Studies involving the cloning and disruption of the gene for acyl-CoA:diacylglycerol acyltransferase (DGAT) have shown that alternative mechanisms exist for triglyceride synthesis. In this study, we cloned and characterized a second mammalian DGAT, DGAT2, which was identified by its homology to a DGAT in the fungus Mortierella rammaniana. DGAT2 is a member of a gene family that has no homology with DGAT1 and includes several mouse and human homologues that are candidates for additional DGAT genes. The expression of DGAT2 in insect cells stimulated triglyceride synthesis 6-fold in assays with cellular membranes, and DGAT2 activity was dependent on the presence of fatty acyl-CoA and diacylglycerol, indicating that this protein is a DGAT. Activity was not observed for acyl acceptors other than diacylglycerol. DGAT2 activity was inhibited by a high concentration (100 mM) of MgCl 2 in an in vitro assay, a characteristic that distinguishes DGAT2 from DGAT1. DGAT2 is expressed in many tissues with high expression levels in the liver and white adipose tissue, suggesting that it may play a significant role in mammalian triglyceride metabolism.

SLE is among the leading causes of death in young females, underscoring its impact as an important public health issue.

Background: No large population-based studies have been done on systemic lupus erythematosus (SLE) mortality trends in the United States. Objective: To identify secular trends and population characteristics associated with SLE mortality. Design: Population-based study using a national mortality database and census data. Setting: United States. Participants: All U.S. residents, 1968 through 2013. Measurements: Joinpoint trend analysis of annual age-standardized mortality rates (ASMRs) for SLE and non-SLE causes by sex, race/ethnicity, and geographic region; multiple logistic regression analysis to determine independent associations of demographic variables and period with SLE mortality. Results: There were 50 249 SLE deaths and 100 851 288 non-SLE deaths from 1968 through 2013. Over this period, the SLE ASMR decreased less than the non-SLE ASMR, with a 34.6% cumulative increase in the ratio of the former to the latter. The non-SLE ASMR decreased every year starting in 1968, whereas the SLE ASMR decreased between 1968 and 1975, increased between 1975 and 1999, and decreased thereafter. Similar patterns were seen in both sexes, among black persons, and in the South. However, statistically significant increases in the SLE ASMR did not occur among white persons over the 46-year period. Females, black persons, and residents of the South had higher SLE ASMRs and larger cumulative increases in the ratio of the SLE to the non-SLE ASMR (31.4%, 62.5%, and 58.6%, respectively) than males, other racial/ethnic groups, and residents of other regions, respectively. Multiple logistic regression showed independent associations of sex, race, and region with SLE mortality risk and revealed significant racial/ethnic differences in associations of SLE mortality with sex and region. Limitations: Underreporting of SLE on death certificates may have resulted in underestimates of SLE ASMRs. Accuracy of coding on death certificates is difficult to ascertain. Conclusion: Rates of SLE mortality have decreased since 1968 but remain high relative to non-SLE mortality, and significant sex, racial, and regional disparities persist.

Despite a marked improvement in 10-year survival for systemic lupus erythematosus (SLE) patients over the past five decades, mortality rates from SLE remain high compared to those in the general population. SLE was also among the leading causes of death in young women in the United States during 2000-2015. However, it is encouraging that SLE mortality rates and the ratios of SLE mortality rates to non-SLE mortality rates have decreased every year since the late 1990s. Despite this improvement, disparities in SLE mortality persist according to sex, race, age, and place of residence. Furthermore, demographic and geographic variables seem to modify the effect of each other in influencing SLE mortality, leading to interactions between sex/race/ethnicity-associated factors and geographic differences. In other words, individuals of the same sex/race/ethnicity had differences in SLE mortality depending on where they lived. These observations highlight SLE as an important public health issue. The recognition of SLE as a leading cause of death in the general population might spur targeted public health programs and research funding to address the high lupus mortality. Lupus (2018) 27, 1577-1581.