Bolini et al. review the multiple faces of γδ T cells in cancer and discuss challenges in unlocking their full potential as actionable targets for cancer immunotherapy. Image credit: Lorenzo Galluzzi.
Successful implantation requires precise coordination of uterine epithelial receptivity, stromal decidualization, and immune homeostasis during a narrow peri-implantation window. Although retinoic acid (RA) signaling has been implicated in female reproduction, the endogenous and isoform-specific roles of retinoic acid receptors (RARs) remain poorly defined. Here, we combined isoform-specific genetic mouse models, transcriptomic profiling, and functional studies in mouse and human stromal cells to determine how RAR signaling regulates early pregnancy. We found that RARG is the dominant RAR isoform required for female fertility in mice, as its deletion severely impaired implantation, whereas combined loss of all RAR isoforms caused complete reproductive failure. RAR deficiency disrupted multiple sequential reproductive processes, including sperm transport and fertilization, suppression of uterine estrogen receptor activity, acquisition of stromal decidualization competence, and maintenance of uterine immune homeostasis. Transcriptomic analyses identified conserved epithelial and mesenchymal programs altered across independent RAR-deficient mouse models and revealed significant overlap with endometrial gene signatures from women with recurrent implantation failure. In human endometrial stromal cells, suppression of the RARA isoform consistently disrupted decidualization across three independent primary cell lines and an immortalized cell model. Together, these findings identify RAR signaling as a critical regulator of early pregnancy and reveal conserved, isoform-specific functions required for early pregnancy.
Yan Yin, Emily Y. So, Eliana Wolf, Vivian Robles Pinos, Meade Haller, Renjie Shang, Sylvia C. Hewitt, Alex Tak, Brent M. Bany, David Y. Chen, Mengcheng Shen, Francesco J. DeMayo, Liang Ma
Microglia play essential yet poorly understood roles in brain development, including axon guidance, regulation of neurogenesis, and pruning of neuronal projections. Congenital hydrocephalus (CH), characterized by enlarged cerebrospinal fluid (CSF)-filled ventricles, is a leading cause of pediatric brain surgery, but its molecular mechanisms remain unclear. We have identified what we believe to be novel, recurrent, damaging missense variants in the SH3-binding domain of the adaptor protein Growth Factor Receptor-Bound Protein 2 (GRB2) in unrelated patients with CH. GRB2 is significantly co-expressed with one of its known upstream receptor tyrosine kinase partners, CSF1R, in the developing human brain, particularly in a microglial subtype associated with regulation of neural stem cells. Immunoprecipitation validated GRB2-CSF1R binding in mouse microglial cells and human monocyte cell line. Cx3cr1-Grb2fl/fl mice engineered with conditional deletion of Grb2 in microglia exhibit congenital absence of microglia and early postnatal severe communicating (non-obstructive) hydrocephalus, mimicking GRB2-mutant patients. The severe ventriculomegaly of Cx3cr1-Grb2fl/fl mice is associated with both depletion of cerebral cortical neurons and impairment of glia-lymphatic-mediated CSF flow. Together, these findings implicate a role of GRB2 in microglia that could be essential for brain development and CSF homeostasis.
Phan Q. Duy, Benjamin C. Reeves, Huanxing Sun, Xueyan Peng, Pazhanichamy Kalailingam, Garrett Allington, Evan Dennis, Le Thi Hao, Lei Wang, David Rufino-Ramos, Shujuan Zhao, Qiang Li, Neel H. Mehta, William C. Davalan, Mason Blacker, Anthony J. Piscopo, Shozeb Haider, Baojian Fan, Kedous Y. Mekbib, Shuai Shao, Carol Nelson-Williams, TuKiet T. Lam, Benjamin P. Kleinstiver, Patricia L. Musolino, Seth L. Alper, Sheng Chih Jin, Erica L. Herzog, Kristopher T. Kahle
Membranous nephropathy (MN) is an autoimmune kidney disease and a major cause of nephrotic syndrome in adults. Although autoantibodies against phospholipase A2 receptor 1 (PLA2R) and complement activation are central to disease pathogenesis, the mechanisms by which anti-PLA2R antibodies activate complement at the podocyte surface remain incompletely defined. Here, we cloned 14 patient-derived anti-PLA2R monoclonal antibodies (mAbs) and found that they predominantly recognized the N-terminal cysteine-rich (CysR) and C-type lectin domain 1 (CTLD1) regions of PLA2R. Individual anti-PLA2R mAbs induced little or no complement-dependent cytotoxicity (CDC) of PLA2R-expressing podocytes in vitro. In contrast, paired mAbs targeting distinct epitopes, particularly CysR and CTLD1, markedly enhanced CDC. This effect was strongest for IgG1 and IgG3 antibodies, whereas IgG4 alone did not activate complement but modulated CDC in combination with IgG1. Purified IgG from patients with PLA2R-associated MN similarly induced CDC, which was augmented by addition of anti-PLA2R IgG1 and reduced by anti-PLA2R IgG4 or Fab fragments targeting CysR or CTLD1. In human PLA2R-expressing mice, paired anti-PLA2R antibodies increased glomerular complement deposition and induced albuminuria. These findings identify epitope pairing as a key determinant of complement activation in PLA2R-associated MN and support epitope-specific targeting strategies as a promising avenue for therapeutic intervention.
Tsai-Yi Wu, Kun-Hua Tu, Larissa Seifert, Kung-Wei Lin, Han-Po Shih, Yu-Fang Lo, Jhan-Jie Peng, Gunther Zahner, Oliver Kretz, You-Ning Lin, Chen-Xuan Kang, Jing-Ya Ding, Yi-Ran Tu, Li-Yi Ma, Ya-Ting Chuang, Chia-Chi Lo, Yu-Huan Tsai, Chih-Wei Yang, Nicola M. Tomas, Cheng-Lung Ku
Pain is a common and disabling feature of myotonic disorders, yet its biological basis remains poorly understood and no targeted analgesic therapies currently exist. Here, we demonstrate that skeletal muscle hyperexcitability is sufficient to initiate a persistent pain state independent of inflammation, nerve injury, or overt tissue damage. Using complementary pharmacological and genetic models of myotonia resulting from loss of the voltage-gated skeletal muscle chloride channel ClC-1 function, we show that transient and chronic myotonia produce robust mechanical, thermal, and cold hypersensitivity, as well as spontaneous pain-like behavior. Notably, pain-like behaviors induced by transient myotonia persist long after overt motor symptoms have resolved, suggesting that a transient episode of muscle hyperexcitability is sufficient to trigger prolonged alterations in nociceptive processing. Physiological recordings revealed altered excitability of dorsal root ganglion and superficial dorsal horn neurons and enhanced sensory-evoked activity in the parabrachial nucleus, indicating altered nociceptive processing across multiple levels of the pain neuraxis. Transient myotonia increased total sodium current density in sensory neurons, with a shift toward a greater tetrodotoxin-resistant current fraction. Pharmacological inhibition with the NaV1.8-directed analgesic Suzetrigine markedly attenuated pain-like behaviors in both models of myotonia. Together, these findings establish a link between myotonia and persistent alterations in nociceptive processing and identify NaV1.8-directed analgesia as a promising therapeutic strategy for myotonia-associated pain.
Tyler S. Nelson, Aida Calderon-Rivera, Heather N. Allen, Alaina L Waters, Emanuel Loeza-Alcocer, Jorge B. Pineda-Farias, Narges Pachenari, Santiago Loya-Lopez, Kimberly Gomez, Erick J. Rodriguez-Palma, Paz Duran, Michael S. Gold, Rajesh Khanna
Transport of nucleoside chemotherapeutic drugs into tumor cells is primarily accomplished through Equilibrative Nucleoside Transporter 1 (ENT1), considered to be constitutively-active, redistributing drugs across lipid bilayers via facilitated diffusion. Here we discover that ENT1 is not constitutively-active but rather requires activation of acid sphingomyelinase (ASMase) by gemcitabine, generating ceramide-rich platforms (CRPs) on external plasma membranes of endothelial and tumor cells into which ENT1 inserts, dimerizing therein to functionalize transmembrane gemcitabine transport. Whereas sarcoma cells synthesize minimal ASMase, they take up gemcitabine poorly in vitro and in murine xenografts. A strategy designed to augment gemcitabine-induced ASMase secretion into the extravascular space by ASMase-rich neo-angiogenic cells, which then targets tumor cell plasma membranes, yields “bystander” CRPs on sarcoma cells and ENT1 insertion therein, conferring markedly-enhanced gemcitabine uptake and xenograft response. Engaging this biology in a prospective Phase II clinical trial in advanced sarcoma yielded robust volumetric changes in evaluated tumors that developed early and were often durable.
Aditya Ganju, Shyam Rao, Mark A. Dickson, Robert A. Lefkowitz, Chris Thompson, Jin Cheng, Katia Manova, Adriana Haimovitz-Friedman, Gary Schwartz, Zhigang Zhang, Zvi Fuks, William D. Tap, Richard Kolesnick
The cyclic GMP-AMP synthase (cGAS)–stimulator of interferon genes (STING) pathway is a key component of innate immunity, linking DNA detection to inflammatory and antiviral responses. Originally identified as a sensor for microbial DNA, cGAS is now understood to also respond to endogenous cytosolic DNA, and the pathway has been implicated in a wide range of physiological and pathological processes, including cancer, autoimmunity, neuroinflammation, and aging. This review series, organized by Dr. Alex Stegh, consolidates current knowledge and highlights emerging developments that may lead to therapeutic targeting of the cGAS-STING pathway across a range of disorders.
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