RNase L represses hair follicle regeneration through altered innate immune signaling

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Abstract

Mammalian injury responses are predominantly characterized by fibrosis and scarring rather than functional regeneration. This limited regenerative capacity in mammals could reflect a loss of pro-regeneration programs or active suppression by genes functioning akin to tumor suppressors. To uncover programs governing regeneration in mammals, we screened transcripts in human subjects following laser rejuvenation treatment and compared them to mice with enhanced Wound Induced Hair Neogenesis (WIHN), a rare example of mammalian organogenesis. We found that Rnasel-/- mice exhibit an increased regenerative capacity, with elevated WIHN through enhanced IL-36α. Consistent with RNase L’s known role to stimulate caspase-1, we found that pharmacologic inhibition of caspases promoted regeneration in an IL-36 dependent manner in multiple epithelial tissues. We identified a negative feedback loop, where RNase L activated caspase-1 restrains the pro-regenerative dsRNA-TLR3 signaling cascade through the cleavage of toll-like adaptor protein TRIF. Through integrated single-cell RNA sequencing and spatial transcriptomic profiling, we confirmed Oas & Il36 genes to be highly expressed at the site of wounding and are elevated in Rnasel-/- mice wounds. This work suggests that RNase L functions as a regeneration repressor gene, in a functional tradeoff that tempers immune hyper-activation during viral infection at the cost of inhibiting regeneration.

Authors

Charles S. Kirby, Nasif Islam, Eric Wier, Martin P. Alphonse, Evan Sweren, Gaofeng Wang, Haiyun Liu, Dongwon Kim, Ang Li, Sam S. Lee, Andrew M. Overmiller, Yingchao Xue, Sashank Reddy, Nathan K. Archer, Lloyd S. Miller, Jianshi Yu, Weiliang Huang, Jace W. Jones, Sooah Kim, Maureen A. Kane, Robert H. Silverman, Luis A. Garza

Estrogen receptor alpha ablation reverses muscle fibrosis and inguinal hernias

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Abstract

Fibrosis of the lower abdominal muscle (LAM) contributes to muscle weakening and inguinal hernia formation, an ailment affecting a noteworthy fifty percent of men by age 75, necessitating surgical correction as the singular therapy. Despite its prevalence, the mechanisms driving LAM fibrosis and hernia development remain poorly understood. Utilizing a humanized mouse model that replicates elevated skeletal muscle tissue estrogen concentrations akin to aging men, we identified estrogen receptor alpha (ESR1) as a key driver of LAM fibroblast proliferation, extracellular matrix deposition, and hernia formation. Fibroblast-specific ESR1 ablation effectively prevented muscle fibrosis and herniation, while pharmacological ESR1 inhibition with fulvestrant reversed hernias and restored normal muscle architecture. Multiomic analyses on in vitro LAM fibroblasts unveiled an estrogen/ESR1-mediated activation of a distinct profibrotic cistrome and gene expression signature, concordant with observations in inguinal hernia tissues in human males. Our findings hold significant promise for prospective medical interventions targeting fibrotic conditions and presenting non-surgical avenues for addressing inguinal hernias.

Authors

Tanvi Potluri, Tianming You, Ping Yin, John S. Coon V, Jonah J. Stulberg, Yang Dai, David J Escobar, Richard L. Lieber, Hong Zhao, Serdar E. Bulun

Sleep-wake variation in body temperature regulates tau secretion and correlates with CSF and plasma tau

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Abstract

Sleep disturbance is bidirectionally associated with increased risks of Alzheimer’s disease and other tauopathies. While the sleep-wake cycle regulates interstitial and cerebrospinal fluid (CSF) tau levels, the underlying mechanisms remain unknown. Understanding these mechanisms is crucial given evidence indicates that tau pathology spreads through neuron-to-neuron transfer, involving the secretion and internalization of pathological tau forms. Here, we combine in vitro, in vivo and clinical methods to reveal a pathway by which changes in body temperature (BT) over the sleep-wake cycle modulate extracellular tau levels. In mice, higher BT during wakefulness and sleep-deprivation increased CSF and plasma tau levels, while also upregulating unconventional protein secretion pathway-I (UPS-I) components, including (i) intracellular tau dephosphorylation, (ii) caspase-3-mediated cleavage of tau (TauC3) and (iii) its membrane translocation through binding to PIP2 and syndecan-3. In humans, the increase in CSF and plasma tau levels observed post-wakefulness correlated with BT increase during wakefulness. By demonstrating that sleep-wake variation in BT regulates extracellular tau levels, our findings highlight the importance of thermoregulation in linking sleep disturbances to tau-mediated neurodegeneration, and the preventative potential of thermal interventions.

Authors

Geoffrey Canet, Felipe Da Gama Monteiro, Emma Rocaboy, Sofia Diego-Diaz, Boutheyna Khelaifia, Kelly Godbout, Aymane Lachhab, Jessica Kim, Daphne I. Valencia, Audrey Yin, Hau-Tieng Wu, Jordan C. Howell, Emily Blank, Francis Laliberté, Nadia Fortin, Emmanuelle Boscher, Parissa Fereydouni-Forouzandeh, Stéphanie Champagne, Isabelle Guisle, Sébastien S. Hébert, Vincent Pernet, Haiyan Liu, William Lu, Ludovic Debure, David M. Rapoport, Indu Ayappa, Andrew W. Varga, Ankit Parekh, Ricardo S. Osorio, Steve Lacroix, Mark P. Burns, Brendan P. Lucey, Esther M. Blessing, Emmanuel Planel

5-HT orchestrates Histone Serotonylation and Citrullination to Drive Neutrophil Extracellular Traps and Liver Metastasis

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Abstract

Serotonin (5-HT) is a neurotransmitter that has been linked to tumorigenesis. Whether and how 5-HT modulates cells in the microenvironment to regulate tumor metastasis remains to be largely unknown. Here, we demonstrate that 5-HT is secreted by neuroendocrine prostate cancer (NEPC) cells to communicate with neutrophils and to induce neutrophil extracellular traps (NETs) in the liver, which in turn facilitates the recruitment of disseminated cancer cells and promotes liver metastasis. 5-HT induces histone serotonylation (H3Q5ser) and orchestrates histone citrullination (H3cit) in neutrophils to trigger chromatin decondensation and facilitate the formation of NETs. Interestingly, we uncover in this process a reciprocally reinforcing effect between H3Q5ser and H3cit and a crosstalk between the respective writers TGM2 and PAD4. Genetic ablation or pharmacological targeting of TGM2, or inhibiting 5-HT transporter (SERT) with the FDA-approved antidepressant drug fluoxetine reduces H3Q5ser and H3cit modifications, suppresses NETs formation, and effectively inhibits NEPC, small cell lung cancer, and thyroid medullary cancer liver metastasis. Collectively, the 5-HT-triggered NETs production highlights a new targetable neurotransmitter-immune axis in driving liver metastasis of neuroendocrine cancers.

Authors

Kaiyuan Liu, Yingchao Zhang, Genyu Du, Xinyu Chen, Lingling Xiao, Luyao Jiang, Na Jing, Penghui Xu, Chaoxian Zhao, Yiyun Liu, Huifang Zhao, Yujiao Sun, Jinming Wang, Chaping Cheng, Deng Wang, Jiahua Pan, Wei Xue, Pengcheng Zhang, Zhi-Gang Zhang, Wei-Qiang Gao, Shu-Heng Jiang, Kai Zhang, Helen He Zhu

Transcription of hepatitis B surface antigen shifts from cccDNA to integrated HBV DNA during treatment

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Abstract

The cornerstone of functional cure for chronic hepatitis B (CHB) is hepatitis B surface antigen (HBsAg) loss from blood. HBsAg is encoded by covalently closed circular DNA (cccDNA) and HBV DNA integrated into the host genome (iDNA). Nucleos(t)ide analogues (NUCs), the mainstay of CHB treatment, rarely lead to HBsAg loss, which we hypothesized was due to continued iDNA transcription despite decreased cccDNA transcription. To test this, we applied a novel multiplex droplet digital PCR that identifies the dominant source of HBsAg mRNAs to 3436 single cells from paired liver biopsies from ten people with CHB and HIV receiving NUCs. With increased NUC duration, cells producing HBsAg mRNAs shifted from chiefly cccDNA to chiefly iDNA. This shift was due to both a reduction in the number of cccDNA-containing cells and diminished cccDNA-derived transcription per cell; furthermore, it correlated with reduced detection of proteins deriving from cccDNA but not iDNA. Despite this shift in the primary source of HBsAg, rare cells remained with detectable cccDNA-derived transcription, suggesting a source for maintaining the replication cycle. Functional cure must address both iDNA and residual cccDNA transcription. Further research is required to understand the significance of HBsAg when chiefly derived from iDNA.

Authors

Maraake Taddese, Tanner Grudda, Giulia Belluccini, Mark Anderson, Gavin Cloherty, Hyon S. Hwang, Monika Mani, Che-Min Lo, Naomi Esrig, Mark S. Sulkowski, Richard K. Sterling, Yang Zhang, Ruy M. Ribeiro, David L. Thomas, Chloe L. Thio, Ashwin Balagopal

Monocytes and interstitial macrophages contribute to hypoxic pulmonary hypertension

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Abstract

Hypoxia is a major cause of pulmonary hypertension (PH) worldwide, and it is likely that interstitial pulmonary macrophages contribute to this vascular pathology. We observed in hypoxia-exposed mice an increase in resident interstitial macrophages, which expanded through proliferation and expressed the monocyte recruitment ligand CCL2. We also observed an increase in CCR2+ macrophages through recruitment, which express the protein thrombospondin-1 that functionally activates TGF-beta to cause vascular disease. Blockade of monocyte recruitment with either CCL2 neutralizing antibody treatment or CCR2 deficiency in the bone marrow compartment suppressed hypoxic PH. These data were supported by analysis of plasma samples from humans who travelled from low (225m) to high (3500m) elevation, revealing an increase in thrombospondin-1 and TGF-beta expression following ascent, which was blocked by dexamethasone prophylaxis. In the hypoxic mouse model, dexamethasone prophylaxis recapitulated these findings by mechanistically suppressing CCL2 expression and CCR2+ monocyte recruitment. These data suggest a pathologic cross-talk between two discrete interstitial macrophage populations, which can be therapeutically targeted.

Authors

Rahul Kumar, Kevin Nolan, Biruk Kassa, Neha Chanana, Tsering Palmo, Kavita Sharma, Kanika Singh, Claudia Mickael, Dara Fonseca Balladares, Julia Nilsson, Amit Prabhakar, Aastha Mishra, Michael H. Lee, Linda Sanders, Sushil Kumar, Ari B. Molofsky, Kurt R. Stenmark, Dean Sheppard, Rubin M. Tuder, Mohit D. Gupta, Tashi Thinlas, Qadar Pasha, Brian B. Graham

Elevated protein lactylation promotes immunosuppressive microenvironment and therapeutic resistance in pancreatic ductal adenocarcinoma

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Abstract

Metabolic reprogramming shapes tumor microenvironment (TME) and may lead to immunotherapy resistance in pancreatic ductal adenocarcinoma (PDAC). Elucidating the impact of pancreatic cancer cell metabolism in the TME is essential to therapeutic interventions. “Immune cold” PDAC is characterized by elevated lactate levels resulting from tumor cell metabolism, abundance of pro-tumor macrophages, and reduced cytotoxic T cell in the TME. Analysis of 18F-FDG uptake in patients showed that increased global protein lactylation in PDAC correlates with worse clinical outcomes in immunotherapy. Inhibition of lactate production in pancreatic tumors via glycolysis or mutant-KRAS inhibition reshaped the TME, thereby increasing their sensitivity to immune checkpoint blockade (ICB) therapy. In pancreatic tumor cells, lactate induces K63 lactylation of Endosulfine alpha (ENSA-K63la), a crucial step that triggers STAT3-CCL2 signaling. Consequently, elevated CCL2 secreted by tumor cells facilitates tumor-associated macrophage (TAM) recruitment to the TME. High levels of lactate also drive transcriptional reprogramming in TAMs via ENSA-STAT3 signaling, promoting an immunosuppressive environment. Targeting ENSA-K63la or CCL2 enhances the efficacy of ICB therapy in murine and humanized pancreatic tumor models. In conclusion, elevated lactylation reshapes the TME and promotes immunotherapy resistance in PDAC. Therapeutic approach targeting ENSA-K63la or CCL2 has shown promise in sensitizing pancreatic cancer immunotherapy.

Authors

Kang Sun, Xiaozhen Zhang, Jiatao Shi, Jinyan Huang, Sicheng Wang, Xiang Li, Haixiang Lin, Danyang Zhao, Mao Ye, Sirui Zhang, Li Qiu, Minqi Yang, Chuyang Liao, Lihong He, Mengyi Lao, Jinyuan Song, Na Lu, Yongtao Ji, Hanshen Yang, Lingyue Liu, Xinyuan Liu, Yan Chen, Shicheng Yao, Qianhe Xu, Jieru Lin, Yan Mao, Jingxin Zhou, Xiao Zhi, Ke Sun, Xiongbin Lu, Xueli Bai, Tingbo Liang

HoxBlinc lncRNA reprograms CTCF-independent TADs to drive leukemic transcription and HSC dysregulation in NUP98-rearranged leukemia

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Abstract

Although nucleoporin 98 (NUP98) fusion oncogenes often drive aggressive pediatric leukemia by altering chromatin structure and expression of HOX genes, underlying mechanisms remain elusive. Here, we report that a Hoxb-associated lncRNA HoxBlinc was aberrantly activated in NUP98-PHF23 fusion-driven leukemias. HoxBlinc chromatin occupancies led to elevated MLL1 recruitment and aberrant homeotic topologically associated domains (TADs) that enhanced chromatin accessibilities and activated homeotic/hematopoietic oncogenes. HoxBlinc-depletion in NUP98 fusion-driven leukemia impaired HoxBlinc binding, TAD integrity, MLL1 recruitment, and MLL1-driven chromatin signature within HoxBlinc-defined TADs in a CTCF-independent manner, leading to inhibited homeotic/leukemic oncogenes that mitigated NUP98 fusion-driven leukemogenesis in xenografted mouse models. Mechanistically, HoxBlinc overexpression in mouse hematopoietic compartment induced leukemias resembling those in NUP98-PHF23 knock-in mice via enhancing HoxBlinc chromatin binding, TAD formation, and Hox gene aberration leading to expansion of hematopoietic stem and progenitor cell (HSPC) and myeloid/lymphoid subpopulations. Thus, our studies reveal a CTCF-independent role of HoxBlinc in leukemic TAD organization and oncogene regulatory networks.

Authors

Karina Hamamoto, Ganqian Zhu, Qian Lai, Julia Lesperance, Huacheng Luo, Ying Li, Nupur Nigam, Arati Sharma, Feng-Chun Yang, David Claxton, Yi Qiu, Peter D. Aplan, Mingjiang Xu, Suming Huang

Small molecule modulators of B56-PP2A restore 4E-BP function to suppress eIF4E-dependent translation in cancer cells

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Abstract

Dysregulated eIF4E-dependent translation is a central driver of tumorigenesis and therapy resistance. eIF4E binding proteins (4E-BP1/2/3) are major negative regulators of eIF4E-dependent translation that are inactivated in tumors through inhibitory phosphorylation or downregulation. Previous studies have linked PP2A phosphatase(s) to activation of 4E-BP1. Here, we leveraged biased small molecule activators of PP2A (SMAPs) to explore the role of B56-PP2A(s) in 4E-BP regulation and the potential of B56-PP2A activation for restoring translational control in tumors. SMAP treatment promoted PP2A-dependent hypophosphorylation of 4E-BP1/2, supporting a role for B56-PP2As (e.g., B56α-PP2A) as 4E-BP phosphatases. Unexpectedly, SMAPs induced transcriptional upregulation of 4E-BP1 through a B56 PP2A→TFE3/TFEB→ATF4 axis. Cap-binding and co-immunoprecipitation assays showed that B56-PP2A(s) activation blocks assembly of the eIF4F translation initiation complex, and cap-dependent translation assays confirmed the translation inhibitory effects of SMAPs. Thus, B56-PP2A(s) orchestrate a translation repressive program involving transcriptional induction and activation of 4E-BP1. Notably, SMAPs promoted 4E-BP1-dependent apoptosis in tumor cells and potentiated 4E-BP1 function in the presence of ERK or mTOR inhibitors, agents that rely on inhibition of eIF4E-dependent translation for antitumor activity. These findings, combined with the ability of SMAPs to regulate 4E-BP1 in vivo, highlight the potential of PP2A activators for cancer therapy and overcoming therapy resistance.

Authors

Michelle A. Lum, Kayla A. Jonas, Shreya Parmar, Adrian R. Black, Caitlin M. O'Connor, Stephanie Dobersch, Naomi Yamamoto, Tess M. Robertson, Aidan Schutter, Miranda Giambi, Rita A. Avelar, Analisa DiFeo, Nicholas T. Woods, Sita Kugel, Goutham Narla, Jennifer D. Black

Neonatal but not Juvenile Gene Therapy Reduces Seizures and Prolongs Lifespan in SCN1B-Dravet Syndrome Mice

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Abstract

Dravet syndrome (DS) is a developmental and epileptic encephalopathy (DEE) that begins in the first year of life. While most cases of DS are caused by variants in SCN1A, variants in SCN1B, encoding voltage-gated sodium channel β1 subunits, are also linked to DS or to the more severe early infantile DEE. Both disorders fall under the OMIM term DEE52. Scn1b null mice model DEE52, with spontaneous generalized seizures and death in 100% of animals in the third postnatal week. Scn1b null cortical parvalbumin-positive interneurons and pyramidal neurons are hypoexcitable. The goal of this study was to develop a proof-of-principle gene replacement strategy for DEE52. We tested an adeno-associated viral vector encoding β1 subunit cDNA (AAV-Navβ1) in Scn1b null mice. We demonstrated that AAV-Navβ1 drives β1 protein expression in excitatory and inhibitory neurons in mouse brain. Bilateral intracerebroventricular administration of AAV-Navβ1 in Scn1b null mice at postnatal day (P) 2, but not at P10, reduced spontaneous seizure severity and duration, prolonged life span, prevented hyperthermia-induced seizures, and restored cortical neuron excitability. AAV-Navβ1 administration to WT mice resulted in β1 overexpression in brain but no obvious adverse effects. This work lays the foundation for future development of a gene therapeutic strategy for SCN1B-linked DEE patients.

Authors

Chunling Chen, Yukun Yuan, Heather A. O'Malley, Robert Duba-Kiss, Yan Chen, Karl Habig, Yosuke Niibori, Samantha L. Hodges, David R. Hampson, Lori L. Isom