The RIG-I-like receptor LGP2 inhibits Dicer-dependent processing of long double-stranded RNA and blocks RNA interference in mammalian cells
In vertebrates, the presence of viral RNA in the cytosol is sensed by members of the RIG-I-like receptor (RLR) family, which signal to induce production of type I interferons (IFN). These key antiviral cytokines act in a paracrine and autocrine manner to induce hundreds of interferon-stimulated genes (ISGs), whose protein products restrict viral entry, replication and budding. ISGs include the RLRs themselves: RIG-I, MDA5 and, the least-studied family member, LGP2. In contrast, the IFN system is absent in plants and invertebrates, which defend themselves from viral intruders using RNA interference (RNAi). In RNAi, the endoribonuclease Dicer cleaves virus-derived double-stranded RNA (dsRNA) into small interfering RNAs (siRNAs) that target complementary viral RNA for cleavage. Interestingly, the RNAi machinery is conserved in mammals, and we have recently demonstrated that it is able to participate in mammalian antiviral defence in conditions in which the IFN system is suppressed. In contrast, when the IFN system is active, one or more ISGs act to mask or suppress antiviral RNAi. Here, we demonstrate that LGP2 constitutes one of the ISGs that can inhibit antiviral RNAi in mammals. We show that LGP2 associates with Dicer and inhibits cleavage of dsRNA into siRNAs both in vitro and in cells. Further, we show that in differentiated cells lacking components of the IFN response, ectopic expression of LGP2 interferes with RNAi-dependent suppression of gene expression. Conversely...
Esene et al,1 in their brilliantly conceived and presented manuscript, “Misclassification of Case Control Studies in Neurosurgery and Proposed Solutions,” raise very good and valid points about the misclassification of published research manuscripts and potential harm done by the mislabeling or misrepr esentation of manuscript content. They eloquently demonstrate that, although many studies have been published with the inclusion of “case control study” in the title or methodology to describe the study design, often such studies are not “case control studies” but rather “cohor...
Controversy exists regarding which treatment option (full endoscopic vascular decompression or endoscopic-assisted vascular decompression) is better in the treatment of trigeminal neuralgia (TN). One group suggests that the most of the procedure should be done under a microscope and that endoscopic assistance should be undertaken to detect vessels placed anterior to the nerve and to confirm that the decompression has been performed properly. Other group believes that the whole procedure can be done safely with the use of a full endoscopic technique.
Evaluating alternatives to the invasive pterional craniotomy is critical, as it will help practitioners make safe and effective clinical decisions. We read the review1 published in a recent issue of WORLD NEUROSURGERY. However, Rychen et al's results are questionable due to several methodological issues listed as follows.
We studied with keen interest the article by Wang et al1 regarding clinical behavior and prognosis of gliomas in human immunodeficiency virus (HIV) patients.
We would like to thank Dr. Yang and his or her colleagues for their excellent and deep review of our article. In their letter to the editor,1 they made several recommendations for our article.
I read with great interest the article by Dubey et al.1 They reported a successful result of a large number of patients with trigeminal neuralgia and technical tips. I myself use endoscope for assistance to observe the dead corner behind the suprameatal tubercle and near the Meckel cave, and the panoramic view that the endoscope provides is useful for thorough observation of the cisternal portion of the trigeminal nerve. However, I am doubtful about the usefulness of totally endoscopic microvascular decompression (MVD) for several reasons.
In the recently published article by Loewenstern et al,1 the authors attempted to determine the utility of optical coherence tomography (OCT) in the diagnosis and management of compressive optic neuropathy secondary to fibrous dysplasia (FD). OCT is a relatively new imaging modality, which uses high-resolution cross-sections of the retina to determ ine the retinal nerve fiber layer (RNFL) thickness. The study evaluated 6 patients with cranial base FD for optic nerve compression and RNFL thinning, using computed tomography (CT) and OCT, respectively.
We read with great interest the recent study by Zhu et al1 entitled “Rupture Risk of Cerebral Arteriovenous Malformations During Pregnancy and Puerperium: A Single-Center Experience and Pooled Data Analysis.” The authors performed a retrospective study to compare risk of rupture in pregnant and nonpregnant female patients with arteriovenous malfor mation (AVM) and assess current evidence regarding rupture risk of AVM during pregnancy and puerperium by pooled data analysis. They concluded that an increase in annual rate of cerebral AVM hemorrhage during pregnancy and puerperium was found.