Causes and Risk Factors for Absenteeism among Medical Staff in German Specialized Lung Clinics during the COVID Pandemic.

BACKGROUND: Staff shortages pose a major challenge to the health system. OBJECTIVES: The objective of this study was to clarify the role of different causative factors we investigated on staff absenteeism during the COVID pandemic. METHODS: The prospective multicentre cohort study assessed the private and professional impact of the pandemic on health care workers (HCWs) using a specially developed questionnaire. HCWs from 7 specialist lung clinics throughout Germany were surveyed from December 1 to December 23, 2021. The current analysis addresses pandemic-related absenteeism. RESULTS: 1,134 HCW (55% female; 18.4% male, 26.3% not willing to provide information on age or gender) participated. 72.8% had received at least one vaccination dose at the time of the survey, and 9.4% reported a COVID infection. Of those with positive tests, 98% reported home quarantine for median (IQR) 14 (12-17) days; 10.3% of those who ultimately tested negative also reported quarantine periods of 14 (7-14) days. 32.2% of vaccinated respondents reported absenteeism due to vaccine reactions of 2 (1-3) days. Overall, 37% (n = 420) of HCW reported pandemic-related absenteeism, with 3,524 total days of absenteeism, of which 2,828 were due to illness/quarantine and 696 to vaccination effects. Independent risk factors for COVID-related absenteeism ≥5 days included already having COVID, but also concern about long-term effects of COVID (OR 1,782, p = 0.014); risk factors for vaccine-related absenteeism ≥2 days included concerns of late effects of vaccination (OR 2.2, 95% CI: 1.4-3.1, p < 0.000). CONCLUSION: Staff shortages due to quarantine or infections and vaccine reactogenicity have put a strain on German respiratory specialists. The fact that staff concerns also contributed to absenteeism may be helpful in managing future pandemic events to minimize staff absenteeism.

Gender Differences in Health Care Workers' Risk-Benefit Trade-Offs for COVID-19 Vaccination.

BACKGROUND: Gender differences in vaccine acceptance among health care workers (HCWs) are well documented, but the extent to which these depend on occupational group membership is less well studied. We aimed to determine vaccine acceptance and reasons of hesitancy among HCWs of respiratory clinics in Germany with respect to gender and occupational group membership. METHODS: An online questionnaire for hospital staff of all professional groups was created to assess experiences with and attitudes towards COVID-19 and the available vaccines. Employees of five clinics were surveyed from 15 to 28 March 2021. RESULTS: 962 employees (565 [72%] female) took part in the survey. Overall vaccination acceptance was 72.8%. Nurses and physicians showed greater willingness to be vaccinated than members of other professions (72.8%, 84.5%, 65.8%, respectively; p = 0.006). In multivariate analyses, worries about COVID-19 late effects (odds ratio (OR) 2.86; p < 0.001) and affiliation with physicians (OR 2.20; p = 0.025) were independently associated with the willingness for vaccination, whereas age <35 years (OR 0.61; p = 0.022) and worries about late effects of vaccination (OR 0.13; p < 0.001) predicted vaccination hesitancy; no differences were seen with respect to gender. In separate analyses for men and women, only for men worries about COVID-19 late effects were relevant, while among women, age <35 years, worries about late effects of vaccination and worries about COVID-19 late effects played a role. CONCLUSIONS: There was no overall difference in vaccination acceptance between male and female HCWs, but there were gender-specific differences in the individual reasons on which this decision-making was based.

Transcriptional regulation of mouse mast cell protease-2 by interleukin-15.

Mast cells (MCs) play a critical role in innate and adaptive immunity through the release of cytokines, chemokines, lipid mediators, biogenic amines, and proteases. We recently showed that the activities of MC proteases are transcriptionally regulated by intracellularly retained interleukin-15 (IL-15), and we provided evidence that this cytokine acts as a specific regulator of mouse mast cell protease-2 (mMCP-2). Here, we show that in wild-type bone marrow-derived mast cells (BMMCs) IL-15 inhibits mMCP-2 transcription indirectly by inducing differential expression and mMCP-2 promoter binding of the bifunctional transcription factors C/EBPbeta and YY1. In wild-type BMMCs, C/EBPbeta expression predominates over YY1 expression, and thus C/EBPbeta preferentially binds to the mMCP-2 promoter. In IL-15-deficient BMMCs, the opposite is found: YY1 expression predominates and binds to the mMCP-2 promoter at the expense of C/EBPbeta. Hypertranscription of the mMCP-2 gene in IL-15-deficient BMMCs is associated with histone acetylation and, intriguingly, with methylation of non-CpG dinucleotides within the MCP-2 promoter. This suggests a novel model of cytokine-controlled protease transcription: non-CpG methylation maintains a chromosomal domain in an "open" configuration that is permissive for gene expression.

A hypomorphic Cbx3 allele causes prenatal growth restriction and perinatal energy homeostasis defects.

Mammals have three HP1 protein isotypes HP1 beta (CBX1), HP1 alpha (CBX3) and HP1 alpha (CBX5) that are encoded by the corresponding genes Cbx1, Cbx3 and Cbx5. Recent work has shown that reduction of CBX3 protein in homozygotes for a hypomorphic allele (Cbx3hypo) causes a severe postnatal mortality with around 99 percent of the homozygotes dying before weaning. It is not known what the causes of the postnatal mortality are. Here we show that Cbx3hypo/hypo conceptuses are significantly reduced in size and the placentas exhibit a haplo-insufficiency. Late gestation Cbx3hypo/hypo placentas have reduced mRNA transcripts for genes involved in growth regulation, amino acid and glucose transport. Blood vessels within the Cbx3hypo/hypo placental labyrinth are narrower than wild-type. Newborn Cbx3hypo/hypo pups are hypoglycemic, the livers are depleted of glycogen reserves and there is almost complete loss of stored lipid in brown adipose tissue (BAT). There is a 10-fold reduction in expression of the BAT-specific Ucp1 gene, whose product is responsible for nonshivering themogenesis. We suggest that it is the small size of the Cbx3hypo/hypo neonates, a likely consequence of placental growth and transport defects, combined with a possible inability to thermoregulate that causes the severe postnatal mortality.

Epigenotype switching at the CD14 and CD209 genes during differentiation of human monocytes to dendritic cells.

Using an in vitro model for the differentiation of human blood-derived monocytes into dendritic cells (DCs), we have undertaken an investigation of epigenetic changes that take place at CD14 and CD209 (DC-SIGN) genes that encode cell surface antigens that are crucial for the function of monocytes and DCs, respectively. Upon differentiation the cell surface expression of CD14 is lost, whilst CD209 expression is increased. These reciprocal changes are associated with the loss of epigenetic markers of "activation" at the CD14 locus, but the acquisition of the same at the CD209 locus. There is little change in "repressive" histone marks and CpG methylation at the CD14 locus. By contrast there are changes in both the "repressive" histone marks and CpG methylation at the CD209 locus. In particular, two CpG dinucleotides, designated CpG2 and CpG3, show a marked demethylation at the CD209 promoter upon differentiation. These data provide insight into the epigenetic demands that are necessary to effect the reciprocal changes in expression of the CD14 and CD209 genes upon terminal differentiation of monocytes into DCs. For repression of the active CD14 gene the loss of "activation" histone modifications is likely necessary and sufficient for silencing. By contrast the activation of the silent CD209 gene appears to require an acquisition of "active" histone modifications and concomitant loss of both "repressive" histone marks and CpG methylation.

Increased expression of beta-defensin 1 (DEFB1) in chronic obstructive pulmonary disease.

On-going airway inflammation is characteristic for the pathophysiology of chronic obstructive pulmonary disease (COPD). However, the key factors determining the decrease in lung function, an important clinical parameter of COPD, are not clear. Genome-wide linkage analyses provide evidence for significant linkage to airway obstruction susceptibility loci on chromosome 8p23, the location of the human defensin gene cluster. Moreover, a genetic variation in the defensin beta 1 (DEFB1) gene was found to be associated with COPD. Therefore, we hypothesized that DEFB1 is differently regulated and expressed in human lungs during COPD progression. Gene expression of DEFB1 was assessed in bronchial epithelium and BAL fluid cells of healthy controls and patients with COPD and using bisulfite sequencing and ChIP analysis, the epigenetic control of DEFB1 mRNA expression was investigated. We can demonstrate that DEFB1 mRNA expression was significantly increased in bronchopulmonary specimen of patients with COPD (n = 34) vs. healthy controls (n = 10) (p<0.0001). Furthermore, a significant correlation could be detected between DEFB1 and functional parameters such as FEV(1) (p = 0.0024) and the FEV(1)/VC ratio (p = 0.0005). Upregulation of DEFB1 mRNA was paralleled by changes in HDAC1-3, HDAC5 and HDAC8 mRNA expression. Whereas bisulfite sequencing revealed no differences in the methylation state of DEFB1 promoter between patients with COPD and controls, ChIP analysis showed that enhanced DEFB1 mRNA expression was associated with the establishment of an active histone code. Thus, expression of human DEFB1 is upregulated and related to the decrease in pulmonary function in patients with COPD.

H3K9me3-binding proteins are dispensable for SETDB1/H3K9me3-dependent retroviral silencing.

BACKGROUND: Endogenous retroviruses (ERVs) are parasitic sequences whose derepression is associated with cancer and genomic instability. Many ERV families are silenced in mouse embryonic stem cells (mESCs) via SETDB1-deposited trimethylated lysine 9 of histone 3 (H3K9me3), but the mechanism of H3K9me3-dependent repression remains unknown. Multiple proteins, including members of the heterochromatin protein 1 (HP1) family, bind H3K9me2/3 and are involved in transcriptional silencing in model organisms. In this work, we address the role of such H3K9me2/3 "readers" in the silencing of ERVs in mESCs. RESULTS: We demonstrate that despite the reported function of HP1 proteins in H3K9me-dependent gene repression and the critical role of H3K9me3 in transcriptional silencing of class I and class II ERVs, the depletion of HP1α, HP1ß and HP1γ, alone or in combination, is not sufficient for derepression of these elements in mESCs. While loss of HP1α or HP1ß leads to modest defects in DNA methylation of ERVs or spreading of H4K20me3 into flanking genomic sequence, respectively, neither protein affects H3K9me3 or H4K20me3 in ERV bodies. Furthermore, using novel ERV reporter constructs targeted to a specific genomic site, we demonstrate that, relative to Setdb1, knockdown of the remaining known H3K9me3 readers expressed in mESCs, including Cdyl, Cdyl2, Cbx2, Cbx7, Mpp8, Uhrf1 and Jarid1a-c, leads to only modest proviral reactivation. CONCLUSION: Taken together, these results reveal that each of the known H3K9me3-binding proteins is dispensable for SETDB1-mediated ERV silencing. We speculate that H3K9me3 might maintain ERVs in a silent state in mESCs by directly inhibiting deposition of active covalent histone marks.

HP1gamma function is required for male germ cell survival and spermatogenesis.

BACKGROUND: HP1 proteins are conserved components of eukaryotic constitutive heterochromatin. In mammals, there are three genes that encode HP1-like proteins, termed HP1alpha, HP1beta and HP1gamma, which have a high degree of homology This paper describes for the first time, to our knowledge, the physiological function of HP1gamma using a gene-targeted mouse. RESULTS: While targeting the Cbx3 gene (encoding the HP1gamma protein) with a conditional targeting vector, we generated a hypomorphic allele (Cbx3hypo), which resulted in much reduced (barely detectable) levels of HP1gamma protein. Homozygotes for the hypomorphic allele (Cbx3hypo/hypo) are rare, with only 1% of Cbx3hypo/hypo animals reaching adulthood. Adult males exhibit a severe hypogonadism that is associated with a loss of germ cells, with some seminiferous tubules retaining only the supporting Sertoli cells (Sertoli cell-only phenotype). The percentage of seminiferous tubules that are positive for L1 ORF1 protein (ORF1p) in Cbx3hypo/hypo testes is greater than that for wild-type testes, indicating that L1 retrotransposon silencing is reversed, leading to ectopic expression of ORF1p in Cbx3hypo/hypo germ cells. CONCLUSIONS: The Cbx3 gene product (the HP1gamma protein) has a non-redundant function during spermatogenesis that cannot be compensated for by the other two HP1 isotypes. The Cbx3hypo/hypo spermatogenesis defect is similar to that found in Miwi2 and Dnmt3L mutants. The Cbx3 gene-targeted mice generated in this study provide an appropriate model for the study of HP1gamma in transposon silencing and parental imprinting.

HP1-beta is required for development of the cerebral neocortex and neuromuscular junctions.

HP1 proteins are thought to be modulators of chromatin organization in all mammals, yet their exact physiological function remains unknown. In a first attempt to elucidate the function of these proteins in vivo, we disrupted the murine Cbx1 gene, which encodes the HP1-beta isotype, and show that the Cbx1(-/-) -null mutation leads to perinatal lethality. The newborn mice succumbed to acute respiratory failure, whose likely cause is the defective development of neuromuscular junctions within the endplate of the diaphragm. We also observe aberrant cerebral cortex development in Cbx1(-/-) mutant brains, which have reduced proliferation of neuronal precursors, widespread cell death, and edema. In vitro cultures of neurospheres from Cbx1(-/-) mutant brains reveal a dramatic genomic instability. Our results demonstrate that HP1 proteins are not functionally redundant and that they are likely to regulate lineage-specific changes in heterochromatin organization.

Ki-67 protein is associated with ribosomal RNA transcription in quiescent and proliferating cells.

The nuclear Ki-67 protein (pKi-67) has previously been shown to be exclusively expressed in proliferating cells. As a result, antibodies against this protein are widely used as prognostic tools in cancer diagnostics. Here we show, that despite the strong downregulation of pKi-67 expression in non-proliferating cells, the protein can nevertheless be detected at sites linked to ribosomal RNA (rRNA) synthesis. Although this finding does not argue against the use of pKi-67 as a proliferation marker, it has wide ranging implications for the elucidation of pKi-67 function. Employing the novel antibody TuBB-9, we could further demonstrate that also in proliferating cells, a fraction of pKi-67 is found at sites linked to the rRNA transcription machinery during interphase and mitosis. Moreover, chromatin immunoprecipitation (ChIP) assays provided evidence for a physical association of pKi-67 with chromatin of the promoter and transcribed region of the rRNA gene cluster. These data strongly suggest a role for pKi-67 in the early steps of rRNA synthesis.