Two functional forms of the Meckel-Gruber syndrome protein TMEM67 generated by proteolytic cleavage by ADAMTS9 mediate Wnt signaling and ciliogenesis.

TMEM67 mutations are the major cause of Meckel-Gruber syndrome. TMEM67 is involved in both ciliary transition zone assembly, and non-canonical Wnt signaling mediated by its extracellular domain. How TMEM67 performs these two separate functions is not known. We identify a novel cleavage motif in the extracellular domain of TMEM67 cleaved by the extracellular matrix metalloproteinase ADAMTS9. This cleavage regulates the abundance of two functional forms: A C-terminal portion which localizes to the ciliary transition zone regulating ciliogenesis, and a non-cleaved form which regulates Wnt signaling. By characterizing three TMEM67 ciliopathy patient variants within the cleavage motif utilizing mammalian cell culture and C. elegans, we show the cleavage motif is essential for cilia structure and function, highlighting its clinical significance. We generated a novel non-cleavable TMEM67 mouse model which develop severe ciliopathies phenocopying Tmem67 -/- mice, but in contrast, undergo normal Wnt signaling, substantiating the existence of two functional forms of TMEM67.

Excessive cleavage of von Willebrand factor multimers by ADAMTS13 may predict the progression of transplant-associated thrombotic microangiopathy.

Background: Transplant-associated thrombotic microangiopathy (TA-TMA) is a fatal complication of hematopoietic stem cell transplantation and is characterized by severe thrombocytopenia, hemolytic anemia, and organ dysfunction. In response to several possible triggers, dynamic multimetric change in von Willebrand factor (VWF) may contribute to inducing microthrombi in circulation in TA-TMA. Objectives: By performing VWF multimer analysis and measuring VWF-degradation product (DP), we unraveled the relationship between multimeric changes in circulating VWF and the pathogenesis of TA-TMA. Methods: This study analyzed 135 plasma samples from 14 patients who underwent allogeneic hematopoietic stem cell transplantation at a single institute. VWF-associated markers, namely VWF:antigen (VWF:Ag), VWF-DP/VWF:Ag ratio, VWF:ristocetin cofactor activity, VWF:ristocetin cofactor activity/VWF:Ag ratio, and ADAMTS13 activity, were analyzed in these samples collected every 7 days. Results: There were 2 patients with definite thrombotic microangiopathy (TMA) and 6 patients who presented with probable TMA that did not progress to definite TMA. Each plasma sample was classified into 3 groups: definite TMA, probable TMA, and non-TMA. VWF multimer analysis showed the absence of high-molecular-weight VWF multimers in probable TMA, whereas the appearance of unusually large VWF multimers was observed in definite TMA. The median value of the VWF-DP/VWF:Ag ratio in probable TMA was elevated to 4.17, suggesting that excessive cleavage of VWF multimers by VWF cleaving enzyme, ADAMTS13, resulted in the loss of high-molecular-weight VWF multimers. Conclusion: During the transition from probable to definite TMA, drastic VWF multimer changes imply a switch from bleeding to thrombotic tendencies. Extensive VWF-DP and VWF multimer analyses provided novel insights.

Decreased histone H3K9 dimethylation in synergy with DNA demethylation of Spi-1 binding site contributes to ADAMTS-5 expression in articular cartilage of osteoarthritis mice.

Osteoarthritis (OA) is defined by articular cartilage degeneration, synovial membrane inflammation, and abnormal bone remodeling. Recent study has discovered that OA development is linked to an aberrant epigenetic modification of OA-related genes. Our previous research showed that DNA demethylation in ADAMTS-5 promoter region had a substantial impact on ADAMTS-5 expression in the mouse OA model. This process facilitated the binding of Spi-1 to ADAMTS-5 promoter. While alterations in histone methylation have been documented during embryonic development and cancer development, there is a paucity of data on the change in OA pathogenesis. Even no data have been reported on the role of histone modifications in ADAMTS-5 activation in OA. Following our previous study on the role of DNA methylation, we aimed to examine the contribution of histone H3K9 dimethylation in ADAMTS-5 activation in OA. Additionally, we aimed to elucidate the molecular mechanisms underlying the cooperative interaction between DNA methylation and histone H3K9 dimethylation. The potential for anti-OA intervention therapy which is based on modulating histone H3K9 dimethylation is also explored. We demonstrated that a reduction in histone H3K9 dimethylation, along with DNA demethylation of the Spi-1 binding site, had a role in ADAMTS-5 activation in the articular cartilage of OA mice. Significantly, the conditional deletion of histone demethylase to be identified as lysine-specific demethylase 1 (LSD1) in articular cartilage could alleviate the degenerative features of OA mice. Our study demonstrates the direct impact of histone H3K9 dimethylation on gene expression, which in turn contributes to OA development. This research enhances our understanding of the underlying causes of OA.

Electroacupuncture promotes angiogenesis by regulating miR-142-5p and activating ADAMTS1/PI3K/AKT pathway in ischemic stroke rats. / 电针调控miR-142-5p和ADAMTS1/PI3K/AKTé€šè·¯ä¿ƒè¿›ç¼ºè¡€æ€§è„‘å’ä¸­å¤§é¼ è¡€ç®¡æ–°ç”Ÿçš„æœºåˆ¶ç ”ç©¶.

OBJECTIVES: To observe the effect of electroacupuncture on miR-142-5p and ADAMTS1/PI3K/AKT pathway in rats with ischemic stroke, so as to explore the regulatory mechanism of electroacupuncture on angiogenesis after ischemic stroke. METHODS: This study was divided into two parts. The first part of the experiment：SD rats were randomly divided into sham operation group, model group and electroacupuncture group. There were 20 rats in each group. The middle cerebral artery occlusion (MCAO) rat model was prepared using a modified Longa's method. In the electroacupuncture group, "Shuigou" (GV26) was selected for electroacupuncture intervention (4 Hz/20 Hz) for 30 min each time. The rats in the electroacupuncture group were given electroacupuncture immediately after successful modeling, once a day for 4 times. Hunter score and TTC staining were used to observe the neurological deficits and infarct volumes respectively；HE staining was used to observe the cortical pathological changes；immunohistochemistry was used to determine the changes of cerebral microvascular density. Real-time quantitative PCR and Western blot were used to observe the miR-142-5p expression, mRNA and protein expression levels of ADAMTS1, VEGF, PI3K, AKT, eNOS in ischemic cortex. The second part of the experiment：The rats were randomly divided into electroacupuncture+control group and electroacupuncture+miR-142-5p Antagomir group with 8 rats in each group. MCAO model was established after injection. Electroacupuncture+control group was given 0.9% sodium chloride solution injected into the right ventricle.The rats in the electroacupuncture+miR-142-5p Antagomir group were injected with miR-142-5p inhibitor into the right ventricle 30 min before modeling. Rats in electroacupuncture+control group and electroacupuncture+miR-142-5p Antagomir group were all given the same electroacupuncture treatment. Real-time fluorescence quantitative PCR was used to observe the effect of miR-142-5p Antagomir on the expression of miR-142-5p and ADAMTS1 mRNA. The effect of miR-142-5p Antagomir on ADAMTS1 protein was observed by Western blot. RESULTS: In the first part of the experiment, compared with the sham operation group, the Hunter score in the model group was significantly increased (P<0.01)；the volume of cerebral infarction in the model group was significantly increased (P<0.01)；the degree of brain edema and neuronal necrosis and the density of cerebral microvessels was increased；the cerebral microvascular density was significantly increased (P<0.01)；the expression levels of miR-142-5p and the mRNA expression levels of VEGF, AKT and eNOS were significantly decreased (P<0.01, P<0.05), and the protein expression levels of VEGF, p-AKT and eNOS were significantly down-regulated (P<0.01), while the mRNA expression levels of ADAMTS1 and PI3K, and the protein expression levels of ADAMTS1 and p-PI3K were all up-regulated (P<0.01, P<0.05) in the model group. Compared with the model group, after intervention, the Hunter score in the electroacupuncture group was decreased (P<0.01), the volume of cerebral infarction was significantly decreased (P<0.01)；the degree of brain edema and neuronal necrosis were alleviated；the cerebral microvascular density was significantly increased (P<0.01)；the expression of miR-142-5p and the mRNA expression of VEGF, PI3K, AKT and eNOS were increased (P<0.01), the protein expressions of VEGF, p-PI3K, p-AKT and eNOS were increased (P<0.01, P<0.05), while the mRNA and protein expression of ADAMTS1 were decreased (P<0.05, P<0.01). After injection of miR-142-5p inhibitor, compared with electroacupuncture+control group, the expression of miR-142-5p in electroacupuncture+miR-142-5p Antagomir group was decreased(P<0.05), while the mRNA and protein expression of ADAMTS1 were increased (P<0.01, P<0.05). CONCLUSIONS: Electroacupuncture at GV26 can improve the neurological damage of ischemic stroke rats, reduce the volume of cerebral infarction and promote angiogenesis. The mechanism may be associated with the function of electroacupuncture in promoting the expression of miR-142-5p, so as to inhibit the expression of its target gene ADAMTS1, mediate the up-regulation of VEGF expression, activate PI3K/AKT pathway, promote the release of eNOS, and participate in promoting angiogenesis in ischemic stroke rats.

The Highs and Lows of ADAMTS13 Activity.

Severe deficiency of ADAMTS13 (<10 iu/dL) is diagnostic of thrombotic thrombocytopenic purpura (TTP) and leads to accumulation of ultra-large vWF multimers, platelet aggregation, and widespread microthrombi, which can be life-threatening. However, the clinical implications of a low ADAMTS13 activity level are not only important in an acute episode of TTP. In this article, we discuss the effects of low ADAMTS13 activity in congenital and immune-mediated TTP patients not only at presentation but once in a clinical remission. Evidence is emerging of the clinical effects of low ADAMTS13 activity in other disease areas outside of TTP, and here, we explore the wider impact of low ADAMTS13 activity on the vascular endothelium and the potential for recombinant ADAMTS13 therapy in other thrombotic disease states.

Autoantibodies to ADAMTS13 in human immunodeficiency virus-associated thrombotic thrombocytopenic purpura.

BACKGROUND AND OBJECTIVES: Thrombotic thrombocytopenic purpura (TTP) is a potentially fatal thrombotic microangiopathic disorder that can result from human immunodeficiency virus (HIV) infection. The pathogenesis involves a deficiency of the von Willebrand factor (vWF) cleaving protease ADAMTS13 (a disintegrin and metalloprotease with thrombospondin motifs member 13) and the presence of anti-ADAMTS13 autoantibodies. However, there is insufficient information regarding the epitope specificity and reactivity of these autoantibodies. This study aimed to perform epitope-mapping analysis to provide novel insights into the specific epitopes on ADAMTS13 domains affected by autoantibodies. MATERIALS AND METHODS: The study analysed 59 frozen citrate plasma samples from HIV-associated TTP patients in South Africa, measuring ADAMTS13 activity using Technozyme® ADAMTS13 activity test, total immunoglobulin (Ig) M and IgA antibodies levels using ELISA kit and purifying IgG antibodies using NAb™ Protein G spin columns. A synthetic ADAMTS13 peptide library was used for epitope mapping. RESULTS: Overall, 90% of samples showed anti-ADAMTS13 IgG autoantibodies, with 64% of these antibodies being inhibitory, as revealed by mixing studies. Samples with ADAMTS13 antigen levels below 5% showed high anti-ADAMTS13 IgG autoantibody titres (≥50 IU/mL), whereas those with 5%-10% levels had low autoantibody titres (<50 IU/mL).The metalloprotease, cysteine-rich and spacer domains were 100% involved in binding anti-ADAMTS13 IgG antibodies, with 58% of samples containing antibodies binding to the C-terminal part of the ADAMTS13 disintegrin-like domain, indicating different pathogenic mechanisms. CONCLUSION: The metalloprotease, cysteine-rich and spacer domains are the primary targets for anti-ADAMTS13 IgG autoantibodies in patients with HIV-associated TTP. These findings suggest potential effects on the proteolytic activity of ADAMTS13, highlighting the complex nature of the pathogenic mechanisms involved.

Efficacy and safety of daratumumab in multiresistant immune-mediated thrombotic thrombocytopenic purpura.

The immunosuppressive treatment of immune-mediated thrombotic thrombocytopenic purpura (iTTP) in patients with intolerance or refractoriness to the B-cell depleting monoclonal antibody rituximab remains debated. Daratumumab, a plasma cell-directed monoclonal antibody targeting CD38, represents a therapeutic option, but data are scarce. The French Thrombotic Microangiopathies Reference Center conducted a nationwide survey on iTTP patients treated with daratumumab. Nine episodes from seven patients were identified. Treatment was administered for A Disintegrin And Metalloproteinase with ThromboSpondin-1 motifs, 13th member (ADAMTS13) relapses while patients were otherwise in clinical response (N = 8), or during the acute phase of the disease following rituximab intolerance (N = 1). Patients have received a median of three previous therapeutic lines. ADAMTS13 activity improved in eight cases following daratumumab administration, including three cases where ADAMTS13 normalized. ADAMTS13 relapses occurred in three patients; in two cases, retreatment with daratumumab was successful. Median ADAMTS13 relapse-free survival was not reached; 12-month ADAMTS13 relapse-free survival was 56%. Daratumumab-related adverse events occurred in five cases and were non-severe infusion-related reactions in all cases. These results suggest that daratumumab may be an effective treatment option for iTTP patients with intolerance or refractoriness to rituximab.

A comparative study of anti-ADAMTS-13 antibody dynamics in immune-mediated thrombotic thrombocytopenic purpura.

Background: Thrombotic thrombocytopenic purpura, particularly its immune-mediated variant (iTTP), necessitates accurate diagnostic approaches for effective management. Objectives: To compare a chemiluminescence immunoassay (CLIA) and an enzyme-linked immunosorbent assay (ELISA) for testing ADAMTS-13 activity and detecting anti-ADAMTS-13 autoantibodies (AAbs) in patients with iTTP. Methods: This study involved 31 paired samples from 12 iTTP patients. ADAMTS-13 activity was measured using the HemosIL AcuStar (Instrumentation Laboratory, CLIA) and Technozym (Technoclone) activity assay (ELISA). The presence of AAbs was assessed using Technozym ADAMTS-13-INH assay (ELISA) and HemosIL AcuStar activity (CLIA) within a Bethesda assay following mixing with normal pool plasma. von Willebrand factor (VWF) multimers were analyzed using the HYDRASYS-2 SCAN system and the HYDRAGEL 5- or 11-VW Multimer kits (Sebia). VWF activity levels were measured with the HemosIL AcuStar VWF:GPIbR on the ACL AcuStar Analyzer (IL). Results: For ADAMTS-13 activity, a strong linear relationship and no bias between CLIA and ELISA were confirmed (slope = 1.01 [0.91, 1.11], intercept = 0.00 [-0.47, 0]). However, significant discrepancies were found in AAb detection during remission phases with ADAMTS-13 activity between 10% and 50%, with CLIA and ELISA showing significant divergence (P < .001, Cohen's g = 0.34). Consistently, VWF multimers and activity levels exhibited significantly different values between remission samples with ADAMTS-13 activity below 50% and above 50%. In longitudinal analysis of patients with multiple iTTP relapses, positivity to CLIA appears to precede ELISA in predicting exacerbations. Conclusion: While CLIA and ELISA might be interchangeable for assessing ADAMTS-13 activity, they are not equivalent for detecting AAbs, particularly in patients in clinical remission with ADAMTS-13 activity between 10% and 50%.

Chrysin downregulates the expression of ADAMTS-4 in foam cells.

BACKGROUND: Chrysin, a polyphenolic compound, possesses antioxidant and anti-inflammatory properties. In this study, we investigated the effect of chrysin on the expression of A disintegrin and metalloproteinase with thrombospondin motifs-4 (ADAMTS-4), a protease enzyme involved in degrading extracellular matrix associated with atherosclerosis. METHODS AND RESULTS: We have studied the cell viability by MTT assay and foam cell formation by oil red O staining. The mRNA and protein expression of ADAMTS-4 was studied using quantitative polymerase chain reaction (qPCR) and Western blotting, respectively. Our study showed that chrysin significantly downregulates the expression of ADAMTS-4 in foam cells. CONCLUSION: Chrysin's ability to downregulate the expression of ADAMTS-4, a protease involved in degrading the extracellular matrix, bestows upon it a new therapeutic potential for managing atherosclerosis.

Association of Sjögren's syndrome with immune-mediated thrombotic thrombocytopenic purpura and posterior reversible encephalopathy syndrome: A case report.

Background: A patient with Sjögren's syndrome (SS), immune-mediated thrombotic thrombocytopenic purpura (ITTP), and posterior reversible encephalopathy syndrome (PRES) was reported, and all published cases with thrombotic thrombocytopenic purpura (TTP), PRES, and SS were retrieved and analysed. The patient's clinical data and treatment procedure have been discussed. Case summary: A 45-year-old Chinese female was hospitalized with headache and low platelet count. She had previously presented to a local hospital with a 7-month history of epigastric discomfort and anorexia, and was diagnosed with SS and ITTP. Laboratory investigations after admission showed platelet (PLT) of 13*10^9/L, red blood cell (RBC) fragments of 6 %, ADAMTS13 Activity＜0.2 %, anti-ADAMTS13 IgG of 88.3U/mL. Brain magnetic resonance imaging (MRI) showed gyriform restricted diffusion along with increased T2-FLAIR signal in the left frontal cortex and bilateral parietal temporal cortex. She was diagnosed with SS, ITTP and PRES, and received the treatment of methylprednisolone, cyclosporine, plasma exchange, IVIG, and rituximab. This patient did not experience the recurrence during the 8-month follow-up period. Conclusion: ITTP and PRES are rare manifestations of SS. After a suspected or confirmed diagnosis of ITTP, plasma exchange and immunosuppressive therapy should be immediately administered. We suggest that rituximab could have additional therapeutic value for SS combined with ITTP and PRES.

Association of ADAMTS-5 gene polymorphisms with the susceptibility to knee osteoarthritis in a Chinese Han population.

BACKGROUND: Osteoarthritis (OA) is the most prevalent type of arthritis and the main reason for progressive disability in middle-aged and older people. Studies of candidate genes may provide a novel insight and treatment strategy for knee osteoarthritis (KOA). The aim of this study was to investigate the relationship between KOA susceptibility and single-nucleotide polymorphism (SNP) of the ADAMTS-5 gene. MATERIALS AND METHODS: The case group included 188 patients from Luoyang Orthopedic Hospital with clinically and radiographically diagnosed primary KOA, and the control group included 100 age-matched individuals without KOA. Fifteen ADAMTS-5 SNPs were assayed using MALDI-TOF MS. Allelic and haplotypic frequencies were compared between the groups. The relationship between genotype distribution and risk of KOA was analyzed by multivariate logistic regression. RESULTS: The frequency of A allele in rs2249350 site in the KOA group was significantly lower (odds ratio [OR]: 0.761; 95% confidence interval [95% CI]: 0.612-0.947; P = 0.016), while that of C allele was higher than that in the control group (OR: 1.176; 95% CI: 1.025-1.351; P = 0.016). AA genotype and gene model, especially recessive gene model at rs2249350 locus, negatively correlated with KOA risk after adjustment for sex, body mass index, age, and occupation (AA vs. CC: OR: 0.288; 95% CI: 0.124-0.669; P = 0.004; AA vs. CA + CC: OR: 0.348; 95% CI: 0.162-0.749; P = 0.007). Meanwhile, one protective haplotype, GA (rs229054, rs2249350) (OR: 0.763; 95% CI: 0.614-0.949; P = 0.017), and one high-risk haplotype, GC (rs229054, rs2249350) (OR: 1.259; 95% CI: 1.032-1.537; P = 0.019), were found in this study. CONCLUSION: Despite a limited sample size, our study suggests that the rs2249350 polymorphism in the ADAMTS-5 gene is one of the genetic factors influencing the risk of KOA. The A allele and AA genotype of rs2249350 may protect from KOA, whereas C allele and CC genotype increase the risk of KOA. In addition, the GA haplotype (rs229054, rs2249350) might be associated with a decreased risk of KOA, whereas the GC haplotype (rs229054, rs2249350) may be a risk factor for KOA. Additional larger-sized studies in more ethnically diverse populations are needed to confirm these findings.

A novel role of ADAMTS16 in renal fibrosis through activating TGF-ß/Smad signaling.

Chronic Kidney Disease (CKD) has emerged as a global public health concern, with its primary pathological basis being Renal Fibrosis (RF), crucial to halt its progression to End-Stage Renal Disease (ESRD). However, effective treatment options are currently lacking. Therefore, exploring the mechanisms of RF, identifying drug targets and diagnostic biomarkers are important. In this study, we identified ADAMTS16 as a newly expressed regulatory factor highly expressed in renal fibrosis tissue. ADAMTS16 interacts with latency-associated peptide (LAP)-transforming growth factor (TGF)-ß, leading to the activation of TGF-ß. Loss of ADAMTS16 expression effectively reduces TGF-ß-dependent transcription activity. Furthermore, the use of RRFR tetrapeptide derived from ADAMTS16 can activate the TGF-ß/Smad signaling axis, promoting RF. In summary, ADAMTS16 is induced in the progression of CKD, interacting with LAP-TGF-ß and potentially activating SMAD2/3. Therefore, targeting ADAMTS16 may serve as a crucial new strategy to alleviate RF and treat CKD patients.

Adamts9 is required for the development of primary ovarian follicles and maintenance of female sex in zebrafish.

Previous studies have suggested that adamts9 (a disintegrin and metalloprotease with thrombospondin type-1 motifs, member 9), an extracellular matrix (ECM) metalloprotease, participates in primordial germ cell (PGC) migration and is necessary for female fertility. In this study, we found that adamts9 knockout (KO) led to reduced body size, and female-to-male sex conversion in late juvenile or adult zebrafish; however, primary sex determination was not affected in early juveniles of adamts9 KO. Overfeeding and lowering the rearing density rescued growth defects in female adamts9 KO fish but did not rescue defects in ovarian development in adamts9 KO. Delayed PGC proliferation, significantly reduced number and size of Stage IB follicles (equivalent to primary follicles) in early juveniles of adamts9 KO, and arrested development at Stage IB follicles in mid- or late-juveniles of adamts9 KO are likely causes of female infertility and sex conversion. Via RNAseq, we found significant enrichment of differentially expressed genes involved in ECM organization during sexual maturation in ovaries of wildtype fish; and significant dysregulation of these genes in adamts9 KO ovaries. RNAseq analysis also showed enrichment of inflammatory transcriptomic signatures in adult ovaries of these adamts9 KO. Taken together, our results indicate that adamts9 is critical for development of primary ovarian follicles and maintenance of female sex, and loss of adamts9 leads to defects in ovarian follicle development, female infertility, and sex conversion in late juveniles and mature adults. These results show that the ECM and extracellular metalloproteases play major roles in maintaining ovarian follicle development in zebrafish.

Identification and Validation of Prognostic Markers for Endometriosis-Associated Ovarian Cancer.

Background: Growing evidence suggests that endometriosis (EMs) is a risk factor for endometriosis-associated ovarian cancer (EAOC). The aim was to identify and validate gene signatures associated with EMs that may serve as potential biomarkers for evaluating the prognosis of patients with EAOC. Methods: The data of EMs and control samples was obtained from GEO database. The weighted gene co-expression network analysis (WGCNA) identified modular genes significantly associated with EMs. The KEGG pathway and GO functional enrichment analyses were also performed. Univariate Cox regression analysis was conducted to screen marker genes associated with the prognosis of EAOC patients. Finally, RT-qPCR and immunohistochemical verified the expression of ADAMTS19 and TUBB in normal ovarian and EAOC tissues, and the biological functions of ADAMTS19 and TUBB were preliminarily explored by CCK8 and Transwell assays. Results: The WGCNA identified 2 co-expression modules, which in total included 615 genes, and 7642 differentially expressed genes (DEGs) were detected thorough analysis of the EAOC dataset. After taking the intersection of 615 modular genes and 7642 DEGs, 214 shared genes were obtained, and univariate COX regression analysis pointed 10 genes associated with the prognosis of EAOC. Moreover, it was demonstrated by RT-qPCR and immunohistochemical staining experiments that ADAMTS19 expression was elevated, while TUBB expression was reduced in EAOC compared with normal ovarian cells and tissues. Finally, cell experiments revealed that ADAMTS19 promoted the proliferation and invasion in EAOC cells, while overexpression of TUBB inhibited these processes. Conclusions: The present study identified and validated new EMs-associated gene markers, which could serve as potential biomarkers for assessing the prognostic risk of EAOC patients. In addition, some of these genes may have significance as novel therapeutic targets and could be used to guide clinical applications.

Von Willebrand factor exacerbates heart failure through formation of neutrophil extracellular traps.

BACKGROUND AND AIMS: Heart failure (HF) is a leading cause of mortality worldwide and characterized by significant co-morbidities and dismal prognosis. Neutrophil extracellular traps (NETs) aggravate inflammation in various cardiovascular diseases; however, their function and mechanism of action in HF pathogenesis remain underexplored. This study aimed to investigate the involvement of a novel VWF-SLC44A2-NET axis in HF progression. METHODS: NET levels were examined in patients with HF and mouse models of transverse aortic constriction (TAC) HF. PAD4 knockout mice and NET inhibitors (GSK-484, DNase I, NEi) were used to evaluate the role of NETs in HF. RNA sequencing was used to investigate the downstream mechanisms. Recombinant human ADAMTS13 (rhADAMTS13), ADAMTS13, and SLC44A2 knockouts were used to identify novel upstream factors of NETs. RESULTS: Elevated NET levels were observed in patients with HF and TAC mouse models of HF. PAD4 knockout and NET inhibitors improved the cardiac function. Mechanistically, NETs induced mitochondrial dysfunction in cardiomyocytes, inhibiting mitochondrial biogenesis via the NE-TLR4-mediated suppression of PGC-1α. Furthermore, VWF/ADAMTS13 regulated NET formation via SLC44A2. Additionally, sacubitril/valsartan amplifies the cardioprotective effects of the VWF-SLC44A2-NET axis blockade. CONCLUSIONS: This study established the role of a novel VWF-SLC44A2-NET axis in regulating mitochondrial homeostasis and function, leading to cardiac apoptosis and contributing to HF pathogenesis. Targeting this axis may offer a potential therapeutic approach for HF treatment.

Practical Considerations for the Use of the Rapid AcuStar® ADAMTS13 Activity Assay in the Diagnosis of Acute Thrombotic Thrombocytopenic Purpura (TTP).

Introduction: Conventional practice in the management of acute TTP entails empirical treatment of suspected cases whilst awaiting confirmatory ADAMTS13 deficiency testing. Rapid ADAMTS13 assays offer increased accessibility and rapid diagnostics. The new automated HemosIL AcuStar® ADAMTS13 assay has seen increasing use among UK TTP Specialist Centres alongside the traditional ELISA method to confirm severe ADAMTS13 deficiency. Methods: A multi-centre retrospective case-control study was performed to review patients demonstrating discrepant ADAMTS13 activity results measured using rapid (AcuStar®) and ELISA assays in parallel from September 2019 to December 2021. Cases were compared with a cohort of suspected TTP patients exhibiting no difference in assay results and in relation to their presenting characteristics and pre-test probability of a diagnosis of TTP. Results: Where the clinical index of suspicion for TTP was high at presentation, acute TTP was confirmed using the AcuStar® assay < 0.2 IU/dL and subsequently < 10 IU/dL by ELISA with zero incidence of discrepancy. For patients with low clinical suspicion of acute TTP, a discrepancy between the AcuStar® and ELISA assay results was observed in 2% of cases; 5-10 IU/dL in AcuStar®, confirmed as >20 IU/dL by ELISA. A concurrent cancer diagnosis or sepsis was observed in 40% of discrepant cases. Conclusions: Where acute TTP is strongly suspected, there is a good correlation between the rapid AcuStar® ADAMTS13 assay and the conventional ELISA assay. Where the clinical suspicion of acute TTP is low, caution should be exercised in the interpretation of the ADAMTS13 activity using the AcuStar® assay. Accurate interpretation requires robust ADAMTS13 testing algorithms to be incorporated into diagnostic pathways.

Refractory Thrombotic Thrombocytopenic Purpura in a Patient With Triple X Syndrome.

Clinical manifestations of triple X syndrome (karyotype 47, XXX) can include autoimmune diseases. We describe the occurrence of acquired thrombotic thrombocytopenic purpura (TTP), an autoimmune condition, refractory to plasmapheresis and rituximab in a patient with triple X syndrome who required vincristine administration for disease remission. To our knowledge, this rare coexistence is the first of its kind reported in Brazil.

Diagnostic Challenges in a Case of Immune-Mediated Thrombotic Thrombocytopenic Purpura With Severe ADAMTS13 Deficiency.

Thrombotic Thrombocytopenic Purpura (TTP) is rare and potentially life-threatening thrombotic microangiopathy (TMA) caused by acquired immune-mediated or congenital deficiency of the von Willebrand factor regulatory enzyme, a Disintegrin And Metalloproteinase with a Thrombospondin Type 1 motif, member 13 (ADAMTS13) which cause microthrombi to form and occlude the microvasculature. The occurrence of acute kidney injury (AKI) in TTP is rare and often underestimated due to confusion with hemolytic uremic syndrome (HUS). A 23-year-old Mestizo male patient presented with altered mental status, hemolytic anemia, thrombocytopenia, intermittent fever, laboratory tests suggestive of thrombotic microangiopathy, and clinical findings consistent with acute kidney injury. Predictive values of the platelet count, lactate dehydrogenase, absent active cancer, schistocytes, mean corpuscular volume, international normalized ratio, creatinine (PLASMIC) score, were used to assess the likelihood of ADAMTS13 deficiency, were employed, and enzymatic activity testing confirmed severe protein deficiency. Honduras' lack of advanced diagnostic capabilities is underscored, emphasizing the urgent need to invest in precision medical technology. ADAMTS13 testing allows for a more precise diagnosis of TTP, which is crucial for early diagnosis and timely treatment.

Atypical Presentation of Thrombotic Thrombocytopenic Purpura (TTP) as an Initial Manifestation of Systemic Lupus Erythematosus (SLE) in a Young Male.

Thrombotic thrombocytopenic purpura (TTP) is a rare but life-threatening hematologic disorder characterized by thrombocytopenia, microangiopathic hemolytic anemia, neurologic symptoms, renal impairment, and fever. The etiology of TTP often involves a severe deficiency in ADAMTS13 activity, resulting in the accumulation of ultra-large von Willebrand factor multimers and subsequent microvascular thrombosis. Systemic lupus erythematosus (SLE) is a chronic autoimmune disease that can affect multiple organ systems, and although the initial presentation of SLE with TTP is rare, it necessitates a comprehensive diagnostic and therapeutic approach. We present a case of a 27-year-old male with no significant past medical history who developed altered mental status, headache, and right-sided numbness, leading to the diagnosis of TTP and subsequent detection of SLE.

Neuroprotective effects of resveratrol through modulation of PI3K/Akt/GSK-3ß pathway and metalloproteases.

To analyze the expressional changes in the PI3K/Akt/GSK-3ß pathway and metalloprotease in the cellular Alzheimer's Disease (AD) model with the effect of antioxidant resveratrol. Neuron-like cells were obtained by a two-step method of neuronal differentiation by using a combination of retinoic acid (RA) and brain-derived factor (BDNF) exposure. Then, the application of the amyloid beta peptide 25-35 (Aß25-35) to the cell culture mimicked the environmental toxicity observed in AD. Afterward, cell viability and apoptosis assays were performed to determine whether the resveratrol exerts a cytotoxic and apoptotic effect. Finally, the expressional changes in genes in the cellular AD model with the effect of resveratrol were analyzed by Real-Time PCR. The analysis in silico was assessed using the STRING V12.0 database in each group. Apoptosis data findings were decreased by 1.5-fold and 2.5-fold respectively by Differentiated+Resveratrol (RES) and RES when compared to control but no significant difference was observed between RES and AD model groups. Real-time PCR analysis results revealed PI3K (3.38-fold), AKT (3.95-fold), and RELN (1.99-fold) expressions were significantly higher (p < .001), and also GSK-3ß, TAU, ADAMTS-4, ADAMTS-5, and TIMP-3 gene expression levels were significantly downregulated (2.53-, 1.79-, 2.85-, 4.09-, and 6.62-fold, respectively) in the Differentiated+Aß + RES groups compared to the Differentiated+Aß group (p < .001). Network analysis shows the functional enrichment of 23 Alzheimer-related GO terms in the Wnt signaling, proteolysis, and extracellular matrix organization pathways. Resveratrol has inhibited GSK-3ß by activating the PI3K/Akt insulin pathway in a neurotoxic environment. In addition, TAU, RELN, metalloproteases, and their inhibitors associated with Alzheimer's pathology have been regulated supporting the neuroprotective effect of resveratrol.