Abudi-Sinreich, S;Bodine, SP;Yokoyama, T;Tolman, NJ;Tyrlik, M;Testa, LC;Han, CG;Dorward, HM;Wincovitch, SM;Anikster, Y;Gahl, WA;Cinar, R;Gochuico, BR;Malicdan, MCV;
PMID: 35509004 | DOI: 10.1186/s12931-022-02002-z
HPS-1 is a genetic type of Hermansky-Pudlak syndrome (HPS) with highly penetrant pulmonary fibrosis (HPSPF), a restrictive lung disease that is similar to idiopathic pulmonary fibrosis (IPF). Hps1ep/ep (pale ear) is a naturally occurring HPS-1 mouse model that exhibits high sensitivity to bleomycin-induced pulmonary fibrosis (PF). Traditional methods of administering bleomycin as an intratracheal (IT) route to induce PF in this model often lead to severe acute lung injury and high mortality rates, complicating studies focusing on pathobiological mechanisms or exploration of therapeutic options for HPSPF.To develop a murine model of HPSPF that closely mimics the progression of human pulmonary fibrosis, we investigated the pulmonary effects of systemic delivery of bleomycin in Hps1ep/ep mice using a subcutaneous minipump and compared results to oropharyngeal delivery of bleomycin.Our study revealed that systemic delivery of bleomycin induced limited, acute inflammation that resolved. The distinct inflammatory phase preceded a slow, gradually progressive fibrogenesis that was shown to be both time-dependent and dose-dependent. The fibrosis phase exhibited characteristics that better resembles human disease with focal regions of fibrosis that were predominantly found in peribronchovascular areas and in subpleural regions; central lung areas contained relatively less fibrosis.This model provides a preclinical tool that will allow researchers to study the mechanism of pulmonary fibrosis in HPS and provide a platform for the development of therapeutics to treat HPSPF. This method can be applied on studies of IPF or other monogenic disorders that lead to pulmonary fibrosis.
Acta neuropathologica communications
Singh, AK;Mahalingam, R;Squillace, S;Jacobson, KA;Tosh, DK;Dharmaraj, S;Farr, SA;Kavelaars, A;Salvemini, D;Heijnen, CJ;
PMID: 35093182 | DOI: 10.1186/s40478-022-01315-w
Cisplatin is used to combat solid tumors. However, patients treated with cisplatin often develop cognitive impairments, sensorimotor deficits, and peripheral neuropathy. There is no FDA-approved treatment for these neurotoxicities. We investigated the capacity of a highly selective A3 adenosine receptor (AR) subtype (A3AR) agonist, MRS5980, to prevent and reverse cisplatin-induced neurotoxicities. MRS5980 prevented cisplatin-induced cognitive impairment (decreased executive function and impaired spatial and working memory), sensorimotor deficits, and neuropathic pain (mechanical allodynia and spontaneous pain) in both sexes. At the structural level, MRS5980 prevented the cisplatin-induced reduction in markers of synaptic integrity. In-situ hybridization detected Adora3 mRNA in neurons, microglia, astrocytes and oligodendrocytes. RNAseq analysis identified 164 genes, including genes related to mitochondrial function, of which expression was changed by cisplatin and normalized by MRS5980. Consistently, MRS5980 prevented cisplatin-induced mitochondrial dysfunction and decreased signs of oxidative stress. Transcriptomic analysis showed that the A3AR agonist upregulates genes related to repair pathways including NOTCH1 signaling and chromatin modification in the cortex of cisplatin-treated mice. Importantly, A3AR agonist administration after completion of cisplatin treatment resolved cognitive impairment, neuropathy and sensorimotor deficits. Our results highlight the efficacy of a selective A3AR agonist to prevent and reverse cisplatin-induced neurotoxicities via preventing brain mitochondrial damage and activating repair pathways. An A3AR agonist is already in cancer, clinical trials and our results demonstrate management of neurotoxic side effects of chemotherapy as an additional therapeutic benefit.
Chen, HR;Chen, CW;Kuo, YM;Chen, B;Kuan, IS;Huang, H;Lee, J;Anthony, N;Kuan, CY;Sun, YY;
PMID: 34976198 | DOI: 10.7150/thno.64033
Rationale: Monocytes belong to the mononuclear phagocyte system and are immune responders to tissue injury and infection. There were also reports of monocytes transforming to microglia-like cells. Here we explore the roles of monocytes in microglia ontogeny and the pathogenesis of neonatal cerebral hypoxic-ischemic (HI) brain injury in mice. Methods: We used three genetic methods to track the development of monocytes, including CX3CR1GFP/+; CCR2RFP/+ reporter mice, adoptive transfer of GFP+ monocytes, and fate-mapping with CCR2-CreER mice, in neonatal mouse brains with or without lipopolysaccharide (LPS, 0.3 mg/kg)-sensitized Vannucci HI. We also used genetic (CCR2RFP/ RFP, CCR2 knockout) and pharmacological methods (RS102895, a CCR2 antagonist) to test the roles of monocytic influx in LPS/HI brain injury. Results: CCR2+ monocytes entered the late-embryonic brains via choroid plexus, but rapidly became CX3CR1+ amoeboid microglial cells (AMCs). The influx of CCR2+ monocytes declined after birth, but recurred after HI or LPS-sensitized HI (LPS/HI) brain injury, particularly in the hippocampus. The CCR2-CreER-based fate-mapping showed that CCR2+ monocytes became CD68+ TNFα+ macrophages within 4 d after LPS/HI, and maintained as TNFα+ MHCII+ macrophages or persisted as Tmem119+ Sall1+ P2RY12+ ramified microglia for at least five months after injury. Genetic deletion of the chemokine receptor CCR2 markedly diminished monocytic influx, the expression of pro- and anti-inflammatory cytokines, and brain damage. Post-LPS/HI application of RS102895 also reduced inflammatory responses and brain damage, leading to better cognitive functions. Conclusion: These results suggest that monocytes promote acute inflammatory responses and may become pathological microglia long after the neonatal LPS/HI insult. Further, blocking the influx of monocytes may be a potential therapy for neonatal brain injury.
Combining Multiplex Fluorescence in situ Hybridization with Fluorescent Immunohistochemistry on Fresh Frozen or Fixed Mouse Brain Sections
Journal of visualized experiments : JoVE
Dereli, AS;Bailey, EJ;Kumar, NN;
PMID: 34251373 | DOI: 10.3791/61709
Fluorescent in situ hybridization (FISH) is a molecular technique that identifies the presence and spatial distribution of specific RNA transcripts within cells. Neurochemical phenotyping of functionally identified neurons usually requires concurrent labelling with multiple antibodies (targeting protein) using immunohistochemistry (IHC) and optimization of in situ hybridization (targeting RNA), in tandem. A "neurochemical signature" to characterize particular neurons may be achieved however complicating factors include the need to verify FISH and IHC targets before combining the methods, and the limited number of RNAs and proteins that may be targeted simultaneously within the same tissue section. Here we describe a protocol, using both fresh frozen and fixed mouse brain preparations, which detects multiple mRNAs and proteins in the same brain section using RNAscope FISH followed by fluorescence immunostaining, respectively. We use the combined method to describe the expression pattern of low abundance mRNAs (e.g., galanin receptor 1) and high abundance mRNAs (e.g., glycine transporter 2), in immunohistochemically identified brainstem nuclei. Key considerations for protein labelling downstream of the FISH assay extend beyond tissue preparation and optimization of FISH probe labelling. For example, we found that antibody binding and labelling specificity can be detrimentally affected by the protease step within the FISH probe assay. Proteases catalyze hydrolytic cleavage of peptide bonds, facilitating FISH probe entry into cells, however they may also digest the protein targeted by the subsequent IHC assay, producing off target binding. The subcellular location of the targeted protein is another factor contributing to IHC success following FISH probe assay. We observed IHC specificity to be retained when the targeted protein is membrane bound, whereas IHC targeting cytoplasmic protein required extensive troubleshooting. Finally, we found handling of slide-mounted fixed frozen tissue more challenging than fresh frozen tissue, however IHC quality was overall better with fixed frozen tissue, when combined with RNAscope.
Zika virus induces neuronal and vascular degeneration in developing mouse retina
Acta neuropathologica communications
Li, Y;Shi, S;Xia, F;Shan, C;Ha, Y;Zou, J;Adam, A;Zhang, M;Wang, T;Liu, H;Shi, PY;Zhang, W;
PMID: 34034828 | DOI: 10.1186/s40478-021-01195-6
Zika virus (ZIKV), a mosquito-borne flavivirus, can cause severe eye disease and even blindness in newborns. However, ZIKV-induced retinal lesions have not been studied in a comprehensive way, mechanisms of ZIKV-induced retinal abnormalities are unknown, and no therapeutic intervention is available to treat or minimize the degree of vision loss in patients. Here, we developed a novel mouse model of ZIKV infection to evaluate its impact on retinal structure. ZIKV (20 plaque-forming units) was inoculated into neonatal wild type C57BL/6J mice at postnatal day (P) 0 subcutaneously. Retinas of infected mice and age-matched controls were collected at various ages, and retinal structural alterations were analyzed. We found that ZIKV induced progressive neuronal and vascular damage and retinal inflammation starting from P8. ZIKV-infected retina exhibited dramatically decreased thickness with loss of neurons, initial neovascular tufts followed by vessel dilation and degeneration, increased microglia and leukocyte recruitment and activation, degeneration of astrocyte network and gliosis. The above changes may involve inflammation and endoplasmic reticulum stress-mediated cell apoptosis and necroptosis. Moreover, we evaluated the efficacy of preclinical drugs and the safety of ZIKV vaccine candidate in this mouse model. We found that ZIKV-induced retinal abnormalities could be blocked by a selective flavivirus inhibitor NITD008 and a live-attenuated ZIKV vaccine candidate could potentially induce retinal abnormalities. Overall, we established a novel mouse model and provide a direct causative link between ZIKV and retinal lesion in vivo, which warrants further investigation of the underlying mechanisms of ZIKV-induced retinopathy and the development of effective therapeutics.
Host IL11 Signaling Suppresses CD4+ T cell-Mediated Antitumor Responses to Colon Cancer in Mice
Cancer immunology research
Huynh, J;Baloyan, D;Chisanga, D;Shi, W;O'Brien, M;Afshar-Sterle, S;Alorro, M;Pang, L;Williams, DS;Parslow, AC;Thilakasiri, P;Eissmann, MF;Boon, L;Masson, F;Chand, AL;Ernst, M;
PMID: 33906864 | DOI: 10.1158/2326-6066.CIR-19-1023
IL11 is a member of the IL6 family of cytokines and signals through its cognate receptor subunits, IL11RA and glycoprotein 130 (GP130), to elicit biological responses via the JAK/STAT signaling pathway. IL11 contributes to cancer progression by promoting the survival and proliferation of cancer cells, but the potential immunomodulatory properties of IL11 signaling during tumor development have thus far remained unexplored. Here, we have characterized a role for IL11 in regulating CD4+ T cell-mediated antitumor responses. Absence of IL11 signaling impaired tumor growth in a sporadic mouse model of colon cancer and syngeneic allograft models of colon cancer. Adoptive bone marrow transfer experiments and in vivo depletion studies demonstrated that the tumor-promoting activity of IL11 was mediated through its suppressive effect on host CD4+ T cells in the tumor microenvironment. Indeed, when compared with Il11ra-proficient CD4+ T cells associated with MC38 tumors, their Il11ra-deficient counterparts displayed elevated expression of mRNA encoding the antitumor mediators IFNγ and TNFα. Likewise, IL11 potently suppressed the production of proinflammatory cytokines (IFNγ, TNFα, IL6, and IL12p70) by CD4+ T cells in vitro, which we corroborated by RNAscope analysis of human colorectal cancers, where IL11RAhigh tumors showed less IFNG and CD4 expression than IL11RAlow tumors. Therefore, our results ascribe a tumor cell-extrinsic immunomodulatory role to IL11 during colon cancer development that could be amenable to an anticytokine-based therapy.See related commentary by van der Burg.
Shukla R, Prevot TD, French L, Isserlin R, Rocco BR, Banasr M, Bader GD, Sibille E.
PMID: - | DOI: 10.1016/j.celrep.2018.09.034
Background Aging is accompanied by altered thinking (cognition) and feeling (mood), functions that depend on information processing by brain cortical cell microcircuits. We hypothesized that age-associated long-term functional and biological changes are mediated by gene transcriptomic changes within neuronal cell-types forming cortical microcircuits, namely excitatory pyramidal cells (PYC) and inhibitory GABAergic neurons expressing vasoactive intestinal peptide (Vip), somatostatin (Sst) and parvalbumin (Pvalb). Methods To test this hypothesis, we assessed locomotor, anxiety-like and cognitive behavioral changes between young (2 months, n=9) and old (22 months, n=12) male C57BL/6 mice, and performed frontal cortex cell-type specific molecular profiling, using laser-capture microscopy and RNA sequencing. Results were analyzed by neuroinformatics and validated by fluorescent in situ hybridization. Results Old-mice displayed increased anxiety and reduced working memory. The four cell-types displayed distinct age-related transcriptomes and biological pathway profiles, affecting metabolic and cell signaling pathways, and selective markers of neuronal vulnerability (Ryr3), resilience (Oxr1), and mitochondrial dynamics (Opa1), suggesting high age-related vulnerability of PYCs, and variable degree of adaptation in GABAergic neurons. Correlations between gene expression and behaviors suggest that changes in cognition and anxiety associated with age are partly mediated by normal age-related cell changes, and that additional age-independent decreases in synaptic and signaling pathways, notably in PYC and SST-neurons further contribute to behavioral changes. Conclusions Our study demonstrates cell-dependent differential vulnerability and coordinated cell-specific cortical microcircuit molecular changes with age. Collectively, the results suggest intrinsic molecular links between aging, cognition and mood-related behaviors with SST-neurons contributing evenly to both behavioral conditions.
Wang, X;Ramos, R;Phan, AQ;Yamaga, K;Flesher, JL;Jiang, S;Oh, JW;Jin, S;Jahid, S;Kuan, CH;Nguyen, TK;Liang, HY;Shettigar, NU;Hou, R;Tran, KH;Nguyen, A;Vu, KN;Phung, JL;Ingal, JP;Levitt, KM;Cao, X;Liu, Y;Deng, Z;Taguchi, N;Scarfone, VM;Wang, G;Paolilli, KN;Wang, X;Guerrero-Juarez, CF;Davis, RT;Greenberg, EN;Ruiz-Vega, R;Vasudeva, P;Murad, R;Widyastuti, LHP;Lee, HL;McElwee, KJ;Gadeau, AP;Lawson, DA;Andersen, B;Mortazavi, A;Yu, Z;Nie, Q;Kunisada, T;Karin, M;Tuckermann, J;Esko, JD;Ganesan, AK;Li, J;Plikus, MV;
PMID: 37344645 | DOI: 10.1038/s41586-023-06172-8
Niche signals maintain stem cells in a prolonged quiescence or transiently activate them for proper regeneration1. Altering balanced niche signalling can lead to regenerative disorders. Melanocytic skin nevi in human often display excessive hair growth, suggesting hair stem cell hyperactivity. Here, using genetic mouse models of nevi2,3, we show that dermal clusters of senescent melanocytes drive epithelial hair stem cells to exit quiescence and change their transcriptome and composition, potently enhancing hair renewal. Nevus melanocytes activate a distinct secretome, enriched for signalling factors. Osteopontin, the leading nevus signalling factor, is both necessary and sufficient to induce hair growth. Injection of osteopontin or its genetic overexpression is sufficient to induce robust hair growth in mice, whereas germline and conditional deletions of either osteopontin or CD44, its cognate receptor on epithelial hair cells, rescue enhanced hair growth induced by dermal nevus melanocytes. Osteopontin is overexpressed in human hairy nevi, and it stimulates new growth of human hair follicles. Although broad accumulation of senescent cells, such as upon ageing or genotoxic stress, is detrimental for the regenerative capacity of tissue4, we show that signalling by senescent cell clusters can potently enhance the activity of adjacent intact stem cells and stimulate tissue renewal. This finding identifies senescent cells and their secretome as an attractive therapeutic target in regenerative disorders.
Badia-Soteras, A;Heistek, T;Kater, M;Mak, A;Negrean, A;van den Oever, M;Mansvelder, H;Khakh, B;Min, R;Smit, A;Verheijen, M;
| DOI: 10.1016/j.biopsych.2022.10.013
Background The formation and retrieval of fear memories depends on orchestrated synaptic activity of neuronal ensembles within the hippocampus and it is becoming increasingly evident that astrocytes residing in the environment of these synapses play a central role in shaping cellular memory representations. Astrocyte distal processes, known as leaflets, fine-tune synaptic activity by clearing neurotransmitters and limiting glutamate diffusion. However, how astroglial synaptic coverage contributes to mnemonic processing of fearful experiences remains largely unknown. Methods We used electron microscopy to observe changes in astroglial coverage of hippocampal synapses during consolidation of fear memory in mice. To manipulate astroglial synaptic coverage, we depleted Ezrin, an integral leaflet-structural protein, from hippocampal astrocytes using CRISRP/Cas9 gene editing. Next, a combination of FRET analysis, genetically encoded glutamate sensors and whole-cell patch-clamp recordings was used to determine whether the proximity of astrocyte leaflets to the synapse is critical for synaptic integrity and function. Results We found that consolidation of a recent fear memory is accompanied by a transient retraction of astrocyte leaflets from hippocampal synapses and increased activation of NMDA-receptors. Accordingly, astrocyte-specific depletion of Ezrin resulted in shorter astrocyte leaflets and reduced astrocyte contact with the synaptic cleft, which consequently boosted extrasynaptic glutamate diffusion and NMDA-receptor activation. Importantly, after fear conditioning, these cellular phenotypes translated to increased retrieval-evoked activation of CA1 pyramidal neurons and enhanced fear memory expression. Conclusion Together, our data show that withdrawal of astrocyte leaflets from the synaptic cleft is an experience-induced temporally-regulated process that gates the strength of fear memories.
Qin, D;Liu, S;Lu, Y;Yan, Y;Zhang, J;Cao, S;Chen, M;Chen, N;Huang, W;Wang, L;Chen, X;Zhang, L;
PMID: 36168631 | DOI: 10.7150/thno.74194
Background: Leucine-rich repeat-containing G protein-coupled receptor 5 (Lgr5) is a target gene of Wnt/β-Catenin which plays a vital role in hepatic development and regeneration. However, the regulation of Lgr5 gene and the fate of Lgr5 + cells in hepatic physiology and pathology are little known. This study aims to clarify the effect of metabolic nuclear receptors on Lgr5 + cell fate in liver. Methods: We performed cell experiments with primary hepatocytes, Hep 1-6, Hep G2, and Huh 7 cells, and animal studies with wild-type (WT), farnesoid X receptor (FXR) knockout mice, peroxisome proliferator-activated receptor α (PPARα) knockout mice and Lgr5-CreERT2; Rosa26-mTmG mice. GW4064 and CDCA were used to activate FXR. And GW7647 or Wy14643 was used for PPARα activation. Regulation of Lgr5 by FXR and PPARα was determined by QRT-PCR, western blot (WB) and RNAscope in situ hybridization (ISH) and immunofluorescence (IF), luciferase reporter assay, electrophoretic mobility shift assay (EMSA) and chromatin immunoprecipitation (ChIP). Diethyl 1,4-dihydro-2,4,6-trimethyl-3,5-pyridinedicarboxylate (DDC) diet was used to induce liver injury. Results: Pharmacologic activation of FXR induced Lgr5 expression, whereas activation of PPARα suppressed Lgr5 expression. Furthermore, FXR and PPARα competed for binding to shared site on Lgr5 promoter with opposite transcriptional outputs. DDC diet triggered the transition of Lgr5 + cells from resting state to proliferation. FXR activation enhanced Lgr5 + cell expansion mainly by symmetric cell division, but PPARα activation prevented Lgr5 + cell proliferation along with asymmetric cell division. Conclusion: Our findings unravel the opposite regulatory effects of FXR and PPARα on Lgr5 + cell fate in liver under physiological and pathological conditions, which will greatly assist novel therapeutic development targeting nuclear receptors.
Ye, D;Yuan, J;Yang, Y;Yue, Y;Hu, Z;Fadera, S;Chen, H;
PMID: 36152518 | DOI: 10.1016/j.ebiom.2022.104277
Adeno-associated viral (AAV) vectors are currently the leading platform for gene therapy with the potential to treat a variety of central nervous system (CNS) diseases. There are numerous methods for delivering AAVs to the CNS, such as direct intracranial injection (DI), intranasal delivery (IN), and intravenous injection with focused ultrasound-induced blood-brain barrier disruption (FUS-BBBD). However, non-invasive and efficient delivery of AAVs to the brain with minimal systemic toxicity remain the major challenge. This study aims to investigate the potential of focused ultrasound-mediated intranasal delivery (FUSIN) in AAV delivery to brain.Mice were intranasally administered with AAV5 encoding enhanced green fluorescence protein (AAV5-EGFP) followed by FUS sonication in the presence of systemically injected microbubbles. Mouse brains and other major organs were harvested for immunohistological staining, PCR quantification, and in situ hybridization. The AAV delivery outcomes were compared with those of DI, FUS-BBBD, and IN delivery.FUSIN achieved safe and efficient delivery of AAV5-EGFP to spatially targeted brain locations, including a superficial brain site (cortex) and a deep brain region (brainstem). FUSIN achieved comparable delivery outcomes as the established DI, and displayed 414.9-fold and 2073.7-fold higher delivery efficiency than FUS-BBBD and IN. FUSIN was associated with minimal biodistribution in peripheral organs, which was comparable to that of DI.Our results suggest that FUSIN is a promising technique for non-invasive, efficient, safe, and spatially targeted AAV delivery to the brain.National Institutes of Health (NIH) grants R01EB027223, R01EB030102, R01MH116981, and UG3MH126861.
El Eid, L;Reynolds, CA;Tomas, A;Ben Jones, ;
PMID: 36007775 | DOI: 10.1016/j.phrs.2022.106411
Glucagon-like peptide-1 receptor (GLP-1R) is a well-studied incretin hormone receptor and target of several therapeutic drugs for type 2 diabetes (T2D), obesity and, more recently, cardiovascular disease. Some signalling pathways downstream of GLP-1R may be responsible for drug adverse effects such as nausea, while others mediate therapeutic outcomes of incretin-based T2D therapeutics. Understanding the interplay between different factors that alter signalling, trafficking, and receptor activity, including biased agonism, single nucleotide polymorphisms and structural modifications is key to develop the next-generation of personalised GLP-1R agonists. However, these interactions remain poorly described, especially for novel therapeutics such as dual and tri-agonists that target more than one incretin receptor. Comparison of GLP-1R structures in complex with G proteins and different peptide and non-peptide agonists has revealed novel insights into important agonist-residue interactions and networks crucial for receptor activation, recruitment of G proteins and engagement of specific signalling pathways. Here, we review the latest knowledge on GLP-1R structure and activation, providing structural evidence for biased agonism and delineating important networks associated with this phenomenon. We survey current biased agonists and multi-agonists at different stages of development, highlighting possible challenges in their translational potential. Lastly, we discuss findings related to non-synonymous genomic variants of GLP1R and the functional importance of specific residues involved in GLP-1R function. We propose that studies of GLP-1R polymorphisms, and specifically their effect on receptor dynamics and pharmacology in response to biased agonists, could have a significant impact in delineating precision medicine approaches and development of novel therapeutics.
