enrichment of mesenchymal stromal cells and skeletal stem cells in al-BM, suggesting a more supportive microenvironment. These findings indicate that al-BM provides a unique microenvironment conducive to higher frequency of HSCs, offering new insights into site-specific hematopoiesis.

Keywords:  HSCs; MSCs; al-BM; alveolar bone marrow; bone marrow microenvironment; hematopoietic stem cells; mandible; mesenchymal stromal cells; niche; oncostatin M; quiescence; skeletal stem cells; stem cell frequency

DOI:  https://doi.org/10.1016/j.stemcr.2024.11.004
Cell Stem Cell. 2024 Dec 05. pii: S1934-5909(24)00402-8. [Epub ahead of print]31(12): 1847-1864.e6

Self-organization of the hematopoietic vascular niche and emergent innate immunity on a chip.

Andrei Georgescu, Joseph Hai Oved, Jonathan H Galarraga, Thomas Cantrell, Samira Mehta, Brian M Dulmovits, Timothy S Olson, Pouria Fattahi, Anni Wang, Pelin L Candarlioglu, Asli Muvaffak, Michele M Kim, Sezin Aday Aydin, Jeongyun Seo, Eric S Diffenderfer, Anthony Lynch, G Scott Worthen, Dan Dongeun Huh.

  Here, we present a bioengineering approach to emulate the human bone marrow in vitro. Our developmentally inspired method uses self-organization of human hematopoietic stem and progenitor cells and vascular endothelial cells cultured in a three-dimensional microphysiological system to create vascularized, perfusable tissue constructs that resemble the hematopoietic vascular niche of the human marrow. The microengineered niche is capable of multilineage hematopoiesis and can generate functionally mature human myeloid cells that can intravasate into perfused blood vessels, providing a means to model the mobilization of innate immune cells from the marrow. We demonstrate the application of this system by presenting a specialized model of ionizing radiation-induced bone marrow injury and a multiorgan model of acute innate immune responses to bacterial lung infection. Furthermore, we introduce an advanced platform that enables large-scale integration and automated experimentation of the engineered hematopoietic tissues for preclinical screening of myelotoxicity due to anti-cancer drugs.

Keywords:  bone marrow; drug testing; hematopoiesis; hematopoietic stem cells; immune cells; in vitro models; lung-on-a-chip; microphysiological systems; myelosuppresion; organ-on-a-chip

DOI:  https://doi.org/10.1016/j.stem.2024.11.003
Cell Stem Cell. 2024 Dec 05. pii: S1934-5909(24)00407-7. [Epub ahead of print]31(12): 1730-1731

Making blood from iPSCs: Reaching for the most sought-after prize.

Anna Bigas, Gayathri M Kartha.

After many years of little progress, there is now hope for improved in vitro production of hematopoietic stem cells (HSCs). Ng et al.1 have developed defined conditions that allow the generation of HSCs from induced pluripotent stem cells (iPSCs) with unprecedented blood-repopulating capacity.

DOI: https://doi.org/10.1016/j.stem.2024.11.008
Stem Cell Rev Rep. 2024 Dec 12.

An Injectable Solution for Preservation of Hematopoietic Stem and Progenitors Cells in Hypothermic Condition.

Jean Chevaleyre, Laura Rodriguez, Esther Attebi, Pascale Duchez, Zoran Ivanovic.

  To ensure the preservation of functional hematopoietic stem cells (HSC) and committed progenitor cells (HPC) at + 4 °C in ex vivo expanded cord blood cell products during worldwide transportation and subsequent infusion-without the need for washing and cell concentration-we developed a conservation medium called Stabilizer of Expanded Cells (SEC), composed exclusively of injectable pharmacological products. The in vivo engraftment assay in immunodeficient mice was used to detect primitive HSCs before and after preservation at + 4 °C. In some experiments, a complex phenotype based on CD34, CD38, and CD133 expression was utilized for this purpose. Committed progenitors (CFU-GM, BFU-E, and CFU-Mix) were detected using methylcellulose culture colony-forming assays. Additionally, in some cases, the energetic metabolism (mitochondrial respiration) was evaluated using Seahorse technology. SEC was able to preserve the functionality of HSCs and HPCs in ex vivo expanded cell populations at + 4 °C for at least 48 h. Furthermore, SEC is also effective in fully preserving HSCs and HPCs in cytapheresis products for at least 72 h. Additionally, SEC enabled the full preservation of HSCs and HPCs for 72 h in freshly collected cord blood, maintaining a normal metabolic profile of CD34+ cells. The SEC medium exhibits a positive effect on the maintenance of both HSCs and HPCs at + 4 °C, regardless of their source. Therefore, SEC can be applied in cell therapy protocols based on HSCs and HPCs with a significant advantage: the product does not need to be washed and concentrated before injection into the patient.

Keywords:  Cell conservation; Cord blood; Ex vivo expansion; Hematopoietic progenitors; Hematopoietic stem cells; Peripheral blood

DOI:  https://doi.org/10.1007/s12015-024-10829-w
bioRxiv. 2024 Nov 26. pii: 2024.11.24.625107. [Epub ahead of print]

Autophagy inhibition induces AML cell death and enhances the efficacy of chemotherapy under hypoxia.

Eunice S Wang, Hannah R S Fay, Kaitlyn M Dykstra, Michael N Phelps, Matthew Johnson, Annemarie Harrigan, Marianna C Giorgi.

Outcomes of relapsed/refractory acute myeloid leukemia (AML) are poor, and strategies to improve outcomes are urgently needed. One important factor promoting relapse and chemoresistance is the ability of AML cells to thrive in vivo within an intrinsically hypoxic bone marrow microenvironment. Here we show that human AML cells exhibit enhanced autophagy, specifically mitophagy (i.e., increased accumulation of mitochondria and decreased mitochondrial membrane potential) under hypoxia. To target this pathway, we investigated the activity of the potent chloroquine-derived autophagy inhibitor, Lys05, on human AML cells, patient samples, and patient derived xenograft models. Inhibition of autophagy by Lys05 in AML cells prevented removal of damaged mitochondria and preferentially enhanced cell death under hypoxia mirroring the marrow microenvironment. Lys05 eradicated human AML cells of all genotypes including p53 mutant cells. Lys05 treatment in primary AML xenografted mice decreased CD34+CD38- human cells and prolonged overall survival. Moreover, Lys05 overcame hypoxia-induced chemoresistance and improved the efficacy of cytarabine, venetoclax, and azacytidine in vitro and in vivo in AML models. Our results demonstrate the importance of autophagy, specifically mitophagy, as a critical survival and chemoresistance mechanism of AML cells under hypoxic marrow conditions. Therapeutic targeting of this pathway in future clinical studies for AML is warranted.

DOI: https://doi.org/10.1101/2024.11.24.625107
Cell Stem Cell. 2024 Dec 11. pii: S1934-5909(24)00400-4. [Epub ahead of print]

Gene editing without ex vivo culture evades genotoxicity in human hematopoietic stem cells.

Jing Zeng, My Anh Nguyen, Pengpeng Liu, Lucas Ferreira da Silva, Sébastien Levesque, Linda Y Lin, David G Justus, Karl Petri, Kendell Clement, Shaina N Porter, Archana Verma, Nola R Neri, Tolulope Rosanwo, Marioara-Felicia Ciuculescu, Daniela Abriss, Esther Mintzer, Stacy A Maitland, Selami Demirci, Hye Ji Cha, Stuart H Orkin, John F Tisdale, David A Williams, Lihua Julie Zhu, Shondra M Pruett-Miller, Luca Pinello, J Keith Joung, Vikram Pattanayak, John P Manis, Myriam Armant, Danilo Pellin, Christian Brendel, Scot A Wolfe, Daniel E Bauer.

  Gene editing the BCL11A erythroid enhancer is a validated approach to fetal hemoglobin (HbF) induction for β-hemoglobinopathy therapy, though heterogeneity in edit allele distribution and HbF response may impact its safety and efficacy. Here, we compare combined CRISPR-Cas9 editing of the BCL11A +58 and +55 enhancers with leading gene modification approaches under clinical investigation. Dual targeting of the BCL11A +58 and +55 enhancers with 3xNLS-SpCas9 and two single guide RNAs (sgRNAs) resulted in superior HbF induction, including in sickle cell disease (SCD) patient xenografts, attributable to simultaneous disruption of core half E-box/GATA motifs at both enhancers. Unintended on-target outcomes of double-strand break (DSB) repair in hematopoietic stem and progenitor cells (HSPCs), such as long deletions and centromere-distal chromosome fragment loss, are a byproduct of cellular proliferation stimulated by ex vivo culture. Editing quiescent HSPCs bypasses long deletion and micronuclei formation and preserves efficient on-target editing and engraftment function.

Keywords:  BCL11A; enhancers; fetal hemoglobin; genotoxicity; hematopoietic stem cells; sickle cell disease; therapeutic gene editing

DOI:  https://doi.org/10.1016/j.stem.2024.11.001
Blood. 2024 Dec 11. pii: blood.2024025618. [Epub ahead of print]

Single-cell epigenetic and clonal analysis decodes disease progression in pediatric acute myeloid leukemia.

Boyu Cui, Lanlan Ai, Minghui Lei, Yongjuan Duan, Chao Tang, Jingliao Zhang, Yan Gao, Xuan Li, Caiying Zhu, Yingchi Zhang, Xiaofan Zhu, Tomoya Isobe, Wenyu Yang, Berthold Gottgens, Ping Zhu.

Pediatric acute myeloid leukemia (pAML) is a clonal disease with recurrent genetic alterations that affect epigenetic states. However, the implications of epigenetic dysregulation in disease progression remain unclear. Here, we interrogated single-cell and clonal level chromatin accessibility of bone marrow samples from 28 pAML patients representing multiple subtypes using mtscATAC-seq, which revealed distinct differentiation hierarchies and abnormal chromatin accessibility in a subtype-specific manner. Innate immune signaling was commonly enhanced across subtypes and related to improved advantage of clonal competition and unfavorable prognosis, with further reinforcement in a relapse-associated leukemia stem cell-like population. We identified a panel of 31 innate immunity related genes to improve the risk classification of pAML patients. By comparing paired diagnosis and post-chemotherapy relapse samples, we showed that primitive cells significantly reduced MHC class II signaling, suggesting an immune evasion mechanism to facilitate their expansion at relapse. Key regulators orchestrating cell cycle dysregulation were identified to contribute to pAML relapse in drug-resistant clones. Our work establishes the single-cell chromatin accessibility landscape at clonal resolution and reveals the critical involvement of epigenetic disruption, offering insights into classification and targeted therapies of pAML patients.

DOI: https://doi.org/10.1182/blood.2024025618
Blood. 2024 Dec 09. pii: blood.2024024429. [Epub ahead of print]

ADAR1-regulated cytoplasmic dsRNA-sensing pathway is a novel mechanism of lenalidomide resistance in multiple myeloma.

Mun Yee Koh, Tae-Hoon Chung, Nicole Xin Ning Tang, Sabrina Hui Min Toh, Jianbiao Zhou, Tze King Tan, Leilei Chen, Wee Joo Chng, Phaik Ju Teoh.

Immunomodulatory agents (IMiDs) are a major class of drugs for treating multiple myeloma (MM); however, acquired resistance to IMiDs remains a significant clinical challenge. While alterations in cereblon (CRBN) and its pathway are known to contribute to IMiD resistance, they account for only 20-30% of cases, and the underlying mechanisms in the majority of the resistance cases remain unclear. Here, we identified ADAR1 as a novel driver of lenalidomide resistance in MM. We showed that lenalidomide activates the MDA5-mediated dsRNA-sensing pathway in MM cells, leading to interferon (IFN)-mediated apoptosis, with ADAR1 as the key regulator. Mechanistically, ADAR1 loss increased lenalidomide sensitivity through endogenous dsRNA accumulation, which in turn triggered dsRNA-sensing pathways and enhanced IFN responses. Conversely, ADAR1 overexpression reduced lenalidomide sensitivity, attributed to increased RNA editing frequency, reduced dsRNA accumulation and suppression of the dsRNA-sensing pathways. In summary, we report the involvement of ADAR1-regulated dsRNA-sensing in modulating lenalidomide sensitivity in MM. These findings highlight a novel RNA-related mechanism underlying lenalidomide resistance and underscore the potential of targeting ADAR1 as a novel therapeutic strategy.

DOI: https://doi.org/10.1182/blood.2024024429
Life Sci. 2024 Dec 05. pii: S0024-3205(24)00887-7. [Epub ahead of print] 123297

M2 macrophages secrete CCL20 to regulate iron metabolism and promote daunorubicin resistance in AML cells.

Zhi-Gang Chen, Yu-Tong Xie, Chao Yang, Tong Xiao, Si-Yu Chen, Jun-Hong Wu, Qiao-Nan Guo, Lei Gao.

  Chemotherapy resistance is a significant clinical challenge in the treatment of leukemia. M2 macrophages have been identified as key contributors to the development of chemotherapy resistance in cancer, yet the precise mechanisms by which macrophages regulate this resistance remain elusive. Our study has identified CCL20 as a pivotal factor in the promotion of chemoresistance in AML cells by M2 macrophages. The chemotherapeutic agent daunorubicin induces a marked increase in ROS and lipid peroxidation levels within AML cells. This is accompanied by the inhibition of the SLC7A11/GCL/GPX4 signaling axis, elevated levels of intracellular free iron, disrupted iron metabolism, and consequent mitochondrial damage, ultimately leading to ferroptosis. Notably, CCL20 enhances the ability of AML cells to maintain iron homeostasis by upregulating SLC7A11 protein activity, mitigating mitochondrial damage, and inhibiting ferroptosis, thereby contributing to chemotherapy resistance. Furthermore, in vivo experiments demonstrated that blocking CCL20 effectively restores the sensitivity of AML cells to daunorubicin chemotherapy. Collectively, these findings underscore the complex interplay between M2 macrophages, CCL20 signaling, and chemotherapy resistance in AML, highlighting potential therapeutic avenues for intervention.

Keywords:  Acute myeloid leukemia; CCL20; Chemoresistance; Ferroptosis; Macrophages

DOI:  https://doi.org/10.1016/j.lfs.2024.123297
Adv Sci (Weinh). 2024 Dec 12. e2308586

PRMT1 Promotes the Self-renewal of Leukemia Stem Cells by Regulating Protein Synthesis.

Min Zhou, Yi Huang, Ping Xu, Shuyi Li, Chen Duan, Xiaoying Lin, Shilai Bao, Waiyi Zou, Jingxuan Pan, Chang Liu, Yanli Jin.

  The application of tyrosine kinase inhibitors (TKIs) has revolutionized the management of chronic myeloid leukemia (CML). However, disease relapse and progression particularly due to persistent leukemia stem cells (LSCs) remain a big challenge in the clinic. Therefore, validation of the therapeutic vulnerability in LSCs is urgently needed. This study verifies the critical role of protein arginine methyltransferase 1 (PRMT1) in the maintenance of CML LSCs. It is found that PRMT1 promotes the survival and serially plating abilities of human primary CML LSCs. Genetic deletion of Prmt1 significantly delays the leukemogenesis and impairs the self-renewal of LSCs in BCR-ABL-driven CML mice. PRMT1 regulates LSCs and leukemia development depending on its methyltransferase activity. Pharmacological inhibition of PRMT1 activity by MS023 remarkably eliminates LSCs and prolongs the survival of CML mice. Mechanistical studies reveal that PRMT1 promotes transcriptional activation of ribosomal protein L29 (RPL29) via catalyzing asymmetric dimethylation of histone H4R3 (H4R3me2a) at its gene promoter region. PRMT1 augments the global protein synthesis via RPL29 in CML LSCs. Taken together, the findings provide new evidence that histone arginine methylation modification regulates protein synthesis in LSCs and highlight PRMT1 as a valuable druggable target for patients with CML.

Keywords:  CML; PRMT1; RPL29; leukemia stem cells; protein synthesis; self‐renewal

DOI:  https://doi.org/10.1002/advs.202308586
Cancer Lett. 2024 Dec 07. pii: S0304-3835(24)00783-3. [Epub ahead of print]611 217388

Bone marrow stromal cells protect myeloma cells from ferroptosis through GPX4 deSUMOylation.

Hongmei Jiang, Qian Li, Xudan Yang, Linchuang Jia, Hao Cheng, Jingya Wang, Sheng Wang, Xin Li, Ying Xie, Jingjing Wang, Yixuan Wang, Meilin Hu, Jing Guo, Ziyi Peng, Mengqi Wang, Tiantian Li, Haifeng Zhao, Lijuan Wang, Zhiqiang Liu.

  Bone marrow stromal cells (BMSCs) are vital for preventing chemotherapy induced apoptosis of multiple myeloma (MM), but roles and machinery in other forms of cell death have not been well elucidated. Here, using an in vitro BMSC-MM interacting model, we observed BMSCs protected MM cells from labile iron pool (LIP) and reactive oxygen species (ROS) triggered ferroptosis by elevating glutathione peroxidase 4 (GPX4). Mechanistically, direct interaction with BMSCs upregulated the expression of SUMO-specific protease 3 (SENP3) in MM cells through CD40/CD40L signaling pathway, and SENP3 de-conjugated SUMO2 at lysine 75 residue to stabilize GPX4 protein, thereby consuming ROS to obviate ferroptosis in MM cells from the Vk∗MYC mouse model, as well as in CD138+B220- cells separated from the Cd40lfl/fl;Prx1Cre/+ mice (CD40-CKO) and Sumo2 knock out (SUMO2-KO) mice. Using the NOD-scid IL2Rgammanull (NSG) mouse based xenograft model and intra-bone MM growth model, we validated that target SENP3 enhanced the killing effect of GPX4 inhibitor RSL3, thereby reduced tumor burden, prolonged survival of mice, and alleviated bone disruption of mice bearing MM tumors. Our study deciphers the mechanism of BMSCs preventing MM cells from spontaneous ferroptosis, and clarifies the therapeutic potential of non-apoptosis strategies in managing refractory or relapsed MM patients.

Keywords:  CD40/CD40L; Ferroptosis; GPX4; Multiple myeloma; Protein posttranslational modification; SENP3

DOI:  https://doi.org/10.1016/j.canlet.2024.217388
Cell Stem Cell. 2024 Dec 05. pii: S1934-5909(24)00376-X. [Epub ahead of print]

BCL11A +58/+55 enhancer-editing facilitates HSPC engraftment and HbF induction in rhesus macaques conditioned with a CD45 antibody-drug conjugate.

Selami Demirci, Jing Zeng, Rahul Palchaudhuri, Chuanfeng Wu, Diana M Abraham, Taha B Hayal, Khaled Essawi, My Anh Nguyen, Ulana Stasula, Rebecca Chu, Alexis Leonard, Shaina N Porter, Muhammad Behroz Naeem Khan, Gabriela Hinojosa, Naoya Uchida, Sogun Hong, Cicera R Lazzarotto, Nola R Neri, Lucas Ferreira da Silva, Danilo Pellin, Archana Verma, Leanne Lanieri, Anjali Bhat, Katelyn Hammond, Tiffany Tate, Stacy A Maitland, Fatemeh Sheikhsaran, Aylin C Bonifacino, Allen E Krouse, Nathaniel S Linde, Theresa Engels, Justin Golomb, Shengdar Q Tsai, Shondra M Pruett-Miller, David T Scadden, Cynthia E Dunbar, Scot A Wolfe, Robert E Donahue, Lisa M Olson, Daniel E Bauer, John F Tisdale.

  Editing the +58 region of the BCL11A erythroid enhancer has shown promise in treating β-globin disorders. To address variations in fetal hemoglobin (HbF) response, we investigated editing both +58 and +55 enhancers. Rhesus macaques transplanted with edited hematopoietic stem/progenitor cells (HSPCs) following busulfan conditioning exhibited durable, high-level (∼90%) editing frequencies post transplantation with sustained HbF reactivation over 4 years, without hematological perturbations. HbF levels were further boosted by stress erythropoiesis or hydroxyurea. Bone marrow analysis revealed that gene edits were predominantly programmed deletions, programmed inversions, and short indels, each disrupting the enhancer core TGN7-9WGATAR half E-box/GATA binding motifs. Nonprogrammed long deletions were disfavored in engrafting cells. CD45 antibody-drug conjugate (ADC) conditioning achieved comparable engraftment and HbF reactivation, whereas lentiviral vector tracking showed polyclonal reconstitution with dynamics similar to animals conditioned with total body irradiation (TBI) or busulfan. Joining CD45-ADC conditioning with combined enhancer editing presents an effective strategy for β-hemoglobinopathies, enabling durable HbF reactivation without chemotherapy.

Keywords:  CRISPR-Cas9; HSC transplantation; antibody conditioning; busulfan; fetal hemoglobin; hydroxyurea; sickle cell disease; therapeutic gene editing; β-globin disorders; γ-globin

DOI:  https://doi.org/10.1016/j.stem.2024.10.014
Mol Cell. 2024 Dec 05. pii: S1097-2765(24)00909-2. [Epub ahead of print]84(23): 4612-4628.e13

Reactive oxygen species control protein degradation at the mitochondrial import gate.

Rachael McMinimy, Andrew G Manford, Christine L Gee, Srividya Chandrasekhar, Gergey Alzaem Mousa, Joelle Chuang, Lilian Phu, Karen Y Shih, Christopher M Rose, John Kuriyan, Baris Bingol, Michael Rapé.

  While reactive oxygen species (ROS) have long been known to drive aging and neurodegeneration, their persistent depletion below basal levels also disrupts organismal function. Cells counteract loss of basal ROS via the reductive stress response, but the identity and biochemical activity of ROS sensed by this pathway remain unknown. Here, we show that the central enzyme of the reductive stress response, the E3 ligase Cullin 2-FEM1 homolog B (CUL2FEM1B), specifically acts at mitochondrial TOM complexes, where it senses ROS produced by complex III of the electron transport chain (ETC). ROS depletion during times of low ETC activity triggers the localized degradation of CUL2FEM1B substrates, which sustains mitochondrial import and ensures the biogenesis of the rate-limiting ETC complex IV. As complex III yields most ROS when the ETC outpaces metabolic demands or oxygen availability, basal ROS are sentinels of mitochondrial activity that help cells adjust their ETC to changing environments, as required for cell differentiation and survival.

Keywords:  FEM1B; TOM complex; electron transport chain; mitochondria; proteasome; reductive stress response; ubiquitin

DOI:  https://doi.org/10.1016/j.molcel.2024.11.004
Oncogene. 2024 Dec 09.

Pseudokinase TRIB3 stabilizes SSRP1 via USP10-mediated deubiquitination to promote multiple myeloma progression.

Haiqin Wang, Long Liang, Yifang Xie, Han Gong, Feifan Fan, Chengcai Wen, Yu Jiang, Shiying Lei, Xili Qiu, Hongling Peng, Mao Ye, Xiaojuan Xiao, Jing Liu.

Multiple myeloma (MM), the world's second most common hematologic malignancy, poses considerable clinical challenges due to its aggressive progression and resistance to therapy. Addressing these challenges requires a detailed understanding of the mechanisms driving MM initiation, progression, and therapeutic resistance. This study identifies the pseudokinase tribble homolog 3 (TRIB3) as a high-risk factor that promotes MM malignancy in vitro and in vivo. Mechanistically, TRIB3 directly interacts with structure-specific recognition protein 1 (SSRP1) and ubiquitin-specific peptidase 10 (USP10), facilitating the formation of a TRIB3/USP10/SSRP1 ternary complex. This complex stabilizes SSRP1 via USP10-mediated deubiquitination, thereby driving MM cell proliferation. Furthermore, a stapled peptide, SP-A, was developed, which effectively disrupts the TRIB3/USP10/SSRP1 complex, leading to a decrease in SSRP1 levels by inhibiting its stabilization through USP10. Notably, SP-A exhibits strong synergistic effects when combined with the proteasome inhibitor bortezomib. Given the critical role of the TRIB3/USP10/SSRP1 complex in MM pathophysiology, it represents a promising therapeutic target for MM treatment. In MM cells, TRIB3, USP10 and SSRP1 form a ternary complex and TRIB3 enhances the deubiquitinating effect of USP10 on SSRP1, leading to malignant progression of MM. In the case of drug intervention, SP-A attenuates the binding of SSRP1 and USP10 by inhibiting protein interactions between TRIB3 and SSRP1 and promoted SSRP1 protein degradation, leading to significant inhibition of MM development. Visual abstract created with Biorender.

DOI: https://doi.org/10.1038/s41388-024-03245-4
Adv Sci (Weinh). 2024 Dec 10. e2407681

PNPO-Mediated Oxidation of DVL3 Promotes Multiple Myeloma Malignancy and Osteoclastogenesis by Activating the Wnt/β-Catenin Pathway.

Zhendong Deng, Shanliang Sun, Nian Zhou, Yumeng Peng, Long Cheng, Xichao Yu, Yuxia Yuan, Mengjie Guo, Min Xu, Yuexin Cheng, Fan Zhou, Nianguang Li, Ye Yang, Chunyan Gu.

  Multiple myeloma (MM) is a cancer of plasma cells caused by abnormal gene expression and interactions within the bone marrow (BM) niche. The BM environment significantly influences the progression of MM. Celastrol, a natural compound derived from traditional Chinese medicine, exhibits significant anticancer effects. This study aimed to identify specific targets of celastrol and develop more effective and less toxic treatment options for MM. Celastrol is used as a probe to determine its specific target, pyridoxine-5'-phosphate oxidase (PNPO). Increased levels of PNPO are associated with poor outcomes in MM patients, and PNPO promotes MM cell proliferation and induces osteoclast differentiation through exosomes. Mechanistically, PNPO oxidizes disheveled 3M282 (DVL3), leading to abnormal activation of the Wnt/β-catenin pathway. Based on the critical sites of PNPOR95/K117, Eltrombopag is identified as a potential therapeutic candidate for MM. In addition, the experiments showed its efficacy in mouse models. Eltrombopag inhibited the growth of MM cells and reduced bone lesions by disrupting the interaction between PNPO and DVL3, as supported by preliminary clinical trials. The study highlights the importance of PNPO as a high-risk gene in the development of MM and suggests that Eltrombopag may be a promising treatment option.

Keywords:  dishevelled 3; eltrombopag; multiple myeloma; pyridoxine‐5′‐phosphate oxidase; wnt/β‐catenin pathway

DOI:  https://doi.org/10.1002/advs.202407681
Blood Cancer Discov. 2024 Dec 09.

The crossroads of clonal evolution, differentiation hierarchy and ontogeny in leukemia development.

Christopher M Sturgeon, Elvin Wagenblast, Franco Izzo, Eirini P Papapetrou.

Transformative technologies to sequence tumor genomes at large scale and single-cell resolution have exposed the repertoire of genetic alterations that are present in leukemia genomes, the timing of their acquisition and patterns of their co-occurrence. In parallel, single-cell multi-omics technologies are allowing us to map the differentiation paths and hierarchical structures of malignant cells and giving us a glimpse into hematopoietic development in prenatal life. We propose that interrogating how the genetic evolution, differentiation hierarchy and ontogeny of malignant myeloid cells intersect with each other, using new experimental systems and multimodal technologies, will fuel the next generation of research breakthroughs.

DOI: https://doi.org/10.1158/2643-3230.BCD-24-0235
Stem Cells Cloning. 2024 ;17 41-58

Advancements in Umbilical Cord Biobanking: A Comprehensive Review of Current Trends and Future Prospects.

Sahar AlOraibi, Sebastien Taurin, Sfoug Alshammary.

  Biobanking has emerged as a transformative concept in advancing the medical field, particularly with the exponential growth of umbilical cord (UC) biobanking in recent decades. UC blood and tissue provide a rich source of primitive hematopoietic stem cells (HSCs) and mesenchymal stem cells (MSCs) for clinical transplantation, offering distinct advantages over alternative adult stem cell sources. However, to fully realize the therapeutic potential of UC-derived stem cells and establish a comprehensive global UC-biobanking network, it is imperative to optimize and standardize UC processing, cryopreservation methods, quality control protocols, and regulatory frameworks, alongside developing effective consent provisions. This review aims to comprehensively explore recent advancements in UC biobanking, focusing on the establishment of rigorous safety and quality control procedures, the standardization of biobanking operations, and the optimization and automation of UC processing and cryopreservation techniques. Additionally, the review examines the expanded clinical applications of UC stem cells, addresses the challenges associated with umbilical cord biobanking and UC-derived stem cell therapies, and discusses the promising role of artificial intelligence (AI) in enhancing various operational aspects of biobanking, streamlining data processing, and improving data analysis accuracy while ensuring compliance with safety and quality standards. By addressing these critical areas, this review seeks to provide insights into the future direction of UC biobanking and its potential to significantly impact regenerative medicine.

Keywords:  artificial intelligence; cryopreservation; hematopoietic stem cells; mesenchymal stem cells; umbilical cord biobanking

DOI:  https://doi.org/10.2147/SCCAA.S481072
Sci Adv. 2024 Dec 13. 10(50): eadn0086

MLL/WDR5 complex recruits centriolar satellite protein Cep72 to regulate microtubule nucleation and spindle formation.

Swathi Chodisetty, Aditi Arora, Kausika Kumar Malik, Himanshu Goel, Shweta Tyagi.

Dysfunction of the centrosome, the major microtubule-organizing center of the cell, is implicated in microcephaly. Haploinsufficiency of mixed-lineage leukemia (MLL/KMT2A) protein causes Wiedemann-Steiner syndrome (WSS), a neurodevelopmental disorder associated with microcephaly. However, whether MLL has a function at the centrosome is not clear. Here, we show that loss of the MLL/WDR5 complex affects microtubule nucleation and regrowth. MLL/WDR5 localize to the pericentriolar material and interact with centriolar satellite protein Cep72 and γ-tubulin ring complex proteins (γ-TuRCs). MLL/WDR5 promote the localization of γ-TuRCs and structural proteins like AKAP9 to the centrosome during interphase and mitosis, a phenotype also observed in cells derived from patients with WSS. During mitosis, loss of MLL, WDR5, and Cep72 affects spindle formation and leads to misaligned chromosomes. Last, we show that MLL and WDR5 recruit Cep72 to the centrosome. Our studies provide insight into an undiscovered role of MLL at the centrosome and elucidate how centriolar satellite proteins like Cep72 can be recruited to the centrosome.

DOI: https://doi.org/10.1126/sciadv.adn0086