Nuclear miRNAs: Gene Regulation Activities.

MicroRNAs (miRNAs) are small non-coding RNAs which contribute to the regulation of many physiological and pathological processes. Conventionally, miRNAs perform their activity in the cytoplasm where they regulate gene expression by interacting in a sequence-specific manner with mature messenger RNAs. Recent studies point to the presence of mature miRNAs in the nucleus. This review summarizes current findings regarding the molecular activities of nuclear miRNAs. These molecules can regulate gene expression at the transcriptional level by directly binding DNA on the promoter or the enhancer of regulated genes. miRNAs recruit different protein complexes to these regions, resulting in activation or repression of transcription, through a number of molecular mechanisms. Hematopoiesis is presented as a paradigmatic biological process whereby nuclear miRNAs possess a relevant regulatory role. Nuclear miRNAs can influence gene expression by affecting nuclear mRNA processing and by regulating pri-miRNA maturation, thus impacting the biogenesis of miRNAs themselves. Overall, nuclear miRNAs are biologically active molecules that can be critical for the fine tuning of gene expression and deserve further studies in a number of physiological and pathological conditions.

Short-term effectiveness of guselkumab in psoriatic arthritis patients and suggestive features of axial involvement: results from a real-life multicentre cohort.

OBJECTIVE: To evaluate the short-term effectiveness of guselkumab in patients with psoriatic arthritis (PsA) and suggestive features of axial involvement in a prospective "real-life" multicentre cohort. METHODS: Between June 2022 and June 2023, PsA patients with axial involvement were evaluated if treated at least for 4 months with guselkumab. The effectiveness was evaluated by BASDAI, ASDAS, DAPSA, and achievement of BASDAI ≤ 4, also exploiting predictive factors. In a group of patients, MRI findings on sacroiliac joints were assessed before and after guselkumab administration. RESULTS: Sixty-seven patients with PsA and suggestive features of axial involvement (age 53.4 ± 11.2 years, male sex 26.9%) were treated with guselkumab. After 4 months, a significant reduction of BASDAI, ASDAS, and DAPSA was observed. A ΔBASDAI of -2.11 ± 0.43 was estimated assessing the mean difference values before and after guselkumab administration and 52.2% of patients reached a BASDAI ≤ 4. In 27 patients, MRI findings on sacroiliac joints were assessed before and after guselkumab administration. A reduction of 0.80 or larger of the sacroiliac joint lesion score was observed in the majority of patients (70.3%) based on MRI improvements, paralleling with the clinical response.No life-threatening side effects were recorded; 17.9% of patients reported minor adverse events mainly injection site reactions. CONCLUSIONS: The short-term effectiveness of guselkumab in patients with PsA and suggestive features of axial involvement was shown. Although further studies are needed, our multicentre "real-life" study may suggest the clinical usability of guselkumab in this context.

The Evaluation of Effectiveness and Safety of Guselkumab in Patients with Psoriatic Arthritis in a Prospective Multicentre "Real-Life" Cohort Study.

INTRODUCTION: Guselkumab is an interleukin-23 (IL-23) inhibitor licensed for the treatment of psoriatic arthritis (PsA). This study aimed to evaluate the 6-month effectiveness of guselkumab in patients with PsA in a "real-life" multicentre patient cohort. We also estimated the drug retention rate (DRR) of gusulkumab, also assessing the impact of comorbidities and patient clinical characteristics, in a collective 18-month prospective follow-up. METHODS: Between December 2021 and September 2023, consecutive patients with PsA were evaluated if treated at least for 6 months with guselkumab in a prospective multicentre study to evaluate the effectiveness of the drug by means of disease activity index for psoriatic arthritis (DAPSA) and cumulative DRR. RESULTS: A total of 111 patients with PsA were evaluated and treated with guselkumab (age 56.8 ± 9.9, male sex 20.7%). These patients were mainly characterised by active and long-standing PsA with median disease duration of 6.0 (7.0) years (55.9% disease duration ≥ 5 years), 55.0% showed comorbidities, 78.4% of patients were previously treated with biologic disease-modifying anti-rheumatic drugs (bDMARDs), and 60.4% concomitantly with conventional synthetic DMARDs (csDMARDs). After 6 months, a significant reduction of DAPSA was observed (ß - 15.47, p = 0.001, 95% CI - 23.15 to - 9.79) with 39.6% of patients achieving a DAPSA ≤ 14. At the end of cumulative follow-up, 71.2% of patients were still treated with guselkumab whereas 24.3% discontinued the drug because of inefficacy. An 18-month DRR of guselkumab of 66.7% was estimated with a mean time of administration of 9.8 ± 4.1 months. The results of the DRR were stratified according to patient clinical characteristics. The DRR of guselkumab appeared to be not influenced by long disease duration, comorbidities, obesity, concomitant csDMARDs, and previous bDMARDs. CONCLUSION: The "real-life" 6-month effectiveness of guselkumab was shown in patients with PsA, mainly characterised by active long-standing disease, previously treated with bDMARDs, and with comorbidities. Furthermore, a good DRR of guselkumab was estimated in the cumulative 18 months of follow-up and appeared to be not influenced by long disease duration, comorbidities, obesity, and previous bDMARDs.