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The study accessed the perceptions of final year students in the Tumu College of Education towards the Pedagogic Knowledge (PK) of their mentors. It also investigated whether statistically significant differences existed in terms of mentees’ gender and programmes of study regarding the pedagogic knowledge of their mentors. The study used a census method to collect data from respondents for the study by distributing a closed-ended five-point Likert scale on Perceptions of Knowledge and Skills in Teaching (PKST) Questionnaires to all 215 students pursuing Early Grade and Primary Programmes, with an 84.2% (181) return rate. However, 175 respondents’ data were used, as six of the questionnaires contained incomplete data. Findings of the study revealed that participants perceived their mentors as having a high measure of PK, with an overall mean value for the student teachers ‘perceptions of their mentors PK of 3.62 (SD =.77). The study also revealed that there was no statistically significant difference in the perceptions of student teachers towards the PK of their mentors in terms of gender or programme of study. However, the study revealed that participants perceived their mentors to be less competent in effectively incorporating information and communication technology (ICT) in the classroom. It is recommended that the Ministry of Education and Ghana Education Service organise capacity building workshops for teachers to improve their competencies in integrating ICT in their classrooms.

The recognition of the immune system as a key component of the tumor microenvironment (TME) led to promising therapeutics. Because such therapies benefit only subsets of patients, understanding the activities of immune cells in the TME is required. Eosinophils are an integral part of the TME especially in mucosal tumors. Nonetheless, their role in the TME and the environmental cues that direct their activities are largely unknown. We report that breast cancer lung metastases are characterized by resident and recruited eosinophils. Eosinophil recruitment to the metastatic sites in the lung was regulated by G protein-coupled receptor signaling but independent of CCR3. Functionally, eosinophils promoted lymphocyte-mediated antitumor immunity. Transcriptome and proteomic analyses identified the TME rather than intrinsic differences between eosinophil subsets as a key instructing factor directing antitumorigenic eosinophil activities. Specifically, TNFα/IFNγ-activated eosinophils facilitated CD4 + and CD8 + T-cell infiltration and promoted antitumor immunity. Collectively, we identify a mechanism by which the TME trains eosinophils to adopt antitumorigenic properties, which may lead to the development of eosinophil-targeted therapeutics. SIGNIFICANCE: These findings demonstrate antitumor activities of eosinophils in the metastatic tumor microenvironment, suggesting that harnessing eosinophil activity may be a viable clinical strategy in patients with cancer., (©2021 American Association for Cancer Research.)

Introduction: Medical work requires complete dedication to work, long hours of absence from home and family, as well as personal sacrifice on various issues. This results in impaired quality of life, and the phenomenon of depression and suicide is more common among physicians than in the general population. The impairment in quality of life and function was defined for years as burnout, and this figure of speech reflected the physician's inability to cope with existing pressures. In recent years, the concept of 'moral injury' has been emerging to explain a significant part of the burnout phenomenon. The term describes the poor mental state of the physician who is forced to make immoral choices as part of the organizational demands. This perception fundamentally changes the concept that the poor function at work and in personal life is only the weakness of the doctor who lacks coping resources and resilience, therefore needing personal support such as yoga and mindfulness exercise. It emphasizes the organization responsibility for change, which will minimize moral dilemmas, thereby the moral injury. This will allow the doctor to live professional, as well as personal life, in an optimal way.

Mortality from breast cancer is almost exclusively a result of tumor metastasis, and lungs are one of the main metastatic sites. Cancer-associated fibroblasts are prominent players in the microenvironment of breast cancer. However, their role in the metastatic niche is largely unknown. In this study, we profiled the transcriptional co-evolution of lung fibroblasts isolated from transgenic mice at defined stage-specific time points of metastases formation. Employing multiple knowledge-based platforms of data analysis provided powerful insights on functional and temporal regulation of the transcriptome of fibroblasts. We demonstrate that fibroblasts in lung metastases are transcriptionally dynamic and plastic, and reveal stage-specific gene signatures that imply functional tasks, including extracellular matrix remodeling, stress response, and shaping the inflammatory microenvironment. Furthermore, we identified Myc as a central regulator of fibroblast rewiring and found that stromal upregulation of Myc transcriptional networks is associated with disease progression in human breast cancer., Competing Interests: OS, YR, LM, YS, OL, OM, HS, NC, DS, CA, RS, AM, RS, IB, IT, NE No competing interests declared, (© 2021, Shani et al.)

Mutations in AUTS2 are associated with autism, intellectual disability, and microcephaly. AUTS2 is expressed in the brain and interacts with polycomb proteins, yet it is still unclear how mutations in AUTS2 lead to neurodevelopmental phenotypes. Here we report that when neuronal differentiation is initiated, there is a shift in expression from a long isoform to a short AUTS2 isoform. Yeast two-hybrid screen identified the splicing factor SF3B1 as an interactor of both isoforms, whereas the polycomb group proteins, PCGF3 and PCGF5, were found to interact exclusively with the long AUTS2 isoform. Reporter assays showed that the first exons of the long AUTS2 isoform function as a transcription repressor, but the part that consist of the short isoform acts as a transcriptional activator, both influenced by the cellular context. The expression levels of PCGF3 influenced the ability of the long AUTS2 isoform to activate or repress transcription. Mouse embryonic stem cells (mESCs) with heterozygote mutations in Auts2 had an increase in cell death during in vitro corticogenesis, which was significantly rescued by overexpressing the human AUTS2 transcripts. mESCs with a truncated AUTS2 protein (missing exons 12-20) showed premature neuronal differentiation, whereas cells overexpressing AUTS2, especially the long transcript, showed increase in expression of pluripotency markers and delayed differentiation. Taken together, our data suggest that the precise expression of AUTS2 isoforms is essential for regulating transcription and the timing of neuronal differentiation.

The historic outbreak of the novel coronavirus (SARS CoV-2) sent concern and even panic around the world due to the unknown nature of this disease. As a result, the US implemented a whole-of government approach to tackle the outbreak of this deadly virus. The national and global impact of an uncontrolled COVID-19 outbreak, threatens the US healthcare system and our way of life with potential to cause riveting economic and national security instability. As a result of the health impact on American society, the US military must also take precaution to preserve and defend our nation's fighting force. This charge has created a unique opportunity for military medicine to take the lead at the front line to combat this biologic viral threat.

Lungs are one of the main sites of breast cancer metastasis. The metastatic microenvironment is essential to facilitate growth of disseminated tumor cells. Cancer-associated fibroblasts (CAF) are prominent players in the microenvironment of breast cancer. However, their role in the formation of a permissive metastatic niche is unresolved. Here we show that IL33 is upregulated in metastases-associated fibroblasts in mouse models of spontaneous breast cancer metastasis and in patients with breast cancer with lung metastasis. Upregulation of IL33 instigated type 2 inflammation in the metastatic microenvironment and mediated recruitment of eosinophils, neutrophils, and inflammatory monocytes to lung metastases. Importantly, targeting of IL33 in vivo resulted in inhibition of lung metastasis and significant attenuation of immune cell recruitment and type 2 immunity. These findings demonstrate a key function of IL33 in facilitating lung metastatic relapse by modulating the immune microenvironment. Our study shows a novel interaction axis between CAF and immune cells and reveals the central role of CAF in establishing a hospitable inflammatory niche in lung metastasis. SIGNIFICANCE: This study elucidates a novel role for fibroblast-derived IL33 in facilitating breast cancer lung metastasis by modifying the immune microenvironment at the metastatic niche toward type 2 inflammation., (©2020 American Association for Cancer Research.)

The most common site of breast cancer metastasis is the bone, occurring in approximately 70% of patients with advanced disease. Bone metastasis is associated with severe morbidities and high mortality. Therefore, deeper understanding of the mechanisms that enable bone-metastatic relapse are urgently needed. We report the establishment and characterization of a bone-seeking variant of breast cancer cells that spontaneously forms aggressive bone metastases following surgical resection of primary tumor. We characterized the modifications in the immune milieu during early and late stages of metastatic relapse and found that the formation of bone metastases is associated with systemic changes, as well as modifications of the bone microenvironment towards an immune suppressive milieu. Furthermore, we characterized the intrinsic changes in breast cancer cells that facilitate bone-tropism and found that they acquire mesenchymal and osteomimetic features. This model provides a clinically relevant platform to study the functional interactions between breast cancer cells and the bone microenvironment, in an effort to identify novel targets for intervention.

The major cause of melanoma mortality is metastasis to distant organs, including lungs and brain. Reciprocal interactions of metastasizing tumor cells with stromal cells in secondary sites play a critical role in all stages of tumorigenesis and metastasis. Changes in the metastatic microenvironment were shown to precede clinically relevant metastases, and may occur prior to the arrival of disseminated tumor cells to the distant organ, thus creating a hospitable "premetastatic niche." Exosomes secreted by tumor cells were demonstrated to play an important role in the preparation of a hospitable metastatic niche. However, the functional role of melanoma-derived exosomes on metastatic niche formation, and the downstream pathways activated in stromal cells at the metastatic niche are largely unresolved. Here we show that extracellular vesicles (EVs) secreted by metastatic melanoma cells that spontaneously metastasize to lungs and to brain, activate proinflammatory signaling in lung fibroblasts and in astrocytes. Interestingly, unlike paracrine signaling by melanoma cells, EVs secreted by metastatic melanoma cells instigated a proinflammatory gene signature in lung fibroblasts but did not activate wound-healing functions, suggesting that tumor cell-secreted EVs activate distinct CAF characteristics and tumor-promoting functions. Moreover, melanoma-secreted EVs also activated proinflammatory signaling in astrocytes, indicating that EV-mediated reprogramming of stromal cells is a general mechanism of modulating the metastatic niche in multiple distant organs. Thus, our study demonstrates that melanoma-derived EVs reprogram tumor-promoting functions in stromal cells in a distinct manner, implicating a central role for tumor-derived EV signaling in promoting the formation of an inflammatory metastatic niche., (© 2019 UICC.)

Cancer-Associated Fibroblasts (CAFs) were shown to orchestrate tumour-promoting inflammation in multiple malignancies, including breast cancer. However, the molecular pathways that govern the inflammatory role of CAFs are poorly characterised. In this study we found that fibroblasts sense damage-associated molecular patterns (DAMPs), and in response activate the NLRP3 inflammasome pathway, resulting in instigation of pro-inflammatory signalling and secretion of IL-1β. This upregulation was evident in CAFs in mouse and in human breast carcinomas. Moreover, CAF-derived inflammasome signalling facilitated tumour growth and metastasis, which was attenuated when NLRP3 or IL-1β were specifically ablated. Functionally, CAF-derived inflammasome promoted tumour progression and metastasis by modulating the tumour microenvironment towards an immune suppressive milieu and by upregulating the expression of adhesion molecules on endothelial cells. Our findings elucidate a mechanism by which CAFs promote breast cancer progression and metastasis, by linking the physiological tissue damage response of fibroblasts with tumour-promoting inflammation.

Melanoma is the deadliest skin cancer due to its high rate of metastasis, frequently to the brain. Brain metastases are incurable; therefore, understanding melanoma brain metastasis is of great clinical importance. We used a mouse model of spontaneous melanoma brain metastasis to study the interactions of melanomas with the brain microenvironment. We find that CXCL10 is upregulated in metastasis-associated astrocytes in mice and humans and is functionally important for the chemoattraction of melanoma cells. Moreover, CXCR3, the receptor for CXCL10, is upregulated in brain-tropic melanoma cells. Targeting melanoma expression of CXCR3 by nanoparticle-mediated siRNA delivery or by shRNA transduction inhibits melanoma cell migration and attenuates brain metastasis in vivo. These findings suggest that the instigation of pro-inflammatory signaling in astrocytes is hijacked by brain-metastasizing tumor cells to promote their metastatic capacity and that the CXCL10-CXCR3 axis may be a potential therapeutic target for the prevention of melanoma brain metastasis., (Copyright © 2019 The Author(s). Published by Elsevier Inc. All rights reserved.)

Cancer-associated fibroblasts (CAFs) are highly prominent in breast tumors, but their functional heterogeneity and origin are still largely unresolved. We report that bone marrow (BM)-derived mesenchymal stromal cells (MSCs) are recruited to primary breast tumors and to lung metastases and differentiate to a distinct subpopulation of CAFs. We show that BM-derived CAFs are functionally important for tumor growth and enhance angiogenesis via up-regulation of Clusterin. Using newly generated transgenic mice and adoptive BM transplantations, we demonstrate that BM-derived fibroblasts are a substantial source of CAFs in the tumor microenvironment. Unlike resident CAFs, BM-derived CAFs do not express PDGFRα, and their recruitment resulted in a decrease in the percentage of PDGFRα-expressing CAFs. Strikingly, decrease in PDGFRα in breast cancer patients was associated with worse prognosis, suggesting that BM-derived CAFs may have deleterious effects on survival. Therefore, PDGFRα expression distinguishes two functionally unique CAF populations in breast tumors and metastases and may have important implications for patient stratification and precision therapeutics., (© 2018 Raz et al.)

Whitewater Arroyo virus belongs to the "New World" group of mammarenaviruses that reside in rodent reservoirs and are prevalent in North and South Americas. Clades B and A/B of New World mammarenaviruses use transferrin receptor 1 (TfR1) for entry. While all of these viruses use rodent-derived TfR1 orthologs, some can also use the human-TfR1 and thereby infect humans. Although we have structural information for TfR1 recognition by pathogenic virus, we do not know what the structural differences are between the receptor-binding domains of pathogenic and non-pathogenic viruses that allow some but not all viruses to utilize the human receptor for entry. The poor understanding of the molecular determinants of mammarenavirus host range, and thus pathogenicity, is partly due to the low sequence similarity between the receptor-binding domains from these viruses and the limited available structural information that preclude the use of modeling approaches. Here we present the first crystal structure of a receptor-binding domain of a non-pathogenic clade A/B mammarenavirus. This structure reveals the magnitude of structural differences within the receptor-binding domains of TfR1-tropic viruses. Our structural and sequence analyses indicate that the same structural incompatibilities with the human receptor equally affect both pathogenic and non-pathogenic mammarenaviruses. Non-pathogenic viruses do not have specific structural elements that prevent them from using the human receptor. Instead, the ability to utilize the human receptor directly depends on the extent of weak interactions throughout the receptor-binding site that in some viruses are sufficiently strong to overcome the structural incompatibilities., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

To effectively infect cells, Lassa virus needs to switch in an endosomal compartment from its primary receptor, α-dystroglycan, to a protein termed LAMP1. A unique histidine triad on the surface of the receptor-binding domain from the glycoprotein spike complex of Lassa virus is important for LAMP1 binding. Here we investigate mutated spikes that have an impaired ability to interact with LAMP1 and show that although LAMP1 is important for efficient infectivity, it is not required for spike-mediated membrane fusion per se Our studies reveal important regulatory roles for histidines from the triad in sensing acidic pH and preventing premature spike triggering. We further show that LAMP1 requires a positively charged His230 residue to engage with the spike complex and that LAMP1 binding promotes membrane fusion. These results elucidate the molecular role of LAMP1 binding during Lassa virus cell entry and provide new insights into how pH is sensed by the spike., Importance: Lassa virus is a devastating disease-causing agent in West Africa, with a significant yearly death toll and severe long-term complications associated with its infection in survivors. In recent years, we learned that Lassa virus needs to switch receptors in a pH-dependent manner to efficiently infect cells, but neither the molecular mechanisms that allow switching nor the actual effects of switching were known. Here we investigate the activity of the viral spike complex after abrogation of its ability to switch receptors. These studies inform us about the role of switching receptors and provide new insights into how the spike senses acidic pH., (Copyright © 2016, American Society for Microbiology. All Rights Reserved.)

Viruses are by definition fully dependent on the cellular translation machinery, and develop diverse mechanisms to co-opt this machinery for their own benefit. Unlike many viruses, human cytomegalovirus (HCMV) does suppress the host translation machinery, and the extent to which translation machinery contributes to the overall pattern of viral replication and pathogenesis remains elusive. Here, we combine RNA sequencing and ribosomal profiling analyses to systematically address this question. By simultaneously examining the changes in transcription and translation along HCMV infection, we uncover extensive transcriptional control that dominates the response to infection, but also diverse and dynamic translational regulation for subsets of host genes. We were also able to show that, at late time points in infection, translation of viral mRNAs is higher than that of cellular mRNAs. Lastly, integration of our translation measurements with recent measurements of protein abundance enabled comprehensive identification of dozens of host proteins that are targeted for degradation during HCMV infection. Since targeted degradation indicates a strong biological importance, this approach should be applicable for discovering central host functions during viral infection. Our work provides a framework for studying the contribution of transcription, translation and degradation during infection with any virus.

The hybrid prokaryotic lipo-beta-lactamase mature and precursor proteins spontaneously form an intramolecular disulphide bond when oxidized in vitro. When expressed in Saccharomyces cerevisiae (in vivo) the lipo-beta-lactamase precursor is in a reduced form whereas the majority of the mature protein is oxidized. The results indicate that in yeast, the lipo-beta-lactamase precursor is first processed (the signal peptide is removed) and then oxidized to form a disulphide bond in the mature protein. Reduced-mature lipo-beta-lactamase was found to reach the yeast periplasm and the process depends on endoplasmic reticulum (ER) entry even though the protein is not oxidized. This result is remarkable since in eukaryotes, disulphide bond formation occurs in the ER. Oxidized mature lipo-beta-lactamase can also be released from the sphaeroplast into the yeast periplasm. Mutant lipo-beta-lactamase genes in which cysteine residue 131 was changed to either tyrosine or threonine, were efficiently processed and secreted in yeast, which is consistent with the finding that reduced-mature non-mutant lipo-beta-lactamase can be secreted. We discuss the possibility that the folding mechanism of lipo-beta-lactamase in vitro may be fundamentally different from the process in the eukaryotic system of S. cerevisiae.