Distal Region Research Articles

RNA binding protein AUF1/HNRNPD regulates nuclear export, stability and translation of SNCA transcripts.

Alpha-synuclein (SNCA) accumulation plays a central role in the pathogenesis of Parkinson's disease. Determining and interfering with the mechanisms that control SNCA expression is one approach to limiting disease progression. Currently, most of our understanding of SNCA regulation is protein-based. Post-transcriptional mechanisms directly regulating SNCA mRNA expression via its 3' untranslated region (3'UTR) were investigated here. Mass spectrometry of proteins pulled down from murine brain lysates using a biotinylated SNCA 3'UTR revealed multiple RNA-binding proteins, of which HNRNPD/AUF1 was chosen for further analysis. AUF1 bound both proximal and distal regions of the SNCA 3'UTR, but not the 5'UTR or CDS. In the nucleus, AUF1 attenuated SNCA pre-mRNA maturation and was indispensable for the export of SNCA transcripts. AUF1 destabilized SNCA transcripts in the cytosol, primarily those with shorter 3'UTRs, independently of microRNAs by recruiting the CNOT1-CNOT7 deadenylase complex to trim the polyA tail. Furthermore, AUF1 inhibited SNCA mRNA binding to ribosomes. These data identify AUF1 as a multi-tasking protein regulating maturation, nucleocytoplasmic shuttling, stability and translation of SNCA transcripts.

Effect of four different mono and multi-wave light-curing units on the Knoop hardness of veneer resin composites

ObjectivesTo evaluate the effect of mono and multi-wave light-curing units (LCUs) on the Knoop hardness of resin-based composites (RBC) that use different photoinitiators. MethodsCentral incisor-shaped specimens 12 mm long, 9 mm wide, and 1.5 mm thick were made from 2 RBCs that use different photoinitiators: Tetric N-Ceram (Ivoclar Vivadent) - and Vittra APS (FGM), both A2E shade. They were light-cured with 4 different LCUs: two claimed to be multi-wave - VALO Grand (Ultradent) and Emitter Now Duo (Schuster); and two were monowave - Radii Xpert (SDI) and Elipar DeepCure-L (3 M Oral Care) using 2 different light exposure protocols: one 40 s exposure centered over the specimen; and two 20 s light exposures that delivered light from two positions to better cover the entire tooth. 16 groups with 10 specimens in each group were made. The Knoop hardness (KH, kg/mm2) was measured at the top and bottom of the specimen in the center and at the cervical, incisal, mesial, and distal peripheral regions. The active tip diameters (mm) and spectral radiant powers (mW/nm) of the LCUs were measured with and without the interposition of the RBC, as well as the radiant exposure beam profiles (J/cm²) delivered to the top of the RBCs. The data was analyzed using Three-way ANOVA and Tukey's tests (α = 0.05). ResultsThe VALO Grand (1029 mW) emitted twice the power of the Radii Xpert (500 mW). The KH values of VI and TN resin composite specimens were significantly affected by the LCU used (p < .001), the measurement location (p < .001), and the surface of the specimen (p < .001). LCUs with wider tip diameters produced greater Knoop hardness values at the peripheries of the 12 mm of long, 9 mm wide specimens. In general, the VALO Grand produced the highest KH values, followed by Elipar DeepCure-L, then by Radii Xpert. The Emitter Now Duo LCU produced the lowest values. Exposing the veneers from two locations reduced the differences between the LCUs and the effect of the measurement location. Only the VALO Grand could fully cover the composite veneer with light when the two locations were used. SignificanceThe light tip must cover the entire restoration to photocure the RBC beneath the light tip.

The maize preligule band is subdivided into distinct domains with contrasting cellular properties prior to ligule outgrowth.

The maize ligule is an epidermis-derived structure that arises from the preligule band (PLB) at a boundary between the blade and sheath. A hinge-like auricle also develops immediately distal to the ligule and contributes to blade angle. Here, we characterize the stages of PLB and early ligule development in terms of topography, cell area, division orientation, cell wall rigidity, and auxin response dynamics. Differential thickening of epidermal cells and localized periclinal divisions contributed to the formation of a ridge within the PLB, which ultimately produces the ligule fringe. Patterns in cell wall rigidity were consistent with the subdivision of the PLB into two regions along a distinct line positioned at the nascent ridge. The proximal region produces the ligule, while the distal region contributes to one epidermal face of the auricles. Whereas the auxin transporter PIN1 accumulated in the PLB, observed differential auxin transcriptional response did not underlie the partitioning of the PLB. Our data demonstrate that two zones with contrasting cellular properties, the preligule and preauricle, are specified within the ligular region prior to ligule outgrowth.

Cryo-EM structure of human PAPP-A2 and mechanism of substrate recognition

Pregnancy-Associated Plasma Protein A isoforms, PAPP-A and PAPP-A2, are metalloproteases that cleave insulin-like growth factor binding proteins (IGFBPs) to modulate insulin-like growth factor signaling. The structures of homodimeric PAPP-A in complex with IGFBP5 anchor peptide, and inhibitor proteins STC2 and proMBP have been recently reported. Here, we present the single-particle cryo-EM structure of the monomeric, N-terminal LG, MP, and the M1 domains (with the exception of LNR1/2) of human PAPP-A2 to 3.13 Å resolution. Our structure together with functional studies provides insight into a previously reported patient mutation that inactivates PAPP-A2 in a distal region of the protein. Using a combinational approach, we suggest that PAPP-A2 recognizes IGFBP5 in a similar manner as PAPP-A and show that PAPP-A2 cleaves IGFBP5 less efficiently due to differences in the M2 domain. Overall, our studies characterize the cleavage mechanism of IGFBP5 by PAPP-A2 and shed light onto key differences with its paralog PAPP-A.

Genome-wide DNase I-hypersensitive site assay reveals distinct genomic distributions and functional features of open chromatin in autopolyploid sugarcane.

The characterization of cis-regulatory DNA elements (CREs) is essential for deciphering the regulation of gene expression in eukaryotes. Although there have been endeavors to identify CREs in plants, the properties of CREs in polyploid genomes are still largely unknown. Here, we conducted the genome-wide identification of DNase I-hypersensitive sites (DHSs) in leaf and stem tissues of the auto-octoploid species Saccharum officinarum. We revealed that DHSs showed highly similar distributions in the genomes of these two S. officinarum tissues. Notably, we observed that approximately 74% of DHSs were located in distal intergenic regions, suggesting considerable differences in the abundance of distal CREs between S. officinarum and other plants. Leaf- and stem-dependent transcriptional regulatory networks were also developed by mining the binding motifs of transcription factors (TFs) from tissue-specific DHSs. Four TEOSINTE BRANCHED 1, CYCLOIDEA, and PCF1 (TCP) TFs (TCP2, TCP4, TCP7, and TCP14) and two ethylene-responsive factors (ERFs) (ERF109 and ERF03) showed strong causal connections with short binding distances from each other, pointing to their possible roles in the regulatory networks of leaf and stem development. Through functional validation in transiently transgenic protoplasts, we isolate a set of tissue-specific promoters. Overall, the DHS maps presented here offer a global view of the potential transcriptional regulatory elements in polyploid sugarcane and can be expected to serve as a valuable resource for both transcriptional network elucidation and genome editing in sugarcane breeding.

Cryo-EM reveals how the mastigoneme assembles and responds to environmental signal changes.

Mastigonemes are thread-like structures adorning the flagella of protists. In Chlamydomonas reinhardtii, filamentous mastigonemes find their roots in the flagella's distal region, associated with the channel protein PKD2, implying their potential contribution to external signal sensing and flagellar motility control. Here, we present the single-particle cryo-electron microscopy structure of the mastigoneme at 3.4 Å. The filament unit, MST1, consists of nine immunoglobulin-like domains and six Sushi domains, trailed by an elastic polyproline-II helix. Our structure demonstrates that MST1 subunits are periodically assembled to form a centrosymmetric, non-polar filament. Intriguingly, numerous clustered disulfide bonds within a ladder-like spiral configuration underscore structural resilience. While defects in the mastigoneme structure did not noticeably affect general attributes of cell swimming, they did impact specific swimming properties, particularly under varied environmental conditions such as redox shifts and heightened viscosity. Our findings illuminate the potential role of mastigonemes in flagellar motility and suggest their involvement in diverse environmental responses.

Biological sex estimation with femoral dimensions: a study of an adult sample from the osteological collection of Granada (Spain)

ABSTRACT Estimating the biological sex is one of the key objectives in a forensic investigation involving unidentified human skeletal remains. The femur is sexually dimorphic and has been extensively employed for the assessment of sex in different populations. The purposes of this article include a detailed macroanatomical characterization of the femur in a modern reference sample of the Spanish population (N = 226; Cemetery of San José in Granada, housed in the Physical Anthropology Laboratory of the University of Granada), based on 15 measurements of the proximal, distal and diaphyseal regions, and the development of univariable and multivariable models that enable the prediction of sex from complete or fragmentary femora. Univariable models were developed with C4.5, a decision-tree algorithm. Furthermore, univariable and multivariable models were generated through logistic regression (LR) with stepwise selection procedures. The models were able to correctly estimate sex in up to 91.2% of the individuals, providing high classification accuracy and low bias under cross-validation. Logistic regression models provide a probabilistic estimate of sex, that acknowledges both the Daubert standard and the fact that biological sex is not strictly dichotomous.

Exploring indicators of success in chronic total occlusion percutaneous coronary intervention with Stingray system-based antegrade dissection re-entry: Insights from retrospective analysis.

The predictors of success of chronic total occlusion (CTO) percutaneous coronary intervention (PCI) through antegrade dissection and re-entry (ADR) using the Stingray system (Stingray ADR) remain elusive, mainly owing to the lack of consecutive angiographic and procedural records of patients. This study aimed to identify indicators that can determine the success of CTO PCI performed using the Stingray ADR technique. The clinical data of 115 patients who underwent CTO PCI through Stingray ADR at the same cardiac center were retrospectively and consecutively collected. Multivariate logistic regression analysis was performed to investigate the indicators of the success of ADR attempts. The technical success rate of Stingray ADR in CTO PCI was 72.2%. The overall technical success rate of CTO recanalization was 78.3% in all CTO PCIs having used Stingray Low Profile balloon. Vessel calcification (odds ratio [OR]: 4.03; 95% confidence interval [CI]: 1.49-11.88; p = 0.008), and retrograde puncture indicator (OR: 4.89; 95% CI: 1.51-17.11; p = 0.009) were identified as independent positive predictors. Blunt/no stump proximal to the occlusion segment (OR: 0.22; 95% CI: 0.06-0.64; p = 0.009), decision time before Stingray ADR (per 1 h increase) (OR: 0.54; 95% CI: 0.31-0.92; p = 0.026), operation duration of Stingray ADR (per 10 min increase) (OR: 0.62; 95% CI: 0.40-0.94; p = 0.028), and puncture site at the intraplaque region (OR: 0.24; 95% CI: 0.06-0.84; p = 0.026) were identified as the four negative independent predictors. This study revealed independent predictors of the success of CTO PCI performed using the Stingray ADR technique. As for CTO characteristics, the presence of calcification in the CTO segment and a tapered stump proximal to the lesion site can facilitate successful Stingray ADR. As for the procedures, the success rate of Stingray ADR can be improved by initiating the technique decisively and promptly, operating the system quickly and accurately and creating a puncture in the distal cap region of CTO under retrograde guidance.

Solutan echinoderms from the Fezouata Shale Lagerstätte (Lower Ordovician, Morocco): diversity, exceptional preservation, and palaeoecological implications

In the Lower Ordovician of Morocco, solutan echinoderms are relatively common, locally abundant, geographically widespread (Central and Eastern Anti-Atlas), and biostratigraphically long-ranging (late Tremadocian–mid Floian) components of the Fezouata Biota. The lower part of the Fezouata Shale (late Tremadocian) yielded one specimen, here tentatively identified as a Castericystis-like syringocrinid, with exceptionally preserved internal soft parts presumably corresponding to the distal region of the gut. Most solutan remains from the Fezouata Shale are assigned to Plasiacystis mobilis, which was already known from the late Tremadocian of France and the Darriwilian of the Czech Republic and United Kingdom. Several isolated dististeles provisionally identified as Plasiacystis sp. may belong to large individuals of P. mobilis or a new taxon. Several specimens of late Tremadocian solutans from the Fezouata Shale, morphologically intermediate between Minervaecystis vidali (late Tremadocian, France) and Plasiacystis mobilis, are assigned to Nimchacystis agterbosi gen. et sp. nov. The diagnosis of the syringocrinid family Minervaecystidae is modified to include the four genera Minervaecystis, Nimchacystis, Pahvanticystis, and Plasiacystis, all characterised by an ovoid theca, a laterally inserted feeding appendage, and a twisted, flattened dististele. Minervaecystids are interpreted as active epibenthic detritus feeders, using their dististele to crawl on soft substrates. The newly described solutan taxa highlight that the benthic communities of Fezouata Biota are more diverse than what was previously described.

Biomechanical evaluation of intramedullary retrograde nail and dynamic condylar screw used in unstable distal femoral fractures.

Distal femur fractures are a common problem in orthopedics. Intramedullary retrograde nails (IRN) and dynamic condylar screws (DCS) are generally used for the treatment of these fractures. In this study, it was aimed to mechanically evaluate and compare these two implants used for the treatment of distal femur fractures. In this study, an AOOTA 33C1.3 fracture was created on the intact femur obtained from computed tomography images. The fractures were fixed with DCS and IRN. Then the created models were imported into the ANSYS Workbench for finite element analysis to determine the most convenient mechanical fixation type. The distal region of the femur was loaded considering 75kg-f, and the created models were constrained in all directions from the femoral head. The intact femur was also analyzed to compare it with the DCS and IRN fixation models. The von Mises stress, strain, and displacement results were examined to determine the damage risk. According to the results, the risk of damage is lower in the model of fixation with IRN. The normal strain distribution in the model fixed with IRN is closer to the model of an intact femur. For this reason, the risk of stress shielding in IRN fixation is less than in DCS fixation. However, the fracture lines were more stable in the fixation with the DCS. In conclusion, fracture fixation with IRN is mechanically more suitable for distal femur fractures in terms of fracture healing.

Clinical aspects of the use of a vascularized mucoperiosteal palatine flap for the reconstruction of soft tissue defects

Dental implantation, as a high-tech innovative direction in modern dentistry, can significantly increase the effectiveness of complex rehabilitation of patients with partial and complete loss of teeth. Methods for surgical treatment of patients with soft tissue deficiency in the area of dentition defects must meet the following requirements: minimally invasive; biological feasibility; predictability; the validity of the patterns of changes in the state of soft tissue structures of the maxillofacial during surgical intervention; the need to restore the morphological and functional components of the donor and recipient beds; the most careful attitude to the bone and soft tissue components of the alveolar crest of the jaws for subsequent dental implantation. The article presents the results of a multi-stage method for restoring soft tissue deficiency in 29 patients aged 37 to 60 years with terminal and included defects in the alveolar part of the lower jaw in the distal region using the developed surgical method for eliminating soft tissue deficiency with a vascularized muco-periosteal flap modeled in the projection of the hard palate. The effectiveness of the developed surgical technique is confirmed by clinical data characterizing the intensity of the postoperative inflammatory process, taking into account the developed criteria indicators, as well as morphological indicators of soft tissues in the projection of the apex of the alveolar part of the lower jaw in the area of dentition defects before and 3, 6, 9, 12 months after surgery. It was established that on the 30th day from the moment of surgical manipulations, the intensity of clinical manifestations of the postoperative inflammatory process in the studied patients was completely absent, and by the 12th month, the increase in the thickness of the soft tissue component in the region of the apex of the alveolar part of the lower jaw in the intervention area increased by 133.3%, at the same time, the value of soft tissue growth ranged from 2.2 mm to 3.7 mm. The analysis of the obtained results revealed the high efficiency of the developed method, allowing to expand the indications for dental implantation.

Effects of heel apex position, apex angle and rocker radius on plantar pressure in the heel region

IntroductionRocker shoes and insoles are used to prevent diabetic foot ulcers in persons with diabetes mellitus and loss of protective sensation, by reducing the plantar pressure in regions with high pressure values (>200 kPa) (e.g., hallux, metatarsal heads and heel). However, forefoot rocker shoes that reduce pressure in the forefoot inadvertently increase pressure in the heel. No studies focused on mitigating the negative effects on heel pressure by optimizing the heel rocker midsole, yet. Therefore, we analyze the effect of different heel rocker parameters on the heel plantar pressure. MethodsIn-shoe pressure was measured, while 10 healthy participants walked with control shoe and 10 different heel rocker settings. Peak pressure was determined in 7 heel masks, for all shoes. Generalized estimating equations was performed to test the effect of the different shoes on the peak pressure in the different heel masks. ResultsIn the proximal heel, a rocker shoe with distal apex position, small rocker radius and large apex angle (100°), shows the largest significant decrease in peak pressure compared to rocker shoes with more proximally located apex positions. In the midheel and distal heel, the same rocker shoes or any other rocker shoes, analyzed in this study, do not reduce the PP more than 2 % compared to the control shoe. For the midheel and distal heel region with high pressure values (>200 kPa), rocker shoes alone are not the correct option to reduce the pressure to below 200 kPa. ConclusionWhen using rocker shoes to reduce the pressure in the forefoot, a heel rocker midsole with a distal apex position, small rocker radius and apex angle of 100°, mitigates the negative effects on proximal heel pressure. For the midheel and distal heel, other footwear options as an addition or instead of rocker shoes are needed to reduce the pressure.

Spatial distribution of stiffness between and within muscles in paretic and healthy individuals during prone and standing positions

This study investigated the inter- and intramuscular variability of plantar flexors stiffness during prone and standing positions at different muscle lengths in healthy and paretic individuals. To access tissue stiffness, shear wave elastography (SWE) measurements were carried out on two groups: control group (CG; n=14; age 43.9±9.6 years; body mass index [BMI]=24.5±2.5 kg/m2) and stroke survivor group (SSG; n=14; age 43.9±9.6 years; BMI=24.5±2.5 kg/m2). Shear Modulus (μ, kPa) within three plantar flexors (the gastrocnemius medialis [GM], gastrocnemius lateralis [GL], and soleus [SOL]) was obtained during two conditions: prone and standing position, at different angles of dorsiflexion (0°, 10°, and 20°). Measurements were also performed in different proximo-distal regions of each muscle. Muscle activation of the GM, GL, SOL, and tibialis anterior were evaluated during the two conditions. Results showed a high spatial stiffness variability between and within plantar flexors during dorsiflexion. The highest stiffness was observed in the GM, especially in the distal region at 20° in healthy and paretic muscles. In the prone position, the paretic muscle exhibits greater stiffness compared to the healthy muscle (p < 0.05). In contrast, in the standing position, an increase of stiffness in the healthy muscle compared to the paretic muscle was observed (p < 0.05). Thus, mechanical properties are differently affected by stroke depending on active and passive states of ankle muscles during dorsiflexion. In addition, the modification of ankle muscle state change stiffness distribution between and within plantar flexors.

Evaluation of the effect of class II fixed orthodontic treatment on the periradicular bone structure of endodontically treated mandibular molar teeth using fractal dimension analysis

Aim: The aim of this study was to investigate whether changes in periradicular tissues with orthodontic movement of root canal-treated teeth differ from those without root canal treatment using fractal dimension analysis (FA). Methodology: A retrospective archive study was performed using panoramic radiographs taken before (T1) and after (T2) fixed orthodontic treatment. Panoramic radiographs of a total of 32 mandibular 1st and 2nd molar teeth were divided into groups: Group 1 (n:17), the control group, comprised radiographs of mandibular 1st or 2nd teeth without root canal treatment, and Group 2 (n:15) comprised radiographs of 1st or 2nd mandibular molars with root canal treatment. Fractal analyses were performed in four different regions—the periapical, bifurcation, mesial periapical, and distal periapical regions—of the mandibular molar teeth included in the study for a total of 128 analyses. Results: In the control group, orthodontic treatment did not make a statistically significant difference to the fractal dimension values in the four regions of the tooth (p &gt; 0.05). In the endodontically treated group, the fractal dimension values of the mesial periapical regions increased statistically significantly after orthodontic treatment (p &lt; 0.05). Conclusion: The FA values of this study showed that more biological interaction occurred in the root canal treatment group and in the mesial periapical region. Thus, it is important to keep orthodontic force within the tooth’s physiological limits to avoid damaging the tooth in the periapical areas where stress accumulates during orthodontic treatment. How to cite this article: Küçükkaraca E, Sarıçam E. Evaluation of the effect of class II fixed orthodontic treatment on the periradicular bone structure of endodontically treated mandibular molar teeth using fractal dimension analysis. Int Dent Res 2023;13(S1):38-43. https://doi.org/10.5577/idr.2023.vol13.s1.6 Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.

Improving the outcome of distally based anterolateral thigh flap reconstruction: New classification and surgical guidelines

The distally based anterolateral thigh (dALT) flap is associated with a high incidence of venous congestion. This study aimed to investigate factors associated with vascular compromise to improve the outcomes. We retrospectively analyzed 41 dALT flap reconstructions performed between November 2010 and February 2023. The dALT flap was classified into type I, II, or III based on the origin (the descending, oblique, or transverse branch) of the chosen perforator. The distance from the pivot point to the superolateral patella, pedicle length, flap reach, complications, and loss rates were analyzed to identify different dALT flap characteristics. The type Ⅰ flap had a shorter pedicle length (type Ⅰ vs. type Ⅱ, p=0.000; type Ⅰ vs. type Ⅲ, p=0.000) that primarily reached closer regions (distal third of the thigh anterior/lateral knee). Pedicle lengths were similar between type Ⅱ and Ⅲ flaps (p=1.000), most of which reached more distal regions (medial/posterior knee or proximal third of the leg). However, the type Ⅲ flaps had a higher complication rate and flap loss rate, although no significant differences were observed (complication rate, p=0.094; flap loss rate, p=0.071). To achieve more desirable outcomes using the dALT flap, preoperative assessment of flap pedicle length and proper intraoperative maneuvers that avoid compromising the reverse blood circulation are necessary.

Temporal disparity of action potentials triggered in axon initial segments and distal axons in the neocortex.

Neural population activity determines the timing of synaptic inputs, which arrive to dendrites, cell bodies, and axon initial segments (AISs) of cortical neurons. Action potential initiation in the AIS (AIS-APs) is driven by input integration, and the phase preference of AIS-APs during network oscillations is characteristic to cell classes. Distal regions of cortical axons do not receive synaptic inputs, yet experimental induction protocols can trigger retroaxonal action potentials (RA-APs) in axons distal from the soma. We report spontaneously occurring RA-APs in human and rodent cortical interneurons that appear uncorrelated to inputs and population activity. Network-linked triggering of AIS-APs versus input-independent timing of RA-APs of the same interneurons results in disparate temporal contribution of a single cell to in vivo network operation through perisomatic and distal axonal firing.

GATA6 functions at distal enhancer regions to control classical pancreatic ductal carcinoma identity by promoting promoter-proximal pause release

GATA6 functions at distal enhancer regions to control classical pancreatic ductal carcinoma identity by promoting promoter-proximal pause release

Non-Vascularized Fibular Bone Graft for Giant Cell Tumor of the Distal Ulna: A Case Report

Abstract: Cases of bone giant cell tumors (GCT) are rarely found, generally benign and locally aggressive tumors. Surgical resection is the universal standard for treatment of bone GCT. Non vascularized fibular graft (NVFG) is useful in the reconstruction of skeletal defects, especially in cases of scarred and avascular recipient sites and patient with tumor surrounded by poor tissue condition. We report a 53-year-old woman, with a lump in her left hand for three years. X-ray examination revealed a mass with firm border and regular edge that reached the epiphysis expansively with thinning of the cortex in the distal region of the left ulna. Tumor excision was performed with open reduction internal fixation (ORIF) and fibular bone graft. To date, GCT is one of the most obscure and intensively examined bone tumors, and its histological images do not predict the clinical outcome. Moreover, many unanswered questions regard to the treatment and prognosis without any consensus regarding the ideal treatment selection. NVFG osteosynthesis shows encouraging results, and adequate therapy, wound care and patient compliance affect the patient’s outcome. In conclusion, NVFG and internal fixation are effective options for post tumor excision, and osteosynthesis has encouraging result. Keywords: non vascularized fibular graft (NVFG); giant cell tumor; bone graft; ulna

Mapping the epigenomic landscape of human monocytes following innate immune activation reveals context-specific mechanisms driving endotoxin tolerance

BackgroundMonocytes are key mediators of innate immunity to infection, undergoing profound and dynamic changes in epigenetic state and immune function which are broadly protective but may be dysregulated in disease. Here, we aimed to advance understanding of epigenetic regulation following innate immune activation, acutely and in endotoxin tolerant states.MethodsWe exposed human primary monocytes from healthy donors (n = 6) to interferon-γ or differing combinations of endotoxin (lipopolysaccharide), including acute response (2 h) and two models of endotoxin tolerance: repeated stimulations (6 + 6 h) and prolonged exposure to endotoxin (24 h). Another subset of monocytes was left untreated (naïve). We identified context-specific regulatory elements based on epigenetic signatures for chromatin accessibility (ATAC-seq) and regulatory non-coding RNAs from total RNA sequencing.ResultsWe present an atlas of differential gene expression for endotoxin and interferon response, identifying widespread context specific changes. Across assayed states, only 24–29% of genes showing differential exon usage are also differential at the gene level. Overall, 19.9% (6,884 of 34,616) of repeatedly observed ATAC peaks were differential in at least one condition, the majority upregulated on stimulation and located in distal regions (64.1% vs 45.9% of non-differential peaks) within which sequences were less conserved than non-differential peaks. We identified enhancer-derived RNA signatures specific to different monocyte states that correlated with chromatin accessibility changes. The endotoxin tolerance models showed distinct chromatin accessibility and transcriptomic signatures, with integrated analysis identifying genes and pathways involved in the inflammatory response, detoxification, metabolism and wound healing. We leveraged eQTL mapping for the same monocyte activation states to link potential enhancers with specific genes, identifying 1,946 unique differential ATAC peaks with 1,340 expression associated genes. We further use this to inform understanding of reported GWAS, for example involving FCHO1 and coronary artery disease.ConclusionThis study reports context-specific regulatory elements based on transcriptomic profiling and epigenetic signatures for enhancer-derived RNAs and chromatin accessibility in immune tolerant monocyte states, and demonstrates the informativeness of linking such elements and eQTL to inform future mechanistic studies aimed at defining therapeutic targets of immunosuppression and diseases.

Fatigue-induced Alterations of the Patellar Tendon in Elite Sprint Track Cyclists.

This study aims to investigate morphological and mechanical properties and echogenicity of the patellar tendon (PT) after acute fatigue-induced alterations in sprint track cyclists. Fourteen elite track cyclists participated in this study. The exercise protocol consisted of three maximal start accelerations (over a distance of 62.5 m), one maximal start acceleration (at both 125 m and 250 m), and sprints from the standing start. Immediately after testing all measurements, PT stiffness and thickness were set at 5-10-15-20 mm distal from the apex of the patella and 5-10 mm proximal to the tibial tuberosity. CSA was set at proximal, middle, and distal, while echogenicity was at proximal and distal points. The results showed significant increases in PT stiffness at all reference points after start acceleration (p<0.001). PT thickness showed similar results for stiffness, except for location placed at TT-5 (p<0.001). CSA increased significantly in proximal, middle, and distal regions (p<0.001), while echogenicity of the tendon increased in proximal and distal regions (p<0.001) after start acceleration. Regional-dependent alterations of PT thickness and stiffness may be related to anatomical and physiological mechanisms due to acute isometric contraction in the initial phase of standing start. Tendon echogenicity might be also useful in monitoring tendon mechanical properties and defining acute fatigue-induced changes.