RNA-controlled nucleocytoplasmic shuttling of mRNA decay factors regulates mRNA synthesis and a novel mRNA decay pathway

mRNA level is controlled by factors that mediate both mRNA synthesis and decay, including the 5' to 3' exonuclease Xrn1. Here we show that nucleocytoplasmic shuttling of several yeast mRNA decay factors plays a key role in determining both mRNA synthesis and decay. Shuttling is regulated by RNAcontrolled binding of the karyopherin Kap120 to two nuclear localization sequences (NLSs) in Xrn1, location of one ofwhich is conserved fromyeast to human. The decaying RNA binds and masks NLS1, establishing a link between mRNA decay and Xrn1 shuttling. Preventing Xrn1 import, either by deleting KAP120 or mutating the two Xrn1 NLSs, compromises transcription and, unexpectedly, also cytoplasmic decay, uncovering a cytoplasmic decay pathway that initiates in the nucleus.MostmRNAs are degraded by both pathways - the ratio between them represents a full spectrum. Importantly, Xrn1 shuttling is required for proper responses to environmental changes, e.g., fluctuating temperatures, involving proper changes in mRNA abundance and in cell proliferation rate

Increased soluble CD72 in systemic lupus erythematosus is in association with disease activity and lupus nephritis

B cell receptor (BCR) -mediated signals are enhanced when CD72 expression is deficient on B cells in autoimmune diseases. The significance of soluble CD72 (sCD72) has not been elucidated. METHODS: Soluble CD72 was analyzed in the serum of 159 SLE patients, 40 rheumatoid arthritis (RA) patients, and 100 healthy individuals. Correlations between sCD72 and SLE disease activity (SLEDAI) were assessed. RESULTS: Soluble CD72 was found increased in SLE patients, when compared to both RA patients and healthy individuals (20.2 ± 1.2 ng/ml; 10.6 ± 4.6 ng/ml and 7.2 ± 3.3 ng/ml; p < 0.001). Soluble CD72 level was significantly higher in SLE patients with renal involvement than in patients without (31.8 ± 2.3 ng/ml vs 13.9 ± 0.9 ng/ml; p < 0.001) and also with the presence of auto-antibodies. CONCLUSION: Soluble CD72 is significantly increased in SLE patients mainly in those with renal involvement. Increased sCD72 may become a potential biomarker for renal involvement in SLE

Comparable long-term efficacy of Lopinavir/Ritonavir and similar drug-resistance profiles in different HIV-1 subtypes.

BACKGROUND: Analysis of potentially different impact of Lopinavir/Ritonavir (LPV/r) on non-B subtypes is confounded by dissimilarities in the conditions existing in different countries. We retrospectively compared its impact on populations infected with subtypes B and C in Israel, where patients infected with different subtypes receive the same treatment. METHODS: Clinical and demographic data were reported by physicians. Resistance was tested after treatment failure. Statistical analyses were conducted using SPSS. RESULTS: 607 LPV/r treated patients (365 male) were included. 139 had HIV subtype B, 391 C, and 77 other subtypes. At study end 429 (71%) were receiving LPV/r. No significant differences in PI treatment history and in median viral-load (VL) at treatment initiation and termination existed between subtypes. MSM discontinued LPV/r more often than others even when the virologic outcome was good (p = 0.001). VL was below detection level in 81% of patients for whom LPV/r was first PI and in 67% when it was second (P = 0.001). Median VL decrease from baseline was 1.9±0.1 logs and was not significantly associated with subtype. Median CD4 increase was: 162 and 92cells/µl, respectively, for patients receiving LPV/r as first and second PI (P = 0.001), and 175 and 98, respectively, for subtypes B and C (P<0.001). Only 52 (22%) of 237 patients genotyped while under LPV/r were fully resistant to the drug; 12(5%) were partially resistant. In48%, population sequencing did not reveal resistance to any drug notwithstanding the virologic failure. No difference was found in the rates of resistance development between B and C (p = 0.16). CONCLUSIONS: Treatment with LPV/r appeared efficient and tolerable in both subtypes, B and C, but CD4 recovery was significantly better in virologically suppressed subtype-B patients. In both subtypes, LPV/r was more beneficial when given as first PI. Mostly, reasons other than resistance development caused discontinuation of treatment