The Singapore National Precision Medicine Strategy.

Precision medicine promises to transform healthcare for groups and individuals through early disease detection, refining diagnoses and tailoring treatments. Analysis of large-scale genomic-phenotypic databases is a critical enabler of precision medicine. Although Asia is home to 60% of the world's population, many Asian ancestries are under-represented in existing databases, leading to missed opportunities for new discoveries, particularly for diseases most relevant for these populations. The Singapore National Precision Medicine initiative is a whole-of-government 10-year initiative aiming to generate precision medicine data of up to one million individuals, integrating genomic, lifestyle, health, social and environmental data. Beyond technologies, routine adoption of precision medicine in clinical practice requires social, ethical, legal and regulatory barriers to be addressed. Identifying driver use cases in which precision medicine results in standardized changes to clinical workflows or improvements in population health, coupled with health economic analysis to demonstrate value-based healthcare, is a vital prerequisite for responsible health system adoption.

Analysis of COVID-19 Incidence and Severity Among Adults Vaccinated With 2-Dose mRNA COVID-19 or Inactivated SARS-CoV-2 Vaccines With and Without Boosters in Singapore.

Importance: Assessing booster effectiveness of COVID-19 mRNA vaccine and inactivated SARS-CoV-2 vaccine over longer time intervals and in response to any further SARS-CoV-2 variants is crucial in determining optimal COVID-19 vaccination strategies. Objective: To determine levels of protection against severe COVID-19 and confirmed SARS-CoV-2 infection by types and combinations of vaccine boosters in Singapore during the Omicron wave. Design, Setting, and Participants: This cohort study included Singapore residents aged 30 years or more vaccinated with either at least 2 doses of mRNA COVID-19 vaccines (ie, Pfizer-BioNTech BNT162b2 or Moderna mRNA-1273) or inactivated SARS-CoV-2 vaccines (Sinovac CoronaVac or Sinopharm BBIBP-CorV) as of March 10, 2022. Individuals with a known SARS-CoV-2 infection prior to December 27, 2021, an infection on or before the date of their second vaccine dose, or with reinfection cases were excluded. Exposures: Two or 3 doses of Pfizer-BioNTech BNT162b2, Moderna mRNA-1273, Sinovac CoronaVac, or Sinopharm BBIBP-CorV. Main Outcomes and Measures: Notified infections from December 27, 2021, to March 10, 2022, adjusted for age, sex, race, housing status, and calendar days. Estimated booster effectiveness, defined as the relative incidence-rate reduction of severe disease (supplemental oxygen, intensive care, or death) or confirmed infection following 3-dose vaccination compared with 5 months after second mRNA dose, was determined using binomial regression. Results: Among 2 441 581 eligible individuals (1 279 047 [52.4%] women, 846 110 (34.7%) aged 60 years and older), there were 319 943 (13.1%) confirmed SARS-CoV-2 infections, of which 1513 (0.4%) were severe COVID-19 cases. mRNA booster effectiveness against confirmed infection 15 to 60 days after boosting was estimated to range from 31.7% to 41.3% for the 4 boosting combinations (homologous BNT162b2, homologous mRNA-1273, 2-dose BNT162b2/mRNA-1273 booster, and 2-dose mRNA-1273/BNT162b2 booster). Five months and more after boosting, estimated booster effectiveness against confirmed infection waned, ranging from -2.8% to 14.6%. Against severe COVID-19, estimated mRNA booster effectiveness was 87.4% (95% CI, 83.3%-90.5%) 15 to 60 days after boosting and 87.2% (95% CI, 84.2%-89.7%) 5 to 6 months after boosting, with no significant difference comparing vaccine combinations. Booster effectiveness against severe COVID-19 15 days to 330 days after 3-dose inactivated COVID-19 vaccination, regardless of combination, was estimated to be 69.6% (95% CI, 48.7%-81.9%). Conclusions and Relevance: Booster mRNA vaccine protection against severe COVID-19 was estimated to be durable over 6 months. Three-dose inactivated SARS-CoV-2 vaccination provided greater protection than 2-dose but weaker protection compared with 3-dose mRNA.

Distinct mechanisms involving diverse histone deacetylases repress expression of the two gonadotropin beta-subunit genes in immature gonadotropes, and their actions are overcome by gonadotropin-releasing hormone.

The gonadotropins luteinizing hormone (LH) and follicle-stimulating hormone (FSH) are produced in the embryonic pituitary in response to delivery of the hypothalamic gonadotropin releasing hormone (GnRH). GnRH has a pivotal role in reestablishing gonadotropin levels at puberty in primates, and for many species with extended reproductive cycles, these are reinitiated in response to central nervous system-induced GnRH release. Thus, a clear role is evident for GnRH in overcoming repression of these genes. Although the mechanisms through which GnRH actively stimulates LH and FSH beta-subunit (FSHbeta) gene transcription have been described in some detail, there is currently no information on how GnRH overcomes repression in order to terminate reproductively inactive stages. We show here that GnRH overcomes histone deacetylase (HDAC)-mediated repression of the gonadotropin beta-subunit genes in immature gonadotropes. The repressive factors associated with each of these genes comprise distinct sets of HDACs and corepressors which allow for differentially regulated derepression of these two genes, produced in the same cell by the same regulatory hormone. We find that GnRH activation of calcium/calmodulin-dependent protein kinase I (CaMKI) plays a crucial role in the derepression of the FSHbeta gene involving phosphorylation of several class IIa HDACs associated with both the FSHbeta and Nur77 genes, and we propose a model for the mechanisms involved. In contrast, derepression of the LH beta-subunit gene is not CaMK dependent. This demonstration of HDAC-mediated repression of these genes could explain the temporal shut-down of reproductive function at certain periods of the life cycle, which can easily be reversed by the actions of the hypothalamic regulatory hormone.

Gonadotropin-releasing hormone activation of c-jun, but not early growth response factor-1, stimulates transcription of a luteinizing hormone beta-subunit gene.

Transcription of mammalian LH beta-subunit genes (LHbeta) is regulated by GnRH through activation of early growth response factor-1 (Egr-1), which interacts synergistically with steroidogenic factor-1 (Sf-1) and pituitary homeobox-1 (Pitx1) at the promoter; Egr-1 is thought to comprise the major mediator of this effect. However, the proximal promoters of LHbeta genes in lower vertebrates lack an Egr-1 response element yet are responsive to GnRH; we demonstrate here that the promoter of the Chinook salmon LHbeta (csLHbeta) gene is also unresponsive to Egr-1. The homologous LHbeta promoters in other fish contain a conserved estrogen response element-like sequence, which we recently demonstrated is not required for estrogen receptor (ER) alpha association with the csLHbeta gene. Here we show that the estrogen response element-like element is required for the GnRH effect and for a response to c-jun overexpression. Using plasmid immunoprecipitation, we show that after GnRH exposure, c-jun associates with the intact csLHbeta gene promoter through this element. We further show that the effect of c-jun requires its DNA-binding domain and that c-jun interacts with Sf-1 and ERalpha and exerts synergistic effects on promoter activity with Sf-1, ERalpha, and Pitx1. Finally, we demonstrate the role of c-jun in mediating the GnRH effect on this gene through knockdown of c-jun expression or use of a dominant negative. We conclude that c-jun mediation of the GnRH effect on the LHbeta gene may be common in lower vertebrates and may have preceded an evolutionary divergence in the cis-regulatory elements that led to its function being replaced in mammals by Egr-1.

Cross talk in hormonally regulated gene transcription through induction of estrogen receptor ubiquitylation.

Estrogen tightly regulates the levels of circulating gonadotropins, but a direct effect of estrogen receptor alpha (ERalpha) on the mammalian LHbeta gene has remained poorly defined. We demonstrate here that ERalpha can associate with the LHbeta promoter through interactions with Sf-1 and Pitx1 without requiring an estrogen response element (ERE). We show that gonadotropin-releasing hormone (GnRH) promotes ERalpha ubiquitylation and also degradation while stimulating expression of ubc4. GnRH also increases the association and lengthens the cycling time of ERalpha on the LHbeta promoter. The ERalpha association and transactivation of the LHbeta gene, as well as ERalpha degradation, are increased following ubc4 overexpression, while the effects of GnRH are abated following ubc4 knockdown. Our results indicate that ERalpha ubiquitylation and subsequent transactivation of the LHbeta gene can be induced by increasing the levels of the E2 enzyme as a result of signaling by an extracellular hormone, thus providing a new form of cross talk in hormonally stimulated regulation of gene expression.

Multiple mechanisms for Pitx-1 transactivation of a luteinizing hormone beta subunit gene.

The pituitary homeobox factor-1 (Pitx-1) transactivates a number of pituitary-specific genes through direct interaction with other specific transcription factors. We demonstrate here that Pitx-1 plays a crucial role in the regulation of the Chinook salmon luteinizing hormone beta gene promoter through a number of novel mechanisms. On the proximal promoter its action involves a synergistic effect with steroidogenic factor-1 (SF-1) alone or in combination with the estrogen receptor; promoter activity being induced by 9- or 35-fold over controls, respectively. Further upstream, a series of four Pitx-1 response elements (located between 1366 and 1506 bp from the transcriptional start site) is also involved in regulating the promoter activity. The two distal sequences have the greatest effect on the basal activity and are also essential for the gonadotropin-releasing hormone (GnRH) response. Mammalian two-hybrid assays revealed that Pitx-1 can homodimerize. Moreover, circular permutation assays indicate that binding of Pitx-1 to more than one response element induces conformational changes of the target DNA. This constitutes an additional mechanism through which Pitx-1 can mediate transactivation of this gene, allowing the demonstrated interaction of proximal response elements and distal enhancers, thus facilitating the maximal GnRH response that was seen in the longer promoter constructs. Our research also indicates that Pitx-1 is phosphorylated on three residues when bound to the DNA.