naRNA-LL37 composite DAMPs define sterile NETs as self-propagating drivers of inflammation.

Neutrophil extracellular traps (NETs) are a key antimicrobial feature of cellular innate immunity mediated by polymorphonuclear neutrophils (PMNs). NETs counteract microbes but are also linked to inflammation in atherosclerosis, arthritis, or psoriasis by unknown mechanisms. Here, we report that NET-associated RNA (naRNA) stimulates further NET formation in naive PMNs via a unique TLR8-NLRP3 inflammasome-dependent pathway. Keratinocytes respond to naRNA with expression of psoriasis-related genes (e.g., IL17, IL36) via atypical NOD2-RIPK signaling. In vivo, naRNA drives temporary skin inflammation, which is drastically ameliorated by genetic ablation of RNA sensing. Unexpectedly, the naRNA-LL37 'composite damage-associated molecular pattern (DAMP)' is pre-stored in resting neutrophil granules, defining sterile NETs as inflammatory webs that amplify neutrophil activation. However, the activity of the naRNA-LL37 DAMP is transient and hence supposedly self-limiting under physiological conditions. Collectively, upon dysregulated NET release like in psoriasis, naRNA sensing may represent both a potential cause of disease and a new intervention target.

Differential survival of Staphylococcal species in macrophages.

Staphylococcus aureus is considered an extracellular pathogen, yet the bacterium is able to survive within and escape from host cells. An agr/sae mutant of strain USA300 is unable to escape from macrophages but can replicate and survive within. We questioned whether such "non-toxic" S. aureus resembles the less pathogenic coagulase-negative Staphylococcal (CoNS) species like S. epidermidis, S. carnosus, S. lugdunensis, S. capitis, S. warneri, or S. pettenkoferi. We show that the CoNS are more efficiently killed in macrophage-like THP-1 cells or in human primary macrophages. Mutations in katA, copL, the regulatory system graRS, or sigB did not impact bacterial survival in THP-1 cells. Deletion of the superoxide dismutases impaired S. aureus survival in primary macrophages but not in THP-1 cells. However, expression of the S. aureus-specific sodM in S. epidermidis was not sufficient to protect this species from being killed. Thus, at least in those cells, better bacterial survival of S. aureus could not be linked to higher protection from ROS. However, "non-toxic" S. aureus was found to be insensitive to pH, whereas most CoNS were protected when phagosomal acidification was inhibited. Thus, species differences are at least partially linked to differences in sensitivity to acidification.

Fish TLR5 develops a taste for viral RNA.

These days not only humans but also freshwater fish battle with infections by RNA viruses (Zou & Nie, 2017). This observation prompted Liao et al to turn their attention to viral recognition in Grass carp (Ctenopharyngodon idella), the most important cultivated freshwater fish with 5.7 million tons and 13 billion USD in fishery exports per year (FAO, 2021). Grass carp and other freshwater fish, such as the model organism Danio rerio (zebrafish), have a sophisticated innate immune system that helps them to detect microbial and viral pathogens by employing a variety of pattern recognition receptors (PRRs; Zou & Nie, 2017). Toll-like receptors (TLRs) are one class of PRRs that detect microbe-associated molecular patterns (MAMPs), such as flagellin or viral double-stranded (ds)RNA. In mammals, TLR3 is specialized in sensing viral dsRNA (Liu et al, 2008), while TLR5 recognizes the MAMP flagellin (Yoon et al, 2012; Fig 1). The well-established notion of TLR5 as a purely "bacterial" flagellin TLR has now been challenged by Liao et al in this issue of EMBO Reports (Liao et al, 2022). The authors' intriguing and unexpected results indicate that fish TLR5 is involved in viral recognition, a function lost in mammals, and shed light on hitherto inexplicable links of mammalian TLR5 to antiviral immune signaling.

A Baseline Cellular Antiviral State Is Maintained by cGAS and Its Most Frequent Naturally Occurring Variant rs610913.

Upon recognition of aberrantly located DNA, the innate immune sensor cyclic GMP-AMP synthase (cGAS) activates stimulator of IFN genes (STING)/IFN regulatory factor (IRF)3-driven antiviral responses. In this study, we characterized the ability of a specific variant of the human cGAS-encoding gene MB21D1, rs610913, to alter cGAS-mediated DNA sensing and viral infection. rs610913 is a frequent G>T polymorphism resulting in a P261H exchange in the cGAS protein. Data from the International Collaboration for the Genomics of HIV suggested that rs610913 nominally associates with HIV-1 acquisition in vivo. Molecular modeling of cGAS(P261H) hinted toward the possibility for an additional binding site for a potential cellular cofactor in cGAS dimers. However, cGAS(wild-type [WT]) or cGAS(P261H)-reconstituted THP-1 cGAS knockout cells shared steady-state expression of IFN-stimulated genes, as opposed to cells expressing the enzymatically inactive cGAS(G212A/S213A). Accordingly, cGAS(WT) and cGAS(P261H) cells were less susceptible to lentiviral transduction and infection with HIV-1, HSV-1, and Chikungunya virus as compared with cGAS knockout or cGAS(G212A/S213A) cells. Upon DNA challenge, innate immune activation appeared to be mildly reduced upon expression of cGAS(P261H) compared with cGAS(WT). Finally, DNA challenge of PBMCs from donors homozygously expressing rs610913 provoked a trend toward a slightly reduced type I IFN response as compared with PBMCs from GG donors. Taken together, the steady-state activity of cGAS maintains a baseline antiviral state rendering cells more refractory to IFN-stimulated gene-sensitive viral infections. rs610913 failed to grossly differ phenotypically from the WT gene, suggesting that cGAS(P261H) and WT cGAS share a similar ability to sense viral infections in vivo.

Shoulder arthroplasty for inflammatory arthritis is associated with higher rates of medical and surgical complications: a nationwide matched cohort analysis from 2016-2020.

BACKGROUND: Inflammatory arthritis (IA) represents a less common indication for anatomic and reverse total shoulder arthroplasty (TSA) than osteoarthritis (OA). The safety and efficacy of anatomic and reverse TSA in this population has not been as well studied compared to OA. We analyzed the differences in outcomes between IA and OA patients undergoing TSA. METHODS: Patients who underwent primary anatomic total shoulder arthroplasty (aTSA) and reverse total shoulder arthroplasty (rTSA) from 2016-2020 were identified in the Premier Healthcare Database. Inflammatory arthritis (IA) patients were identified using International Classification of Diseases, Tenth Revision, diagnosis codes and compared to osteoarthritis controls. Patients were matched in a 1:8 fashion by age (±3 years), sex, race, and presence of pertinent comorbidities. Patient demographics, hospital factors, and patient comorbidities were compared. Multivariate regression was performed following matching to account for any residual confounding and 90-day complications were compared between the 2 cohorts. Descriptive statistics and regression analysis were employed with significance set at P < .05. RESULTS: Prior to matching, 5685 IA cases and 93,539 OA controls were identified. Patients with IA were more likely to be female, have prolonged length of stay and increased total costs (P < .0001). After matching and multivariate analysis, 4082 IA cases and 32,656 controls remained. IA patients were at increased risk of deep wound infection (OR 3.14, 95% CI 1.38-7.16, P = .006), implant loosening (OR 4.11, 95% CI 1.17-14.40, P = .027), and mechanical complications (OR 6.34, 95% CI 1.05-38.20, P = .044), as well as a decreased risk of postoperative stiffness (OR 0.36, 95% CI 0.16-0.83, P = .002). Medically, IA patients were at increased risk of PE (OR 2.97, 95% CI 1.52-5.77, P = .001) and acute blood loss anemia (OR 1.27, 95% CI 1.12-1.44, P < .0001). DISCUSSION AND CONCLUSION: Inflammatory arthritis represents a distinctly morbid risk profile compared to osteoarthritis patients with multiple increased surgical and postoperative medical complications in patients undergoing aTSA and rTSA. Surgeons should consider these potential complications and employ a multidisciplinary approach in preoperative risk stratification of IA undergoing shoulder replacement.

Evaluation of spin in reviews of biodegradable balloon spacers for massive irreparable rotator cuff tears.

HYPOTHESIS: Clinical studies are often at risk of spin, a form of bias where beneficial claims are overstated while negative findings are minimized or dismissed. Spin is often more problematic in abstracts given their brevity and can result in the misrepresentation of a study's actual findings. The goal of this study is to aggregate primary and secondary studies reporting the clinical outcomes of the use of subacromial balloon spacers in the treatment of massive irreparable rotator cuff tears to identify the incidence of spin and find any significant association with study design parameters. MATERIALS AND METHODS: This study was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Independent searches were completed on 2 databases (PubMed and Embase) for primary studies, systematic and current concepts reviews, and meta-analyses and the results were compiled. Two authors independently screened the studies using a predetermined inclusion criteria and aggregated data including titles, publication journals and years, authors, study design, etc. Each study was independently assessed for the presence of 15 different types of spin. Statistical analysis was conducted to identify associations between study characteristics and spin. RESULTS: Twenty-nine studies met the inclusion criteria for our analysis, of which 10 were reviews or meta-analyses and 19 were primary studies. Spin was identified in every study except for 2 (27/29, 93.1%). Type 3 spin, "Selective reporting of or overemphasis on efficacy outcomes or analysis favoring the beneficial effect of the experimental intervention" and type 9 spin, "Conclusion claims the beneficial effect of the experimental treatment despite reporting bias" were most frequently noted in our study, both observed in 12/29 studies (41.4%). Date of publication, and adherence to Preferred Reporting Items for Systematic Reviews and Meta-Analyses or "The International Prospective Register of Systematic Reviews" were study characteristics associated with a higher rate of certain types of spin. There was a statistically significant association between disclosure of external study funding source and the presence of spin type 4, but none of the other forms of spin. CONCLUSION: Spin is highly prevalent in the abstracts of primary studies, systematic reviews, and meta-analyses discussing the use of subacromial balloon spacer technology in the treatment of massive irreparable rotator cuff tears. Our findings revealed that spin in the abstract tended to favor the balloon spacer intervention. Further efforts are required in the future to mitigate spin within the abstracts of published manuscripts.

Effect of BMI on Complications Following Total Shoulder Arthroplasty: A Population-Wide Analysis.

BACKGROUND: Evidence regarding the effect of body mass index (BMI) on complications following anatomic shoulder arthroplasty (aTSA) and reverse shoulder arthroplasty (rTSA) remains controversial. This high-powered study examines the effect of BMI on surgical and medical complications following anatomic shoulder arthroplasty (aTSA) and reverse shoulder arthroplasty (rTSA). METHODS: This retrospective cohort study was conducted using the Premier Healthcare Database (PHD) to query all adult patients who underwent primary, elective TSA (aTSA, rTSA) from 2016 to 2020. Patients eligible for inclusion were identified using ICD-10 and CPT codes for primary TSA. Patients were stratified into three subgroups based on BMI (BMI <30 kg/m2, BMI 30-35 kg/m2, BMI > 35 kg/m2). The primary endpoints assessed were 90-day risks of postoperative complications, revisions, and readmissions among the three BMI groups undergoing primary TSA. RESULTS: A total of 32,645 patients were analyzed; 10,951 patients underwent aTSA and 21,694 patients underwent rTSA. Patient populations for aTSA and rTSA differed significantly across all BMI categories in terms of age, sex, cost of care, and insurance status. After multivariate regression analysis, there was no increased risk of surgical complications in the aTSA and rTSA cohorts with BMI 30-35 kg/m2 and BMI > 35 kg/m2. In the aTSA cohort, rates of acute respiratory failure (adjusted Odds Ratio (aOR) 2.65) was all significantly higher in the BMI > 35 kg/m2 group. As for rTSA cohort, acute respiratory failure (aOR 1.67) and acute renal failure (aOR 1.53) were significantly higher in the BMI > 35 kg/m2 group. CONCLUSION: While we found no increased risk of immediate postoperative surgical risks, patients with a BMI > 35 kg/m2 demonstrated greater risk of medical complications after rTSA. Given this trend, providers should exercise caution in patient selection for TSA and counsel obese patients as to these increased risks. Future studies should aim to provide a more comprehensive picture of the effect of BMI on functional outcomes after TSA.

Outcomes of multiligament knee injury treated with versus without internal brace suture augmentation.

PURPOSE: To compare the postoperative outcomes between Internal Brace (IB) and non-IB patients who underwent surgical management of multiple-ligament knee injuries (MLKI). METHODS: Patients who underwent surgical management of MLKI at two institutions between 2010 and 2020 were identified and offered participation in the study via the collection of postoperative functional outcomes for MLKI; Lysholm Knee score, Multiligament Quality of Life (ML-QOL), Patient-Reported Outcomes Measurement Information System (PROMIS) computer adaptive testing (CAT), Pain Interference (PI), Physical Function (PF), and Mobility instruments (MI). The postoperative outcomes and reoperation rates were compared between the IB group and non-IB group. RESULTS: One hundred and twenty-six patients were analyzed; 89 were included in the IB group (31.5% female; age 35.6 ± 1.4 years), and 37 were included in the non-IB group (25.7% female; age 38.8 ± 2.4 years). Mean follow-up time of the entire cohort was 37.9 ± 4.7 months [IB: 21.8 + 1.63; non-IB: 76.4 ± 6.2, p < 0.001). The IB group achieved similar PROMIS CAT [PROMIS Pain (51.8 + 1.1 vs. 52.1 + 1.6, p = 0.8736), Physical Function (46.6 + 1.2 vs. 46.4 + 1.8, p = 0.9168), Mobility (46.0 + 1.0 vs. 43.7 + 1.6, p = 0.2185)], ML-QOL [ML-QOL Physical Impairment (36.6 + 2.5 vs. 43.5 ± 4.2, p = 0.1485), Emotional Impairment (42.5 + 2.9 vs. 48.6 ± 4.6, p = 0.2695), Activity Limitation (34.5 + 2.8 vs. 36.2 ± 4.3, p = 0.7384), Societal Involvement (39.1 + 3.0 vs. 41.7 + 4.2, p = 0.6434)] and Lysholm knee score (64.9 + 2.5 vs. 60.4 + 4.0, p = 0.3397) postoperatively compared the non-IB group, but the differences were not significant. CONCLUSION: In this cohort of patients with MLKI treated with versus without IB, outcomes and reoperation rates trended toward favoring IB, but the study was not sufficiently powered to reach statistical significance. Internal bracing could be useful in the management of MLKI. In the future, matched patient cohorts with more patients are warranted to further evaluate the clinical impact of the internal brace in MLKI.

Delayed NLRP3 inflammasome inhibition ameliorates subacute stroke progression in mice.

BACKGROUND: Ischemic stroke immediately evokes a strong neuro-inflammatory response within the vascular compartment, which contributes to primary infarct development under vessel occlusion as well as further infarct growth despite recanalization, referred to as ischemia/reperfusion injury. Later, in the subacute phase of stroke (beyond day 1 after recanalization), further inflammatory processes within the brain parenchyma follow. Whether this second wave of parenchymal inflammation contributes to an additional/secondary increase in infarct volumes and bears the potential to be pharmacologically targeted remains elusive. We addressed the role of the NLR-family pyrin domain-containing protein 3 (NLRP3) inflammasome in the subacute phase of ischemic stroke. METHODS: Focal cerebral ischemia was induced in C57Bl/6 mice by a 30-min transient middle cerebral artery occlusion (tMCAO). Animals were treated with the NLRP3 inhibitor MCC950 therapeutically 24 h after or prophylactically before tMCAO. Stroke outcome, including infarct size and functional deficits as well as the local inflammatory response, was assessed on day 7 after tMCAO. RESULTS: Infarct sizes on day 7 after tMCAO decreased about 35% after delayed and about 60% after prophylactic NLRP3 inhibition compared to vehicle. Functionally, pharmacological inhibition of NLRP3 mitigated the local inflammatory response in the ischemic brain as indicated by reduction of infiltrating immune cells and reactive astrogliosis. CONCLUSIONS: Our results demonstrate that the NLRP3 inflammasome continues to drive neuroinflammation within the subacute stroke phase. NLRP3 inflammasome inhibition leads to a better long-term outcome-even when administered with a delay of 1 day after stroke induction, indicating ongoing inflammation-driven infarct progression. These findings may pave the way for eagerly awaited delayed treatment options in ischemic stroke.

The Effects of Wearing a 3-Ply or KN95 Face Mask on Cerebral Blood Flow and Oxygenation.

BACKGROUND: The SARS-CoV-2 virus has impacted life in many ways, one change being the use of face masks. Their effect on MRI-based measurements of cerebral oxygen levels with quantitative susceptibility mapping (QSM) and cerebral blood flow (CBF) is not known. PURPOSE: This study investigated whether wearing a face mask leads to changes in CBF and cerebral venous oxygen saturation measured with MRI. STUDY TYPE: Repeated-measures cohort study. POPULATION: A total of 16 healthy volunteers (eight male, eight female; 22-36 years) were recruited for the 3-ply study. Ten of the 16 participants (five male, five female; 23-36 years) took part in the KN95 study. FIELD STRENGTH/SEQUENCE: A 3 T, single-delay 3D gradient-and spin-echo pseudo-continuous arterial spin labeling (pCASL) scan for CBF quantification, and gradient-echo for QSM and oxygenation quantification. ASSESSMENT: Gray matter CBF and magnetic susceptibility were assessed by masking the pCASL CBF map and the QSM map to the T1 -weighted gray matter tissue segmentation. Venous oxygenation was determined from venous segmentation of QSM maximum intensity projections. STATISTICAL TESTS: Paired Student's t-tests and Cohen's d effect sizes were used to compare the face mask and no face mask scans for gray matter CBF, gray matter magnetic susceptibility, and cerebral venous oxygen saturation. Standard t-tests were used to assess whether the order of scanning with and without a mask had any impact. A statistical cut off of P < 0.05 was used. RESULTS: The 3-ply masks increased gray matter CBF from an average of 43.99 mL/(100 g*min) to 46.81 mL/(100 g*min). There were no significant changes in gray matter magnetic susceptibility (P = 0.07), or cerebral venous oxygen saturation (P = 0.36) for the 3-ply data set. The KN95 masks data set showed no statistically significant changes in gray matter CBF (P = 0.52) and magnetic susceptibility (P = 0.97), or cerebral venous oxygen saturation (P = 0.93). DATA CONCLUSION: The changes in blood flow and oxygenation due to face masks are small. Only CBF increased significantly due to wearing a 3-ply mask. EVIDENCE LEVEL: 2 TECHNICAL EFFICACY: Stage 3.

Elite Athletes Successfully Return to the Preinjury Level of Sport Following Ankle Syndesmosis Injuries: A Systematic Review and Meta-Analysis.

OBJECTIVE: To comprehensively review and report the outcomes of ankle syndesmotic injury management in elite athletes. DATA SOURCES: Three databases were searched for articles reporting the rate of return to sport following treatment of ankle syndesmotic injuries in elite athletes (collegiate or professional level). Ten articles and 440 athletes were included. Articles reporting the rate of return to sport following high ankle sprain injury in elite athletes. Data collected included demographics, type of treatment received, and return to sport (RTS) information. A random effects model was used. MAIN RESULTS: The estimated overall rate of RTS was 99% (95% CI, 95.5-99.9). The mean time to RTS was 38 ± 18 (range, 14-137) days. Of the 440 athletes, 269 (269/440%, 61%) were treated nonoperatively (nonoperative group); the rate of RTS was 99.6%, and the athletes returned at a mean time of 29 ± 14 (range, 13-45) days. A total of 171 athletes (171 of 440%, 39%) underwent surgical treatment (operative group). All (171 of 171%, 100%) athletes returned at a mean time of 50.3 ± 13 (range, 41-137) days. Almost all athletes who underwent surgery had suture button fixation (164 of 171 athletes, 96%), and the mean time to RTS was 7 weeks with 9.1% complication rate. CONCLUSIONS: Elite athletes with ankle syndesmosis injury return to sport at an extremely high rates, following operative or nonoperative treatment. Return to the preinjury level of competition should be expected at 4 weeks and 7 weeks in high-level athletes who undergo nonoperative and operative management, respectively. Suture button fixation was used by the majority of studies reporting surgical management of ankle syndesmosis injuries in athletes.

Orientation dependence of R2 relaxation in the newborn brain.

In MRI the transverse relaxation rate, R2 = 1/T2, shows dependence on the orientation of ordered tissue relative to the main magnetic field. In previous studies, orientation effects of R2 relaxation in the mature brain's white matter have been found to be described by a susceptibility-based model of diffusion through local magnetic field inhomogeneities created by the diamagnetic myelin sheaths. Orientation effects in human newborn white matter have not yet been investigated. The newborn brain is known to contain very little myelin and is therefore expected to exhibit a decrease in orientation dependence driven by susceptibility-based effects. We measured R2 orientation dependence in the white matter of human newborns. R2 data were acquired with a 3D Gradient and Spin Echo (GRASE) sequence and fiber orientation was mapped with diffusion tensor imaging (DTI). We found orientation dependence in newborn white matter that is not consistent with the susceptibility-based model and is best described by a model of residual dipolar coupling. In the near absence of myelin in the newborn brain, these findings suggest the presence of residual dipolar coupling between rotationally restricted water molecules. This has important implications for quantitative imaging methods such as myelin water imaging, and suggests orientation dependence of R2 as a potential marker in early brain development.

Recent insights into the regulatory networks of NLRP3 inflammasome activation.

The NACHT, LRR and PYD domains-containing protein 3 (NLRP3) inflammasome is a fascinating cellular machinery endowed with the capacity for rapid proteolytic processing of the pro-inflammatory cytokine IL-1ß and the cell death effector gasdermin D (GSDMD). Although its activity is essential to fight infection and support tissue homeostasis, the inflammasome complex, which consists of the danger sensor NLRP3, the adaptor apoptosis-associated speck-like protein containing a CARD (ASC; also known as PYCARD), caspase-1 and probably other regulatory proteins, also bears considerable potential for detrimental inflammation, as observed in human conditions such as gout, heart attack, stroke and Alzheimer's disease. Thus, multi-layered regulatory networks are required to ensure the fine balance between rapid responsiveness versus erroneous activation (sufficient and temporally restricted versus excessive and chronic activity) of the inflammasome. These involve multiple activation, secretion and cell death pathways, as well as modulation of the subcellular localization of NLRP3, and its structure and activity, owing to post-translational modification by other cellular proteins. Here, we discuss the exciting progress that has recently been made in deciphering the regulation of the NLRP3 inflammasome. Additionally, we highlight open questions and describe areas of research that warrant further exploration to obtain a more comprehensive molecular and cellular understanding of the NLRP3 inflammasome.

Monofractal analysis of functional magnetic resonance imaging: An introductory review.

The following review will aid readers in providing an overview of scale-free dynamics and monofractal analysis, as well as its applications and potential in functional magnetic resonance imaging (fMRI) neuroscience and clinical research. Like natural phenomena such as the growth of a tree or crashing ocean waves, the brain expresses scale-invariant, or fractal, patterns in neural signals that can be measured. While neural phenomena may represent both monofractal and multifractal processes and can be quantified with many different interrelated parameters, this review will focus on monofractal analysis using the Hurst exponent (H). Monofractal analysis of fMRI data is an advanced analysis technique that measures the complexity of brain signaling by quantifying its degree of scale-invariance. As such, the H value of the blood oxygenation level-dependent (BOLD) signal specifies how the degree of correlation in the signal may mediate brain functions. This review presents a brief overview of the theory of fMRI monofractal analysis followed by notable findings in the field. Through highlighting the advantages and challenges of the technique, the article provides insight into how to best conduct fMRI fractal analysis and properly interpret the findings with physiological relevance. Furthermore, we identify the future directions necessary for its progression towards impactful functional neuroscience discoveries and widespread clinical use. Ultimately, this presenting review aims to build a foundation of knowledge among readers to facilitate greater understanding, discussion, and use of this unique yet powerful imaging analysis technique.

The crystal structure of lipopolysaccharide binding protein reveals the location of a frequent mutation that impairs innate immunity.

Lipopolysaccharide (LPS) binding protein (LBP) is an acute-phase protein that initiates an immune response after recognition of bacterial LPS. Here, we report the crystal structure of murine LBP at 2.9 Å resolution. Several structural differences were observed between LBP and the related bactericidal/permeability-increasing protein (BPI), and the LBP C-terminal domain contained a negatively charged groove and a hydrophobic "phenylalanine core." A frequent human LBP SNP (allelic frequency 0.08) affected this region, potentially generating a proteinase cleavage site. The mutant protein had a reduced binding capacity for LPS and lipopeptides. SNP carriers displayed a reduced cytokine response after in vivo LPS exposure and lower cytokine concentrations in pneumonia. In a retrospective trial, the LBP SNP was associated with increased mortality rates during sepsis and pneumonia. Thus, the structural integrity of LBP may be crucial for fighting infections efficiently, and future patient stratification might help to develop better therapeutic strategies.

Flagellin hypervariable region determines symbiotic properties of commensal Escherichia coli strains.

Escherichia coli represents a classical intestinal gram-negative commensal. Despite this commensalism, different E. coli strains can mediate disparate immunogenic properties in a given host. Symbiotic E. coli strains such as E. coli Nissle 1917 (EcN) are attributed beneficial properties, e.g., promotion of intestinal homeostasis. Therefore, we aimed to identify molecular features derived from symbiotic bacteria that might help to develop innovative therapeutic alternatives for the treatment of intestinal immune disorders. This study was performed using the dextran sodium sulphate (DSS)-induced colitis mouse model, which is routinely used to evaluate potential therapeutics for the treatment of Inflammatory Bowel Diseases (IBDs). We focused on the analysis of flagellin structures of different E. coli strains. EcN flagellin was found to harbor a substantially longer hypervariable region (HVR) compared to other commensal E. coli strains, and this longer HVR mediated symbiotic properties through stronger activation of Toll-like receptor (TLR)5, thereby resulting in interleukin (IL)-22-mediated protection of mice against DSS-induced colitis. Furthermore, using bone-marrow-chimeric mice (BMCM), CD11c+ cells of the colonic lamina propria (LP) were identified as the main mediators of these flagellin-induced symbiotic effects. We propose flagellin from symbiotic E. coli strains as a potential therapeutic to restore intestinal immune homeostasis, e.g., for the treatment of IBD patients.

BILN: A Human-Readable Line Notation for Complex Peptides.

We present an easy, human-readable line notation to describe even complex peptides.

Evaluation of spin in systematic reviews and meta-analyses of superior capsular reconstruction.

BACKGROUND: Small, preliminary studies and the systematic reviews on superior capsular reconstruction (SCR) that collate data are at increased risk spin. This study's primary objective was to identify, describe, and account for the incidence of spin in systematic reviews of SCR. This study's secondary objective was to characterize the studies in which spin was identified to determine whether identifiable patterns of characteristics exist among studies with spin. METHODS: This study was conducted per Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines using a predetermined protocol. A search was conducted on the PubMed and Embase databases for systematic reviews and meta-analyses on SCR. Screening and data extraction were conducted independently by 2 authors. Each included study's abstract was assessed for the presence of the 15 most common types of spin, with full texts reviewed during cases of disagreement or for clarification. General data that were extracted included study title, authors, publication year, journal, level of evidence, study design, funding source, reported adherence to PRISMA guidelines, preregistration of the study protocol, and primary and secondary outcome measures. Full texts were used in the assessment of study quality per AMSTAR 2. RESULTS: We identified 53 studies during our search, of which 17 met the inclusion criteria. At least 1 form of spin was observed in all 17 studies. The most common types of spin were type 5 ("The conclusion claims the beneficial effect of the experimental treatment despite a high risk of bias in primary studies") and type 9 ("Conclusion claims the beneficial effect of the experimental treatment despite reporting bias"), both of which were observed in 11 studies (11 of 17, 65%). A statistically significant association between lower level of evidence and type 5 ("The conclusion claims the beneficial effect of the experimental treatment despite a high risk of bias in primary studies") was observed (P = .0175). A statistically significant association was also found between more recent year of publication and the spin category misleading interpretation (P = .0398), and between lower AMSTAR 2 score and type 13 ("Failure to specify the direction of the effect when it favors the control intervention") (P = .0260). No other statistical associations between other study characteristics were observed. CONCLUSION: Spin is highly prevalent in abstracts of SCR systematic reviews and meta-analyses. An association was found between the presence of spin and lower level of evidence, year of publication, and AMSTAR 2 ratings.

Conversion rates and timing to total knee arthroplasty following anterior cruciate ligament reconstruction: a US population-based study.

PURPOSE: To define the rate of subsequent TKA following ACLR in a large US cohort and to identify factors that influence the risk of later undergoing TKA after ACLR. METHODS: The California's Office of Statewide Health Planning and Development (OSHPD) database was queried from 2000 to 2014 to identify patients who underwent primary ACLR (ACL group). An age-and gender-matched cohort that underwent appendectomy was selected as the control group. The cumulative incidence of TKA was calculated and ten-year survival was investigated using Kaplan-Meier analysis with failure defined as conversion to arthroplasty. Univariate and multivariate analyses were performed to explore the risk factors for conversion to TKA following ACLR. RESULTS: A total of 100,580 ACLR patients (mean age 34.48 years, 66.1%male) were matched to 100,545 patients from the general population. The ACL cohort had 1374 knee arthroplasty events; conversion rate was 0.71% at 2-year follow-up, 2.04% at 5-year follow-up, and 4.86% at 10-year follow-up. This conversion rate was higher than that of the control group at all time points, with an odds ratio of 3.44 (p<0.001) at 10-year follow-up. Decreasing survivorship following ACLR was observed with increasing age, female gender, and worker's compensation insurance, while increased survivorship was found in patients of Hispanic and Asian Pacific Islander racial heritage and those who underwent concomitant meniscal repair. CONCLUSIONS: In this US statewide study, the rate of TKA after ACLR is higher than reported elsewhere, with significantly increased odds when compared to a control group. Age, gender, concomitant knee procedures and other socioeconomic factors influence the rate of conversion to TKA following ACLR.

The NLRP3 inflammasome drives inflammation in ischemia/reperfusion injury after transient middle cerebral artery occlusion in mice.

PURPOSE: Cerebral ischemia induces a profound neuro-inflammatory response, but the underlying molecular mechanisms are poorly understood. Inflammasomes (NLRP1, NLRP3, NLRC4, AIM2) are intracellular multi-protein complexes which can induce sets of pro-inflammatory cyto- and chemokines, and thereby guide inflammation. We, here, assessed the functional role of NLRP3 in ischemia/reperfusion (I/R) injury in a mouse model of transient cerebral ischemia. METHODS: Ischemic stroke was induced in C57Bl/6 mice by 60 min transient middle cerebral artery occlusion (tMCAO) and 3, 7 or 23 h of reperfusion, a paradigm of I/R injury. The expression patterns of inflammasomes in the ischemic hemispheres were evaluated by semiquantitative real-time PCR and Western Blot analysis accompanied by protein localization using immunocytochemistry. Finally, animals were treated with the inflammasome inhibitors Sulforaphane, Genipin, MCC950 or vehicle, directly before or upon recanalization after tMCAO. Stroke outcome was assessed, including infarct size and functional deficits, local inflammatory response, neuronal survival as well as blood-brain barrier function on day 1 after tMCAO. RESULTS: After tMCAO the relative gene expression levels of NLRP3 increased 20-30x within 1 day in the ischemic hemisphere which translated into an increased expression of NLRP3 in neurons. Accordingly, the gene expression levels of the NLRP3-modulator, Bruton's Tyrosine Kinase (BTK), and the NLRP3-inducible cytokine IL-1ß significantly rose. Lesser or non-significant changes were seen for the other inflammasomes. Application of inflammasome inhibitors covering all inflammasomes or specifically NLRP3 significantly reduced infarct volumes when given before or after tMCAO and was accompanied by clear evidence for reduced activation of caspase 1. This stroke attenuating effect coincided with less immune cell infiltration in the ischemic hemisphere and preservation of the blood-brain barrier integrity. CONCLUSIONS: Our data show that induction of the NLRP3 inflammasome in neurons drives neuroinflammation in acute ischemic stroke. Early blockade of NLRP3 protects from I/R injury by mitigating inflammation and stabilizing the blood-brain barrier.