Deposition Of Calcium Salts Research Articles

Abstract 4124430: Calcinosis Cutis and Heart Failure---A Rare Manifestation Which Should Never Be Ignored!

Introduction: Heart failure can be a manifestation of underlying immune mediated myopathies like dermatomyositis/polymyositis which can present in broad range of clinical manifestations and sometimes dermatologic lesions can be the only manifestation of these underlying pathologies without typically involving the muscle weakness. Calcinosis cutis is the deposition of calcium salts in the skin and subcutaneous tissue. There are five subtypes of calcinosis cutis, dystrophic, metastatic, idiopathic, iatrogenic and calciphylaxis. Case summary: 70-year-old female was evaluated for bilateral lower extremity swelling. Past medical history was significant for Graves’ disease, atrial fibrillation, mechanical aortic valve on warfarin, hypertension, hyperlipidemia, ascending aortic aneurysm. Work up showed BNP of 4700 pg/ml with normal cardiac enzymes. Transthoracic echocardiogram revealed newly reduced ejection fraction of 25—30% with severely dilated left ventricle. Patient refused cardiac catheterization. Nuclear stress test showed no evidence of ischemia. Patient was started on guideline directed medical therapy and biventricular Implantable cardioverter defibrillator device was placed as per cardiology recommendation. Six months later patient developed multiple calcinosis cutis lesions on abdominal wall requiring surgical excisions. Endocrine work up including PTH, serum Ca level was normal, however creatin kinase level was high normal (150 U/L). Serum aldolase was ordered which was found to be elevated(25U/L). Muscle biopsy was performed as per recommendations of rheumatology which was diagnostic of dermatomyositis. Patient was started on high dose steroids and methotrexate and eventually IV immunoglobulins as per rheumatology recommendation. Follow up echocardiogram revealed improved ejection fraction to 40--45% with resolution of any further lesion of calcinosis cutis afterwards. Conclusion: Cardiac involvement such as congestive heart failure can be a part of presentation of underlying untreated myopathies. Calcinosis cutis can be the only clinical manifestation of dermatomyositis affecting heart. Etiology of calcinosis cutis in patients with heart failure should be worked up properly. Dystrophic calcinosis cutis is the subtype associated with underlying autoimmune connective tissue diseases.

RNA Coating Promotes Peri-Implant Osseointegration.

In addition to transmitting and carrying genetic information, RNA plays an important abiotic role in the world of nanomaterials. RNA is a natural polyanionic biomacromolecule, and its ability to promote osteogenesis by binding with other inorganic materials as an osteogenic induction agent was discovered only recently. However, whether it can promote osseointegration on implants has not been reported. Here, we investigated the effect of the RNA-containing coating materials on peri-implant osseointegration. Total RNA extracted from rat muscle tissue was used as an osteogenic induction agent, and hyaluronic acid (HA) was used to maintain its negative charge. In simulated body fluids (SBF), in vitro studies demonstrated that the resulting material encouraged calcium salt deposition. Cytological experiments showed that the RNA-containing coating induced greater cell adhesion and osteogenic differentiation in comparison to the control. The results of animal experiments showed that the RNA-containing coating had osteoinductive and bone conduction activities, which are beneficial for bone formation and osseointegration. Therefore, the RNA-containing coatings are useful for the surface modification of titanium implants to promote osseointegration.

Infected Tumoral Calcinosis Associated With Rheumatoid Arthritis.

Tumoral calcinosis (TC) is a syndrome of unknown etiology characterized by calcium salt deposition in soft tissues.1 A case of infected TC with rheumatoid arthritis (RA) is described.

LncRNA MEG3 promotes aortic valve calcification by inducing osteoblast differentiation via Wnt catenin signaling pathway

Abstract Background Calcific aortic valve stenosis (CAVS) is the most common valvular heart disease in elderly population. This study aimed to investigate the role of long non-coding RNAs (lncRNAs) in the development of CAVS. Methods ldlr-/-mice were feeding with western diet for 6 months to induce CAVS. RNA-seq analysis was performed to identify differentially expressed molecular signaling between aortic valves of CAVS mice and control mice. The degree of aortic stenosis was detected by ultrasound. Calcium salt deposits were detected by Haematoxylin and eosin (H&E) staining, Von Kossa staining and alizarin red S staining. PCR and western blotting were employed to detect osteogenic differentiation markers after various interventions. Results A mouse CAVS model was successfully established, as evidenced by increased thickness and calcium deposition in the aortic valve leaflets and increased transvalvular peak jet velocity. RNA-seq analysis showed that lncRNA MEG3 was significantly enriched in aortic valves of CAVS mice as compared to that of control mice. MEG3 expression in aortic valve, assessed by RNA in situ hybridization and PCR, was also significantly upregulated during the osteoblast differentiation of AVICs in vitro. Gain- and loss-of-function experiments indicate that MEG3 could indeed promote osteoblast differentiation of primary AVICs as evidenced by increased calcified nodule formation and expressions of osteoblast differentiation markers (Runx2 and osterix). Consistent with these in vitro data, MEG3 knockdown in vivo through tail injection of antisense oligonucleotide chain MEG3 (ASO-MEG3) at 6 weeks interval for 12 weeks significantly attenuated aortic valve calcification in CAVS mice. Subsequent KEGG analysis demonstrated that the Wnt/β-catenin signaling pathway was significantly enriched during the CAVS progression. Overexpression of MEG3 activated the Wnt/β-catenin signaling pathway and upregulated osteogenic protein expressions, while this upregulation could be significantly ameliorated by Dickkopf 1, a Wnt/β-catenin pathway inhibitor. Conclusion Present study demonstrates that LncRNA MEG3 could promote aortic valve calcification by inducing osteoblast differentiation via activating Wnt/β-catenin signaling pathway. Our results provide experimental evidence of targeting MEG3 and Wnt/β-catenin signaling pathway as potential promising therapeutic option for prevention and treatment of aortic valve calcification.

Calcifications et métabolisme phosphocalcique

Extraosseous calcifications correspond to ubiquitous deposits of intra-tissue calcium salts leading to dysfunction of the affected tissue or organ. There are two types: metastatic calcifications and dystrophic calcifications. Their formation mechanism is by mimicking the physiological mineralization process with an "osteoblast-like" cell. The cause of extra-osseous calcification is variable and depends on risk factors. If the subject is young, you will have to think about a genetic syndrome!

8165 A Case Of Rhabdomyolysis-Induced Hypocalcemia And Hypercalcemia

Abstract Disclosure: A. Desai: None. A.L. Izzi: None. B. Flores Chang: None. A. Sajan: None. Introduction: Rhabdomyolysis is a syndrome characterized by muscle breakdown and the release of intracellular muscle contents into circulation. It is associated with electrolyte abnormalities and acute renal failure that can lead to prolonged hospitalization. We report a case of persistent hypercalcemia from recovery of acute renal failure and severe rhabdomyolysis. Case Description: A 47-year-old man with past medical history of polysubstance use initially presented with opiate-induced acute encephalopathy and respiratory failure. He developed severe rhabdomyolysis during the hospital course leading to acute renal failure requiring hemodialysis with hypocalcemia. The initial labs showed corrected calcium 6.2 mg/dL [9.2-11.0], ionized calcium 3.48 mg/dL [4.65-5.28], creatinine kinase level was >72,600 U/L [38-174], BUN 110 mg/dL [8-23], creatinine 7.8 mg/dL [0.6-1.2], and GFR 7 ml/min/BSA. His renal function improved over the next several days in the hospital. The serum creatinine improved to 4 mg/dL, BUN 49 mg/dL and GFR 20 ml/min/BSA respectively after couple of intermittent dialysis sessions. Six days after the last hemodialysis session, patient developed severe hypercalcemia with corrected calcium values ranging from 13.5 to 14.7 mg/dL and ionized calcium 7.41 mg/dL. Labs showed PTH 10 pg/mL [15-65], 1,25-dihydroxyvitamin D <10.0 pg/dL [21-65] and 25-OH Vitamin D levels 15.3 ng/ mL [30-96], which is consistent non-PTH medicated hypercalcemia. The 24-hour urine calcium was 696 mg [0-300 mg/24 hrs, 2900 cc]. PTH-related peptide was not collected. He was treated with intermittent doses of calcitonin and a single dose of pamidronate when the calcium levels were >13 mg/dL. Hypercalcemia resolved in eleven days after initially noted to have hypercalcemia. The corrected calcium improved to 10.1 mg/dL on the day of discharge. Discussion:Severe rhabdomyolysis is associated with acute kidney injury. The initial hypocalcemic phase during rhabdomyolysis is due to entry of calcium into damaged myocytes and deposition of calcium salts in damaged muscle. This is seen in the oliguric phase of acute kidney injury. After the recovery of rhabdomyolysis, the polyuric phase persists during renal recovery. During this time, up to one third of patients may have rebound hypercalcemia due to massive muscle calcium release. As per case reports the hypercalcemia phase lasts from 8 days to 3.5 months. In our case, the patient initially developed hypocalcemia in the oliguric phase of acute kidney injury from rhabdomyolysis. He developed hypercalcemia in the polyuric phase of renal recovery. The hypercalcemia resolved with intravenous hydration, calcitonin and pamidronate. Rhabdomyolysis is a rare cause for both hypocalcemia and hypercalcemia. Our case highlights the biphasic calcium response associated with rhabdomyolysis in the setting of renal impairment and recovery. Presentation: 6/1/2024

Medullary Nephrocalcinosis

Medullary nephrocalcinosis is a clinical variant of chronic kidney disease characterized by diffuse deposition of calcium and phosphate salts in the parenchyma, leading to inflammatory-dystrophic changes and the development of chronic renal failure. Medullary nephrocalcinosis is divided into primary (develops in previously unaltered kidneys and initially affects the proximal part of the nephron) and secondary (simultaneously affects all parts of the renal glomeruli, causing nephrosclerosis and increasing the risk of chronic kidney disease). The article describes two clinical cases of medullary nephrocalcinosis with different etiological factors. In the first case, the disease developed against the background of regular use of third-generation cephalosporins (ceftriaxone), while in the second case, it resulted from lipid and purine metabolism disorders. The genetic and etiopathogenetic aspects of medullary nephrocalcinosis are discussed. Given the importance of determining the causes and pathogenetic mechanisms of medullary nephrocalcinosis, the need for thorough diagnostics in adult patients with changes in the renal parenchyma accompanied by hyperparathyroidism, hyper- or normocalcemia, hypophosphatemia, hypomagnesemia, and hypercalciuria is emphasized. Diagnostic workup should include genetic, metabolic, and iatrogenic components of kidney damage.

Abalone shells bioenhanced carboxymethyl chitosan/collagen/PLGA bionic hybrid scaffolds achieving biomineralization and osteogenesis for bone regeneration

Inspired by the formation of natural abalone shells (AS) similar to calcium salt deposition in human orthodontics, AS is used as an emulsifier in the scaffold to solve the problem of coexistence of natural and synthetic polymers and promote new bone formation. In this study, AS-stabilized and reinforced carboxymethyl chitosan/collagen/PLGA porous bionic composite scaffolds (AS/CMCS/Col/PLGA) were fabricated through the emulsion polymerization and bionic hybrid technology. As the addition of AS increased from 0.75 to 3.0 wt%, homogeneous distribution of flower-like particles could be observed on the inner surface of the scaffold, and its mechanical properties were improved. Particularly, 3.0 wt% AS-doped scaffolds (S3 and C + S3) exhibited excellent inorganic mineral deposition and osteoblast proliferation and differentiation abilities in vitro. In a SD rat calvarial defect model, they effectively promoted new bone formation in the defect and accelerated expression of osteogenic-angiogenic related proteins (COLI, OCN, VEGF). By virtue of its combined merits including good mechanical properties, inducing mineralization crystallization and facilitating osteogenesis, the 3.0 wt% AS-doped scaffold promises to be employed as a novel bone repair material for bone tissue regeneration.

Antibiotic-induced gut microbiota disruption promotes vascular calcification by reducing short-chain fatty acid acetate

BackgroundVascular calcification is a common vascular lesion associated with high morbidity and mortality from cardiovascular events. Antibiotics can disrupt the gut microbiota (GM) and have been shown to exacerbate or attenuate several human diseases. However, whether antibiotic-induced GM disruption affects vascular calcification remains unclear.MethodsAntibiotic cocktail (ABX) treatment was utilized to test the potential effects of antibiotics on vascular calcification. The effects of antibiotics on GM and serum short-chain fatty acids (SCFAs) in vascular calcification mice were analyzed using 16 S rRNA gene sequencing and targeted metabolomics, respectively. Further, the effects of acetate, propionate and butyrate on vascular calcification were evaluated. Finally, the potential mechanism by which acetate inhibits osteogenic transformation of VSMCs was explored by proteomics.ResultsABX and vancomycin exacerbated vascular calcification. 16 S rRNA gene sequencing and targeted metabolomics analyses showed that ABX and vancomycin treatments resulted in decreased abundance of Bacteroidetes in the fecal microbiota of the mice and decreased serum levels of SCFAs. In addition, supplementation with acetate was found to reduce calcium salt deposition in the aorta of mice and inhibit osteogenic transformation in VSMCs. Finally, using proteomics, we found that the inhibition of osteogenic transformation of VSMCs by acetate may be related to glutathione metabolism and ubiquitin-mediated proteolysis. After adding the glutathione inhibitor Buthionine sulfoximine (BSO) and the ubiquitination inhibitor MG132, we found that the inhibitory effect of acetate on VSMC osteogenic differentiation was weakened by the intervention of BSO, but MG132 had no effect.ConclusionABX exacerbates vascular calcification, possibly by depleting the abundance of Bacteroidetes and SCFAs in the intestine. Supplementation with acetate has the potential to alleviate vascular calcification, which may be an important target for future treatment of vascular calcification.

Intravenous treatment of calcinosis cutis with sodium thiosulfate - A case series.

Calcinosis cutis is defined as the deposition of calcium salts in the skin. The dystrophic form is the most common and usually occurs in chronic inflammatory processes associated with collagenoses. Therapeutic options include surgical excision as well as a few pharmacological treatments. Overall, the evidence for the known therapeutic interventions is very limited and there is a lack of valid recommendations. Intravenous sodium thiosulfate has been used successfully in the treatment of calciphylaxis. In our case series, five patients with dystrophic calcinosis cutis received intravenous sodium thiosulfate for at least six cycles on five consecutive days per month, with single doses of 12.5g and 25.0g, respectively. A reduction in the calcified lesions could not be proven with certainty, but stable disease conditions were achieved. Intravenous sodium thiosulfate may counteract the progression of calcinosis cutis. The successful use of epicutaneously applied sodium thiosulfate, as described in the literature, suggests that a higher cutaneous bioavailability can be achieved to exert a lytic effect on calcinosis cutis. This is further supported by the reported efficacy of high-dose sodium thiosulfate in the treatment of calciphylaxis.

Target analysis and identification of curcumin against vascular calcification

To investigate the mechanism of curcumin (CUR) on vascular calcification (VC), we screen for common targets of CUR and atherosclerosis and verify the targets genes in vivo and in vitro experiments. The common targets of CUR and AS were screened and obtained using different databases. These target genes were analyzed by GO and KEGG pathway enrichment analysis. PPI network analysis was performed and to analyze the key targets. A rat VC model was constructed and CUR was fed for three weeks. The changes of vascular structure and calcium salt deposition were observed in H&E and Von Kossa staining. Further, the expression of these target proteins was detected in the primary VSMCs of VC. The 31 common targets were obtained. GO functional enrichment analysis obtained 1284 terms and KEGG pathway enriched 66 pathways. The key genes were identified in the cytoHubba plugin. The molecular docking analysis showed that CUR bound strongly to EGFR, STAT3 and BCL2. The animal experiments showed the deposition calcium salt reduced by the CUR administration. These proteins BMP2, RUNX2, EGFR, STAT3 and BAX expression were upregulated in VC group and CUR attenuated the upregulated expression. The signal protein Akt and p65 expression increased in VC group and decreased in CUR group. We identified some common target genes of CUR and AS and identified these key genes. The anti-VC effect of CUR was associated with the inhibition of upregulation of EGFR, STAT3 and RUNX2 expression in VSMCs.

Impact of Extracellular Matrix Injury on the Calcification of Artificial Bovine Pericardial Leaflets: An Experimental Study.

To investigate the role of extracellular matrix (ECM) injury in bioprosthetic valve calcification, we constructed an ECM damage model by applying a 15 N stress to the bovine pericardium sample in both transverse and longitudinal directions after tissue cross-linking, whereas no stress was applied in the control group. Then we implanted two pieces of bovine pericardium on both sides of the dorsal midline in Wistar rats from both groups and measured the calcium content of the implanted bovine pericardium. The results showed that the calcium content of experimental group was significantly higher than that of control group (p < 0.05). Second, we implanted prosthetic valves made from bovine pericardium in the experimental and control groups into small-tailed Han sheep (Ovis aries). After 180 days, the prosthetic valve was removed for gross and histopathological observation as well as quantitative analysis of calcium. We found a higher average calcium content in bovine pericardium from the experimental group than that from controls. Furthermore, calcium salt deposition was detected on the ventricular surface of valves along with roughened valve leaflets in the experimental group. Our data support the hypothesis that the bovine pericardium with ECM injury is more prone to calcification.

A Dynamic Cellular Model as an Emerging Platform to Reproduce the Complexity of Human Vascular Calcification In Vitro.

Vascular calcification (VC) is a cardiovascular disease characterized by calcium salt deposition in vascular smooth muscle cells (VSMCs). Standard in vitro models used in VC investigations are based on VSMC monocultures under static conditions. Although these platforms are easy to use, the absence of interactions between different cell types and dynamic conditions makes these models insufficient to study key aspects of vascular pathophysiology. The present study aimed to develop a dynamic endothelial cell-VSMC co-culture that better mimics the in vivo vascular microenvironment. A double-flow bioreactor supported cellular interactions and reproduced the blood flow dynamic. VSMC calcification was stimulated with a DMEM high glucose calcification medium supplemented with 1.9 mM NaH2PO4/Na2HPO4 (1:1) for 7 days. Calcification, cell viability, inflammatory mediators, and molecular markers (SIRT-1, TGFβ1) related to VSMC differentiation were evaluated. Our dynamic model was able to reproduce VSMC calcification and inflammation and evidenced differences in the modulation of effectors involved in the VSMC calcified phenotype compared with standard monocultures, highlighting the importance of the microenvironment in controlling cell behavior. Hence, our platform represents an advanced system to investigate the pathophysiologic mechanisms underlying VC, providing information not available with the standard cell monoculture.

CircTOP1 targeted regulation of PTBP1 expression promotes the progression of coronary artery calcification

Coronary artery calcification (CAC) is a hallmark event in the pathogenesis of cardiovascular disease, involving the phenotypic transformation of vascular smooth muscle cells (VSMC) towards an osteogenic state. Despite this understanding, the molecular mechanisms governing the VSMC osteogenic switch remain incompletely elucidated. Here, we sought to examine the potential role of circular RNA (circRNA) in the context of CAC. Through transcriptome analysis of circRNA-seq, we identified circTOP1 as a potential candidate circRNA in individuals with CAC. Furthermore, we observed that overexpression of circTOP1 exacerbated vascular calcification in a CAC model. Subsequent pull-down assays revealed an interaction between circTOP1 and PTBP1, a putative target gene of circTOP1 in the context of CAC. In both in vivo and in vitro experiments, we observed heightened expression of circTOP1 and PTBP1 in the CAC model, and noted that reducing circTOP1 expression effectively reduced calcium salt deposits and mineralized nodules in model mice. Additionally, in vitro experiments demonstrated that overexpression of PTBP1 reversed the weakening of signaling caused by silencing circTOP1, thereby exacerbating the osteogenic transition and calcification of VSMC. Collectively, our findings suggested that circTOP1 promotes CAC by modulating PTBP1 expression to mediate VSMC transdifferentiation.

GALNT3 Mutation in Hyperphosphatemic Familial Tumoral Calcinosis – Novel Etiology of Secondary Amyloidosis

Tumoral calcinosis is a rare syndrome characterized by calcium salt deposition in different periarticular soft tissue regions. We report this case of tumoral calcinosis with history of persistent soft tissue calcifications for over three decades. He presented with nephrotic syndrome and kidney biopsy revealed secondary amyloidosis. Genetic evaluation revealed GALNT3 mutation and diagnosis of hyperphosphatemic familial tumoral calcinosis was made. With this case report, we want to reiterate the need to consider tumoral calcinosis in secondary amyloidosis differentials and the pivotal role of genetic workup in chronic soft tissue calcifications.

Hydroxycitric acid inhibits ectopic calcification of renal interstitial fibroblasts by suppressing cell apoptosis

Ectopic calcification of the renal interstitium as an important cause of renal stone formation. Hydroxycitric acid (HCA), a derivative of citric acid, has antioxidant properties and inhibits the crystallisation of calcium salts.The study found that HCA has an inhibitory effect on calcification and calcium salt deposition in fibroblasts. Additionally, HCA was found to reduce calcification-induced oxidative damage and apoptosis.Animal experiments also showed that HCA reduced calcium salt deposition and expression of calcification-related proteins. Cellular transcriptomic analysis demonstrated that HCA can regulate the changes in cellular transcriptome caused by calcification in culture. HCA can effectively inhibit the calcification of renal interstitial fibroblasts, reducing the risk of stone formation by inhibiting calcification culture-induced apoptosis and calcium salt deposition. Therefore, HCA is a promising alternative drug for inhibiting renal stone formation.

Treatment of calcinosis cutis associated with autoimmune connective tissue diseases.

Calcinosis cutis is a condition that is commonly associated with autoimmune connective tissue diseases. It is characterized by the deposition of insoluble calcium salts in the skin and subcutaneous tissue, which can cause pain, impair function, and have significant impacts on quality of life. Calcinosis cutis is difficult to manage because there is no generally accepted treatment: evidence supporting treatments is mostly comprised of case reports and case series, sometimes yielding mixed findings. Both pharmacologic and procedural interventions have been proposed to improve calcinosis cutis, and each may be suited to different clinical scenarios. This review summarizes current treatment options for calcinosis cutis, with discussion of recommendations based on patient-specific factors and disease severity.

Calcinosis Prevalence in Autoimmune Connective Tissue Diseases-A Retrospective Study.

Background/Objectives: Calcinosis cutis is the deposition of insoluble calcium salts, which may cause inflammation, ulceration, pain, and restricted joint mobility. It rarely develops in damaged tissues (dystrophic subtype), most frequently in autoimmune connective tissue diseases (CTDs), but there is very limited data on the prevalence. Also, therapy remains an unsolved issue. In this study, we aimed to collect data on the prevalence of calcinosis in CTD patients to highlight that it is a considerable problem. Methods: A retrospective study was conducted in our department to assess the epidemiology of dystrophic calcinosis in CTDs between January 2003 and January 2024. Results: A total of 839 CTD patients were identified, of whom 56 had calcinosis (6.67%). The mean age of the calcinosis patients at diagnosis of underlying CTD was 41.16 ± 19.47 years. The mean time interval from the onset of calcinosis was 5.96 ± 8.62 years. Systemic sclerosis was the most common CTD complicated by calcinosis (n = 22). Conclusions: Our results are comparable to those reported previously in the literature. Although calcinosis is rare in the overall population, it is a present and unsolved problem in CTD patients. Therefore, further studies are needed on the factors involved in the development and progression of calcinosis as well as its treatment.

#2382 Renal tubule-derived EVs carrying complement 3 aggravate CKD vascular calcification by downregulating autophagy in vascular smooth muscle cells

Abstract Background and Aims Vascular calcification (VC) is a serious complication of chronic kidney disease (CKD) patients, recognized in KDIGO guidelines as a leading risk factor for cardiovascular diseases. Despite acknowledgment, the mechanisms of VC in CKD remain unclear. The kidneys intricately regulate blood vessel pathophysiology. Clinical studies suggest a correlation between elevated blood complement levels in CKD and arterial calcification, hinting at complement involvement in CKD-associated VC. Renal-origin complement, a significant source of circulating complement, activates in CKD. Extracellular vesicles (EVs), mediating intercellular communication, transport complement-related proteins in various physiological and pathological processes. Studies suggest that plasma EV rather than EV-depleted plasma causes pathogenic calcium salt deposition in smooth muscle cells. This study explores how renal-origin EVs carrying complement mediate CKD-associated VC. Method From October 2021 to August 2023, data from 110 clinical patients were gathered, encompassing both blood C3 levels and CT images of the thoracic aorta. Subsequently, we conducted a scoring analysis of the CT images and carried out correlation analyses. A CKD-associated VC model was induced by feeding C57BL/6j mice an adenine and high-phosphate diet for 16 weeks. Techniques, including WB, PCR, and immunofluorescence, detected complement activation and localization in renal tissues. EVs were isolated from kidney tissue and plasma and identified by NTA, electron microscopy, WB, etc. WB examined C3 and tubular markers of EVs. At the same time, the Elisa method was used to detect C3 in plasma, plasma EV, and EV-depleted plasma. Immunofluorescence investigated tubular-derived EVs uptake in calcified arteries. Tubular-derived EVs, C3a, C3aR receptor inhibitors (SB290157), and autophagy inhibitors (3-MA) intervened in high-phosphate-induced vascular smooth muscle cells (VSMCs). PCR and WB assessed calcification indicators, complement receptors, and autophagy-related indicators. Alizarin Red staining observed calcification nodules. Transcriptome sequencing was performed on control, high-phosphate, and renal tubular-derived EV intervention groups of VSMCs. An in vivo model infused renal tubular-derived EVs and injected C3aR inhibitors and autophagy inhibitors, measuring complement activation and VC indicators. Results There is a correlation between C3 and thoracic aorta calcium score in CKD patients, with a correlation coefficient of 0.3750 (P &amp;lt; 0.01). The CKD-associated VC mice model revealed complement C3 activation in renal tubules, secreted into the blood through EVs. The C3 proportion of plasma EV in CKD patients was significantly higher than that in the control group, but there was no statistical difference between the EV-depleted plasma control group and the CKD group. Immunofluorescence indicated tubular-derived EV uptake by the calcified vascular wall. In vitro, tubular-derived EVs enhanced VSMC osteogenic differentiation and upregulated C3aR, mimicking C3a intervention effects. C3aR receptor inhibitors produced opposing effects. Transcriptome sequencing suggested renal tubular-derived EVs downregulated VSMC autophagy-related pathways; in vitro autophagy inhibition reversed osteogenic differentiation. In vivo, reinfusing renal tubular-derived EVs exacerbated complement activation and VC, while injecting C3aR inhibitors and autophagy inhibitors alleviated CKD-associated VC. Conclusion This study confirms that tubular-derived EVs carrying C3 downregulate autophagy in VSMCs, mediating CKD-associated VC. These findings provide insights into understanding CKD-associated VC initiation and progression, revealing potential therapeutic targets.

Comparison of ePTFE membranes with fluorine-free alternatives considering durability of laminated fabrics using hydrostatic pressure testing

Pleasant wearing comfort is achieved using laminated fabrics containing a waterproof and breathable membrane. The most used membrane type is expanded polytetrafluoroethylene. Due to the negative impact of perfluoroalkyl and polyfluoroalkyl substances on the environment, fluorine-free alternative materials are necessary. In this work, alternative membrane materials, polyurethane and polyethylene terephthalate, were compared with expanded polytetrafluoroethylene. First, the mass per unit area, thickness, tensile properties, water vapor resistance, and hydrostatic pressure of corresponding laminates were determined. Furthermore, their durability, which is an essential aspect of sustainability, was investigated. Therefore, they were hydrolyzed, weathered, washed, and incorrectly treated (e.g. washed with fabric softener) and then investigated for hydrostatic pressure resistance, by scanning electron microscopy, infrared spectroscopy, and digital microscopy. It was shown that polyethylene terephthalate and expanded polytetrafluoroethylene are comparable with respect to breathability, waterproofness (&gt;20 bar), and durability. However, the hydrostatic pressure resistance (approximately 11 bar) and the water vapor resistance values (&gt;23 m2 · Pa · W−1) of microporous polyurethane membranes are poorer, but they still provide suitable alternatives. In addition, a beginning degradation of polyurethane could be proved after hydrolysis and weathering. Furthermore, the deposition of calcium salts on all membranes was observed after washing with tap water, fabric softener, and washing agents.