The benefits of contributing to the citizen science platform iNaturalist as an identifier.

As the number of observations submitted to the citizen science platform iNaturalist continues to grow, it is increasingly important that these observations can be identified to the finest taxonomic level, maximizing their value for biodiversity research. Here, we explore the benefits of acting as an identifier on iNaturalist.

Transition to Self-compatibility Associated With Dominant S-allele in a Diploid Siberian Progenitor of Allotetraploid Arabidopsis kamchatica Revealed by Arabidopsis lyrata Genomes.

A transition to selfing can be beneficial when mating partners are scarce, for example, due to ploidy changes or at species range edges. Here, we explain how self-compatibility evolved in diploid Siberian Arabidopsis lyrata, and how it contributed to the establishment of allotetraploid Arabidopsis kamchatica. First, we provide chromosome-level genome assemblies for two self-fertilizing diploid A. lyrata accessions, one from North America and one from Siberia, including a fully assembled S-locus for the latter. We then propose a sequence of events leading to the loss of self-incompatibility in Siberian A. lyrata, date this independent transition to ∼90 Kya, and infer evolutionary relationships between Siberian and North American A. lyrata, showing an independent transition to selfing in Siberia. Finally, we provide evidence that this selfing Siberian A. lyrata lineage contributed to the formation of the allotetraploid A. kamchatica and propose that the selfing of the latter is mediated by the loss-of-function mutation in a dominant S-allele inherited from A. lyrata.

Luminore CopperTouch Surface Coating Effectively Inactivates SARS-CoV-2, Ebola Virus, and Marburg Virus In Vitro.

We investigated the ability of Luminore CopperTouch copper and copper-nickel surfaces to inactivate filoviruses and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The copper and copper-nickel surfaces inactivated 99.9% of Ebola and Marburg viruses after 30 min, and the copper surfaces inactivated 99% of SARS-CoV-2 in 2 h. These data reveal that Ebola virus, Marburg virus, and SARS-CoV-2 are inactivated by exposure to copper ions, validating Luminore CopperTouch as an efficacious tool for infection control.

The Glycoprotein of the Live-Attenuated Junin Virus Vaccine Strain Induces Endoplasmic Reticulum Stress and Forms Aggregates prior to Degradation in the Lysosome.

Argentine hemorrhagic fever is a potentially lethal disease that is caused by Junin virus (JUNV). There are currently around 5 million individuals at risk of infection within regions of endemicity in Argentina. The live attenuated vaccine strain Candid #1 (Can) is approved for use in regions of endemicity and has substantially decreased the number of annual Argentine hemorrhagic fever (AHF) cases. The glycoprotein (GPC) gene is primarily responsible for attenuation of the Can strain, and we have shown that the absence of an N-linked glycosylation motif in the subunit G1 of the glycoprotein complex of Can, which is otherwise present in the wild-type pathogenic JUNV, causes GPC retention in the endoplasmic reticulum (ER). Here, we show that Can GPC aggregates in the ER of infected cells, forming incorrect cross-chain disulfide bonds, which results in impaired GPC processing into G1 and G2. The GPC fails to cleave into its G1 and G2 subunits and is targeted for degradation within lysosomes. Cells infected with the wild-type Romero (Rom) strain do not produce aggregates that are observed in Can infection, and the stress on the ER remains minimal. While the mutation of the N-linked glycosylation motif (T168A) is primarily responsible for the formation of aggregates, other mutations within G1 that occurred earlier in the passage history of the Can strain also contribute to aggregation of the GPC within the ER.IMPORTANCE The development of vaccines and therapeutics to combat viral hemorrhagic fevers remains a top priority within the Implementation Plan of the U.S. Department of Health and Human Services Public Health Emergency Medical Countermeasures Enterprise. The Can strain, derived from the pathogenic XJ strain of JUNV, has been demonstrated to be both safe and protective against AHF. While the vaccine strain is approved for use in regions of endemicity within Argentina, the mechanisms of Can attenuation have not been elucidated. A better understanding of the viral genetic determinants of attenuation will improve our understanding of the mechanisms contributing to disease pathogenesis and provide critical information for the rational design of live attenuated vaccine candidates for other viral hemorrhagic fevers.

Biocompatibility of new materials based on nano-structured nitinol with titanium and tantalum composite surface layers: experimental analysis in vitro and in vivo.

A technology for obtaining materials from nanostructured nitinol with titanium- or tantalum-enriched surface layers was developed. Surface layers enriched with titanium or tantalum were shown to provide a decrease in the formation of reactive oxygen species and long-lived protein radicals in comparison to untreated nitinol. It was determined that human peripheral vessel myofibroblasts and human bone marrow mesenchymal stromal cells grown on nitinol bases coated with titanium or tantalum-enriched surface layers exhibit a nearly two times higher mitotic index. Response to implantation of pure nitinol, as well as nano-structure nitinol with titanium or tantalum-enriched surface layers, was expressed though formation of a mature uniform fibrous capsule peripherally to the fragment. The thickness of this capsule in the group of animals subjected to implantation of pure nitinol was 1.5 and 3.0-fold greater than that of the capsule in the groups implanted with nitinol fragments with titanium- or tantalum-enriched layers. No signs of calcinosis in the tissues surrounding implants with coatings were observed. The nature and structure of the formed capsules testify bioinertia of the implanted samples. It was shown that the morphology and composition of the surface of metal samples does not alter following biological tests. The obtained results indicate that nano-structure nitinol with titanium or tantalum enriched surface layers is a biocompatible material potentially suitable for medical applications.

Machupo Virus Expressing GPC of the Candid#1 Vaccine Strain of Junin Virus Is Highly Attenuated and Immunogenic.

UNLABELLED: Machupo virus (MACV) is the causative agent of Bolivian hemorrhagic fever. Our previous study demonstrated that a MACV strain with a single amino acid substitution (F438I) in the transmembrane domain of glycoprotein is attenuated but genetically unstable in mice. MACV is closely related to Junin virus (JUNV), the causative agent of Argentine hemorrhagic fever. Others and our group have identified the glycoprotein to be the major viral factor determining JUNV attenuation. In this study, we tested the compatibility of the glycoprotein of the Candid#1 live-attenuated vaccine strain of JUNV in MACV replication and its ability to attenuate MACV in vivo. Recombinant MACV with the Candid#1 glycoprotein (rMACV/Cd#1-GPC) exhibited growth properties similar to those of Candid#1 and was genetically stable in vitro. In a mouse model of lethal infection, rMACV/Cd#1-GPC was fully attenuated, more immunogenic than Candid#1, and fully protective against MACV infection. Therefore, the MACV strain expressing the glycoprotein of Candid#1 is safe, genetically stable, and highly protective against MACV infection in a mouse model. IMPORTANCE: Currently, there are no FDA-approved vaccines and/or treatments for Bolivian hemorrhagic fever, which is a fatal human disease caused by MACV. The development of antiviral strategies to combat viral hemorrhagic fevers, including Bolivian hemorrhagic fever, is one of the top priorities of the Implementation Plan of the U.S. Department of Health and Human Services Public Health Emergency Medical Countermeasures Enterprise. Here, we demonstrate for the first time that MACV expressing glycoprotein of Candid#1 is a safe, genetically stable, highly immunogenic, and protective vaccine candidate against Bolivian hemorrhagic fever.

Highly Pathogenic New World and Old World Human Arenaviruses Induce Distinct Interferon Responses in Human Cells.

UNLABELLED: The arenavirus family includes several important pathogens that cause severe and sometimes fatal diseases in humans. The highly pathogenic Old World (OW) arenavirus Lassa fever virus (LASV) is the causative agent of Lassa fever (LF) disease in humans. LASV infections in severe cases are generally immunosuppressive without stimulating interferon (IFN) induction, a proinflammatory response, or T cell activation. However, the host innate immune responses to highly pathogenic New World (NW) arenaviruses are not well understood. We have previously shown that the highly pathogenic NW arenavirus, Junin virus (JUNV), induced an IFN response in human A549 cells. Here, we report that Machupo virus (MACV), another highly pathogenic NW arenavirus, also induces an IFN response. Importantly, both pathogenic NW arenaviruses, in contrast to the OW highly pathogenic arenavirus LASV, readily elicited an IFN response in human primary dendritic cells and A549 cells. Coinfection experiments revealed that LASV could potently inhibit MACV-activated IFN responses even at 6 h after MACV infection, while the replication levels of MACV and LASV were not affected by virus coinfection. Our results clearly demonstrated that although all viruses studied herein are highly pathogenic to humans, the host IFN responses toward infections with the NW arenaviruses JUNV and MACV are quite different from responses to infections with the OW arenavirus LASV, a discovery that needs to be further investigated in relevant animal models. This finding might help us better understand various interplays between the host immune system and highly pathogenic arenaviruses as well as distinct mechanisms underlying viral pathogenesis. IMPORTANCE: Infections of humans with the highly pathogenic OW LASV are accompanied by potent suppression of interferon or proinflammatory cytokine production. In contrast, infections with the highly pathogenic NW arenavirus JUNV are associated with high levels of IFNs and cytokines in severe and fatal cases. Arenaviruses initially target macrophages and dendritic cells, which are potent IFN/cytokine-producers. In human macrophages, JUNV reportedly does not trigger IFN responses. We here demonstrated that JUNV activated IFN responses in human dendritic cells. MACV, another highly pathogenic NW arenavirus, also activated IFN responses. LASV did not induce detectable IFN responses, in spite of higher replication levels, and blocked the MACV-triggered IFN response in a coinfection assay. Although these viruses are highly pathogenic to humans, our study highlights distinct innate immune responses to infections with the NW arenaviruses JUNV and MACV and to infection with the OW arenavirus LASV and provides important insights into the virus-host interaction and pathogenesis.

Animal Model of Sensorineural Hearing Loss Associated with Lassa Virus Infection.

UNLABELLED: Approximately one-third of Lassa virus (LASV)-infected patients develop sensorineural hearing loss (SNHL) in the late stages of acute disease or in early convalescence. With 500,000 annual cases of Lassa fever (LF), LASV is a major cause of hearing loss in regions of West Africa where LF is endemic. To date, no animal models exist that depict the human pathology of LF with associated hearing loss. Here, we aimed to develop an animal model to study LASV-induced hearing loss using human isolates from a 2012 Sierra Leone outbreak. We have recently established a murine model for LF that closely mimics many features of human disease. In this model, LASV isolated from a lethal human case was highly virulent, while the virus isolated from a nonlethal case elicited mostly mild disease with moderate mortality. More importantly, both viruses were able to induce SNHL in surviving animals. However, utilization of the nonlethal, human LASV isolate allowed us to consistently produce large numbers of survivors with hearing loss. Surviving mice developed permanent hearing loss associated with mild damage to the cochlear hair cells and, strikingly, significant degeneration of the spiral ganglion cells of the auditory nerve. Therefore, the pathological changes in the inner ear of the mice with SNHL supported the phenotypic loss of hearing and provided further insights into the mechanistic cause of LF-associated hearing loss. IMPORTANCE: Sensorineural hearing loss is a major complication for LF survivors. The development of a small-animal model of LASV infection that replicates hearing loss and the clinical and pathological features of LF will significantly increase knowledge of pathogenesis and vaccine studies. In addition, such a model will permit detailed characterization of the hearing loss mechanism and allow for the development of appropriate diagnostic approaches and medical care for LF patients with hearing impairment.

The glycoprotein precursor gene of Junin virus determines the virulence of the Romero strain and the attenuation of the Candid #1 strain in a representative animal model of Argentine hemorrhagic fever.

UNLABELLED: The New World arenavirus Junin virus (JUNV) is the causative agent of Argentine hemorrhagic fever (AHF), a potentially deadly disease endemic to central regions of Argentina. The live-attenuated Candid #1 (Can) strain of JUNV is currently used to vaccinate the human population at risk. However, the mechanism of attenuation of this strain is still largely unknown. Therefore, the identification and functional characterization of viral genetic determinants dictating JUNV virulence or attenuation would significantly improve the understanding of the mechanisms underlying AHF and facilitate the development of novel, more effective, and safer vaccines. Here, we utilized a reverse genetics approach to generate recombinant JUNV (rJUNV) strains encoding different gene combinations of the pathogenic Romero (Rom) and attenuated Can strains of JUNV. All strains of rJUNV exhibited in vitro growth kinetics similar to those of their parental counterparts. Analysis of virulence of the rJUNV in a guinea pig model of lethal infection that closely reproduces the features of AHF identified the envelope glycoproteins (GPs) as the major determinants of pathogenesis and attenuation of JUNV. Accordingly, rJUNV strains expressing the full-length GPs of Rom and Can exhibited virulent and attenuated phenotypes, respectively, in guinea pigs. Mutation F427I in the transmembrane region of JUNV envelope glycoprotein GP2 has been shown to attenuate the neurovirulence of JUNV in suckling mice. We document that in the guinea pig model of AHF, mutation F427I in GP2 is also highly attenuating but insufficient to prevent virus dissemination and development of mild clinical and pathological symptoms, indicating that complete attenuation of JUNV requires additional mutations present in Can glycoprotein precursor (GPC). IMPORTANCE: Development of antiviral strategies against viral hemorrhagic fevers, including AHF, is one of the top priorities within the Implementation Plan of the U.S. Department of Health and Human Services Public Health Emergency Medical Countermeasures Enterprise. Live-attenuated Candid #1 strain, derived from the 44th mouse brain passage of the prototype XJ strain of JUNV, has been demonstrated to be safe, immunogenic, and highly protective and is currently licensed for human use in Argentina. However, the bases for the attenuated phenotype of Candid #1 have not been established. Therefore, the identification and functional characterization of viral genetic factors implicated in JUNV pathogenesis and attenuation would significantly improve the understanding of the molecular mechanisms underlying AHF and facilitate the development of novel antiviral strategies.

A substitution in the transmembrane region of the glycoprotein leads to an unstable attenuation of Machupo virus.

Machupo virus (MACV) is the etiologic agent of Bolivian hemorrhagic fever (BHF). Utilizing a reverse-genetics system recently developed, we report the rescue of a rationally modified recombinant MACV containing a single mutation in the transmembrane region of the glycoprotein. Following challenge of susceptible mice, we identified a significant reduction in virulence in the novel virus. We also identified an instability leading to reversion of the single mutation to a wild-type genotype.

Rescue of a recombinant Machupo virus from cloned cDNAs and in vivo characterization in interferon (αß/γ) receptor double knockout mice.

Machupo virus (MACV) is the etiological agent of Bolivian hemorrhagic fever (BHF), a reemerging and neglected tropical disease associated with high mortality. The prototypical strain of MACV, Carvallo, was isolated from a human patient in 1963, but minimal in vitro and in vivo characterization has been reported. To this end, we utilized reverse genetics to rescue a pathogenic MACV from cloned cDNAs. The recombinant MACV (rMACV) had in vitro growth properties similar to those of the parental MACV. Both viruses caused similar disease development in alpha/beta and gamma interferon receptor knockout mice, including neurological disease development and high mortality. In addition, we have identified a novel murine model with mortality and neurological disease similar to BHF disease reported in humans and nonhuman primates.

Mice lacking functional STAT1 are highly susceptible to lethal infection with Lassa virus.

Lassa fever (LF) is a potentially lethal human disease that is caused by the arenavirus Lassa virus (LASV). Annually, around 300,000 infections with up to 10,000 deaths occur in regions of Lassa fever endemicity in West Africa. Here we demonstrate that mice lacking a functional STAT1 pathway are highly susceptible to infection with LASV and develop lethal disease with pathology similar to that reported in humans.

Development and characterization of a first-in-class adjustable-dose gene therapy system.

INTRODUCTION: Despite significant potential, gene therapy has been relegated to the treatment of rare diseases, due in part to an inability to adjust dosage following initial administration. Other significant constraints include cost, specificity, antigenicity, and systemic toxicity of current generation technologies. To overcome these challenges, we developed a first-in-class adjustable-dose gene therapy system, with optimized biocompatibility, localization, durability, and cost. METHODS: A lipid nanoparticle (LNP) delivery system was developed and characterized by dynamic light scattering for size, zeta potential, and polydispersity. Cytocompatibility and transfection efficiency were optimized in vitro using primary human adipocytes and preadipocytes. Durability, immunogenicity, and adjustment of expression were evaluated in C57BL/6 and B6 albino mice using in vivo bioluminescence imaging. Biodistribution was assessed by qPCR and immunohistochemistry; therapeutic protein expression was quantified by ELISA. RESULTS: Following LNP optimization, in vitro transfection efficiency of primary human adipocytes reached 81.3 % ± 8.3 % without compromising cytocompatibility. Critical physico-chemical properties of the system (size, zeta potential, polydispersity) remained stable over a broad range of genetic cassette sizes (1,871-6,203 bp). Durable expression was observed in vivo over 6 months, localizing to subcutaneous adipose tissues at the injection site with no detectable transgene in the liver, heart, spleen, or kidney. Gene expression was adjustable using several physical and pharmacological approaches, including cryolipolysis, focused ultrasound, and pharmacologically inducible apoptosis. The ability of transfected adipocytes to express therapeutic transgenes ranging from peptides to antibodies, at potentially clinically relevant levels, was confirmed in vitro and in vivo. CONCLUSION: We report the development of a novel, low-cost therapeutic platform, designed to enable the replacement of subcutaneously administered protein treatments with a single-injection, adjustable-dose gene therapy.

Single Injection AAV2-FGF18 Gene Therapy Reduces Cartilage Loss and Subchondral Bone Damage in a Mechanically Induced Model of Osteoarthritis.

BACKGROUND: Osteoarthritis (OA) is a highly debilitating, degenerative pathology of cartilaginous joints affecting over 500 million people worldwide. The global economic burden of OA is estimated at $260-519 billion and growing, driven by aging global population and increasing rates of obesity. To date, only the multi-injection chondroanabolic treatment regimen of Fibroblast Growth Factor 18 (FGF18) has demonstrated clinically meaningful disease-modifying efficacy in placebo-controlled human trials. Our work focuses on the development of a novel single injection disease-modifying gene therapy, based on FGF18's chondroanabolic activity. METHODS: OA was induced in Sprague-Dawley rats using destabilization of the medial meniscus (DMM) (3 weeks), followed by intra-articular treatment with 3 dose levels of AAV2-FGF18, rh- FGF18 protein, and PBS. Durability, redosability, and biodistribution were measured by quantifying nLuc reporter bioluminescence. Transcriptomic analysis was performed by RNA-seq on cultured human chondrocytes and rat knee joints. Morphological analysis was performed on knee joints stained with Safranin O/Fast Green and anti-PRG antibody. RESULTS: Dose-dependent reductions in cartilage defect size were observed in the AAV2-FGF18- treated joints relative to the vehicle control. Total defect width was reduced by up to 76% and cartilage thickness in the thinnest zone was increased by up to 106%. Morphologically, the vehicle- treated joints exhibited pronounced degeneration, ranging from severe cartilage erosion and bone void formation, to subchondral bone remodeling and near-complete subchondral bone collapse. In contrast, AAV2-FGF18-treated joints appeared more anatomically normal, with only regional glycosaminoglycan loss and marginal cartilage erosion. While effective at reducing cartilage lesions, treatment with rhFGF18 injections resulted in significant joint swelling (19% increase in diameter), as well as a decrease in PRG4 staining uniformity and intensity. In contrast to early-timepoint in vitro RNA-seq analysis, which showed a high degree of concordance between protein- and gene therapy-treated chondrocytes, in vivo transcriptomic analysis, revealed few gene expression changes following protein treatment. On the other hand, the gene therapy treatment exhibited a high degree of durability and localization over the study period, upregulating several chondroanabolic genes while downregulating OA- and fibrocartilage-associated markers. CONCLUSION: FGF18 gene therapy treatment of OA joints can provide benefits to both cartilage and subchondral bone, with a high degree of localization and durability.

Functional interferon system is required for clearance of lassa virus.

Lassa virus (LASV) is the causative agent of Lassa hemorrhagic fever (LF) in humans, a deadly disease endemic to West Africa that results in 5,000 to 10,000 deaths annually. Here we present results demonstrating that functional type I and type II interferon (IFN) signaling is required for efficient control of LASV dissemination and clearance.

From everywhere all at once: Several colonization routes available to Svalbard in the early Holocene.

For many arctic species, the spatial (re-)colonization patterns after the last Pleistocene glaciation have been described. However, the temporal aspects of their colonization are largely missing. Did one route prevail early, while another was more important later? The high Arctic archipelago Svalbard represents a good model system to address timeframe of postglacial plant colonization. Svalbard was almost fully glaciated during last glacial maximum and (re-)colonization of vascular plants began in early Holocene. Early Holocene climatic optimum (HCO) supported an expanded establishment of a partly thermophilic vegetation. Today, we find remnants of this vegetation in sheltered regions referred to as "Arctic biodiversity hotspots". The oldest record of postglacial plant colonization to Svalbard is found in Ringhorndalen-Flatøyrdalen. Even though thermophilic species could establish also later in Holocene, only HCO was favorable for vast colonization, and only hotspots offered stable conditions for thermophilic populations throughout Holocene. Thus, these relic populations may reflect colonization patterns of HCO. We investigate whether the colonization direction of thermophilic plants (Arnica angustifolia, Campanula uniflora, Pinguicula alpina, Tofieldia pusilla, and Vaccinium uliginosum ssp. microphyllum) in Ringhorndalen-Flatøyrdalen was uniform and different from later colonization events in other localities and non-thermophilic plants (Arenaria humifusa, Bistorta vivipara, Juncus biglumis, Oxyria digyna, and Silene acaulis). We analyzed plastid haplotypes of the 10 taxa from Ringhorndalen-Flatøyrdalen, from later-colonized localities in Svalbard, and from putative source regions outside Svalbard. Only rare and thermophilic taxa Campanula uniflora and Vaccinium uliginosum ssp. microphyllum provided results suggesting at least two colonization events from different source regions. Tofieldia pusilla and all the non-thermophilic plants showed no clear phylogeographically differentiation within Svalbard. Two of the thermophilic species showed no sequence variation. Based on the results, a uniform colonization direction to Svalbard in early Holocene is not probable; several source areas and dispersal directions were contemporarily involved.

Adeno-Associated Virus-Delivered Fibroblast Growth Factor 18 Gene Therapy Promotes Cartilage Anabolism.

OBJECTIVE: To determine the characterization of chondrogenic properties of adeno-associated virus type 2 (AAV2)-delivered hFGF18, via analysis of effects on primary human chondrocyte proliferation, gene expression, and in vivo cartilage thickness changes in the tibia and meniscus. DESIGN: Chondrogenic properties of AAV2-FGF18 were compared with recombinant human FGF18 (rhFGF18) in vitro relative to phosphate-buffered saline (PBS) and AAV2-GFP negative controls. Transcriptome analysis was performed using RNA-seq on primary human chondrocytes treated with rhFGF18 and AAV2-FGF18, relative to PBS. Durability of gene expression was assessed using AAV2-nLuc and in vivo imaging. Chondrogenesis was evaluated by measuring weight-normalized thickness in the tibial plateau and the white zone of the anterior horn of the medial meniscus in Sprague-Dawley rats. RESULTS: AAV2-FGF18 elicits chondrogenesis by promoting proliferation and upregulation of hyaline cartilage-associated genes, including COL2A1 and HAS2, while downregulating fibrocartilage-associated COL1A1. This activity translates to statistically significant, dose-dependent increases in cartilage thickness in vivo within the area of the tibial plateau, following a single intra-articular injection of the AAV2-FGF18 or a regimen of 6 twice-weekly injections of rhFGF18 protein relative to AAV2-GFP. In addition, we observed AAV2-FGF18-induced and rhFGF18-induced increases in cartilage thickness of the anterior horn of the medial meniscus. Finally, the single-injection AAV2-delivered hFGF18 offers a potential safety advantage over the multi-injection protein treatment as evidenced by reduced joint swelling over the study period. CONCLUSION: AAV2-delivered hFGF18 represents a promising strategy for the restoration of hyaline cartilage by promoting extracellular matrix production, chondrocyte proliferation, and increasing articular and meniscal cartilage thickness in vivo after a single intra-articular injection.

Comparative evaluation of rhFGF18 and rhGDF11 treatment in a transient ischemia stroke model.

Background: Pharmacological treatments for ischemic stroke remain limited to thrombolysis, which is associated with increased risk of potentially fatal hemorrhage. Treatments with Recombinant Human Fibroblast Growth Factor 18 (rhFGF18) and Growth and Differentiation Factor 11 (rhGDF11) appear promising based on different preclinical models. The goal of this study was to compare the effects of rhFGF18 and rhGDF11 directly on survival, behavioral deficits, and histological fingerprint of cerebral ischemia in the Wistar rat middle cerebral artery occlusion (MCAO) model of stroke. Methods: Ischemia-reperfusion injury was induced using a 2-hour transient MCAO. Animals were administered rhFGF18 (infusion), rhGDF11 (multi-injection), or Phosphate Buffered Saline (PBS) vehicle control and followed for 42 days. Motor-Cognitive deficits were evaluated using the Morris Water Maze at Days 0 (pre-MCAO), 7, 21, and 42. Histopathological assessments were performed on Days 21 and 42. Results: Day 7 post-ischemia water maze performance times increased 38.3%, 2.1%, and 23.1% for PBS, rhFGF18, and rhGDF11-treated groups, respectively. Fraction of neurons with abnormal morphology (chromatolysis, pyknotic nuclei, somal degeneration) decreased in all groups toward Day 42 and was lowest for rhFGF18. AChE-positive fiber density and activity increased over time in the rhFGF18 group, remained unchanged in the rhGDF11 treatment arm, and declined in the PBS control. Metabolic increases were greatest in rhGDF11 treated animals, with both rhFGF18 and rhGDF11 achieving improvements over PBS, as evidenced by increased succinate dehydrogenase and lactate dehydrogenase activity. Finally, rhFGF18 treatment exhibited a trend for reduced mortality relative to PBS (5.6%, 95% CI [27.3%, 0.1% ] vs. 22.2%, 95% CI [47.6%, 6.4% ]). Conclusions: rhFGF18 treatment appears promising in improving survival and promoting motor-cognitive recovery following cerebral ischemia-reperfusion injury.

African Mountain Thistles: Three New Genera in the Carduus-Cirsium Group.

The floras on the highest mountains in tropical eastern Africa are among the most unique floras in the world. Despite the exceptionally high concentration of endemic species, these floras remain understudied from an evolutionary point of view. In this study, we focus on the Carduus-Cirsium group (subtribe Carduinae) to unravel the evolutionary relationships of the species endemic to the tropical Afromontane and Afroalpine floras, aiming to improve the systematics of the group. We applied the Hyb-Seq approach using the Compositae1061 probe set on 190 samples (159 species), encompassing representatives of all genera of Carduinae. We used two recently developed pipelines that enabled the processing of raw sequence reads, identification of paralogous sequences and segregation into orthologous alignments. After the implementation of a missing data filter, we retained sequences from 986 nuclear loci and 177 plastid regions. Phylogenomic analyses were conducted using both concatenated and summary-coalescence methods. The resulting phylogenies were highly resolved and revealed three distinct evolutionary lineages consisting of the African species traditionally referred to as Carduus and Cirsium. Consequently, we propose the three new genera Afrocarduus, Afrocirsium and Nuriaea; the latter did notably not belong to the Carduus-Cirsium group. We detected some incongruences between the phylogenies based on concatenation vs. coalescence and on nuclear vs. plastid datasets, likely attributable to incomplete lineage sorting and/or hybridization.

Rescue from cloned cDNAs and in vivo characterization of recombinant pathogenic Romero and live-attenuated Candid #1 strains of Junin virus, the causative agent of Argentine hemorrhagic fever disease.

The New World arenavirus Junin virus (JUNV) is the causative agent of Argentine hemorrhagic fever (AHF), which is associated with high morbidity and significant mortality. Several pathogenic strains of JUNV have been documented, and a highly attenuated vaccine strain (Candid #1) was generated and used to vaccinate the human population at risk. The identification and functional characterization of viral genetic determinants associated with AHF and Candid #1 attenuation would contribute to the elucidation of the mechanisms contributing to AHF and the development of better vaccines and therapeutics. To this end, we used reverse genetics to rescue the pathogenic Romero and the attenuated Candid #1 strains of JUNV from cloned cDNAs. Both recombinant Candid #1 (rCandid #1) and Romero (rRomero) had the same growth properties and phenotypic features in cultured cells and in vivo as their corresponding parental viruses. Infection with rRomero caused 100% lethality in guinea pigs, whereas rCandid #1 infection was asymptomatic and provided protection against a lethal challenge with Romero. Notably, Romero and Candid #1 trans-acting proteins, L and NP, required for virus RNA replication and gene expression were exchangeable in a minigenome rescue assay. These findings support the feasibility of studies aimed at determining the contribution of each viral gene to JUNV pathogenesis and attenuation. In addition, we rescued Candid #1 viruses with three segments that efficiently expressed foreign genes introduced into their genomes. This finding opens the way for the development of a safe multivalent arenavirus vaccine.