MicroRNA-146a is upregulated by and negatively regulates TLR2 signaling

TLR signaling is a crucial component of the innate immune response to infection. MicroRNAs (miRNAs) have been shown to be upregulated during TLR signaling. Specifically, microRNA-146a (miR-146a) plays a key role in endotoxin tolerance by downregulating interleukin-1 receptor-associated kinase 1 (IRAK-1). The aim of this study was to assess the role of miR-146a in the TLR2 signaling and development of bacterial lipoprotein (BLP) self-tolerance and cross-tolerance to bacteria. Expression of miR-146a increased in a dose- and time-dependent manner in BLP-stimulated human THP-1 promonocytic cells. In BLP-tolerised cells miR-146a was even further upregulated in response to BLP re-stimulation (p,0.001). Restimulation of BLP-tolerised cells with heat-killed gram-negative Salmonella typhimurium (S. typhimurium), but not grampositive Staphylococcus aureus (S. aureus), led to significant overexpression of miR-146a (p,0.05). Transfection of naive cells with a miR-146a mimic substantially suppressed TNF-a production (p,0.05). Furthermore, overexpression of miR-146a resulted in strong reduction in IRAK-1 and phosphorylated IkBa expression in naive and S. typhimurium-stimulated THP-1 cells. Collectively, miR-146a is upregulated in response to BLP and bacterial stimulation in both naive and BLP-tolerised cells. Overexpression of miR-146a induces a state analogous to tolerance in BLP-stimulated cells and therefore may represent a future target for exogenous modulation of tolerance during microbial infection and sepsi

The impact of routine open nonsuction drainage on fluid accumulation after thyroid surgery: a prospective randomised clinical trial.

Background: Thyroid drains following thyroid surgery are routinely used despite minimal supportive evidence. Our aim in this study is to determine the impact of routine open drainage of the thyroid bed postoperatively on ultrasound-determined fluid accumulation at 24 hours. Methods: We conducted a prospective randomised clinical trial on patients undergoing thyroid surgery. Patients were randomly assigned to a drain group (n = 49) or a no-drain group (n = 44) immediately prior to wound closure. Patients underwent a neck ultrasound on day 1 and day 2 postoperatively. After surgery, we evaluated visual analogue scale pain scores, postoperative analgesic requirements, self-reported scar satisfaction at 6 weeks and complications. Results: There was significantly less mean fluid accumulated in the drain group on both day 1, 16.4 versus 25.1 ml (P-value = 0.005), and day 2, 18.4 versus 25.7 ml (P-value = 0.026), following surgery. We found no significant differences between the groups with regard to length of stay, scar satisfaction, visual analogue scale pain score and analgesic requirements. There were four versus one wound infections in the drain versus no-drain groups. This finding was not statistically significant (P = 0.154). No life-threatening bleeds occurred in either group. Conclusions: Fluid accumulation after thyroid surgery was significantly lessened by drainage. However, this study did not show any clinical benefit associated with this finding in the non-emergent setting. Drains themselves showed a trend indicating that they may augment infection rates. The results of this study suggest that the frequency of acute life-threatening bleeds remains extremely low following abandoning drains. We advocate abandoning routine use of thyroid drains. Trial registration: ISRCTN94715414

Breast cancer management pathways during the COVID-19 pandemic: outcomes from the UK ‘Alert Level 4’ phase of the B-MaP-C study

Abstract: Background: The B-MaP-C study aimed to determine alterations to breast cancer (BC) management during the peak transmission period of the UK COVID-19 pandemic and the potential impact of these treatment decisions. Methods: This was a national cohort study of patients with early BC undergoing multidisciplinary team (MDT)-guided treatment recommendations during the pandemic, designated ‘standard’ or ‘COVID-altered’, in the preoperative, operative and post-operative setting. Findings: Of 3776 patients (from 64 UK units) in the study, 2246 (59%) had ‘COVID-altered’ management. ‘Bridging’ endocrine therapy was used (n = 951) where theatre capacity was reduced. There was increasing access to COVID-19 low-risk theatres during the study period (59%). In line with national guidance, immediate breast reconstruction was avoided (n = 299). Where adjuvant chemotherapy was omitted (n = 81), the median benefit was only 3% (IQR 2–9%) using ‘NHS Predict’. There was the rapid adoption of new evidence-based hypofractionated radiotherapy (n = 781, from 46 units). Only 14 patients (1%) tested positive for SARS-CoV-2 during their treatment journey. Conclusions: The majority of ‘COVID-altered’ management decisions were largely in line with pre-COVID evidence-based guidelines, implying that breast cancer survival outcomes are unlikely to be negatively impacted by the pandemic. However, in this study, the potential impact of delays to BC presentation or diagnosis remains unknown

miR-146a is involved in BLP-induced self-tolerance.

<p>(<b>A</b> and <b>B</b>) Human THP-1 cells were pre-incubated with either culture medium (naive) or 100 ng/ml BLP (BLP-tolerised) for 18 h, and further stimulated with 1,000 ng/ml BLP for 6 h (<b>A</b>) or 24 h (<b>B</b>). (<b>C</b> and <b>D</b>) THP-1 cells were transfected with 40 nM of either miR-146a mimic or miRNA negative control (<b>C</b>) and then stimulated with 1,000 ng/ml BLP for 6 h (<b>D</b>). TNF-α concentrations in the culture supernatants were assessed by ELISA and miR-146a levels in THP-1 cells were detected by real-time PCR. Data are presented as mean ± SE of three independent experiments and each experiment was conducted in triplicate. *<i>p</i><0.05, **<i>p</i><0.01 compared with naive cells or miRNA negative control-transfected cells.</p

miR-146a participates in BLP-induced cross-tolerance to gram-negative bacteria.

<p>(<b>A</b> and <b>B</b>) Human THP-1 cells were pre-incubated with either culture medium (naive) or 100 ng/ml BLP (BLP-tolerised) for 18 h, and further stimulated with 1×10⁶ CFU/ml heat-killed <i>S. typhimurium</i> (<i>S. typhi</i>) or 1×10⁷ CFU/ml heat-killed <i>S. aureus</i> for 6 h. (<b>C</b> and <b>D</b>) THP-1 cells were pre-incubated with various doses of BLP for 18 h, and further stimulated with 1×10⁶ CFU/ml <i>S. typhimurium</i> for 6 h. (<b>E</b> and <b>F</b>) THP-1 cells were transfected with 40 nM of either miR-146a mimic or miRNA negative control and then stimulated with 1×10⁶ CFU/ml <i>S. typhimurium</i> (<b>E</b>) or 1×10⁷ CFU/ml <i>S. aureus</i> (<b>F</b>) for 6 h. TNF-α concentrations in the culture supernatants were assessed by ELISA, and miR-146a levels in THP-1 cells were detected by real-time PCR and expressed as fold expression. Data are presented as mean ± SE of three independent experiments, and each experiment was conducted in triplicate. *<i>p</i><0.05, **<i>p</i><0.01 compared with naive cells or miRNA negative control-transfected cells.</p