Cell biology
Abstract
High-grade serous ovarian cancer (HGSOC) is the most prevalent and aggressive histological subtype of ovarian cancer and often presents with metastatic disease. The drivers of metastasis in HGSOC remain enigmatic. APOBEC3A (A3A), an enzyme that generates mutations across various cancers, has been proposed as a mediator of tumor heterogeneity and disease progression. However, the role of A3A in HGSOC has not been explored. We observed an association between high levels of APOBEC3-mediated mutagenesis and poor overall survival in primary HGSOC. We experimentally addressed this correlation by modeling A3A expression in HGSOC, and this resulted in increased metastatic behavior of HGSOC cells in culture and distant metastatic spread in vivo, which was dependent on catalytic activity of A3A. A3A activity in both primary and cultured HGSOC cells yielded consistent alterations in expression of epithelial-mesenchymal transition (EMT) genes resulting in hybrid EMT and mesenchymal signatures, providing a mechanism for their increased metastatic potential. Inhibition of key EMT factors TWIST1 and IL-6 resulted in mitigation of A3A-dependent metastatic phenotypes. Our findings define the prevalence of A3A mutagenesis in HGSOC and implicate A3A as a driver of HGSOC metastasis via EMT, underscoring its clinical relevance as a potential prognostic biomarker. Our study lays the groundwork for the development of targeted therapies aimed at mitigating the deleterious effect of A3A-driven EMT in HGSOC.
Authors
Jessica M. Devenport, Thi Tran, Brooke R. Harris, Dylan Fingerman, Rachel A. DeWeerd, Lojain H. Elkhidir, Danielle LaVigne, Katherine Fuh, Lulu Sun, Jeffrey J. Bednarski, Ronny Drapkin, Mary M. Mullen, Abby M. Green
Abstract
Glioblastoma (GBM) is the most lethal brain cancer, with GBM stem cells (GSCs) driving therapeutic resistance and recurrence. Targeting GSCs offers a promising strategy for preventing tumor relapse and improving outcomes. We identify SUV39H1, a histone-3, lysine-9 methyltransferase, as critical for GSC maintenance and GBM progression. SUV39H1 is upregulated in GBM compared with normal brain tissues, with single-cell RNA-seq showing its expression predominantly in GSCs due to super-enhancer–mediated activation. Knockdown of SUV39H1 in GSCs impaired their proliferation and stemness. Whole-cell RNA-seq analysis revealed that SUV39H1 regulates G2/M cell cycle progression, stem cell maintenance, and cell death pathways in GSCs. By integrating the RNA-seq data with ATAC-seq data, we further demonstrated that knockdown of SUV39H1 altered chromatin accessibility in key genes associated with these pathways. Chaetocin, an SUV39H1 inhibitor, mimics the effects of SUV39H1 knockdown, reducing GSC stemness and sensitizing cells to temozolomide, a standard GBM chemotherapy. In a patient-derived xenograft model, targeting SUV39H1 inhibits GSC-driven tumor growth. Clinically, high SUV39H1 expression correlates with poor glioma prognosis, supporting its relevance as a therapeutic target. This study identifies SUV39H1 as a crucial regulator of GSC maintenance and a promising therapeutic target to improve GBM treatment and patient outcomes.
Authors
Chunying Li, Qiqi Xie, Sugata Ghosh, Bihui Cao, Yuanning Du, Giau V. Vo, Timothy Y. Huang, Charles Spruck, Richard L. Carpenter, Y. Alan Wang, Q. Richard Lu, Kenneth P. Nephew, Jia Shen
Abstract
Intervertebral disc degeneration (IDD) is associated with low back pain, a leading cause of disability worldwide. Fibrosis of nucleus pulposus (NP) is a principal component of IDD, featuring an accumulation of myofibroblast-like cells. Previous study indicated matrix metalloproteinase 12 (MMP12) expression is upregulated in IDD but its role remains largely unexplored. We here showed that TGF-β1 could promote myofibroblast-like differentiation of human NP cells along with an induction of MMP12 expression. Intriguingly, MMP12 knockdown not only ameliorated the myofibroblastic phenotype but also increased chondrogenic marker expression. Transcriptome analysis revealed that the MMP12-mediated acquisition of myofibroblast phenotype was coupled to processes related to fibroblast activation and osteogenesis and pathways mediated by MAPK and Wnt signaling. Injury induced mouse IDD showed NP fibrosis with marked increase of collagen deposition and αSMA-expressing cells. In contrast, MMP12 knockout mice exhibited largely reduced collagen I and III but increased collagen II and aggrecan deposition, indicating an inhibition of NP fibrosis along with an enhanced cartilaginous matrix remodeling. Consistently, an increase of SOX9+/CNMD+ but decrease of αSMA+ NP cells was found in the knockout. Altogether, our findings suggest a pivotal role of MMP12 in myofibroblast generation, thereby regulating NP fibrosis in IDD.
Authors
Yi Sun, Wai Kit Tam, Manyu Zhu, Qiuji Lu, Mengqi Yu, Yuching Hsu, Peng Chen, Peng Zhang, Minmin Lyu, Yongcan Huang, Zhaomin Zheng, Xintao Zhang, Victor Y. Leung
Abstract
Lynch syndrome (LS), caused by inherited mutations in DNA mismatch repair genes including MSH2, carries a 60% lifetime risk of developing endometrial cancer (EC). Beyond hypermutability, mechanisms driving LS-associated EC remain unclear. We investigated MSH2 loss in EC pathogenesis using a mouse model (PR-Cre Msh2LoxP/LoxP, abbreviated Msh2KO), primary cell lines, human tissues, and human EC cells with isogenic MSH2 knockdown. By eight months, 58% of Msh2KO mice developed endometrial atypical hyperplasia (AH), a precancerous lesion. At 12-16 months, 47% of Msh2KO mice exhibited either AH or ECs with histologic similarities to human LS-ECs. Transcriptomic profiling of EC from Msh2KO mice revealed mitochondrial dysfunction-related pathway alterations. Subsequent studies in vitro and in vivo revealed mitochondrial dysfunction based upon two mechanisms: mitochondrial content reduction and structural disruptions in retained mitochondria. Human LS-ECs also exhibited mitochondrial content reduction compared to non-LS-ECs. Functional studies demonstrated metabolic reprogramming of MSH2-deficient EC cells, including reduced oxidative phosphorylation and increased susceptibility to glycolysis suppression. These findings identified mitochondrial dysfunction and metabolic disruption as consequences of MSH2 deficiency in EC. Mitochondrial and metabolic aberrations should be evaluated as biomarkers for endometrial carcinogenesis or risk stratification and represent potential targets for cancer interception in women with LS.
Authors
Mikayla Borthwick Bowen, Brenda Melendez, Qian Zhang, Diana Moreno, Leah Peralta, Wai-Kin Chan, Collene Jeter, Lin Tan, M. Anna Zal, Philip L. Lorenzi, Kenneth Dunner Jr., Richard K. Yang, Russell R. Broaddus, Joseph Celestino, Nisha Gokul, Elizabeth Whitley, Deena M. Scoville, Tae Hoon KIM, Jae-Wook Jeong, Rosemarie Schmandt, Karen Lu, Hyun-Eui Kim, Melinda S. Yates
Abstract
The omentum is the primary site of metastasis for ovarian cancer (OC). Interactions between cancer cells and adipocytes drive an invasive and pro-metastatic phenotype. Here we studied cancer cell-adipocyte crosstalk by using a direct co-culture model with immortalized human visceral pre-adipocytes (VNPAD) and OC cells. We demonstrate increased proliferation, invasiveness, and resistance to cisplatin of co-cultured compared to mono-cultured OC cells. RNA-sequencing of OC cells from co-culture vs. mono-culture revealed significant transcriptomic changes, identifying over 200 differentially expressed genes (DEGs) common to OVCAR5 and OVCAR8 cell lines. Enriched pathways included PI3K/AKT and Complement activation. Lipid transfer into OC cells from adipocytes induced upregulation of complement C3 and C5 proteins. Inhibiting C3 or C5 reversed the invasive phenotype and C3 knockdown reduced tumor progression in-vivo. Increased C3 expression was observed in omental implants compared to primary ovarian tumors and C3 secretion was higher in OC ascites from high BMI vs. low BMI patients. C3 upregulation in OC cells involved activation of ATF4-mediated integrated stress response (ISR). Overall, adipocyte-cancer cell interactions promote invasiveness and tumorigenesis via lipid transfer, activating ISR, and upregulating complement proteins C3 and C5.
Authors
Andres Valdivia, Ana Isac, Horacio Cardenas, Guangyuan Zhao, Yaqi Zhang, Hao Huang, Jian-Jun Wei, Mauricio Cuello-Fredes, Sumie Kato, Fernán Gómez-Valenzuela, Francoise A. Gourronc, Aloysius J. Klingelhutz, Daniela Matei
Abstract
Hypertension and transient increases in blood pressure from extreme exertion are risk factors for aortic dissection in patients with age-related vascular degeneration or inherited connective tissue disorders. Yet, a common experimental model of angiotensin II-induced aortopathy in mice appears independent of high blood pressure as lesions do not occur in response to an alternative vasoconstrictor, norepinephrine, and are not prevented by co-treatment with a vasodilator, hydralazine. We investigated vasoconstrictor administration to adult mice following 1 week of disrupted TGFβ signaling in smooth muscle cells (SMCs). Norepinephrine increased blood pressure and induced aortic dissection by 7 days and even within 30 minutes (as did angiotensin II) that was prevented by hydralazine. Initial medial injury manifested as blood extravasation among SMCs and fibrillar matrix, progressive delamination from accumulation of blood, and stretched or ruptured SMCs with persistent attachments to elastic fibers. Altered regulatory contractile molecule expression was not of pathological importance. Rather, reduced synthesis of extracellular matrix yielded a vulnerable aortic phenotype by decreasing medial collagen, most dynamically basement membrane-associated multiplexin collagen, and impairing cell-matrix adhesion. We conclude that transient and sustained increases in blood pressure can cause dissection in aortas rendered vulnerable by inhibition of TGFβ-driven extracellular matrix production by SMCs.
Authors
Bo Jiang, Pengwei Ren, Changshun He, Mo Wang, Sae-Il Murtada, María Jesús Ruiz-Rodríguez, Yu Chen, Abhay B. Ramachandra, Guangxin Li, Lingfeng Qin, Roland Assi, Martin A. Schwartz, Jay D. Humphrey, George Tellides
Abstract
Temporomandibular joint (TMJ) osteoarthritis with pain is a highly prevalent disorder affecting patients’ quality of life. A comprehensive understanding of cell type diversity and its dynamics in painful TMJ osteoarthritis (TMJOA) is lacking. Here, we utilized an inflammatory TMJOA mouse model via intra-articular injection of CFA. TMJOA mice exhibited cartilage remodeling, bone loss, synovitis, increased osteoarthritis (OA) score, and orofacial pain, recapitulating hallmark symptoms in patients. Single-cell transcriptomic profiling of the TMJ was performed in conjunction with mouse genetic labeling, tissue clearing, light sheet and confocal 3D imaging, multiplex RNAscope, and immunodetection. We visualized, reconstructed, and analyzed the distribution and density of nociceptive innervation of TMJ at single-axon levels. We systematically mapped the heterogeneity and anatomical position of blood endothelial cells, synovial fibroblasts, and immune cells, including Cx3cr1-positive barrier macrophages. Importantly, TMJOA mice exhibited enhanced neurovascular coupling, sublining fibroblast hyperplasia, inflammatory immune cell expansion, disrupted signaling-dependent cell-cell interaction, and a breakdown of the sandwich-like organization consisting of synovial barrier macrophages and fibroblasts. By utilizing a mouse model with combined TMJ pain history and OA, we reveal the cellular diversity, anatomical structure, and cell dynamics of the TMJ at single-cell resolution, which facilitate our understanding and potential targeting of TMJOA.
Authors
Supawadee Jariyasakulroj, Yang Shu, Ziying Lin, Jingyi Chen, Qing Chang, Pao-Fen Ko, Jian-Fu Chen
Abstract
The proof-of-principle of the therapeutic potential of heat shock protein 47 (HSP47) for diseases characterized by defects in the collagen I synthesis is here proved in osteogenesis imperfecta (OI), a prototype of collagen disorders. Most of the OI mutations delay collagen I chains folding, increasing their exposure to post translational modifications that affect collagen secretion and impact extracellular matrix fibrils assembly. As model, we used primary fibroblasts from OI individuals with defect in the collagen prolyl-3-hydroxylation complex, since are characterized by the synthesis of homogeneously overmodified collagen molecules. We demonstrated that the exogenous recombinant HSP47 (rHSP47) is uptaken by the cells and localizes at the ER exit sites and ER Golgi intermediate compartment. rHSP47 treatment increased collagen secretion, reduced collagen post translational modifications and intracellular collagen retention and ameliorated the general ER proteostasis, leading to improved cellular homeostasis and vitality. These positive changes were also mirrored by an increased collagen content in the OI matrix. A mutation dependent effect was found in fibroblasts from three probands with collagen I mutations, for which rHSP47 was effective only in cells with the most N-term defect. A beneficial effect on bone mineralization was proved in vivo in the zebrafish p3h1-/- OI model.
Authors
Roberta Besio, Nadia Garibaldi, Alessandra Sala, Francesca Tonelli, Carla Aresi, Elisa Maffioli, Claudio Casali, Camilla Torriani, Marco Biggiogera, Simona Villani, Antonio Rossi, Gabriella Tedeschi, Antonella Forlino
Abstract
Lymphangioleiomyomatosis (LAM) is a progressive lung disease with limited treatments, largely due to an incomplete understanding of its pathogenesis. Lymphatic endothelial cells (LECs) invade LAM cell clusters, which include HMB-45-positive epithelioid cells and smooth muscle α-actin-expressing LAM-associated fibroblasts (LAMFs). Recent evidence shows that LAMFs resemble cancer-associated fibroblasts, with LAMF-LEC interactions contributing to disease progression. To explore these mechanisms, we used spatial transcriptomics on LAM lung tissues and identified a gene cluster enriched in kinase signaling pathways linked to myofibroblasts and co-expressed with LEC markers. Kinase arrays revealed elevated PDGFR and FGFR in LAMFs. Using a 3D co-culture spheroid model of primary LAMFs and LECs, we observed increased invasion in LAMF-LEC spheroids compared to non-LAM fibroblasts. Treatment with sorafenib, a multikinase inhibitor, significantly reduced invasion, outperforming Rapamycin. We also confirmed TSC2-deficient renal angiomyolipoma cells (TSC2-null AML) as key VEGF-A secretors, which was suppressed by sorafenib in both TSC2-null AML cells and LAMFs. These findings highlight VEGF-A and bFGF as potential therapeutic targets and suggest multikinase inhibition as a promising strategy for LAM.
Authors
Sinem Koc-Gunel, Emily C. Liu, Lalit K. Gautam, Ben A. Calvert, Shubha Murthy, Noa C. Harriott, Janna C. Nawroth, Beiyun Zhou, Vera P. Krymskaya, Amy L. Ryan
Abstract
Renal osteodystrophy is commonly seen in patients with chronic kidney disease (CKD) due to disrupted mineral homeostasis. Given the impaired renal function in these patients, common anti-resorptive agents, including bisphosphonates, must be used with caution or even contraindicated. Therefore, an alternative therapy without renal burden to combat renal osteodystrophy is urgently needed. Here, we report that clinically relevant aerobic exercise significantly prevents high-turnover renal osteodystrophy in CKD mouse and patients without compromising renal function. Mechanistically, 4-week aerobic exercise in CKD mice increased expression of skeletal muscle PPARγ coactivator-1α (PGC-1α) and circulating irisin. Both exercise and irisin administration significantly activated osteoblasts, but not osteoclasts, via integrin αvβ5, thereby conferring bone quality benefits. Removal of irisin-influenced thermogenic adipose tissues or genetic ablation of uncoupling protein 1 did not alter the irisin-conferred anti-osteodystrophy effect. Importantly, in a pilot clinical study, 12-week aerobic exercise in patients with high-grade CKD significantly increased circulating irisin and prevented osteodystrophy progression, without detectable renal burden. The combination of irisin and current anti-resorptive agents effectively rescued renal osteodystrophy in mice. Our work provides mechanistic insights into the role of exercise and irisin in renal osteodystrophy, and highlights a clinically relevant, low-cost, kidney-friendly therapy for patients with this devastating disease.
Authors
Meng Wu, Huilan Li, Xiaoting Sun, Rongrong Zhong, Linli Cai, Ruibo Chen, Madiya Madeniyet, Kana Ren, Zhen Peng, Yujie Yang, Weiqin Chen, Yanling Tu, Miaoxin Lai, Jinxiu Deng, Yuting Wu, Shumin Zhao, Qingyan Ruan, Mei Rao, Sisi Xie, Ying Ye, Jianxin Wan
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