Cause Of Birth Defects Research Articles

Development and validation of a method for the simultaneous analysis of fatty acid ethyl esters, ethyl sulfate and ethyl glucuronide in neonatal meconium: application in two cases of alcohol consumption during pregnancy

Alcohol consumption during pregnancy constitutes one of the leading preventable causes of birth defects and neurodevelopmental disorders in the exposed children. Fatty acid ethyl esters (FAEEs), ethyl glucuronide (EtG) and ethyl sulfate (EtS) have been studied as potential biomarkers of alcohol consumption. However, most analytical approaches proposed for their analysis in meconium samples consist of separated extraction procedures requiring the use of two meconium aliquots, which is costly in terms of both time and materials. Therefore, the aim of this study was to develop and validate a method for the simultaneous extraction of 9 FAEEs, EtG and EtS from one meconium aliquot. The sample was homogenized using methanol, and then FAEEs were extracted with hexane while EtG and EtS were isolated using acetonitrile. Then, extracts were applied to solid-phase extraction columns and analysed by gas chromatography mass spectrometry (FAEEs) and liquid chromatography tandem mass spectrometry (EtG and EtS). Calibration curves were linear with r values greater than 0.99. The LODs ranged from 0.8 to 7.5 ng/g for FAEEs and were 0.2 ng/g and 0.8 ng/g for EtS and EtG, respectively. LOQs ranged from 5 to 25 ng/g for FAEEs and were 1 ng/g and 2.5 ng/g for EtS and EtG, respectively. Accuracies and precisions were between 93.8 and 107% and between 3.5 and 9.7%, respectively. The recovery values ranged from 89.1 to 109%. The method proved to be sensitive, specific, simple and fast and allowed for the reduction of the amount of organic solvent used for extraction compared to other published data while higher recoveries were obtained. The method was used for analysis of meconium samples in two cases of mothers who were consuming alcohol during pregnancy.

Application of CRISPR-Cas9 gene editing for congenital heart disease.

Clustered regularly interspaced short palindromic repeats and CRISPR-associated protein 9 (CRISPR-Cas9) is an ancient prokaryotic defense system that precisely cuts foreign genomic DNA under the control of a small number of guide RNAs. The CRISPR-Cas9 system facilitates efficient double-stranded DNA cleavage that has been recently adopted for genome editing to create or correct inherited genetic mutations causing disease. Congenital heart disease (CHD) is generally caused by genetic mutations such as base substitutions, deletions, and insertions, which result in diverse developmental defects and remains a leading cause of birth defects. Pediatric CHD patients exhibit a spectrum of cardiac abnormalities such as septal defects, valvular defects, and abnormal chamber development. CHD onset occurs during the prenatal period and often results in early lethality during childhood. Because CRISPR-Cas9-based genome editing technology has gained considerable attention for its potential to prevent and treat diseases, we will review the CRISPR-Cas9 system as a genome editing tool and focus on its therapeutic application for CHD.

Congenital cytomegalovirus infections in Poland – a national hospital register-based study

Congenital cytomegalovirus (cCMV) infections are common worldwide. CCMV infected newborns are mostly asymptomatic at birth. However, cCMV remains the major infectious cause of congenital abnormalities in the developing foetus and newborns. The aim of the study was to provide recent data on cCMV in Poland. Aretrospective, population-based study was conducted using data from hospital discharge records of patients hospitalized from 2009-2018. CCMV incidence rates were estimated on the basis of data taken from a Polish hospital morbidity study, carried out by the National Institute of Public Health. The study group consisted of 1,916 hospitalized patients with the first-time diagnosis of cCMV. Among them, 52% were patients up to 30 days of age. The median age was 28 days. The average annual incidence of cCMV was 48 per 100,000 live births (95% CI 23.5-73.4). A significantly higher cCMV incidence rate was observed in patients from more urban than rural regions of Poland (55 per 100,000 vs 39 per 100,000; P<0.001). In the study period, 9 hospital deaths (0.5 % of all patients) were reported. The coexistence of nervous system diseases was observed in 26% of cases and hearing loss in 6% of cases. The significantly more cCMV cases were observed in patients from more urban than rural regions of Poland may suggest the presence of territorial factors related to the cCMV incidence in Poland. The relatively high percentage of newborns with hearing loss or neurologic diseases may require activities aimed at reducing the cCMV incidence. The epidemiological data presented may be useful for comparisons with other geographical regions.

Investigation of Some Modifiable Risk Factors That Lead to Congenital Anomalies: A Review Article

Background: Congenital anomalies are inborn errors of development. Genetic and environmental factors are known causes of congenital anomalies. Environmental factors are modifiable risk factors. This review focuses on modifiable risk factors for birth defects. There is a strong link between alcohol use and an increased risk of congenital anomalies. Marijuana can be expected to cause fetal growth restriction; smoking before conception, even with cessation in the first trimester, may also pose a risk for gastroschisis. Benzodiazepines during the first trimester were associated with Dandy–Walker malformation ,anophthalmia or microphthalmia and esophageal atresia. While oral retinoids are absolutely contraindicated, topical retinoids, should conservatively be avoided during pregnancy but if were used by accident, the existing data can reduce the anxiety of happening adverse pregnancy outcomes. Antihypertensives such as labetalol, methyldopa and extended release nifedipine are relatively safe choices. Antiemeticssuch as doxylamine-pyridoxine and metoclopramide may have potential teratogenicity in first trimester. Ondansetron use was not significantly associated with major congenital anomalies but recent meta-analysis suggested more concern. An antiepileptic such as valproate poses the highest risk among antiepileptic drugs, whereas the prevalence of congenital anomalies is the lowest with lamotrigine, levetiracetam, and oxcarbazepine. Education and counseling to women who are planning to become pregnant can reduce the risk of congenital anolamies.

Urine qRT-PCR assay as a screening tool for the detection of congenital human cytomegalovirus infection of infants

Congenital cytomegalovirus (CMV) infection is the most common infectious cause of birth defects. It may cause both, immediate and long term health problems in infants. These include variety of symptoms, such as hearing loss, microcephaly, jaundice, hepatosplenomegaly and seizures. In more severe cases CMV infection can cause the death of an unborn baby and loss of pregnancy. Despite being one of the most extensively studied vertically transmitted infections recently, the adverse effects of vertically transmitted CMV infection are still not well presented to the general public, resulting in a low awareness among potential expectant mothers in Bosnia and Herzegovina. This study aims to elucidate the sensitivity of urine samples for CMV detection in infants as well as to reflect the importance of quantitative real-time PCR (qRT-PCR) in diagnostics of CMV infection in infants. qRT-PCR was used in this study as a technique for the screening of CMV DNA in a cohort of patients based in Sarajevo Canton. These results have shown that urine samples are sufficiently sensitive for the detection of CMV DNA in infants. Furthermore, the simultaneous analysis of several patients has shown a higher number of CMV DNA copies amplified in urine compared to blood samples, derived from the same patient, thus proposing urine as a reliable sample of choice for congenital CMV diagnostics. These findings may propose a need to classify qRT-PCR CMV test among one of the recommended first-trimester pregnancy screening tests, which could help in early detection of CMV infection in Sarajevo Canton.

Human Cytomegalovirus Genomes Survive Mitosis via the IE19 Chromatin-Tethering Domain.

The genomes of DNA tumor viruses regain nuclear localization after nuclear envelope breakdown during mitosis through the action of a viral protein with a chromatin-tethering domain (CTD). Here, we report that the human cytomegalovirus (HCMV) genome is maintained during mitosis by the CTD of the viral IE19 protein. Deletion of the IE19 CTD or disruption of the IE19 splice acceptor site reduced viral genome maintenance and progeny virion formation during infection of dividing fibroblasts, both of which were rescued by IE19 ectopic expression. The discovery of a viral genome maintenance factor during productive infection provides new insight into the mode of HCMV infection implicated in birth defects, organ transplant failure, and cancer.IMPORTANCE Human cytomegalovirus (HCMV) is the leading infectious cause of birth defects, represents a serious complication for immunocompromised HIV/AIDS and organ transplant patients, and contributes to both immunosenescence and cardiovascular diseases. HCMV is also implicated in cancers such as glioblastoma multiforme (GBM) and infects ex vivo-cultured GBM tumor cells. In dividing tumor cells, the genomes of DNA tumor viruses regain nuclear localization after nuclear envelope breakdown during mitosis. This mitotic survival is mediated by a viral protein with a chromatin-tethering domain (CTD). Here, we report that the HCMV genome is maintained in dividing fibroblasts by the CTD of the viral IE19 protein. The discovery of a viral genome maintenance factor during productive infection could help explain viral genome dynamics within HCMV-positive tumors as well as during latency.

Descriptive analyse of a case control study in Portugal: identify to prevent

Abstract Background Prenatal exposure to environmental risk factors are one of the known causes of congenital anomalies (CA). In 2015, a cluster of anorectal anomalies, a rare malformation, in Setúbal district raised interest in researchers. The aim of study was to assess the impact of prenatal exposure of the mothers on the occurrence of CA in the offspring. Methods A Case-control study (1:2) was implemented between 2016-2019. Newborns with CA (cases) and newborns without CA (controls) are identified and recruited. Parents were personally interviewed by a health professional using a standardized questionnaire. A descriptive analyses was performed and cases and controls were described based on maternal residence during pregnancy. Chi-square test was used to compare cases and controls. Results 97 cases and 194 controls were identified. There was a male predominance in the case group (60 vs. 34) and no difference in gestational age between case and control groups. The mean birth weight was similar (3115g in cases vs. 3221g in controls). There was no difference related to mean mother's age nor the presence of maternal chronic disease. Smoking had more expression in the case group (21,2% vs. 16,3%). Moita (37,8%) is the municipality with higher frequency of cases. Musculoskeletal anomalies were the most frequent (35.4%), followed by genital (22.2%) and other anomalies (11%). During the study period, five cases with anorectal anomalies were reported, 4 of them born at 2016 and in 3 the mothers residence place was Moita. Conclusions In this study, the high proportion of cases from Moita suggests a possible environmental exposure to a teratogenic agent. Also smoking during pregnancy could be a high risk to anorectal anomalies, as suggested in other studies. More investment in public health measures could protect population from harmful environments. Key messages Pprenatal exposure to environemental risk factors increase the risk of congenital anomalies. Mothers residence and place of work could be a risk factor to pregnancy.

Cytomegalovirus seroprevalence, recurrence, and antibody levels: Associations with cadmium and lead exposures in the general United States population.

The ubiquitous metals cadmium and lead are immunotoxic, but little is known about their relations to cytomegalovirus (CMV), a widespread herpesvirus. Although CMV infections are mostly asymptomatic, congenital infections are a leading cause of birth defects. In otherwise healthy individuals, there is also some evidence linking subclinical reactivations to accelerated age-related declines in immune function and chronic disease. Our objective was to evaluate associations of blood cadmium and lead biomarkers with CMV infection in a representative sample of the United States population. In seropositive individuals, we also examined associations with CMV-specific immunoglobulin G (IgG) antibody levels and suspected CMV recurrences. Using cross-sectional data from the 1999-2004 National Health and Nutrition Examination Surveys, we fit multivariable survey-weighted regression models accounting for potential confounding by sociodemographic and lifestyle factors and stratifying by age group to allow for heterogeneity. CMV recurrences were defined according to (1) the presence of either CMV-specific immunoglobulin M in sera or CMV viral DNA in urine, and (2) high CMV-specific IgG avidity. We observed null associations for blood cadmium. Increasing blood lead quartiles were related to CMV seropositivity and higher CMV IgG levels (both P trend < 0.01), but not CMV recurrence, only among individuals who were 20-29 years of age. Blood cadmium levels do not appear to be related to immunological markers of CMV infections. The possibility that lead exposures increase the risk of CMV infection and impair immune control of the virus in young adults was suggested. Prospective studies are needed to confirm.

Genotype and Phenotype Analyses in Pediatric Patients with HNF1B Mutations.

HNF1B mutations, one of the most common causes of congenital anomalies of the kidney and urinary tract, manifest as various renal and extrarenal phenotypes. We analyzed the genotype-phenotype correlations in 14 pediatric patients with HNF1B mutations. Genetic studies revealed total gene deletion in six patients (43%). All patients had bilateral renal abnormalities, primarily multiple renal cysts. Twelve patients exhibited progressive renal functional deterioration, and six of them progressed to kidney failure. The annual reduction in estimated glomerular filtration rate was−2.1 mL/min/1.73 m2. Diabetes developed in five patients (36%), including one patient with new-onset diabetes after transplantation. Neurological deficits were noted in three patients (21%), one with total gene deletion and two with missense mutations. Pancreatic abnormalities were more frequent in patients with missense mutations than in patients with other types of mutations. Genotype showed no significant correlation with renal outcomes or other extrarenal manifestations. The HNF1B scores at the times of onset and genetic diagnosis were <8 in two patients and one patient, respectively. Diagnosis of HNF1B mutations is clinically difficult because of extreme phenotypic variability and incomplete penetrance. Furthermore, some phenotypes develop with age. Therefore, patient age should be taken into consideration to increase the diagnostic rate, because some phenotypes develop with age.

Progress Toward Rubella Elimination - Western Pacific Region, 2000-2019.

Rubella is the leading vaccine-preventable cause of birth defects. Rubella typically manifests as a mild febrile rash illness; however, infection during pregnancy, particularly during the first trimester, can result in miscarriage, fetal death, or a constellation of malformations known as congenital rubella syndrome (CRS), commonly including one or more visual, auditory, or cardiac defects (1). In 2012, the Regional Committee of the World Health Organization (WHO) Western Pacific Region (WPR)* committed to accelerate rubella control, and in 2017, resolved that all countries or areas (countries) in WPR should aim for rubella elimination† as soon as possible (2,3). WPR countries are capitalizing on measles elimination activities, using a combined measles and rubella vaccine, case-based surveillance for febrile rash illness, and integrated diagnostic testing for measles and rubella. This report summarizes progress toward rubella elimination and CRS prevention in WPR during 2000-2019. Coverage with a first dose of rubella-containing vaccine (RCV1) increased from 11% in 2000 to 96% in 2019. During 1970-2019, approximately 84 million persons were vaccinated through 62 supplementary immunization activities (SIAs) conducted in 27 countries. Reported rubella incidence increased from 35.5 to 71.3 cases per million population among reporting countries during 2000-2008, decreased to 2.1 in 2017, and then increased to 18.4 in 2019 as a result of outbreaks in China and Japan. Strong sustainable immunization programs, closing of existing immunity gaps, and maintenance of high-quality surveillance to respond rapidly to and contain outbreaks are needed in every WPR country to achieve rubella elimination in the region.

The Value of a Nulliparous Uterus.

The Value of a Nulliparous Uterus.

Evolution and Genetic Diversity of Primate Cytomegaloviruses.

Cytomegaloviruses (CMVs) infect many mammals, including humans and non–human primates (NHPs). Human cytomegalovirus (HCMV) is an important opportunistic pathogen among immunocompromised patients and represents the most common infectious cause of birth defects. HCMV possesses a large genome and very high genetic diversity. NHP–infecting CMVs share with HCMV a similar genomic organization and coding content, as well as the course of viral infection. Recent technological advances have allowed the sequencing of several HCMV strains from clinical samples and provided insight into the diversity of NHP–infecting CMVs. The emerging picture indicates that, with the exclusion of core genes (genes that have orthologs in all herpesviruses), CMV genomes are relatively plastic and diverse in terms of gene content, both at the inter– and at the intra–species level. Such variability most likely underlies the strict species–specificity of these viruses, as well as their ability to persist lifelong and with relatively little damage to their hosts. However, core genes, despite their strong conservation, also represented a target of adaptive evolution and subtle changes in their coding sequence contributed to CMV adaptation to different hosts. Indubitably, important knowledge gaps remain, the most relevant of which concerns the role of viral genetics in HCMV–associated human disease.

Killer cell proteases can target viral immediate-early proteins to control human cytomegalovirus infection in a noncytotoxic manner

Human cytomegalovirus (HCMV) is the most frequent viral cause of congenital defects and can trigger devastating disease in immune-suppressed patients. Cytotoxic lymphocytes (CD8+ T cells and NK cells) control HCMV infection by releasing interferon-γ and five granzymes (GrA, GrB, GrH, GrK, GrM), which are believed to kill infected host cells through cleavage of intracellular death substrates. However, it has recently been demonstrated that the in vivo killing capacity of cytotoxic T cells is limited and multiple T cell hits are required to kill a single virus-infected cell. This raises the question whether cytotoxic lymphocytes can use granzymes to control HCMV infection in a noncytotoxic manner. Here, we demonstrate that (primary) cytotoxic lymphocytes can block HCMV dissemination independent of host cell death, and interferon-α/β/γ. Prior to killing, cytotoxic lymphocytes induce the degradation of viral immediate-early (IE) proteins IE1 and IE2 in HCMV-infected cells. Intriguingly, both IE1 and/or IE2 are directly proteolyzed by all human granzymes, with GrB and GrM being most efficient. GrB and GrM cleave IE1 after Asp398 and Leu414, respectively, likely resulting in IE1 aberrant cellular localization, IE1 instability, and functional impairment of IE1 to interfere with the JAK-STAT signaling pathway. Furthermore, GrB and GrM cleave IE2 after Asp184 and Leu173, respectively, resulting in IE2 aberrant cellular localization and functional abolishment of IE2 to transactivate the HCMV UL112 early promoter. Taken together, our data indicate that cytotoxic lymphocytes can also employ noncytotoxic ways to control HCMV infection, which may be explained by granzyme-mediated targeting of indispensable viral proteins during lytic infection.

Rubella in Pregnancy

AbstractRubella, commonly known as ‘German Measles’ is a common childhood viral disease that may affect adults as well. More than half of the infections are either asymptomatic or present with mild flu like illness with a typical maculopapular rash. In contrast, primary rubella infection in pregnancy, especially in the first trimester, can have serious consequences, namely miscarriage, intrauterine fetal demise or congenital rubella syndrome (CRS). WHO recognizes CRS as the ‘leading vaccine preventable cause of birth defects’. Antenatal management primarily is based on testing for immunity in the first trimester and recognizing acute maternal infection. A correct interpretation of maternal serology using IgG avidity along with IgM and IgG is imperative to avoid false positive diagnoses. Diagnosis of fetal infection is by detection of Rubella virus specific RTPCR in amniotic fluid and is indicated if maternal seroconversion is seen in the periconceptional period and/or the first trimester or if there are ultrasound features suggestive of fetal infection. Since there is no treatment available to either prevent mother to child transmission or to treat fetal infection, the mainstay is prevention. India is amongst the 11 countries of WHO South East Asia Region who are committed to control of Rubella and CRS by 2020.

Murine Cytomegalovirus Protein pM49 Interacts with pM95 and Is Critical for Viral Late Gene Expression.

Late gene expression of betaherpesviruses and gammaherpesviruses is tightly controlled by virus-encoded transactivation factors (vTFs). We recently proved that the 6 vTFs of murine cytomegalovirus (MCMV) form a complex to regulate late gene transcription. pM49, one of the vTFs that has not been studied before, was identified to be a component of the complex that interacts with pM95. In this study, we began to investigate the potential role of pM49 in viral late gene expression. A recombinant MCMV expressing C-terminal FLAG-tagged pM49 was constructed to study the expression kinetics and localization of pM49. pM49 was expressed at the late time of virus infection. Inhibition of viral DNA synthesis by phosphonate sodium phosphonic acid (PAA) abolished pM49 expression, indicating that it is a late protein. pM49 colocalized with pM44 at the viral replication compartment, similarly to other viral vTFs that have been reported. Mutant virus lacking full-length pM49 expression failed to express viral late genes, leading to nonproductive infection. The expression of immediate early and early genes was not affected, and viral DNA synthesis was only minimally affected during pM49-deficient virus infection. All of these data support the role of pM49 in viral late gene expression. After a series of mutagenesis analyses, two key residues, K325 and C326, were identified as required for pM49-pM95 interaction. Cells expressing pM49 with either single mutation of these two residues failed to rescue the late gene expression and support the replication of pM49-deficient virus. Our results indicated that pM49-pM95 interaction is essential for viral late gene expression.IMPORTANCE Cytomegalovirus (CMV) infections result in morbidity and mortality in immunocompromised individuals, and the virus is also a major cause of birth defects in newborns. Currently, because of the unavailability of vaccines against this virus and restricted antiviral therapies with low toxicity, as well as the emergency of resistant strain of this virus, the understanding of viral late gene regulation may provide clues to study new antiviral drugs or vaccines. In this study, we report that MCMV protein pM49 is critical for viral late gene transcription, based on its interaction with pM95. This finding reveals the important role of pM49-pM95 interaction in the regulation of viral late gene expression and that it could be a future potential target for therapeutic intervention in CMV diseases.

Requirements for guinea pig cytomegalovirus tropism and antibody neutralization on placental amniotic sac cells

Congenital cytomegalovirus (cCMV) is a leading cause of birth defects. The guinea pig is the only small cCMV animal model. Guinea pig cytomegalovirus (GPCMV) encodes similar glycoprotein complexes to human CMV (HCMV) including gB and the gH-based pentamer complex (PC). In HCMV, both gB and PC are neutralizing antibody antigens. The relevance of GPCMV PC for virus tropism and vaccine target remains controversial. A novel guinea pig placental amniotic sac epithelial (GPASE) cell-line did not express viral cell receptor platelet derived growth factor receptor alpha (PDGFRA) and resulted in requirement for the PC for GPCMV infection unless PDGFRA was ectopically expressed. High titer anti-gB sera from a GPCMV gB vaccine study was evaluated for GPCMV neutralizing capability on GPASE cells in comparison to convalescent sera from GPCMV(PC+) or GPCMV(PC-) infected animals. Anti-gB sera neutralized fibroblast infection but was less effective compared to anti-GPCMV(PC-), which had antibodies to gH/gL. However, both anti-GPCMV(PC-) and anti-gB sera similarly had reduced neutralizing capability on GPASE and renal epithelial cells in comparison to anti-GPCMV(PC+) sera, which had additional antibodies to PC. Overall, results demonstrate the importance of the PC for GPCMV tropism to various cell types that lack PDGFRA expression and the limited ability of anti-gB sera to neutralize GPCMV on non-fibroblast cells despite the essential nature of gB glycoprotein.

Animal models of gene-alcohol interactions.

Most birth defects arise from complex interactions between multiple genetic and environmental factors. However, our current understanding of how these interactions and their contributions affect birth defects remains incomplete. Human studies are limited in their ability to identify the fundamental causes of birth defects due to ethical and practical limitations. Animal models provide a great number of resources not available to human studies and they have been critical in advancing our understanding of birth defects and the complex interactions that underlie them. In this review, we discuss the use of animal models in the context of gene-environment interactions that underlie birth defects. We focus on alcohol which is the most common environmental factor associated with birth defects. Prenatal alcohol exposure leads to a wide range of cognitive impairments and structural deficits broadly termed fetal alcohol spectrum disorders (FASD). We discuss the broad impact of prenatal alcohol exposure on the developing embryo and elaborate on the current state of gene-alcohol interactions. Additionally, we discuss how animal models have informed our understanding of the genetics of FASD. Ultimately, these topics will provide insight into the use of animal models in understanding gene-environment interactions and their subsequent impact on birth defects.

2331. Seroprevalence of Cytomegalovirus in Pregnant Women and Birth Prevalence of Congenital Cytomegalovirus Infection in Henan Province, China

BackgroundCongenital cytomegalovirus infection (cCMVi) is the leading viral cause of birth defects and developmental disabilities in newborns. The epidemiology of cCMVi in settings with high cytomegalovirus (CMV) seroprevalence, such as China, is not well studied. This study sought to describe maternal CMV seroprevalence and cCMVi prevalence at birth in Henan Province, China.MethodsA multicenter prospective cohort study was conducted in three counties of Henan Province in China from June 2015 through May 2018. Pregnant women were enrolled early in pregnancy and followed up through delivery. Serum specimens were collected at enrollment for CMV immunoglobulin G serological testing. Saliva and urine specimens were collected in newborns within 72 hours after birth and tested with real-time polymerase chain reaction for CMV DNA. cCMVi was defined as CMV DNA positive in the infants’ urine or saliva specimens.ResultsA total of 6327 pregnant women underwent CMV serological testing and 6062 were CMV seropositive (95.8%). The maternal age was 26.8 ± 4.3 (mean ± SD) years. There were 49 (0.7%) newborns identified with cCMVi among 6705 newborns screened. Lower maternal education level (middle school or lower), younger maternal age (<25 years) and twin-pregnancy were associated with higher cCMVi prevalence (P = 0.04, 0.016, and 0.001, respectively).ConclusionDespite a high maternal CMV seroprevalence in this large cohort study from China, the birth prevalence of cCMVi is similar to other studies in settings of high and medium CMV seroprevalence. In settings of high maternal CMV seroprevalence, additional research is needed to ascertain the relative contribution of non-primary CMV infections during pregnancy to congenital transmission.Disclosures All authors: No reported disclosures.

Human Cytomegalovirus pUL37x1 Is Important for Remodeling of Host Lipid Metabolism.

Human cytomegalovirus (HCMV) replication requires host metabolism. Infection alters the activity in multiple metabolic pathways, including increasing fatty acid elongation and lipid synthesis. The virus-host interactions regulating the metabolic changes associated with replication are essential for infection. While multiple host factors, including kinases and transcription factors, important for metabolic changes that occur following HCMV infection have been identified, little is known about the viral factors required to alter metabolism. In this study, we tested the hypothesis that pUL37x1 is important for the metabolic remodeling that is necessary for HCMV replication using a combination of metabolomics, lipidomics, and metabolic tracers to measure fatty acid elongation. We observed that fibroblast cells infected with wild-type (WT) HCMV had levels of metabolites similar to those in cells infected with a mutant virus lacking the UL37x1 gene, subUL37x1. However, we found that relative to WT-infected cells, subUL37x1-infected cells had reduced levels of two host proteins that were previously demonstrated to be important for lipid metabolism during HCMV infection: fatty acid elongase 7 (ELOVL7) and the endoplasmic reticulum (ER) stress-related kinase PERK. Moreover, we observed that HCMV infection results in an increase in phospholipids with very-long-chain fatty acid tails (PL-VLCFAs) that contain 26 or more carbons in one of their two tails. The levels of many PL-VLCFAs were lower in subUL37x1-infected cells than in WT-infected cells. Overall, we conclude that although pUL37x1 is not necessary for network-wide metabolic changes associated with HCMV infection, it is important for the remodeling of a subset of metabolic changes that occur during infection.IMPORTANCE Human cytomegalovirus (HCMV) is a common pathogen that asymptomatically infects most people and establishes a lifelong infection. However, HCMV can cause end-organ disease that results in death in the immunosuppressed and is a leading cause of birth defects. HCMV infection depends on host metabolism, including lipid metabolism. However, the viral mechanisms for remodeling of metabolism are poorly understood. In this study, we demonstrate that the viral UL37x1 protein (pUL37x1) is important for infection-associated increases in lipid metabolism, including fatty acid elongation to produce very-long-chain fatty acids (VLCFAs). Furthermore, we found that HCMV infection results in a significant increase in phospholipids, particularly those with VLCFA tails (PL-VLCFAs). We found that pUL37x1 was important for the high levels of fatty acid elongation and PL-VLCFA accumulation that occur in HCMV-infected cells. Our findings identify a viral protein that is important for changes in lipid metabolism that occur following HCMV infection.

Congenital anomalies from a physics perspective. The key role of “manufacturing” volatility

Genetic and environmental factors are traditionally seen as the sole causes of congenital anomalies. In this paper we introduce a third possible cause, namely random “manufacturing” discrepancies with respect to “design” values. A clear way to demonstrate the existence of this component is to “turn off” the two others and to see whether or not there is still remaining variability. Perfect clones raised under well controlled laboratory conditions fulfill the conditions for such a test. Carried out for four different species, the test reveals a variability remainder of the order of 15% in terms of coefficient of variation (i.e. ratio of standard deviation to average, subsequently denoted by CV). As an example, the CV of the volume of E. coli (Escherichia Coli) bacteria immediately after binary fission is of that order.In short, “manufacturing” discrepancies occur randomly, even when no harmful mutation or environmental factors are involved. If the pathway is particularly long or requires exceptional accuracy, output dispersion will be high and may lead to malformations. This effect will be referred to as the random dispersion effect. We conjecture that it will be particularly significant when major changes occur; this includes the early phase of embryogenesis or the first steps leading from stem cells to differentiated (organ-specific) cells.The dispersion effect not only causes malformations but also innocuous variability. For instance monozygotic (MZ) twins resemble each other but are not strictly identical. It is not uncommon to see only one of the twins of a MZ pair showing a congenital defect (see Appendix A).Not surprisingly, there is a strong connection between congenital defects and infant mortality. In the wake of birth there is a gradual elimination of defective units and this screening accounts for the decline of postnatal infant mortality. In humans, for reasons which are not yet understood, this decline continues until the age of about 10 years. Neither do we understand why, as a function of age, the downward trend of human infant mortality follows a power law with an exponent around 1 (whereas for fish it is about 3, see Bois et al. 2019a). Apart from this trend, post-natal death rates also have humps and peaks associated with various inabilities and defects.In short, infant mortality rates convert the case-by-case and mostly qualitative problem of congenital malformations into a global quantitative effect which, so to say, summarizes what goes wrong in the embryonic phase.Based on the natural assumption that for simple organisms (e.g. rotifers) the manufacturing processes are shorter than for more complex organisms (e.g. mammals), fewer congenital anomalies are expected and therefore also lower infant mortality. How this conjecture can be tested is outlined in our conclusion.