Is Antibiotic Prophylaxis Needed for the Extraction of Premolars for Orthodontic Purposes?

Introduction Antibiotic prophylaxis for tooth extractions is a common practice in dentistry to prevent postoperative infections. However, the routine use of antibiotics has been questioned due to concerns about bacterial resistance and potential side effects. This study aimed to evaluate the necessity of postoperative antibiotics in patients undergoing orthodontic tooth extraction. Materials and methods This prospective study involved 100 patients requiring orthodontic tooth extraction, divided into two groups. The patients were recruited from Saveetha Dental College and Hospital, Chennai, India, after obtaining approval from the Institutional Human Ethics Committee, Saveetha Dental College (approval number: IHEC/SDC/OMFS-2103/23/293). Group 1 (n = 50) received antibiotics (amoxicillin 500 mg, three times a day for three days) after extraction, while Group 2 (n = 50) did not receive antibiotics. Postoperative infection was assessed on postoperative days (POD) 3 and 7. Data analysis was conducted using IBM SPSS Statistics for Windows, version 26.0 (released 2019, IBM Corp., Armonk, NY). Categorical variables were presented as frequencies and percentages, and differences between groups were assessed using chi-square or Fisher's exact tests. A p-value of <0.05 was considered statistically significant. Results The incidence of postoperative infection was recorded in both groups. In group 1 at POD 3 and POD 7, there were two patients and one patient with infection, respectively. In group 2 at POD 3 and POD 7, there were four patients and two patients with infection, respectively. Conclusion The findings of this study suggest that the routine administration of antibiotics for the non-traumatic extraction of teeth in healthy patients might not be necessary. The absence of postoperative infections in patients who did not receive antibiotics indicates that antibiotics may be avoidable in many cases of orthodontic tooth extraction. These results emphasize the importance of reconsidering the widespread use of antibiotics to combat the growing concern of bacterial resistance. Antibiotics should be prescribed judiciously, only for patients with specific medical conditions who are prone to infection. One of the limitations of this study is the limited sample size; hence, studies with larger and heterogeneous groups should be done to validate the same.

Comparison of the Efficacy of Corticosteroids With Enzymatic Agents in the Postoperative Sequelae for Lower Third Molar Surgery: A Prospective Study.

Introduction The presence of impacted third molars is a prevalent problem associated with varying degrees of difficulty in extraction and potential consequences, including pain, swelling, and trismus. According to studies, enzymatic combinations, such as bromelain, rutoside, trypsin, and serratiopeptidase, are known to have a very promising role in reducing inflammation and promoting wound healing. This study compared natural enzymatic agents with corticosteroids for postoperative pain, swelling, and trismus in the impacted lower third molar surgery. Objectives The present study aimed to compare the efficacy of prednisolone, a combination of trypsin, chymotrypsin, bromelain, rutoside, and papain, and serratiopeptidase in the postoperative sequelae after surgical extraction of impacted mandibular third molars. The primary objective was to assess the difference in swelling between the three groups. The secondary objectives were to assess the difference in postoperative pain and trismus between the three groups. Materials and methods A total of 150 patients who presented to the department of oral and maxillofacial surgery for surgical removal of an impacted mandibular third molar with a moderately difficult score of 5-7 in the Pederson difficulty index were chosen for a prospective study. Patients were categorized into three groups based on the postoperative drug prescribed. In group 1, prednisolone 10 mg was prescribed; in group 2, a combination of trypsin, chymotrypsin, bromelain, rutoside, and papain was prescribed; and in group 3, serratiopeptidase 15 mg was prescribed. All patients were prescribed a combination drug of aceclofenac 100 mg and paracetamol 325 mg twice daily as a standard analgesic. Swelling, pain, and trismus in each patient were recorded preoperatively and at postoperative day one and day seven. The Friedman test was employed to evaluate the variation in pain levels within the groups over time, while the Kruskal-Wallis test was utilized to investigate the disparity in pain levels between the groups. The difference in swelling and trismus within the groups across the timeline was measured by repeated measures analysis of variance (ANOVA), and the difference in swelling and trismus between the groups was measured by one-way ANOVA. A p-value below 0.05 was deemed to be statistically significant. Results Group 1 showed less swelling, pain, and trismus on both postoperative day one and day seven compared to group 2 and group 3, which was a statistically significant difference (P < 0.05). It was found that swelling, pain, and trismus measurements in postoperative day one and day seven in group 2 were comparatively less than in group 3. Neither group demonstrated any side effects or other complications during the follow-up period. Conclusion It can be concluded that the use of prednisolone postoperatively following surgical removal of the mandibular third molar provided better relief with regard to pain, trismus, and swelling compared to the enzymatic agents. Among enzymatic agents, a combination of trypsin, chymotrypsin, bromelain, rutoside, and papain was better in reducing pain, trismus, and swelling than serratiopeptidase drug.

Retreatment with HBV siRNA Results in Additional Reduction in HBV Antigenemia and Immune Stimulation in the AAV-HBV Mouse Model.

BACKGROUND AND AIMS: Treatment with siRNAs that target HBV has demonstrated robust declines in HBV antigens. This effect is also observed in the AAV-HBV mouse model, which was used to investigate if two cycles of GalNAc-HBV-siRNA treatment could induce deeper declines in HBsAg levels or prevent rebound, and to provide insights into the liver immune microenvironment. METHODS: C57Bl/6 mice were transduced with one of two different titers of AAV-HBV for 28 days, resulting in stable levels of HBsAg of about 103 or 105 IU/mL. Mice were treated for 12 weeks (four doses q3wk) per cycle with 3 mg/kg of siRNA-targeting HBV or an irrelevant sequence either once (single treatment) or twice (retreatment) with an 8-week treatment pause in between. Blood was collected to evaluate viral parameters. Nine weeks after the last treatment, liver samples were collected to perform phenotyping, bulk RNA-sequencing, and immunohistochemistry. RESULTS: Independent of HBsAg baseline levels, treatment with HBV-siRNA induced a rapid decline in HBsAg levels, which then plateaued before gradually rebounding 12 weeks after treatment stopped. A second cycle of HBV-siRNA treatment induced a further decline in HBsAg levels in serum and the liver, reaching undetectable levels and preventing rebound when baseline levels were 103 IU/mL. This was accompanied with a significant increase in inflammatory macrophages in the liver and significant upregulation of regulatory T-cells and T-cells expressing immune checkpoint receptors. CONCLUSIONS: Retreatment induced an additional decline in HBsAg levels, reaching undetectable levels when baseline HBsAg levels were 3log10 or less. This correlated with T-cell activation and upregulation of Trem2.

Sustained Liver HBsAg Loss and Clonal T- and B-Cell Expansion upon Therapeutic DNA Vaccination Require Low HBsAg Levels.

BACKGROUND: Suppression of HBV DNA, inhibition of HBV surface (HBsAg) production and therapeutic vaccination to reverse HBV-specific T-cell exhaustion in chronic HBV patients are likely required to achieve a functional cure. In the AAV-HBV mouse model, therapeutic vaccination can be effective in clearing HBV when HBsAg levels are low. Using a single-cell approach, we investigated the liver immune environment with different levels of HBsAg and sustained HBsAg loss through treatment with a GalNAc-HBV-siRNA followed by therapeutic vaccination. METHODS: AAV-HBV-transduced C57BL/6 mice were treated with GalNAc-HBV-siRNA to lower HBsAg levels and then vaccinated using a DNA vaccine. We used single-cell RNA and V(D)J sequencing to understand liver immune microenvironment changes. RESULTS: GalNAc-HBV-siRNA, followed by therapeutic vaccination, achieved sustained HBsAg loss in all mice. This was accompanied by CD4 follicular helper T-cell induction, polyclonal activation of CD8 T cells and clonal expansion of plasma cells that were responsible for antibody production. CONCLUSIONS: This study provides novel insights into liver immune changes at the single-cell level, highlighting the correlation between induced reduction of HBsAg levels and clonal expansion of CD4, CD8 T cells and plasma cells in the liver upon HBV siRNA and subsequent therapeutic vaccination.

Comparison of Pain Perception Between Local Infiltration and Inferior Alveolar Nerve Block Injection Techniques in Patients Undergoing Orthodontic Lower Premolar Extractions.

Introduction The most frequently used local anesthesia administration techniques for extraction of lower teeth in dentistry are local infiltration and inferior alveolar nerve block. Therapeutic extraction of premolars is the most common procedure done for patients undergoing orthodontic treatment. Inferior alveolar nerve block has been used most commonly for extraction of mandibular posterior teeth; however, it is a technique-sensitive procedure and has complications such as facial nerve palsy, trismus, and long duration of anesthesia. Local infiltration is a simple and effective technique for anesthetizing teeth prior to extraction. Aim This study aims to compare the efficacy of local anesthesia administered through inferior alveolar nerve block and local infiltration techniques for extraction of lower premolar teeth for orthodontic purposes. Materials and methods A prospective comparative study was conducted for a period of six months in which a total of 100 patients who were referred for extraction of lower premolar teeth for orthodontic purposes were included. Among 100 patients, 60 patients were males, and 40 patients were females with a mean age of 16.5 ± 1.25 years. The patients were equally divided into two groups, in which Group 1 received local infiltration and Group 2 received an inferior alveolar nerve block. The outcome parameters assessed were pain during injection and pain during extraction using the visual analog scale (VAS) score and Wong-Baker Faces Pain Rating Scale score. Statistical analysis was done using an independent sample t-test with SPSS version 23.0 software (IBM Corp., Armonk, NY) at p < 0.05 considered statistically significant. Results The difference in mean pain scores between the two groups during injection as assessed using the Faces Pain Rating Scale (p = 0.001) and VAS (p = 0.001) was statistically significant, with the infiltration group exhibiting less pain than the inferior alveolar nerve block group. The difference in mean pain scores between the two groups during extraction as assessed using the Faces Pain Rating Scale (p = 0.308) and VAS (p = 0.350) was statistically not significant, with the infiltration group not significantly differing from the inferior alveolar nerve block group. Thus, the pain during local infiltration was significantly lesser when compared to the inferior alveolar nerve block during injection, whereas pain perception during extraction was similar in patients with both injection techniques. Conclusion It can be concluded that local infiltration is less painful for the patient during injection and as efficacious as nerve block for extraction, hence local infiltration can be routinely used for lower premolar orthodontic extractions.

Multi-omic profiling reveals early immunological indicators for identifying COVID-19 Progressors.

We sought to better understand the immune response during the immediate post-diagnosis phase of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by identifying molecular associations with longitudinal disease outcomes. Multi-omic analyses identified differences in immune cell composition, cytokine levels, and cell subset-specific transcriptomic and epigenomic signatures between individuals on a more serious disease trajectory (Progressors) as compared to those on a milder course (Non-progressors). Higher levels of multiple cytokines were observed in Progressors, with IL-6 showing the largest difference. Blood monocyte cell subsets were also skewed, showing a comparative decrease in non-classical CD14-CD16+ and intermediate CD14+CD16+ monocytes. In lymphocytes, the CD8+ T effector memory cells displayed a gene expression signature consistent with stronger T cell activation in Progressors. These early stage observations could serve as the basis for the development of prognostic biomarkers of disease risk and interventional strategies to improve the management of severe COVID-19. BACKGROUND: Much of the literature on immune response post-SARS-CoV-2 infection has been in the acute and post-acute phases of infection. TRANSLATIONAL SIGNIFICANCE: We found differences at early time points of infection in approximately 160 participants. We compared multi-omic signatures in immune cells between individuals progressing to needing more significant medical intervention and non-progressors. We observed widespread evidence of a state of increased inflammation associated with progression, supported by a range of epigenomic, transcriptomic, and proteomic signatures. The signatures we identified support other findings at later time points and serve as the basis for prognostic biomarker development or to inform interventional strategies.

Transcription factor expression repertoire basis for epigenetic and transcriptional subtypes of colorectal cancers.

Colorectal cancers (CRCs) form a heterogenous group classified into epigenetic and transcriptional subtypes. The basis for the epigenetic subtypes, exemplified by varying degrees of promoter DNA hypermethylation, and its relation to the transcriptional subtypes is not well understood. We link cancer-specific transcription factor (TF) expression alterations to methylation alterations near TF-binding sites at promoter and enhancer regions in CRCs and their premalignant precursor lesions to provide mechanistic insights into the origins and evolution of the CRC molecular subtypes. A gradient of TF expression changes forms a basis for the subtypes of abnormal DNA methylation, termed CpG-island promoter DNA methylation phenotypes (CIMPs), in CRCs and other cancers. CIMP is tightly correlated with cancer-specific hypermethylation at enhancers, which we term CpG-enhancer methylation phenotype (CEMP). Coordinated promoter and enhancer methylation appears to be driven by downregulation of TFs with common binding sites at the hypermethylated enhancers and promoters. The altered expression of TFs related to hypermethylator subtypes occurs early during CRC development, detectable in premalignant adenomas. TF-based profiling further identifies patients with worse overall survival. Importantly, altered expression of these TFs discriminates the transcriptome-based consensus molecular subtypes (CMS), thus providing a common basis for CIMP and CMS subtypes.

Extraoral Versus Intraoral Approach for Removal of Styloid Process in Treatment of Eagle's Syndrome: A Report of Two Cases.

Eagle's syndrome, a condition associated with the elongation of the styloid process or calcification of the stylohyoid ligament, is clinically characterized by throat and neck pain radiating into the mastoid region. The diagnosis can be made through a thorough history, correct clinical and pathological correlation and radiographic examination. The elongated styloid process can be treated conservatively or surgically. Conservative treatment options include transpharyngeal injections of steroids and lignocaine, nonsteroidal anti-inflammatory drugs, diazepam, and the application of heat. The surgical management of Eagle's syndrome consists of two major approaches: the transoral and the transcervical approaches. In this paper, we present a comparative study of two cases of classic bilateral elongated styloid process syndrome, treated with transcervical styloidectomy and transoral styloidectomy, their surgical time, intraoperative difficulties and complications, and recovery time. In conclusion, the management of Eagle's syndrome requires a comprehensive approach that includes a thorough preoperative evaluation of the length of the styloid process via imaging and digital palpation. The choice of surgical approach, whether extraoral or transpharyngeal, should be based on factors such as the surgeon's experience and the patient's comorbidities, as well as the length and palpability of the styloid process. Our comparative study of two cases treated with transcervical and transoral styloidectomy demonstrated that the extraoral method offers a direct and well-controlled approach for excessive styloid processes, while the transpharyngeal approach is preferred for cases where the process can be easily identified by palpation. Therefore, proper patient selection and preoperative planning are essential to achieving successful outcomes with minimal complications.

Multi-omic Profiling Reveals Early Immunological Indicators for Identifying COVID-19 Progressors.

The pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has led to a rapid response by the scientific community to further understand and combat its associated pathologic etiology. A focal point has been on the immune responses mounted during the acute and post-acute phases of infection, but the immediate post-diagnosis phase remains relatively understudied. We sought to better understand the immediate post-diagnosis phase by collecting blood from study participants soon after a positive test and identifying molecular associations with longitudinal disease outcomes. Multi-omic analyses identified differences in immune cell composition, cytokine levels, and cell subset-specific transcriptomic and epigenomic signatures between individuals on a more serious disease trajectory (Progressors) as compared to those on a milder course (Non-progressors). Higher levels of multiple cytokines were observed in Progressors, with IL-6 showing the largest difference. Blood monocyte cell subsets were also skewed, showing a comparative decrease in non-classical CD14-CD16+ and intermediate CD14+CD16+ monocytes. Additionally, in the lymphocyte compartment, CD8+ T effector memory cells displayed a gene expression signature consistent with stronger T cell activation in Progressors. Importantly, the identification of these cellular and molecular immune changes occurred at the early stages of COVID-19 disease. These observations could serve as the basis for the development of prognostic biomarkers of disease risk and interventional strategies to improve the management of severe COVID-19.

G9a/GLP Targeting Ameliorates Pulmonary Vascular Remodeling in Pulmonary Arterial Hypertension.

Pulmonary arterial hypertension (PAH) is characterized by progressive vascular remodeling of small pulmonary arteries (PAs) causing sustained elevation of PA pressure, right ventricular failure, and death. Similar to cancer cells, PA smooth muscle cells (PASMCs), which play a key role in pulmonary vascular remodeling, have adopted multiple mechanisms to sustain their survival and proliferation in the presence of stress. The histone methyltransferase G9a and its partner protein GLP (G9a-like protein) have been shown to exert oncogenic effects and to serve as a buffer against an exaggerated transcriptional response. Therefore, we hypothesized that upregulation of G9a and GLP in PAH plays a pivotal role in pulmonary vascular remodeling by maintaining the abnormal phenotype of PAH-PASMCs. We found that G9a is increased in PASMCs from patients with PAH as well as in remodeled PAs from animal models. Pharmacological inhibition of G9a/GLP activity using BIX01294 and UNC0642 significantly reduced the prosurvival and proproliferative potentials of cultured PAH-PASMCs. Using RNA sequencing, further exploration revealed that G9a/GLP promotes extracellular matrix production and affords protection against the negative effects of an overactive stress response. Finally, we found that therapeutic treatment with BIX01294 reduced pulmonary vascular remodeling and lowered mean PA pressure in fawn-hooded rats. Treatment of Sugen/hypoxia-challenged mice with BIX01294 also improved pulmonary hemodynamics and right ventricular function. In conclusion, these findings indicate that G9a/GLP inhibition may represent a new therapeutic approach in PAH.

Comparison of the Effectiveness of Four Different Irrigation Solutions on Postoperative Sequelae in Patients Undergoing Lower Third Molar Surgery: A Prospective Study.

Introduction Oral and maxillofacial surgeons frequently perform the removal of impacted mandibular third molars. The success of this surgical intervention depends on meticulous surgical technique and the use of appropriate irrigants to minimize complications in the postoperative period.  Aim The aim of this study was to evaluate the efficacy of four different irrigation solutions (povidone-iodine, metronidazole, chlorhexidine gluconate (CHX), and normal saline) on postoperative sequelae like pain, trismus, swelling, and alveolar osteitis following surgical extraction of the impacted mandibular third molars. Materials and methods The current research was a randomized study carried out at Saveetha Dental College and Hospital in Chennai, India, from December 2022 to March 2023. The study population consisted of 112 participants who were referred to the Oral and Maxillofacial Surgery for the surgical removal of impacted mandibular third molars. The population was divided into four groups, with 28 in each group. They were categorized as A, B, C, and D based on the final irrigation solution used after surgical removal of the impacted teeth. In group A, patients received 0.5% povidone-iodine as the final irrigation solution; group B received 1% metronidazole; group C received 0.12% chlorhexidine gluconate (CHX); and group D received 0.9% normal saline. Patients were examined on the first and seventh postoperative days to assess pain, swelling, trismus, and alveolar osteitis. The results were analyzed with SPSS Statistics for Windows, Version 23.0 (Released 2015; IBM Corp., Armonk, New York, United States) software for Windows (Microsoft Corporation, Redmond, Washington, United States). A p-value less than 0.05 was considered statistically significant.  Results Group B experienced significantly less pain than groups A, C, and D on the first and seventh postoperative days (p<0.05). The facial swelling was significantly less on the first and seventh postoperative day in group B compared to groups A, B, and D (p<0.05). There was no statistically significant variation observed in trismus (mouth opening) across the groups on both the first postoperative and seventh postoperative days. The presence of alveolar osteitis was seen in groups A, C, and D, but no instances were reported in group B. Conclusion It can be concluded that among the four irrigation solutions used in the lower third molar surgery, metronidazole irrigation solution yielded the best results in terms of less pain, swelling, and alveolar osteitis followed by chlorhexidine. There was no difference between povidone-iodine irrigation and normal saline irrigation on the postoperative sequelae. Postoperative trismus does not depend on the irrigation solution used in the third molar surgery.

Modified Retromandibular Approach for the Management of Condylar Fractures of the Mandible.

Condylar fractures of the mandible have been of particular interest to surgeons for decades, as there is a big debate regarding the management option: conservative versus surgical modality. Conservative treatment is the preferred treatment modality for condylar head (diacapitular) fractures. Currently, surgical modality is favored and surgeons are opting for open reduction and internal fixation for diacapitular fractures as it reestablishes the anatomical position of the fragments and disc, and permits immediate functional mobility of the jaw, thereby reducing the chances of occurrence of temporomandibular joint ankylosis. This case series enumerates the pros and cons of open reduction and internal fixation of condylar fractures of the mandible occurring at various levels using a modified retromandibular approach and highlights that this can be considered as one of the treatment options for condylar fractures.

A Rare Case of Benign Osteoblastoma of the Mandible.

Benign osteoblastoma is an uncommon, solitary, osteoid, bone-producing tumor containing a rich vascularized delicate fibrous stroma and active osteoblasts. Benign osteoblastoma is a unique benign bone neoplasm that mostly affects the vertebrae and long tubular bones and rarely affects the maxillofacial skeleton. Many bone-producing lesions have clinical, radiological, and histological features that are similar to osteoblastoma. Benign osteoblastoma manifests clinically as localized swelling of the jaw, presenting as an asymptomatic or a symptomatic lesion, and proper investigations are necessary for accurate diagnosis. It usually manifests in the second and third decades of life predominantly in males. In this report, we present a case of benign osteoblastoma of the mandible in a 39-year-old male patient. The lesion was treated by complete surgical excision, and uneventful wound healing was observed during the one-year postoperative follow-up period.

Distinct stromal and immune cell interactions shape the pathogenesis of rheumatoid and psoriatic arthritis.

OBJECTIVES: Immune and stromal cell communication is central in the pathogenesis of rheumatoid arthritis (RA) and psoriatic arthritis (PsA), however, the nature of these interactions in the synovial pathology of the two pathotypes can differ. Identifying immune-stromal cell crosstalk at the site of inflammation in RA and PsA is challenging. This study creates the first global transcriptomic analysis of the RA and PsA inflamed joint and investigates immune-stromal cell interactions in the pathogenesis of synovial inflammation. METHODS: Single cell transcriptomic profiling of 178 000 synovial tissue cells from five patients with PsA and four patients with RA, importantly, without prior sorting of immune and stromal cells. This approach enabled the transcriptomic analysis of the intact synovial tissue and identification of immune and stromal cell interactions. State of the art data integration and annotation techniques identified and characterised 18 stromal and 14 immune cell clusters. RESULTS: Global transcriptomic analysis of synovial cell subsets identifies actively proliferating synovial T cells and indicates that due to differential λ and κ immunoglobulin light chain usage, synovial plasma cells are potentially not derived from the local memory B cell pool. Importantly, we report distinct fibroblast and endothelial cell transcriptomes indicating abundant subpopulations in RA and PsA characterised by differential transcription factor usage. Using receptor-ligand interactions and downstream target characterisation, we identify RA-specific synovial T cell-derived transforming growth factor (TGF)-ß and macrophage interleukin (IL)-1ß synergy in driving the transcriptional profile of FAPα+THY1+ invasive synovial fibroblasts, expanded in RA compared with PsA. In vitro characterisation of patient with RA synovial fibroblasts showed metabolic switch to glycolysis, increased adhesion intercellular adhesion molecules 1 expression and IL-6 secretion in response to combined TGF-ß and IL-1ß treatment. Disrupting specific immune and stromal cell interactions offers novel opportunities for targeted therapeutic intervention in RA and PsA.

An Uncommon Presentation of Ossifying Fibroma in the Maxilla.

Ossifying fibromas are rare, benign, nonaggressive fibro-osseous lesions that manifest in the craniofacial region. Ossifying fibromas are benign tumors of bone, commonly involving the posterior dentate mandible in middle-aged individuals with a female predilection. Clinical manifestations are an asymptomatic expansion of the dentate mandible, with infrequent maxillary lesions. Benign fibro-osseous lesions of the maxilla exhibit similar histopathological findings. Cone-beam computed tomography scan plays an important role in diagnosing and understanding the invasiveness of this lesion. This case report describes an uncommon presentation of ossifying fibroma in the posterior maxilla in an adult male patient. Treatment consisted of surgical excision, and wound healing was uneventful during the one-year postoperative follow-up period.

Atypical Presentation of Peripheral Ossifying Fibroma in the Mandible.

Peripheral ossifying fibroma (POF) is a localized reactive enlargement of the gingiva often associated with the papilla and originate from underneath the periodontium. POF occurs predominantly in females, especially in the anterior maxillary region of young adults. The histopathological examination provides a confirmatory diagnosis of such lesions due to their heterogeneous clinical and radiographic characteristics. This case report describes an atypical presentation of POF in the anterior mandible in an adult male patient. Treatment consisted of complete surgical excision and gingival curettage resulting in uneventful healing during the postoperative follow-up period.

Implication of EZH2 in the Pro-Proliferative and Apoptosis-Resistant Phenotype of Pulmonary Artery Smooth Muscle Cells in PAH: A Transcriptomic and Proteomic Approach.

Pulmonary arterial hypertension (PAH) is a progressive disorder characterized by a sustained elevation of pulmonary artery (PA) pressure, right ventricular failure, and premature death. Enhanced proliferation and resistance to apoptosis (as seen in cancer cells) of PA smooth muscle cells (PASMCs) is a major pathological hallmark contributing to pulmonary vascular remodeling in PAH, for which current therapies have only limited effects. Emerging evidence points toward a critical role for Enhancer of Zeste Homolog 2 (EZH2) in cancer cell proliferation and survival. However, its role in PAH remains largely unknown. The aim of this study was to determine whether EZH2 represents a new factor critically involved in the abnormal phenotype of PAH-PASMCs. We found that EZH2 is overexpressed in human lung tissues and isolated PASMCs from PAH patients compared to controls as well as in two animal models mimicking the disease. Through loss- and gain-of-function approaches, we showed that EZH2 promotes PAH-PASMC proliferation and survival. By combining quantitative transcriptomic and proteomic approaches in PAH-PASMCs subjected or not to EZH2 knockdown, we found that inhibition of EZH2 downregulates many factors involved in cell-cycle progression, including E2F targets, and contributes to maintain energy production. Notably, we found that EZH2 promotes expression of several nuclear-encoded components of the mitochondrial translation machinery and tricarboxylic acid cycle genes. Overall, this study provides evidence that, by overexpressing EZH2, PAH-PASMCs remove the physiological breaks that normally restrain their proliferation and susceptibility to apoptosis and suggests that EZH2 or downstream factors may serve as therapeutic targets to combat pulmonary vascular remodeling.

Rheumatoid arthritis CD14+ monocytes display metabolic and inflammatory dysfunction, a phenotype that precedes clinical manifestation of disease.

INTRODUCTION: This study investigates the metabolic activity of circulating monocytes and their impact on pro-inflammatory responses in RA and explores whether this phenotype is already primed for inflammation before clinical manifestations of disease. METHODS: Blood was collected and CD14+ monocytes isolated from healthy control donors (HC), individuals at-risk (IAR) and RA patients. Monocyte frequency in blood and synovial tissue was assessed by flow cytometry. Inflammatory responses and metabolic analysis ± specific inhibitors were quantified by RT-PCR, Western blot, migration assays, Seahorse-XFe-technology, mitotracker assays and transmission electron microscopy. Transcriptomic analysis was performed on HC, IAR and RA synovial tissue. RESULTS: CD14+ monocytes from RA patients are hyper-inflammatory following stimulation, with significantly higher expression of cytokines/chemokines than those from HC. LPS-induced RA monocyte migratory capacity is consistent with increased monocyte frequency in RA synovial tissue. RA CD14+ monocytes show enhanced mitochondrial respiration, biogenesis and alterations in mitochondrial morphology. Furthermore, RA monocytes display increased levels of key glycolytic enzymes HIF1α, HK2 and PFKFB3 and demonstrate a reliance on glucose consumption, blockade of which abrogates pro-inflammatory mediator responses. Blockade of STAT3 activation inhibits this forced glycolytic flux resulting in metabolic reprogramming and resolution of inflammation. Interestingly, this highly activated monocytic phenotype is evident in IAR of developing disease, in addition to an enhanced monocyte gene signature observed in synovial tissue from IAR. CONCLUSION: RA CD14+ monocytes are metabolically re-programmed for sustained induction of pro-inflammatory responses, with STAT3 identified as a molecular regulator of metabolic dysfunction. This phenotype precedes clinical disease onset and may represent a potential pathway for therapeutic targeting early in disease.

Integration of the Transcriptome and Genome-Wide Landscape of BRD2 and BRD4 Binding Motifs Identifies Key Superenhancer Genes and Reveals the Mechanism of Bet Inhibitor Action in Rheumatoid Arthritis Synovial Fibroblasts.

Fibroblast-like synoviocytes (FLS), one of the main cell types of the rheumatoid arthritis (RA) synovium, possess phenotypic and molecular characteristics of transformed cells. JQ1, an inhibitor of the bromodomain and extra terminal domain family that includes BRD2, BRD3, BRD4, and BRDt, has shown efficacy in models of arthritis. We demonstrate that the active isomer of JQ1 but not its inactive isomer inhibits IL-1ß-induced RA-FLS activation and proliferation. To understand the mechanism of JQ1 action, we subjected JQ1-treated RA-FLS to transcriptional profiling and determined BRD2 and BRD4 cistromes by identifying their global chromatin binding sites. In addition, assay for transposable accessible chromatin by high throughput sequencing was employed to identify open and closed regions of chromatin in JQ1-treated RA-FLS. Through an integrated analysis of expression profiling, Brd2/Brd4 cistrome data, and changes in chromatin accessibility, we found that JQ1 inhibited key BRD2/BRD4 superenhancer genes, downregulated multiple crucial inflammatory pathways, and altered the genome-wide occupancy of critical transcription factors involved in inflammatory signaling. Our results suggest a pleiotropic effect of JQ1 on pathways that have shown to be individually efficacious in RA (in vitro, in vivo, and/or in humans) and provide a strong rationale for targeting BRD2/BRD4 for disease treatment and interception.