Lagadec, F;Carlon-Andres, I;Ragues, J;Port, S;Wodrich, H;Kehlenbach, RH;
PMID: 34757845 | DOI: 10.1128/JVI.01273-21
After receptor-mediated endocytosis and endosomal escape, adenoviral capsids can travel via microtubule organizing centers to the nuclear envelope. Upon capsid disassembly, viral genome import into nuclei of interphase cells then occurs through nuclear pore complexes, involving the nucleoporins Nup214 and Nup358. Import also requires the activity of the classic nuclear export receptor CRM1, as it is blocked by the selective inhibitor leptomycin B. We have now used artificially enucleated as well as mitotic cells to analyze the role of an intact nucleus in different steps of the viral life cycle. In enucleated U2OS cells, viral capsids traveled to the microtubule organizing center, whereas their removal from this complex was blocked, suggesting that this step required nuclear factors. In mitotic cells, on the other hand, CRM1 promoted capsid disassembly and genome release, suggesting a role of this protein that does not require intact nuclear envelopes or nuclear pore complexes and is distinct from its function as a nuclear export receptor. Similar to enucleation, inhibition of CRM1 by leptomycin B also leads to an arrest of adenoviral capsids at the microtubule organizing center. In a small-scale screen using leptomycin B-resistant versions of CRM1, we identified a mutant, CRM1 W142A P143A, that is compromised with respect to adenoviral capsid disassembly, both in interphase and in mitotic cells. Strikingly, this mutant is capable of exporting cargo proteins out of the nucleus of living cells or digitonin-permeabilized cells, pointing to a role of the mutated region that is not directly linked to nuclear export. IMPORTANCE A role of nucleoporins and of soluble transport factors in adenoviral genome import into the nucleus of infected cells in interphase has previously been established. The nuclear export receptor CRM1 promotes genome import, but its precise function is not known. Using enucleated and mitotic cells, we showed that CRM1 does not simply function by exporting a crucial factor out of the nucleus that would then trigger capsid disassembly and genome import. Instead, CRM1 has an export-independent role, a notion that is also supported by a mutant, CRM1 W142A P143A, which is export-competent but deficient in viral capsid disassembly, both in interphase and in mitotic cells.
Investigative ophthalmology & visual science
Ramberg, I;Vieira, FG;Toft, PB;von Buchwald, C;Funding, M;Nielsen, FC;Heegaard, S;
PMID: 34779821 | DOI: 10.1167/iovs.62.14.11
The genomic alterations contributing to the pathogenesis of conjunctival squamous cell carcinomas (SCCs) and their precursor lesions are poorly understood and hamper our ability to develop molecular therapies to reduce the recurrence rates and treatment-related morbidities of this disease. We aimed to characterize the somatic DNA alterations in human papillomavirus (HPV)-positive and HPV-negative conjunctival SCC.Patients diagnosed with conjunctival SCC in situ or SCC treated in ocular oncology referral centers in Denmark were included. HPV detection (HPV DNA PCR, p16 immunohistochemistry, and mRNA in situ hybridization) and targeted capture-based next-generation sequencing of 523 genes frequently involved in cancer were performed to describe the mutational profile based on HPV status.Tumor tissue was available in 33 cases (n = 8 conjunctival SCCs in situ, n = 25 conjunctival SCCs), constituting 25 male and 8 female patients. Nine cases were HPV positive. The HPV-positive SCCs in situ and SCCs were characterized by transcriptionally active high-risk HPV (types 16 and 39) within the tumor cells, frequent mutations in PIK3CA (n = 5/9), and wild-type TP53, CDKN2A, and RB1, while the HPV-negative counterparts harbored frequent mutations in TP53 (n = 21/24), CDKN2A (n = 7/24), and RB1 (n = 6/24).Our findings have delineated two potentially distinct distributions of somatic mutations in conjunctival SCC based on HPV status-pointing to different biological mechanisms of carcinogenesis. The present findings support a causal role of HPV in a subset of conjunctival SCC.
Téblick, A;De Bruyn, L;Van Oudenhove, T;Vander Perre, S;Pauwels, L;Derde, S;Langouche, L;Van den Berghe, G;
PMID: 34698826 | DOI: 10.1210/endocr/bqab222
Sepsis is hallmarked by high plasma cortisol/corticosterone (CORT), low adrenocorticotropic hormone (ACTH), and high pro-opiomelanocortin (POMC). While corticotropin-releasing hormone-(CRH) and arginine-vasopressin (AVP)-driven pituitary POMC expression remains active, POMC processing into ACTH becomes impaired. Low ACTH is accompanied by loss of adrenocortical structure, although steroidogenic enzymes remain expressed. We hypothesized that treatment of sepsis with hydrocortisone (HC) aggravates this phenotype whereas CRH infusion safeguards ACTH-driven adrenocortical structure.In a fluid-resuscitated, antibiotics-treated mouse model of prolonged sepsis, we compared the effects of HC and CRH infusion with placebo on plasma ACTH, POMC, and CORT; on markers of hypothalamic CRH and AVP signaling and pituitary POMC processing; and on the adrenocortical structure and markers of steroidogenesis. In adrenal explants, we studied the steroidogenic capacity of POMC.During sepsis, HC further suppressed plasma ACTH, but not POMC, predominantly by suppressing sepsis-activated CRH/AVP-signaling pathways. In contrast, in CRH-treated sepsis, plasma ACTH was normalized following restoration of pituitary POMC processing. The sepsis-induced rise in markers of adrenocortical steroidogenesis was unaltered by CRH and suppressed partially by HC, which also increased adrenal markers of inflammation. Ex vivo stimulation of adrenal explants with POMC increased CORT as effectively as an equimolar dose of ACTH.Treatment of sepsis with HC impaired integrity and function of the hypothalamic-pituitary-adrenal axis at the level of the pituitary and the adrenal cortex while CRH restored pituitary POMC processing without affecting the adrenal cortex. Sepsis-induced high-circulating POMC may be responsible for ongoing adrenocortical steroidogenesis despite low ACTH.
Grunddal, KV;Jensen, EP;Ørskov, C;Andersen, DB;Windeløv, JA;Poulsen, SS;Rosenkilde, MM;Knudsen, LB;Pyke, C;Holst, JJ;
PMID: 34662392 | DOI: 10.1210/endocr/bqab216
Therapies based on glucagon-like peptide-1 receptor (GLP-1R) agonism are highly effective in treating type 2 diabetes and obesity, but the localization of GLP-1Rs mediating the antidiabetic and other possible actions of GLP-1 is still debated. The purpose with this study was to identify sites of GLP-1R mRNA and protein expression in the mouse gastrointestinal system by means of GLP-1R antibody immunohistochemistry, Glp1r mRNA fluorescence in situ hybridization, and 125I-exendin (9-39) autoradiography. As expected, GLP-1R staining was observed in almost all β-cells in the pancreatic islets, but more rarely in α- and δ-cells. In the stomach, GLP-1R staining was found exclusively in the gastric corpus mucous neck cells, known to protect the stomach mucosa. The Brunner glands were strongly stained for GLP-1R, and pretreatment with GLP-1 agonist exendin-4 caused internalization of the receptor and mucin secretion, while pretreatment with phosphate-buffered saline or antagonist exendin (9-39) did not. In the intestinal mucosa, GLP-1R staining was observed in intraepithelial lymphocytes, lamina propria lymphocytes, and enteroendocrine cells containing secretin, peptide YY, and somatostatin, but not cholecystokinin. GLP-1R staining was seen in nerve fibers within the choline acetyl transferase- and nitric oxide-positive myenteric plexuses from the gastric corpus to the distal large intestine being strongest in the mid- and hindgut area. Finally, intraperitoneal administration of radiolabeled exendin (9-39) strongly labeled myenteric fibers. In conclusion, this study expands our knowledge of GLP-1R localization and suggests that GLP-1 may serve an important role in modulating gastrointestinal health and mucosal protection.
The Journal of rheumatology
Iwamoto, T;Dorschner, JM;Selvaraj, S;Mezzano, V;Jensen, MA;Vsetecka, D;Amin, S;Makol, A;Osborn, T;Moder, K;Chowdhary, VR;Izmirly, P;Belmont, HM;Clancy, RM;Buyon, JP;Wu, M;Loomis, CA;Niewold, TB;
PMID: 34782453 | DOI: 10.3899/jrheum.210391
Previous studies suggest a link between high serum type I interferon (IFN) and lupus nephritis (LN). We determined whether serum IFN activity is associated with subtypes of LN and studied renal tissues and cells to understand the impact of IFN in LN.221 systemic lupus erythematosus (SLE) patients were studied. Serum IFN activity was measured by WISH bioassay. mRNA in-situ hybridization was used in renal tissue to measure expression of the representative IFN-induced gene, interferon-induced protein with tetratricopeptide repeats-1 (IFIT1), and the plasmacytoid dendritic cell (pDC) marker gene C-type lectin domain family-4 member C (CLEC4C or BDCA2). Podocyte cell line gene expression was measured by real-time PCR.Class III/IV LN prevalence was significantly increased in patients with high serum IFN compared with those with low IFN (OR=5.48, p=4.0x10-7). In multivariate regression models, type I IFN was a stronger predictor of class III/IV LN than complement C3 or anti-dsDNA antibody, and could account for the association of these variables with LN. IFIT1 expression was increased in all classes of LN, but most in the glomerular areas of active class III/IV LN kidneys. IFIT1 expression was not closely co-localized with pDCs. IFN directly activated podocyte cell lines to induce chemokines and proapoptotic molecules.Systemic high IFN is involved in the pathogenesis of severe LN. We do not find co-localization of pDCs with IFN signature in renal tissue, and instead observe the greatest intensity of IFN signature in glomerular areas, which could suggest a blood source of IFN.
Journal of Dermatological Science
Xian, J;Shang, M;Dai, Y;Wang, Q;Long, X;Li, J;Cai, Y;Xia, C;Peng, X;
| DOI: 10.1016/j.jdermsci.2021.11.007
Background Psoriasis is a chronic, complicated, and recurrent inflammatory skin disease. However, the precise molecular mechanisms remain largely elusive and the present treatment is unsatisfactory. Objective This study aimed to unravel the functions of long noncoding RNA (lncRNA) AGAP2-AS1 and its biological mechanism in psoriasis pathogenesis, hinting for the new therapeutic targets in psoriasis. Methods The expression of AGAP2-AS1 in the skin tissue of psoriasis patients and healthy controls were detected by qRT-PCR and RNAscope™. Cell Counting Kit‑8 (CCK8) and clone formation assays were utilized to assess proliferation. Methylated RNA immunoprecipitation (MeRIP) was performed to detect the N6-methyladenosine (m6A) modification. RNA immunoprecipitation (RIP) was used to detect the interaction of AGAP2-AS1 with YTH domain family 2(YTHDF2). The relationships among AGAP2-AS1, miR-424-5p and AKT3 were examined by dual-luciferase reporter assay and RIP assay. Results We found that AGAP2-AS1 level was upregulated in the skin tissue of psoriasis patients than that of healthy controls and AGAP2-AS1 could promote proliferation and inhibit apoptosis of keratinocytes. Methyltransferase like 3(METTL3)-mediated m6A modification suppressed the expression of AGAP2-AS1 via YTHDF2-dependent AGAP2-AS1 stability. Thus, downregulation of METTL3 resulted in the upregulation of AGAP2-AS1 in psoriasis. AGAP2-AS1 functioned as a competitive endogenous RNA by sponging miR-424-5p to upregulate AKT3, activate AKT/mTOR pathway, as well as promote cell proliferation in keratinocytes. Conclusion AGAP2-AS1 is upregulated in the skin tissue of psoriasis patients and m6A methylation was involved in its upregulation. AGAP2-AS1 promotes keratinocyte proliferation through miR-424-5p/AKT/mTOR axis and may be a promising target for psoriasis therapy.
Molecular Therapy - Methods & Clinical Development
Schneller, J;Lee, C;Venturoni, L;Chandler, R;Li, A;Myung, S;Cradick, T;Hurley, A;Lagor, W;Bao, G;Venditti, C;
| DOI: 10.1016/j.omtm.2021.11.004
Methylmalonic acidemia (MMA) is a metabolic disorder most commonly caused by mutations in the methylmalonyl-CoA mutase (MMUT) gene. Although adeno-associated viral (AAV) gene therapy has been effective at correcting the disease phenotype in MMA mouse models, clinical translation may be impaired by loss of episomal transgene expression and magnified by the need to treat patients early in life. To achieve permanent correction, we developed a dual AAV strategy to express a codon-optimized MMUT transgene from Alb and tested various CRISPR-Cas9 genome-editing vectors in newly developed knockin mouse models of MMA. For one target site in intron 1 of Alb, we designed rescue cassettes expressing MMUT behind a 2A-peptide or an internal ribosomal entry site sequence. A second guide RNA targeted the initiator codon, and the donor cassette encompassed the proximal albumin promoter in the 5′ homology arm. Although all editing approaches were therapeutic, targeting the start codon of albumin allowed the use of a donor cassette that also functioned as an episome and after homologous recombination, even without the expression of Cas9, as an integrant. Targeting the albumin locus using these strategies would be effective for other metabolic disorders where early treatment and permanent long-term correction are needed.
Frontiers in synaptic neuroscience
Garcia DuBar, S;Cosio, D;Korthas, H;Van Batavia, JP;Zderic, SA;Sahibzada, N;Valentino, RJ;Vicini, S;
PMID: 34675794 | DOI: 10.3389/fnsyn.2021.754786
The pontine nuclei comprising the locus coeruleus (LC) and Barrington's nucleus (BRN) amongst others form the neural circuitry(s) that coordinates arousal and voiding behaviors. However, little is known about the synaptic connectivity of neurons within or across these nuclei. These include corticotropin-releasing factor (CRF+) expressing neurons in the BRN that control bladder contraction and somatostatin expressing (SST+) neurons whose role in this region has not been discerned. To determine the synaptic connectivity of these neurons, we employed optogenetic stimulation with recordings from BRN and LC neurons in brain stem slices of channelrhodopsin-2 expressing SST or CRF neurons. Optogenetic stimulation of CRF+ BRN neurons of Crf Cre ;chr2-yfp mice had little effect on either CRF+ BRN neurons, CRF- BRN neurons, or LC neurons. In contrast, in Sst Cre ;chr2-yfp mice light-activated inhibitory postsynaptic currents (IPSCs) were reliably observed in a majority of LC but not BRN neurons. The GABAA receptor antagonist, bicuculline, completely abolished the light-induced IPSCs. To ascertain if these neurons were part of the neural circuitry that controls the bladder, the trans-synaptic tracer, pseudorabies virus (PRV) was injected into the bladder wall of Crf Cre ;tdTomato or Sst Cre ;tdTomato mice. At 68-72 h post-viral infection, PRV labeled neurons were present only in the BRN, being preponderant in CRF+ neurons with few SST+ BRN neurons labeled from the bladder. At 76 and 96 h post-virus injection, increased labeling was observed in both BRN and LC neurons. Our results suggest SST+ neurons rather than CRF+ neurons in BRN can regulate the activity of LC neurons.
Expert opinion on biological therapy
Pipe, SW;Gonen-Yaacovi, G;Segurado, OG;
PMID: 34781798 | DOI: 10.1080/14712598.2022.2002842
: Hemophilia comprises a group of X-linked hemorrhagic disorders that result from a deficiency of coagulation factors. The disorder affects mainly males and leads to chronic pain, joint deformity, reduced mobility, and increased mortality. Current therapies require frequent administration of replacement clotting factors, but the emergence of alloantibodies (inhibitors) diminishes their efficacy. New therapies are being developed to produce the deficient clotting factors and prevent the emergence of inhibitors.: This article provides an update on the characteristics and disease pathophysiology of hemophilia A, as well as current treatments, with a special focus on ongoing clinical trials related to gene replacement therapies.: Gene replacement therapies provide safe, durable, and stable transgene expression while avoiding the challenges of clotting factor replacement therapies in patients with hemophilia. Improving the specificity of the viral construct and decreasing the therapeutic dose are critical toward minimizing cellular stress, induction of the unfolded protein response, and the resulting loss of protein production in liver cells. Next-generation gene therapies incorporating chimeric DNA sequences in the transgene can increase clotting factor synthesis and secretion, and advance the efficacy, safety, and durability of gene replacement therapy for hemophilia A as well as other blood clotting disorders.
Reviews in the neurosciences
Visvanathar, R;Papanikolaou, M;Nôga, DA;Pádua-Reis, M;Tort, ABL;Blunder, M;
PMID: 34717053 | DOI: 10.1515/revneuro-2021-0109
The field of cannabinoid research has been receiving ever-growing interest. Ongoing debates worldwide about the legislation of medical cannabis further motivates research into cannabinoid function within the central nervous system (CNS). To date, two well-characterized cannabinoid receptors exist. While most research has investigated Cb1 receptors (Cb1Rs), Cb2 receptors (Cb2Rs) in the brain have started to attract considerable interest in recent years. With indisputable evidence showing the wide-distribution of Cb2Rs in the brain of different species, they are no longer considered just peripheral receptors. However, in contrast to Cb1Rs, the functionality of central Cb2Rs remains largely unexplored. Here we review recent studies on hippocampal Cb2Rs. While conflicting results about their function have been reported, we have made significant progress in understanding the involvement of Cb2Rs in modulating cellular properties and network excitability. Moreover, Cb2Rs have been shown to be expressed in different subregions of the hippocampus, challenging our prior understanding of the endocannabinoid system. Although more insight into their functional roles is necessary, we propose that targeting hippocampal Cb2Rs may offer novel therapies for diseases related to memory and adult neurogenesis deficits.
The American journal of pathology
Mulka, KR;Beck, SE;Solis, CV;Johanson, AL;Queen, SE;McCarron, ME;Richardson, MR;Zhou, R;Marinho, P;Jedlicka, A;Guerrero-Martin, S;Shirk, EN;Braxton, AM;Brockhurst, J;Creisher, PS;Dhakal, S;Brayton, CF;Veenhuis, RT;Metcalf Pate, KA;Karakousis, PC;Zahnow, CA;Klein, SL;Jain, SK;Tarwater, PM;Pekosz, AS;Villano, JS;Mankowski, JL;Johns Hopkins COVID-19 Hamster Study Group, ;
PMID: 34767812 | DOI: 10.1016/j.ajpath.2021.10.009
To catalyze SARS-CoV-2 research including development of novel interventive and preventive strategies, we characterized progression of disease in depth in a robust COVID-19 animal model. In this model, male and female golden Syrian hamsters were inoculated intranasally with SARS-CoV-2 USA-WA1/2020. Groups of inoculated and mock-inoculated uninfected control animals were euthanized at 2, 4, 7, 14 and 28 days post-inoculation to track multiple clinical, pathology, virology, and immunology outcomes. SARS-CoV-2-inoculated animals consistently lost body weight during the first week of infection, had higher lung weights at terminal timepoints, and developed lung consolidation per histopathology and quantitative image analysis measurements. High levels of infectious virus and viral RNA were reliably present in the respiratory tract at days 2 and 4 post-inoculation, corresponding with widespread necrosis and inflammation. At day 7, when infectious virus was rare, interstitial and alveolar macrophage infiltrates and marked reparative epithelial responses (type II hyperplasia) dominated in the lung. These lesions resolved over time, with only residual epithelial repair evident by day 28 post-inoculation. The use of quantitative approaches to measure cellular and morphologic alterations in the lung provides valuable outcome measures for developing therapeutic and preventive interventions for COVID-19 using the hamster COVID-19 model.
Sharpe, AL;Trzeciak, M;Eliason, NL;Blankenship, HE;Byrd, BAM;Douglas, PD;Freeman, WM;Beckstead, MJ;
PMID: 34825430 | DOI: 10.1111/adb.13120
Dopamine neurons in the substantia nigra (SN) and ventral tegmental area (VTA) play a central role in the reinforcing properties of abused drugs including methamphetamine and cocaine. Chronic effects of psychostimulants in the SN/VTA also involve non-dopaminergic transmitters, including glutamate and the stress-related peptide corticotropin-releasing factor (CRF). In the SN/VTA, astrocytes express a variety of membrane-bound neurotransmitter receptors and transporters that influence neurotransmission. CRF receptor type 2 (CRF2) activity in the VTA is important for stress-induced relapse and drug-seeking behaviour, but the localization of its effects is incompletely understood. Here, we first identified CRF2 transcript in astrocytes of the SN/VTA using RNA-Seq in Aldh1l1;NuTRAP mice and confirmed it using in situ hybridization (RNAscope) in wild-type mice. We then used immunofluorescence to quantify the astrocytic marker protein S100β, glial-specific glutamate/aspartate transporter GLAST, and CRF2 in the SN/VTA following 12 days of treatment (i.p.) with methamphetamine (3 mg/kg), cocaine (10 mg/kg), or saline. We observed a significant decrease in GLAST immunofluorescence in brains of psychostimulant treated mice compared with saline controls. In addition, we observed increased labelling of CRF2 in drug treated groups, a decrease in the number of S100β positive cells, and an increase of co-staining of CRF2 with both S100β and tyrosine hydroxylase (dopamine neurons). Our results suggest a significant interaction between CRF2, GLAST, and astrocytes in the midbrain that emerges with repeated exposure to psychostimulants. These findings provide rationale for future investigation of astrocyte-based strategies for altering cellular and circuit function in response to stress and drug exposure.