Compound Heterozygosity for Y Box Proteins Causes Sterility Due to Loss of Translational Repression.

The Y-box proteins YBX2 and YBX3 bind RNA and DNA and are required for metazoan development and fertility. However, possible functional redundancy between YBX2 and YBX3 has prevented elucidation of their molecular function as RNA masking proteins and identification of their target RNAs. To investigate possible functional redundancy between YBX2 and YBX3, we attempted to construct Ybx2-/-;Ybx3-/- double mutants using a previously reported Ybx2-/- model and a newly generated global Ybx3-/- model. Loss of YBX3 resulted in reduced male fertility and defects in spermatid differentiation. However, homozygous double mutants could not be generated as haploinsufficiency of both Ybx2 and Ybx3 caused sterility characterized by extensive defects in spermatid differentiation. RNA sequence analysis of mRNP and polysome occupancy in single and compound Ybx2/3 heterozygotes revealed loss of translational repression almost exclusively in the compound Ybx2/3 heterozygotes. RNAseq analysis also demonstrated that Y-box protein dose-dependent loss of translational regulation was inversely correlated with the presence of a Y box recognition target sequence, suggesting that Y box proteins bind RNA hierarchically to modulate translation in a range of targets.

Alterations in urinary collagen peptides in lupus nephritis subjects correlate with renal dysfunction and renal histopathology.

BACKGROUND: The excessive accumulation of extracellular matrix (ECM) in the renal tubulointerstitium is a key component of chronic renal damage in lupus nephritis (LN) and a critical determinant of the disease progression to renal failure. Detection of fibrosis requires renal biopsy and is therefore limited by high risks associated with an invasive procedure. This study explores whether a unique LN urinary peptidome can be identified and whether LN-specific alteration reflects the underlying fibrogenic process of altered ECM turnover. METHOD: Urinary peptides were analyzed for 36 LN and 35 nonrenal systemic lupus erythematosus (SLE) subjects and 58 healthy volunteers (HVs). RESULTS: In total, 70 collagen and 230 noncollagen peptides were significantly changed between LN and nonrenal SLE and between LN and HV and defined as 'LN peptides'; 14 proteases associated with observed LN collagen peptides were identified and activities in 9 proteases were significantly different between LN and nonrenal SLE; 28 collagen peptides were correlated with at least one parameter of clinical renal dysfunction or histolopathology. CONCLUSION: Urinary peptidomic alterations likely reflect pathogenic pathways involving ECM turnover in LN kidneys and potentially could be developed as biomarkers to monitor renal disease progression.

Cre recombinase activity specific to postnatal, premeiotic male germ cells in transgenic mice.

We have generated a transgenic mouse line,Tg(Stra8-cre)1Reb (Stra8-cre), which expresses improved Cre recombinase under the control of a 1.4 Kb promoter region of the germ cell-specific stimulated by retinoic acid gene 8 (Stra8). cre is expressed only in males beginning at postnatal day (P)3 in early-stage spermatogonia and is detected through preleptotene-stage spermatocytes. To further define when cre becomes active, we crossed Stra8-cre males with Tg(ACTB-Bgeo/GFP)21Lbe (Z/EG) reporter females and compared the expression of enhanced green fluorescent protein (EGFP) with the protein encoded by the zinc finger and BTB domain containing 16 (Zbtb16) gene, PLZF-a marker for undifferentiated spermatogonia. Co-expression of EGFP is observed in the majority of PLZF+ cells. We also tested recombination efficiency by mating Stra8-cre;Z/EG males and females with wild-type mice and examining EGFP expression in the offspring. Recombination is detected in >95% of Z/EG+ pups born to Stra8-cre;Z/EG fathers but in none of the offspring born to transgenic mothers, a verification that cre is not functional in females. The postnatal, premeiotic, male germ cell-specific activity of Stra8-cre makes this mouse line a unique resource to study testicular germ cell development.

Anti-LINGO-1 has no detectable immunomodulatory effects in preclinical and phase 1 studies.

OBJECTIVE: To evaluate whether the anti-LINGO-1 antibody has immunomodulatory effects. METHODS: Human peripheral blood mononuclear cells (hPBMCs), rat splenocytes, and rat CD4+ T cells were assessed to determine whether LINGO-1 was expressed and was inducible. Anti-LINGO-1 Li81 (0.1-30 µg/mL) effect on proliferation/cytokine production was assessed in purified rat CD4+ T cells and hPBMCs stimulated with antibodies to CD3 +/- CD28. In humans, the effect of 2 opicinumab (anti-LINGO-1/BIIB033; 30, 60, and 100 mg/kg) or placebo IV administrations was evaluated in RNA from blood and CSF samples taken before and after administration in phase 1 clinical trials; paired samples were assessed for differentially expressed genes by microarray. RNA from human CSF cell pellets was analyzed by quantitative real-time PCR for changes in transcripts representative of cell types, activation markers, and soluble proteins of the adaptive/innate immune systems. ELISA quantitated the levels of CXCL13 protein in human CSF supernatants. RESULTS: LINGO-1 is not expressed in hPBMCs, rat splenocytes, or rat CD4+ T cells; LINGO-1 blockade with Li81 did not affect T-cell proliferation or cytokine production from purified rat CD4+ T cells or hPBMCs. LINGO-1 blockade with opicinumab resulted in neither significant changes in immune system gene expression in blood and CSF, nor changes in CXCL13 CSF protein levels (clinical studies). CONCLUSIONS: These data support the hypothesis that LINGO-1 blockade does not affect immune function. CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that in patients with MS, opicinumab does not have immunomodulatory effects detected by changes in immune gene transcript expression.

Longitudinal analysis of peripheral blood T cell receptor diversity in patients with systemic lupus erythematosus by next-generation sequencing.

INTRODUCTION: T cells play an important role in the pathogenesis of systemic lupus erythematosus (SLE). Clonal expansion of T cells correlating with disease activity has been observed in peripheral blood (PB) of SLE subjects. Recently, next-generation sequencing (NGS) of the T cell receptor (TCR) ß loci has emerged as a sensitive way to measure the T cell repertoire. In this study, we utilized NGS to assess whether changes in T cell repertoire diversity in PB of SLE patients correlate with or predict changes in disease activity. METHODS: Total RNA was isolated from the PB of 11 SLE patients. Each subject had three samples, collected at periods of clinical quiescence and at a flare. Twelve age-matched healthy controls (HC) were used for reference. NGS was used to profile the complementarity-determining region 3 (CDR3) of the rearranged TCR ß loci. RESULTS: Relative to the HC, SLE patients (at quiescence) demonstrated a 2.2-fold reduction in repertoire diversity in a given PB volume (P <0.0002), a more uneven distribution of the repertoire (Gini coefficient, HC vs SLE, P = 0.015), and a trend toward increased percentage of expanded clones in the repertoire (clone size >1.0%, HC vs SLE, P = 0.078). No significant correlation between the overall repertoire diversity and clinical disease activity was observed for most SLE patients with only two of eleven SLE patients showing a decreasing trend in repertoire diversity approaching the flare time point. We did not observe any overlap of CDR3 amino acid sequences or a preferential Vß or Jß gene usage among the top 100 expanded clones from all SLE patients. In both HC and SLE, the majority of the expanded clones were remarkably stable over time (HC = 5.5 ±0.5 months, SLE = 7.2 ±2.4 months). CONCLUSIONS: A significant decrease in T cell repertoire diversity was observed in PB of SLE patients compared to HC. However, in most SLE patients, repertoire diversity did not change significantly with increases in disease activity to a flare. Thus, without a priori knowledge of disease-specific clones, monitoring TCR repertoire in PB from SLE patients is not likely to be useful to predict changes in disease activity.

Intracellular invasion of Orientia tsutsugamushi activates inflammasome in asc-dependent manner.

Orientia tsutsugamushi, a causative agent of scrub typhus, is an obligate intracellular bacterium, which escapes from the endo/phagosome and replicates in the host cytoplasm. O. tsutsugamushi infection induces production of pro-inflammatory mediators including interleukin-1ß (IL-1ß), which is secreted mainly from macrophages upon cytosolic stimuli by activating cysteine protease caspase-1 within a complex called the inflammasome, and is a key player in initiating and maintaining the inflammatory response. However, the mechanism for IL-1ß maturation upon O. tsutsugamushi infection has not been identified. In this study, we show that IL-1 receptor signaling is required for efficient host protection from O. tsutsugamushi infection. Live Orientia, but not heat- or UV-inactivated Orientia, activates the inflammasome through active bacterial uptake and endo/phagosomal maturation. Furthermore, Orientia-stimulated secretion of IL-1ß and activation of caspase-1 are ASC- and caspase-1- dependent since IL-1ß production was impaired in Asc- and caspase-1-deficient macrophages but not in Nlrp3-, Nlrc4- and Aim2-deficient macrophages. Therefore, live O. tsutsugamushi triggers ASC inflammasome activation leading to IL-1ß production, which is a critical innate immune response for effective host defense.

Disruption of murine Tenr results in teratospermia and male infertility.

Gametes rely heavily on posttranscriptional control for their differentiation. Translational control, alternative splicing, and alternative processing of the 3' end of mRNAs are all common during spermatogenesis. Tenr, which encodes a highly conserved 72-kDa protein, is expressed solely in germ cells of the testis from the mid-pachytene stage until the elongating spermatid stage. TENR contains a double-stranded RNA binding domain, is localized to the nucleus, and is phylogenetically related to a family of adenosine deaminases involved in RNA editing. We show here that targeted mutation of the Tenr gene causes male sterility. Tenr mutant males have a reduced sperm count, and Tenr-/- sperm show a decrease in motility and an increase in malformed heads. Despite their sterility, some epididymal sperm from Tenr mutants have normal morphology. The ability of Tenr mutant sperm to fertilize zona pellucida-free oocytes and to bind to, but not fertilize, zona pellucida-intact oocytes suggests that the normal-appearing sperm are not able to penetrate the zona pellucida. These data suggest that TENR plays an essential function in spermatid morphogenesis.