Frontal sinus size in South African Later Stone Age Holocene Khoe-San.

Frontal size variation is comparatively poorly sampled among sub-Saharan African populations. This study assessed frontal sinus size in a sample of Khoe-San skeletal remains from South African Later Stone Age contexts. Volumes were determined from CT scans of 102 adult crania; individual sex could be estimated in 82 cases. Sinus volume is not sexually dimorphic in this sample. The lack of frontal sinus aplasia is concordant with the low incidences recorded for other sub-Saharan African and most other global populations save those that inhabit high latitudes. There is considerable variation in frontal sinus size among global populations, and the Khoe-San possess among the smallest. The Khoe-San have rather diminutive sinuses compared to sub-Saharan Bantu-speaking populations but resemble a northern African (Sudanese) population. Genetic studies indicate the earliest population divergence within Homo sapiens to have been between the Khoe-San and all other living groups, and that this likely occurred in Africa during the span of Marine Isotope Stages 8-6. There is scant information on frontal sinus development among Late Quaternary African fossils that are likely either closely related or attributable to Homo sapiens. Among these, the MIS 3 cranium from Hofmeyr, South Africa, exhibits distinct Khoe-San cranial affinities and despite its large size has a very small frontal sinus. This raises the possibility that the small frontal sinuses of the Holocene South African Khoe-San might be a feature retained from an earlier MIS 3 population.

Illuminating the impact of γδ T cells in man and mice in spondylarthritides.

Spondylarthritides (SpA) are a group of autoinflammatory diseases affecting the spine, peripheral joints, and entheses, including axial spondyloarthritis (axSpA) and psoriatic arthritis. AxSpA has a multifactorial etiology that involves genetic predispositions, such as HLA-B27 and IL-23R. Although HLA-B27 is strongly associated with axSpA, its role remains unclear. GWAS studies have demonstrated that genetic polymorphisms related to the IL-23 pathway occur throughout the spectrum of SpA, including but not limited to axSpA and PsA. IL-23 promotes the production of IL-17, which drives inflammation and tissue damage. This pathway contributes not only to peripheral enthesitis but also to spinal inflammation. γδ T cells in axSpA express IL-23R and RORγt, crucial for their activation, although specific pathogenic cells and factors remain elusive. Despite drug efficacy in PsA, IL-23R inhibition is ineffective in axSpA. Murine models provide valuable insights into the intricate cellular and molecular interactions that contribute to the development and progression of SpA. Those models are useful tools to elucidate the dynamics of γδ T cell involvement, offering insights into disease mechanisms and potential therapeutic targets. This review aims to illuminate the complex interplay between IL-23 and γδ T cells in SpA pathogenesis, emphasizing their roles in chronic inflammation, tissue damage, and disease heterogeneity.

The taphonomic effects of long-term burial in the South African Highveld.

Taphonomy studies the environmental effects on remains from the time of deposition to the time of recovery and has been integrated into the field of forensic anthropology. The changes to skeletal remains are dependent on the method of disposal and the surrounding environment. This study focused on buried remains where the type and chemical composition of the soil and the microorganisms present need to be considered. The aim was to investigate the type, frequency, and correlations of the taphonomic alterations of buried domestic pigs. Six taphonomic alterations were observed which included depositional staining, adipocere formation, bone weathering, acidic soil corrosion, and plant, and animal activity. Depositional staining, weathering and plant activity were the most common alterations followed by adipocere which was present on 92.3% of the remains. The bones were mostly stained dark brown and brown; however, the trunk region was the only region to present with black staining. The right sides were darker than the left due to the body positioning as most pigs were placed on their right sides and thus were in direct contact with the cadaver decomposition island. Additionally, the right sides presented with more adipocere as well as increased plant activity suggesting that the soil retained water. Darker stains were correlated with a more complete skeleton as adipocere provides some protection. The study confirms that there are various complicated relationships between different taphonomic alterations. A good understanding of them is needed in forensic anthropology to assist in reconstructing the events that occur after death.

Disparity in organ distribution in Gauteng province in South Africa: Challenges and solutions.

BACKGROUND: Despite South Africa's rich heritage as pioneers in organ transplantation, access to organs remains a major issue in the Gauteng province. This is secondary to an array of socioeconomic and political factors that have implications for organ distribution. Our aim was to assess the contribution of the public sector to solid organ transplantation in Gauteng province and compare the distribution of solid organs between the recipient groups. METHODS: This was a retrospective registry review of consented brain-dead donors from the public sector within Gauteng from January 1, 2016, to June 30, 2021, coordinated at Charlotte Maxeke Johannesburg Academic Hospital, a tertiary academic hospital. RESULTS: Records of 49 deceased donors were analyzed. Mean donor age was 31.5 years with the age group 30-39 years constituting the majority of deceased donors at 15/49 (30.6%); 10/49 (16%) were from pediatric donors. There was a significant discrepancy in allocation between public and private sector in cardiac (p = .012) and liver allocation (p < .001) and adult and pediatric recipients for all solid organs (p < .001). There was a significant increase in the rate and number (p = .0026) of pediatric kidney transplants occurring after March 1, 2020, when there was a transition to a public sector-mandated kidney transplant waitlist. CONCLUSION: Current disparities in organ distribution have a significant impact on public sector recipients, especially pediatric patients. This is likely secondary to paucity of legislation and resource limitations which would benefit from improved governmental policies and explicit pediatric prioritization policies in transplant units.

Notch ligands are biomarkers of anti-TNF response in RA patients.

Notch and its ligands play a critical role in rheumatoid arthritis (RA) pathogenesis. Hence, studies were conducted to delineate the functional significance of the Notch pathway in RA synovial tissue (ST) cells and the influence of RA therapies on their expression. Morphological studies reveal that JAG1, DLL4, and Notch1 are highly enriched in RA ST lining and sublining CD68+CD14+ MΦs. JAG1 and DLL4 transcription is jointly upregulated in RA MΦs reprogrammed by TLR4/5 ligation and TNF, whereas Syntenin-1 exposure expands JAG1, DLL4, and Notch1 expression levels in these cells. Single-cell RNA-seq data exhibit that JAG1 and Notch3 are overexpressed on all fibroblast-like synoviocyte (FLS) subpopulations, in parallel, JAG2, DLL1, and Notch1 expression levels are modest on RA FLS and are predominately potentiated by TLR4 ligation. Intriguingly, JAG1, DLL1/4, and Notch1/3 are presented on RA endothelial cells, and their expression is mutually reconfigured by TLR4/5 ligation in the endothelium. Synovial JAG1/JAG2/DLL1 or Notch1/3 transcriptomes were unchanged in patients who received disease-modifying anti-rheumatic drugs (DMARDs) or IL-6R Ab therapy regardless of disease activity score. Uniquely, RA MΦs and endothelial cells rewired by IL-6 displayed DLL4 transcriptional upregulation, and IL-6R antibody treatment disrupted RA ST DLL4 transcription in good responders compared to non-responders or moderate responders. Nevertheless, the JAG1/JAG2/DLL1/DLL4 transcriptome was diminished in anti-TNF good responders with myeloid pathotype and was unaltered in the fibroid pathotype except for DLL4. Taken together, our findings suggest that RA myeloid Notch ligands can serve as markers for anti-TNF responsiveness and trans-activate Notch receptors expressed on RA FLS and/or endothelial cells.

The genetic legacy of the expansion of Bantu-speaking peoples in Africa.

The expansion of people speaking Bantu languages is the most dramatic demographic event in Late Holocene Africa and fundamentally reshaped the linguistic, cultural and biological landscape of the continent1-7. With a comprehensive genomic dataset, including newly generated data of modern-day and ancient DNA from previously unsampled regions in Africa, we contribute insights into this expansion that started 6,000-4,000 years ago in western Africa. We genotyped 1,763 participants, including 1,526 Bantu speakers from 147 populations across 14 African countries, and generated whole-genome sequences from 12 Late Iron Age individuals8. We show that genetic diversity amongst Bantu-speaking populations declines with distance from western Africa, with current-day Zambia and the Democratic Republic of Congo as possible crossroads of interaction. Using spatially explicit methods9 and correlating genetic, linguistic and geographical data, we provide cross-disciplinary support for a serial-founder migration model. We further show that Bantu speakers received significant gene flow from local groups in regions they expanded into. Our genetic dataset provides an exhaustive modern-day African comparative dataset for ancient DNA studies10 and will be important to a wide range of disciplines from science and humanities, as well as to the medical sector studying human genetic variation and health in African and African-descendant populations.

Metabolic reprogramming by Syntenin-1 directs RA FLS and endothelial cell-mediated inflammation and angiogenesis.

A novel rheumatoid arthritis (RA) synovial fluid protein, Syntenin-1, and its receptor, Syndecan-1 (SDC-1), are colocalized on RA synovial tissue endothelial cells and fibroblast-like synoviocytes (FLS). Syntenin-1 exacerbates the inflammatory landscape of endothelial cells and RA FLS by upregulating transcription of IRF1/5/7/9, IL-1ß, IL-6, and CCL2 through SDC-1 ligation and HIF1α, or mTOR activation. Mechanistically, Syntenin-1 orchestrates RA FLS and endothelial cell invasion via SDC-1 and/or mTOR signaling. In Syntenin-1 reprogrammed endothelial cells, the dynamic expression of metabolic intermediates coincides with escalated glycolysis along with unchanged oxidative factors, AMPK, PGC-1α, citrate, and inactive oxidative phosphorylation. Conversely, RA FLS rewired by Syntenin-1 displayed a modest glycolytic-ATP accompanied by a robust mitochondrial-ATP capacity. The enriched mitochondrial-ATP detected in Syntenin-1 reprogrammed RA FLS was coupled with mitochondrial fusion and fission recapitulated by escalated Mitofusin-2 and DRP1 expression. We found that VEGFR1/2 and Notch1 networks are responsible for the crosstalk between Syntenin-1 rewired endothelial cells and RA FLS, which are also represented in RA explants. Similar to RA explants, morphological and transcriptome studies authenticated the importance of VEGFR1/2, Notch1, RAPTOR, and HIF1α pathways in Syntenin-1 arthritic mice and their obstruction in SDC-1 deficient animals. Consistently, dysregulation of SDC-1, mTOR, and HIF1α negated Syntenin-1 inflammatory phenotype in RA explants, while inhibition of HIF1α impaired synovial angiogenic imprint amplified by Syntenin-1. In conclusion, since the current therapies are ineffective on Syntenin-1 and SDC-1 expression in RA synovial tissue and blood, targeting this pathway and its interconnected metabolic intermediates may provide a novel therapeutic strategy.

Treatment of rheumatoid arthritis with baricitinib or upadacitinib is associated with reduced scaffold protein NEDD9 levels in CD4+ T cells.

The JAK/STAT pathway plays a crucial role in the pathogenesis of rheumatoid arthritis (RA) and JAK inhibitors have emerged as a new group of effective drugs for RA treatment. Recently, high STAT3 levels have been associated with the upregulation of the scaffold protein NEDD9, which is a regulator of T-cell trafficking and promotes collagen-induced arthritis (CIA). In this study, we aimed to reveal how treatment with JAK inhibitors affects NEDD9 in CD4+ T cells from RA patients. We analyzed NEDD9 expression in CD4+ T cells from 50 patients treated with either baricitinib, tofacitinib, or upadacitinib and performed cell migration assays to assess the potential influence of JAK inhibitor treatment on CD4+ T-cell migration. We observed that treatment with baricitinib and upadacitinib is associated with reduced NEDD9 expression in CD4+ T cells. In contrast, NEDD9 levels were not altered during treatment with tofacitinib. Moreover, treatment with baricitinib was associated with a significantly reduced migratory capacity of effector CD4+ T cells but not with impaired migration of Treg cells. This study reveals previously unknown associations between JAK inhibitor treatment and NEDD9 expression and indicates that JAK inhibitors could reduce effector T-cell migration.

Significance of IL-34 and SDC-1 in the pathogenesis of RA cells and preclinical models.

IL-34 shares a common receptor with M-CSF, while it can bind to other distinct receptors including protein-tyrosine phosphatase zeta (PTPζ), and syndecan1 (SDC-1). In physiological conditions, IL-34 has a critical role in the maintenance and development of Langerhans and microglial cells in part through PTPζ ligation. Conversely, in autoimmune diseases such as rheumatoid arthritis (RA), SDC-1-induced phosphorylation of M-CSFR was responsible for the pathological effect of IL-34 in patient cells and/or preclinical models. Intriguingly, enrichment of IL-34 is strongly linked to rheumatoid factor (RF), disease activity score (DAS)28, erythrocyte sedimentation rate (ESR), c-reactive protein (CRP), and radiographic progression. In parallel, IL-34-induced naïve cell reprogramming into glycolytic RA CD14+CD86+GLUT1+ macrophage was dysregulated via M-CSFR or SDC-1 antibody therapy. Moreover, the inflammatory and erosive imprints of IL-34 arthritic mice were mitigated by glucose uptake inhibition and SDC-1, or RAG deficiency through nullifying macrophage metabolic rewiring and their ability to advance Th1/Th17 cell polarization. Consistently, IL-34-/- and SDC-1-/- mice could effectively impair CIA joint inflammation, osteoclast formation, and neovascularization by restraining monocyte infiltration as well as suppressing the inflammatory macrophage and T effector cell reconfiguration via metabolic deactivation. In conclusion, targeting IL-34/SDC-1 signaling, or its interconnected metabolites can uniquely intercept the crosstalk between glycolytic RA myeloid and lymphoid cells and their ability to trigger arthritis.

Syntenin-1-mediated arthritogenicity is advanced by reprogramming RA metabolic macrophages and Th1 cells.

OBJECTIVES: Syntenin-1, a novel endogenous ligand, was discovered to be enriched in rheumatoid arthritis (RA) specimens compared with osteoarthritis synovial fluid and normal synovial tissue (ST). However, the cellular origin, immunoregulation and molecular mechanism of syntenin-1 are undescribed in RA. METHODS: RA patient myeloid and lymphoid cells, as well as preclinical models, were used to investigate the impact of syntenin-1/syndecan-1 on the inflammatory and metabolic landscape. RESULTS: Syntenin-1 and syndecan-1 (SDC-1) co-localise on RA ST macrophages (MΦs) and endothelial cells. Intriguingly, blood syntenin-1 and ST SDC-1 transcriptome are linked to cyclic citrullinated peptide, erythrocyte sedimentation rate, ST thickness and bone erosion. Metabolic CD14+CD86+GLUT1+MΦs reprogrammed by syntenin-1 exhibit a wide range of proinflammatory interferon transcription factors, monokines and glycolytic factors, along with reduced oxidative intermediates that are downregulated by blockade of SDC-1, glucose uptake and/or mTOR signalling. Inversely, IL-5R and PDZ1 inhibition are ineffective on RA MΦs-reprogrammed by syntenin-1. In syntenin-1-induced arthritis, F4/80+iNOS+RAPTOR+MΦs represent glycolytic RA MΦs, by amplifying the inflammatory and glycolytic networks. Those networks are abrogated in SDC-1-/- animals, while joint prorepair monokines are unaffected and the oxidative metabolites are moderately replenished. In RA cells and/or preclinical model, syntenin-1-induced arthritogenicity is dependent on mTOR-activated MΦ remodelling and its ability to cross-regulate Th1 cells via IL-12 and IL-18 induction. Moreover, RA and joint myeloid cells exposed to Syntenin-1 are primed to transform into osteoclasts via SDC-1 ligation and RANK, CTSK and NFATc1 transcriptional upregulation. CONCLUSION: The syntenin-1/SDC-1 pathway plays a critical role in the inflammatory and metabolic landscape of RA through glycolytic MΦ and Th1 cell cross-regulation (graphical abstract).

The impact of robotic-assisted transperineal biopsy of the prostate on erectile function.

BACKGROUND: Prostate biopsy represents one of the most frequently performed urologic procedures worldwide and therefore presupposes knowledge on potential effects like on the erectile function, especially in extensive or repeated biopsies. The robotic-assisted biopsy system (Mona Lisa) offers a minimal invasive approach via only two incision points ensuring maximal accuracy combined with protection of the neurovascular bundle of the prostate. OBJECTIVE: Our purpose was to analyse the impact of robotic-assisted transperineal biopsy of the prostate on the erectile function. METHODS: Our prospective study analyses the outcomes of 210 patients, who had undergone minimal-invasive, transperineal robotic-assisted biopsy of the prostate at the University Hospital Basel from January 2020 to March 2022 and provided sufficient data. Of these, 157 (74.8%) were included in final analysis. RESULTS: Mean (range) age, prostate volume, PSA and IIEF-5 score at baseline were 63.8 years (46.1-83.6), 46.4 ml (9-310), 13.2 ng/ml (0.2-561), and 18.8 points (6-25), respectively. EF before and 1 month after intervention was assessed with the IIEF-5 questionnaire for the whole cohort. No significant change of IIEF-5 was observed for the whole cohort with a mean (± SD) decrease of 0.4 (± 3.1) points. Except for patients > 69 years, subgroup analysis revealed no change of IIEF-5 in statistically significant manner for all subgroups. Number of biopsy cores (< 20 and ≥ 20), previous biopsies and active surveillance showed no significant influence. CONCLUSION: Our results suggest that the minimally invasive and highly precise robotic technique can spare the erectile function without limiting the extent of biopsy and without compromising diagnostic accuracy.

Safety profile of robotic-assisted transperineal MRI-US-fusion guided biopsy of the prostate.

Introduction: Robotic-assisted transperineal MRI-US-fusion guided biopsy of the prostate is a novel and highly accurate procedure. The aim of this study was to evaluate the MonaLisa prostate biopsy system in terms of safety, tolerability, and patient-related outcomes. Methods: This prospective study included 228 patients, who had undergone Robotic-assisted transperineal MRI-US-fusion guided biopsy of the prostate at the University Hospital Basel between January 2020 and June 2022. Peri-operative side effects, functional outcomes and patient satisfaction were assessed. Results: Mean pain score on the day of biopsy was 1.3 points on VAS, which remained constant on the day after biopsy. Overall, 32 of 228 patients (14%) developed grade I complications according to Clavien-Dindo classification. No higher-grade complications occurred. Gross haematuria, hematospermia and acute urinary retention occurred in 145/228 (63.6%), 98/228 (43%) and 32/228 (14%) patients, respectively. One patient (0.4%) developed urinary tract infection. Conclusions: Robotic-assisted transperineal MRI-US-fusion guided biopsy of the prostate performed under general anesthesia is a safe and well tolerated procedure. This technique allows to omit perioperative prophylaxis and at the same time minimizes the risk of infectious complications. We attribute the favorable risk profile and tolerability to the minimal invasive approach via two entry points.

Truncated isoforms of GPSM2 containing the GoLoco motif region promote CD4+ T-cell migration in SLE.

OBJECTIVE: SLE is an autoimmune disease with a complex pathogenesis. T-cell infiltration into organs contributes to inflammation and organ damage in SLE. Recently, G-protein signalling modulator 2 (GPSM2) has been shown to be implicated in T-cell migration. METHODS: We analysed the expression levels of GPSM2 and of a truncated isoform of GPSM2 containing the GoLoco motif region in CD4+ T cells from patients with SLE and from healthy individuals by western blot. In a next step, we studied the role of the truncated GPSM2 isoform using a CD4+ T-cell migration assay. RESULTS: Our experiments revealed comparable levels of GPSM2 in CD4+ T cells from patients with SLE and healthy controls. In contrast, the truncated 35 kDa isoform of GPSM2 was significantly more highly expressed in CD4+ T cells from patients with SLE as compared with healthy subjects. Antibody-mediated blockade of the 35 kDa GPSM2 isoform reduced the in vitro capacity of CD4+ T cells to migrate towards the chemokine CCL20. CONCLUSIONS: A truncated GPSM2 isoform containing the GoLoco motif region is upregulated in CD4+ T cells from patients with SLE and promotes CD4+ T-cell migration. Targeting this isoform with specific antibodies might be a promising approach to reduce CD4+ T-cell infiltration into inflamed tissues and to prevent organ damage in SLE.

Prognostic factors and scoring systems associated with outcome in pediatric acute liver failure.

BACKGROUND: Pediatric acute liver failure (PALF) is an uncommon, devastating illness with significant mortality. Liver transplantation remains the mainstay of treatment for irreversible PALF. The purpose of this study was to determine the etiology and prognostic factors associated with outcome of PALF in South Africa and to evaluate prognostic scoring systems used. METHODS: Records of 45 pediatric patients younger than 16 years of age who presented with PALF from 1 January 2015 till 31 October 2020 were analysed. Patients were divided into two groups with one group consisting of patients with spontaneous recovery of the liver with supportive treatment (6/45:13.3%) and the second group consisting of patients with poor outcomes who demised (19/45: 42%) or underwent liver transplantation (20/45: 44%). RESULTS: The median age of presentation was 3.3 years (IQR 1.8-6.9) with the 1-5 years age group constituting majority of patients (55.6%). Median time to follow up was 6.1 months (IQR 0.2-28.8). Higher liver injury unit scores were observed in patients who had poorer outcomes (P = 0.008) with a threshold of greater than 246 having a sensitivity of 84% and specificity of 83% (P < 0.001). Higher peak PELD/MELD (P = 0.006) and admission UKELD (P = 0.002) scores, were found in patients with poorer outcomes. Kings College Hospital criteria (KCHC) was useful in predicting which patients would die without liver transplantation (P = 0.002). Liver transplantation was performed in 20/45 (44%) patients with a post transplantation 1 year patient and graft survival of 80%. CONCLUSION: Although, survival of PALF patients was lower than high and other low-middle income countries, outcomes post transplantation were good. Our study demonstrates the utility of dynamic scoring systems in PALF patients, it underscores the need for early referral and clinical monitoring in a tertiary center once the criteria for PALF have been met.

Healthcare disparity and its associations with cytomegalovirus disease in pediatric liver transplant recipients in South Africa.

BACKGROUND: Cytomegalovirus (CMV) infection and disease are preventable complications following pediatric liver transplantation (PLT), despite the use of prophylaxis to minimize the risk of CMV disease. We evaluated the incidence and complications of CMV disease in PLT recipients in South Africa (SA), with particular reference to potential differences in outcome between state and private sector patients. METHODS: Medical records of patients younger than 16 years of age who received liver transplants between January 1, 2012, and August 31, 2018 were analyzed. RESULTS: Records of all 150 PLT patients were retrieved. The median age at transplant was 29.2 months (95% confidence interval 15.6-58.4) and follow-up was 46.3 months (interquartile range 27.6-63.1). Sixty-six (44%) patients were high risk, 79 (52.7%) were intermediate risk, and five (3.3%) were low risk for CMV infection. Forty-three (28.9%) patients had CMV DNAemia following transplantation, and 30 (20.1%) developed CMV disease. Receipt of care in the private sector was consistently associated with a lower hazard of CMV disease (adjusted hazard ratio [aHR] ranging from 0.36 to 0.43) and a consistently lower hazard of death among recipients at high risk for CMV disease and/or those who developed CMV disease (aHR ranging from 0.28 to 0.33). CONCLUSION: Receipt of care in the private health sector was associated with a consistently lower hazard of CMV disease and death in individuals with CMV disease and/or at high risk for CMV disease. Policies aimed at creating a more equitable healthcare system in SA may mitigate the differential burden of illness associated with CMV in PLT recipients.

Regulatory T Cells from Patients with Rheumatoid Arthritis Are Characterized by Reduced Expression of Ikaros Zinc Finger Transcription Factors.

Regulatory T (Treg) cells play an important role in immune tolerance and contribute to the prevention of autoimmune diseases, including rheumatoid arthritis (RA). The differentiation, function and stability of Treg cells is controlled by members of the Ikaros zinc finger transcription factor family. In this study, we aimed to reveal how the expression of Ikaros transcription factors is affected by disease activity in RA. Therefore, we analyzed the ex vivo expression of Ikaros, Helios, Aiolos and Eos in Treg cells, Th17 cells and Th1 cells from RA patients by flow cytometry. We found significantly reduced expression of Helios, Aiolos and Eos in Treg cells from RA patients as compared to healthy controls. Moreover, Helios and Aiolos levels correlated with disease activity, as assessed by DAS28-CRP. In addition, Ikaros, Helios and Aiolos were significantly downregulated in Th1 cells from RA patients, while no difference between healthy individuals and RA was observed in Th17 cells. In summary, Helios and Aiolos expression in Treg cells correlates with disease activity and the expression levels of Ikaros transcription factors are diminished in Treg cells from RA patients. This observation could explain the reduced stability of Treg cells in RA.

Inhibition of IRAK4 dysregulates SARS-CoV-2 spike protein-induced macrophage inflammatory and glycolytic reprogramming.

Escalated innate immunity plays a critical role in SARS-CoV-2 pathology; however, the molecular mechanism is incompletely understood. Thus, we aim to characterize the molecular mechanism by which SARS-CoV-2 Spike protein advances human macrophage (MÏ´) inflammatory and glycolytic phenotypes and uncover novel therapeutic strategies. We found that human MÏ´s exposed to Spike protein activate IRAK4 phosphorylation. Blockade of IRAK4 in Spike protein-stimulated MÏ´s nullifies signaling of IRAK4, AKT, and baseline p38 without affecting ERK and NF-κB activation. Intriguingly, IRAK4 inhibitor (IRAK4i) rescues the SARS-CoV-2-induced cytotoxic effect in ACE2+HEK 293 cells. Moreover, the inflammatory reprogramming of MÏ´s by Spike protein was blunted by IRAK4i through IRF5 and IRF7, along with the reduction of monokines, IL-6, IL-8, TNFα, and CCL2. Notably, in Spike protein-stimulated MÏ´s, suppression of the inflammatory markers by IRAK4i was coupled with the rebalancing of oxidative phosphorylation over metabolic activity. This metabolic adaptation promoted by IRAK4i in Spike protein-activated MÏ´s was shown to be in part through constraining PFKBF3, HIF1α, cMYC, LDHA, lactate expression, and reversal of citrate and succinate buildup. IRAK4 knockdown could comparably impair Spike protein-enhanced inflammatory and metabolic imprints in human MÏ´s as those treated with ACE2, TLR2, and TLR7 siRNA. Extending these results, in murine models, where human SARS-CoV-2 Spike protein was not recognized by mouse ACE2, TLRs were responsible for the inflammatory and glycolytic responses instigated by Spike protein and were dysregulated by IRAK4i therapy. In conclusion, IRAK4i may be a promising strategy for severe COVID-19 patients by counter-regulating ACE2 and TLR-mediated MÏ´ hyperactivation. IRAK4i therapy counteracts MÏ´ inflammatory and glycolytic reprogramming triggered by Spike protein. This study illustrates that SARS-CoV-2 Spike protein activates IRAK4 signaling via ACE2 as well as TLR2 and TLR7 sensing in human MÏ´s. Remarkably, IRAK4i treatment can dysregulate both ACE-dependent and independent (via TLR sensing) SARS-CoV-2 Spike protein-activated inflammatory and metabolic imprints.

Significance of IL-7 and IL-7R in RA and autoimmunity.

While physiological levels of IL-7 are essential for T cell proliferation, survival and co-stimulation, its escalated concentration has been associated with autoimmune diseases such as Rheumatoid arthritis (RA). Expression of IL-7 and IL-7R in RA monocytes is linked to disease activity score and TNF transcription. TNF stimulation can modulate IL-7 secretion and IL-7R frequency in myeloid cells, however, only IL-7R transcription levels are downregulated in anti-TNF responsive patients. Elevated levels of IL-7 in RA synovial tissue and fluid are involved in attracting RA monocytes into the inflammatory joints and remodeling them into proinflammatory macrophages and mature osteoclasts. Further, IL-7 amplification of RA Th1 cell differentiation and IFNγ secretion, can directly prime myeloid IL-7R expression and thereby exacerbate IL-7-mediated joint inflammatory and erosive imprints. In parallel, IL-7 accentuates joint angiogenesis by expanding the production of proangiogenic factors from RA macrophages and endothelial cells. In preclinical models, blockade of IL-7 or IL-7R can effectively impair joint inflammation, osteoclast formation, and neovascularization primarily by impeding monocyte and endothelial cell infiltration as well as inhibition of pro-inflammatory macrophage and Th1/Th17 cell differentiation. In conclusion, disruption of IL-7/IL-7R signaling can uniquely intercept the crosstalk between RA myeloid and lymphoid cells in their ability to trigger neovascularization.

Metabolic reprogramming of macrophages instigates CCL21-induced arthritis.

This study was designed to delineate the functional significance of CCL21 in metabolic reprogramming in experimental arthritis and differentiated rheumatoid arthritis (RA) macrophages (MΦs). To characterize the influence of CCL21 on immunometabolism, its mechanism of action was elucidated by dysregulating glucose uptake in preclinical arthritis and RA MΦs. In CCL21 arthritic joints, the glycolytic intermediates hypoxia-inducible factor 1α (HIF1α), cMYC and GLUT1 were overexpressed compared with oxidative regulators estrogen-related receptor γ and peroxisome proliferator-activated receptor gamma coactivator 1 (PGC1)-α. Interestingly, 2-deoxy-D-glucose (2-DG) therapy mitigated CCL21-induced arthritis by restraining the number of joint F4/80+ iNOS+ MΦs without impacting F4/80+ Arginase+ MΦs. Similar to the preclinical findings, blockade of glycolysis negated CCL21-polarized CD14+ CD86+ GLUT+ MΦ frequency; however, CD14+ CD206+ GLUT+ MΦs were not implicated in this process. In CCL21-induced arthritis and differentiated RA MΦs, the inflammatory imprint was uniquely intercepted by 2-DG via interleukin-6 (IL-6) downregulation. Despite the more expansive inflammatory response of CCL21 in the arthritic joints relative to the differentiated RA MΦs, 2-DG was ineffective in joint tumor necrosis factor-α, IL-1ß, CCL2 and CCL5 enrichment. By contrast, disruption of glycolysis markedly impaired CCL21-induced HIF1α and cMYC signaling in arthritic mice. Notably, in RA MΦs, glycolysis interception was directed toward dysregulating CCL21-enhanced HIF1α transcription. Nonetheless, in concurrence with the diminished IL-6 levels, CCL21 differentiation of CD14+ CD86+ GLUT1+ MΦs was reversed by glycolysis and HIIF1α inhibition. Moreover, in the CCL21 experimental arthritis or differentiated RA MΦs, the malfunctioning metabolic machinery was accompanied by impaired oxidative phosphorylation because of reduced PGC1α or peroxisome proliferator-activated receptor-γ expression. CCL21 reconfigures naïve myeloid cells into glycolytic RA CD14+ CD86+ GLUT+ IL-6high HIF1αhigh MΦs. Therefore, inhibiting the CCL21/CCR7 pathway may provide a promising therapeutic strategy.