LncRNA U90926 is dispensable for the development of obesity-associated phenotypes in vivo.

Obesity is a global health problem characterized by excessive fat accumulation, driven by adipogenesis and lipid accumulation. Long non-coding RNAs (lncRNAs) have recently been implicated in regulating adipogenesis and adipose tissue function. Mouse lncRNA U90926 was previously identified as a repressor of in vitro adipogenesis in 3T3-L1 preadipocytes. Consequently, we hypothesized that, in vivo, U90926 may repress adipogenesis, and hence its deletion would increase weight gain and adiposity. We tested the hypothesis by applying U90926-deficient (U9-KO) mice to a high-throughput phenotyping pipeline. Compared with WT, U9-KO mice showed no major differences across a wide range of behavioral, neurological, and other physiological parameters. In mice fed a standard diet, we have found no differences in obesity-related phenotypes, including weight gain, fat mass, and plasma concentrations of glucose, insulin, triglycerides, and free fatty acids, in U9-KO mice compared to WT. U90926 deficiency lacked a major effect on white adipose tissue morphology and gene expression profile. Furthermore, in mice fed a high-fat diet, we found increased expression of U90926 in adipose tissue stromal vascular cell fraction, yet observed no effect of U90926 deficiency on weight gain, fat mass, adipogenesis marker expression, and immune cell infiltration into the adipose tissue. These data suggest that the U90926 lacks an essential role in obesity-related phenotypes and adipose tissue biology in vivo.

Long Noncoding RNA U90926 Is Induced in Activated Macrophages, Is Protective in Endotoxic Shock, and Encodes a Novel Secreted Protein.

Thousands of long noncoding RNAs are encoded in mammalian genomes, yet most remain uncharacterized. In this study, we functionally characterized a mouse long noncoding RNA named U90926. Analysis of U90926 RNA levels revealed minimal expression across multiple tissues at steady state. However, the expression of this gene was highly induced in macrophages and dendritic cells by TLR activation, in a p38 MAPK- and MyD88-dependent manner. To study the function of U90926, we generated U90926-deficient (U9-KO) mice. Surprisingly, we found minimal effects of U90926 deficiency in cultured macrophages. Given the lack of macrophage-intrinsic effect, we investigated the subcellular localization of U90926 transcript and its protein-coding potential. We found that U90926 RNA localizes to the cytosol, associates with ribosomes, and contains an open reading frame that encodes a novel glycosylated protein (termed U9-ORF), which is secreted from the cell. An in vivo model of endotoxic shock revealed that, in comparison with wild type mice, U9-KO mice exhibited increased sickness responses and mortality. Mechanistically, serum levels of IL-6 were elevated in U9-KO mice, and IL-6 neutralization improved endotoxemia outcomes in U9-KO mice. Taken together, these results suggest that U90926 expression is protective during endotoxic shock, potentially mediated by the paracrine and/or endocrine actions of the novel U9-ORF protein secreted by activated myeloid cells.

Sex differences in susceptibility to influenza A virus infection depend on host genotype.

Infection with the respiratory pathogen influenza A virus (IAV) causes significant morbidity and mortality each year. While host genotype is thought to contribute to severity of disease, naturally occurring genetic determinants remain mostly unknown. Moreover, more severe disease is seen in women compared with men, but genetic mechanisms underlying this sex difference remain obscure. Here, using IAV infection in a mouse model of naturally selected genetic diversity, namely C57BL6/J (B6) mice carrying chromosomes (Chr) derived from the wild-derived and genetically divergent PWD/PhJ (PWD) mouse strain (B6.ChrPWD consomic mice), we examined the effects of genotype and sex on severity of IAV-induced disease. Compared with B6, parental PWD mice were completely protected from IAV-induced disease, a phenotype that was fully recapitulated in the B6.Chr16PWD strain carrying the PWD-derived allele of Mx1. In contrast, several other consomic strains, including B6.Chr3PWD and B6.Chr5PWD, demonstrated greatly increased susceptibility. Notably, B6.Chr5PWD and B6.ChrX.3PWD strains, the latter carrying the distal one-third of ChrX from PWD, exhibited increased morbidity and mortality specifically in male but not female mice. Follow up analyses focused on B6 and B6.ChrX.3PWD strains demonstrated moderately elevated viral load in B6.ChrX3PWD male, but not female mice. Transcriptional profiling demonstrated genotype- and sex-specific gene expression profiles in the infected lung, with male B6.ChrX.3 mice exhibiting the most significant changes, including upregulation of a proinflammatory gene expression program associated with myeloid cells, and altered sex-biased expression of several X-linked genes that represent positional candidates, including Tlr13 and Slc25a53. Taken together, our results identify novel loci on autosomes and the X chromosome regulating IAV susceptibility and demonstrate that sex differences in IAV susceptibility are genotype-dependent, suggesting that future genetic association studies need to consider sex as a covariate.

p38 MAP Kinase Signaling in Microglia Plays a Sex-Specific Protective Role in CNS Autoimmunity and Regulates Microglial Transcriptional States.

Multiple sclerosis (MS) is an autoimmune demyelinating disease of the central nervous system, representing the leading cause of non-traumatic neurologic disease in young adults. This disease is three times more common in women, yet more severe in men, but the mechanisms underlying these sex differences remain largely unknown. MS is initiated by autoreactive T helper cells, but CNS-resident and CNS-infiltrating myeloid cells are the key proximal effector cells regulating disease pathology. We have previously shown that genetic ablation of p38α MAP kinase broadly in the myeloid lineage is protective in the autoimmune model of MS, experimental autoimmune encephalomyelitis (EAE), but only in females, and not males. To precisely define the mechanisms responsible, we used multiple genetic approaches and bone marrow chimeras to ablate p38α in microglial cells, peripheral myeloid cells, or both. Deletion of p38α in both cell types recapitulated the previous sex difference, with reduced EAE severity in females. Unexpectedly, deletion of p38α in the periphery was protective in both sexes. In contrast, deletion of p38α in microglia exacerbated EAE in males only, revealing opposing roles of p38α in microglia vs. periphery. Bulk transcriptional profiling revealed that p38α regulated the expression of distinct gene modules in male vs. female microglia. Single-cell transcriptional analysis of WT and p38α-deficient microglia isolated from the inflamed CNS revealed a diversity of complex microglial states, connected by distinct convergent transcriptional trajectories. In males, microglial p38α deficiency resulted in enhanced transition from homeostatic to disease-associated microglial states, with the downregulation of regulatory genes such as Atf3, Rgs1, Socs3, and Btg2, and increased expression of inflammatory genes such as Cd74, Trem2, and MHC class I and II genes. In females, the effect of p38α deficiency was divergent, exhibiting a unique transcriptional profile that included an upregulation of tissue protective genes, and a small subset of inflammatory genes that were also upregulated in males. Taken together, these results reveal a p38α-dependent sex-specific molecular pathway in microglia that is protective in CNS autoimmunity in males, suggesting that autoimmunity in males and females is driven by distinct cellular and molecular pathways, thus suggesting design of future sex-specific therapeutic approaches.

Genotypic distribution and prevalence of human papillomavirus infection in an apparently healthy female population in Bangladesh.

Objective: Human papillomavirus (HPV) comprises around 120 genotypically related viruses, classified into low- and high-risk HPVs, which are capable of replicating inside the keratinocytes of skin or mucous membranes. Studies suggest that infections with HPV-16 or HPV-18 have a higher rate of developing cancer. The aim of our study was to detect HPV early, and to estimate the genotype-specific prevalence of HPV in apparently healthy and asymptomatic females in Bangladesh. Method: After cervical swab specimen collection, a VIA test was performed to identify any type of abnormality in the cervix. A multiplex PCR amplification of HPV DNA, using L1 consensus primer systems, was performed with type-specific primers, followed by sequencing to detect HPV genotypes. Result: Of the 417 females, 121 were found to be HPV positive. The most prevalent high-risk HPV genotypes were found to be HPV-16 and HPV-18. Different patient demographic parameters, such as age, socioeconomic status, education, and history of first intercourse, were also studied to establish correlations with HPV infection. Conclusion: Our results might provide some insights into factors that influence the development of cervical cancer. They might also help in guiding better patient management, increased public health awareness, further testing, and the implementation of existing vaccines.