Exosomes secreted by macrophages upon copper ion stimulation can promote angiogenesis

Focus on cuproptosis: Exploring new mechanisms and therapeutic application prospects of cuproptosis regulation

Cuproptosis is a novel form of regulated cell death, which plays an important role in the physiological and pathological processes of the human body. Despite the increasing research on cuproptosis-related genes (CRGs) and their correlation with diseases, the pathogenesis of cuproptosis-related diseases remains unclear. Furthermore, there is a lack of reviews on the emerging technologies for regulating cuproptosis in disease treatment. This study delves into the copper-induced cell death mechanism, distinguishing cuproptosis from mechanisms like oxidative stress, glutathione synthesis inhibition, and ubiquitin-proteasome system inhibition. Several long-standing mysteries of diseases such as Wilson's disease and Menkes disease may be attributed to the occurrence of cuproptosis. In addition, we also review the detection indicators related to cuproptosis, providing targets for the diagnosis of cuproptosis-related diseases, and summarize the application value of cuproptosis in tumor therapy to better elucidate the impact of copper in cell death and diseases, and thus to promote the application prospects and possible strategies of cuproptosis-related substances, such as copper ion chelators, copper ion carriers, and copper nanomaterials, in disease therapy.

Identification of copper death-associated molecular clusters and immunological profiles for lumbar disc herniation based on the machine learning

Lumbar disc herniation (LDH) is a common clinical spinal disorder, yet its etiology remains unclear. We aimed to explore the role of cuproptosis-related genes (CRGs) and identify potential diagnostic biomarkers. Our analysis involved interrogating the GSE124272 and GSE150408 datasets for differential gene expression profiles associated with CRGs and immune characteristics. Molecular clustering was performed on LDH samples, followed by expression and immune infiltration analyses. Using the WGCNA algorithm, specific genes within CRG clusters were identified. After selecting the most predictive genes from the optimal model, four machine learning models were constructed and validated. This study identified nine CRGs associated with copper-regulated cell death. Two copper-containing molecular clusters linked to death were detected in LDH samples. Elevated expression and immune infiltration levels were found in LDH patients, particularly in CRG cluster C2. Utilizing XGB, five genes were identified for constructing a diagnostic model, achieving an area under the curve values of 0.715. In conclusion, this research provides valuable insights into the association between LDH and copper-regulated cell death, alongside proposing a promising predictive model.

Buyang Huanwu decoction promotes angiogenesis after cerebral ischemia through modulating caveolin-1-mediated exosome MALAT1/YAP1/HIF-1α axis

BACKGROUND

Angiogenesis is an effective method for promoting neurological function recovery after cerebral ischemia (CI). Buyang Huanwu decoction (BHD) is a traditional Chinese medicinal recipe that is frequently employed for CI treatment. Previous investigations have validated that it promotes angiogenesis following CI. Nevertheless, the precise mechanism by which it does this has yet to be completely understood.

OBJECTIVE

This study aims to examine the underlying mechanism through which BHD facilitates angiogenesis following CI by regulating the exosomal MALAT1/YAP1/HIF-1α signaling axis, specifically via the involvement of caveolin-1 (Cav1), an endocytosis-associated protein.

METHODS

A CI model was created using middle cerebral artery occlusion (MCAO). Following the administration of multiple doses of BHD, various parameters, including the neurobehavioral score, pathological damage, and angiogenesis, were assessed in each group of mice to identify the optimal dosage of BHD for treating CI. The molecular processes underlying the angiogenic implications of BHD following CI were investigated exhaustively by employing single-cell sequencing. Finally, the involvement of Cav1 was confirmed in Cav1 knockout mice and Cav1-silenced stably transfected strains to validate the mechanism by which BHD increases angiogenesis following CI.

RESULTS

BHD could promote angiogenesis after CI. Single-cell sequencing results suggested that its potential mechanism of action might be connected with Cav1 and the exosomal MALAT1/YAP1/HIF-1α signaling axis. BHD could promote angiogenesis after CI by regulating the exosomal MALAT1/YAP1/HIF-1α axis through Cav1, as validated in vivo and in vitro experiments. Accordingly, Cav1 may be a key target of BHD in promoting angiogenesis after CI.

CONCLUSION

This investigation represents the initial attempt to comprehensively ascertain the underlying mechanism of action of BHD in treating CI using single-cell sequencing, gene-knockout mice, and stable transfected cell lines, potentially associated with the modulation of the exosomal MALAT1/YAP1/HIF-1α axis by Cav1. Our findings offer novel empirical evidence for unraveling the regulatory pathways through which Cav1 participates in angiogenesis following CI and shed light on the potential mechanisms of BHD.

Osteo-immunomodulatory effects of macrophage-derived extracellular vesicles treated with biphasic calcium phosphate ceramics on bone regeneration

Literature on osteoimmunology has demonstrated that macrophages have a great influence on biomaterial-induced bone formation. However, there are almost no reports clarifying the osteo-immunomodulatory capacity of macrophage-derived extracellular vesicles (EVs). This study comprehensively investigated the effects of EVs derived from macrophages treated with biphasic calcium phosphate (BCP) ceramics (BEVs) on vital events associated with BCP-induced bone formation such as immune response, angiogenesis, and osteogenesis. It was found that compared with EVs derived from macrophages alone (control, CEVs), BEVs preferentially promoted macrophage polarization towards a wound-healing M2 phenotype, enhanced migration, angiogenic differentiation, and tube formation of human umbilical vein endothelial cells, and induced osteogenic differentiation of mesenchymal stem cells. Analysis of 15 differentially expressed microRNAs (DEMs) related to immune, angiogenesis, and osteogenesis suggested that BEVs exhibited good immunomodulatory, pro-angiogenic, and pro-osteogenic abilities, which might be attributed to their specific miRNA cargos. These findings not only deepen our understanding of biomaterial-mediated osteoinduction, but also suggest that EVs derived from biomaterial-treated macrophages hold great promise as therapeutic agents with desired immunomodulatory capacity for bone regeneration.

A sequential macrophage activation strategy for bone regeneration: A micro/nano strontium-releasing composite scaffold loaded with lipopolysaccharide

Effective tissue repair relies on the orchestration of different macrophage phenotypes, both the M2 phenotype (promotes tissue repair) and M1 phenotype (pro-inflammatory) deserve attention. In this study, we propose a sequential immune activation strategy to mediate bone regeneration, by loading lipopolysaccharide (LPS) onto the surface of a strontium (Sr) ions -contained composite scaffold, which was fabricated by combining Sr-doped micro/nano-hydroxyapatite (HA) and dual degradable matrices of polycaprolactone (PCL) and poly (lactic-co-glycolic acid) (PLGA). Our strategy involves the sequential release of LPS to promote macrophage homing and induce the expression of the pro-inflammatory M1 phenotype, followed by the release of Sr ions to suppress inflammation. In vitro and in vivo experiments demonstrated that, the appropriate pro-inflammatory effects at the initial stage of implantation, along with the anti-inflammatory effects at the later stage, as well as the structural stability of the scaffolds conferred by the composition, can synergistically promote the regeneration and repair of bone defects.

Individual and combined association between nutritional trace metals and the risk of preterm birth in a recurrent pregnancy loss cohort

Background

Recurrent pregnancy loss (RPL) was associated with an elevated risk of pregnancy complications, particularly preterm birth (PTB). However, the risk factors associated with PTB in RPL remained unclear. Emerging evidence indicated that maternal exposure to metals played a crucial role in the development of PTB. The objective of our study was to investigate the individual and combined associations of nutritional trace metals (NTMs) during pregnancy with PTB in RPL.

Methods

Using data from a recurrent pregnancy loss cohort (n = 459), propensity score matching (1:3) was performed to control for covariates. Multiple logistic regression and multiple linear regression were employed to identify the individual effects, while elastic-net regularization (ENET) and Bayesian kernel machine regression (BKMR) were used to examine the combined effects on PTB in RPL.

Results

The logistic regression model found that maternal exposure to copper (Cu) (quantile 4 [Q4] vs. quantile 1 [Q1], odds ratio [OR]: 0.21, 95% confidence interval [CI]: 0.05, 0.74) and zinc (Zn) (Q4 vs. Q1, OR: 0.19, 95%CI: 0.04, 0.77) was inversely associated with total PTB risk. We further constructed environmental risk scores (ERSs) using principal components and interaction terms derived from the ENET model to predict PTB accurately (p < 0.001). In the BKMR model, we confirmed that Cu was the most significant component (PIP = 0.85). When other metals were fixed at the 25th and 50th percentiles, Cu was inversely associated with PTB. In addition, we demonstrated the non-linear relationships of Zn with PTB and the potential interaction between Cu and other metals, including Zn, Ca, and Fe.

Conclusion

In conclusion, our study highlighted the significance of maternal exposure to NTMs in RPL and its association with PTB risk. Cu and Zn were inversely associated with PTB risk, with Cu identified as a crucial factor. Potential interactions between Cu and other metals (Zn, Ca, and Fe) further contributed to the understanding of PTB etiology in RPL. These findings suggest opportunities for personalized care and preventive interventions to optimize maternal and infant health outcomes.

Exogeneous metal ions as therapeutic agents in cardiovascular disease and their delivery strategies

Metal ions participate in many metabolic processes in the human body, and their homeostasis is crucial for life. In cardiovascular diseases (CVDs), the equilibriums of metal ions are frequently interrupted, which are related to a variety of disturbances of physiological processes leading to abnormal cardiac functions. Exogenous supplement of metal ions has the potential to work as therapeutic strategies for the treatment of CVDs. Compared with other therapeutic drugs, metal ions possess broad availability, good stability and safety and diverse drug delivery strategies. The delivery strategies of metal ions are important to exert their therapeutic effects and reduce the potential toxic side effects for cardiovascular applications, which are also receiving increasing attention. Controllable local delivery strategies for metal ions based on various biomaterials are constantly being designed. In this review, we comprehensively summarized the positive roles of metal ions in the treatment of CVDs from three aspects: protecting cells from oxidative stress, inducing angiogenesis, and adjusting the functions of ion channels. In addition, we introduced the transferability of metal ions in vascular reconstruction and cardiac tissue repair, as well as the currently available engineered strategies for the precise delivery of metal ions, such as integrated with nanoparticles, hydrogels and scaffolds.

Optimization of exosome-based cell-free strategies to enhance endogenous cell functions in tissue regeneration

Exosomes, nanoscale extracellular vesicles, play a crucial role in intercellular communication, owing to their biologically active cargoes such as RNAs and proteins. In recent years, they have emerged as a promising tool in the field of tissue regeneration, with the potential to initiate a new trend in cell-free therapy. However, it's worth noting that not all types of exosomes derived from cells are appropriate for tissue repair. Thus, selecting suitable cell sources is critical to ensure their efficacy in specific tissue regeneration processes. Current therapeutic applications of exosomes also encounter several limitations, including low-specific content for targeted diseases, non-tissue-specific targeting, and short retention time due to rapid clearance in vivo. Consequently, this review paper focuses on exosomes from diverse cell sources with functions specific to tissue regeneration. It also highlights the latest engineering strategies developed to overcome the functional limitations of natural exosomes. These strategies encompass the loading of specific therapeutic contents into exosomes, the endowment of tissue-specific targeting capability on the exosome surface, and the incorporation of biomaterials to extend the in vivo retention time of exosomes in a controlled-release manner. Collectively, these innovative approaches aim to synergistically enhance the therapeutic effects of natural exosomes, optimizing exosome-based cell-free strategies to boost endogenous cell functions in tissue regeneration. STATEMENT OF SIGNIFICANCE: Exosome-based cell-free therapy has recently emerged as a promising tool for tissue regeneration. This review highlights the characteristics and functions of exosomes from different sources that can facilitate tissue repair and their contributions to the regeneration process. To address the functional limitations of natural exosomes in therapeutic applications, this review provides an in-depth understanding of the latest engineering strategies. These strategies include optimizing exosomal contents, endowing tissue-specific targeting capability on the exosome surface, and incorporating biomaterials to extend the in vivo retention time of exosomes in a controlled-release manner. This review aims to explore and discuss innovative approaches that can synergistically improve endogenous cell functions in advanced exosome-based cell-free therapies for a broad range of tissue regeneration.

Surface Modification of Titanium Implants by Metal Ions and Nanoparticles for Biomedical Application

Implant surface modification can improve osseointegration and reduce peri-implant inflammation. Implant surfaces are modified with metals because of their excellent mechanical properties and significant functions. Metal surface modification is divided into metal ions and nanoparticle surface modification. These two methods function by adding a finishing metal to the surface of the implant, and both play a role in promoting osteogenic, angiogenic, and antibacterial properties. Based on this, the nanostructural surface changes confer stronger antibacterial and cellular affinity to the implant surface. The current paper reviews the forms, mechanisms, and applications of nanoparticles and metal ion modifications to provide a foundation for the surface modification of implants.

Copper in cancer: From pathogenesis to therapy

One of the basic trace elements for the structure and metabolism of human tissue is copper. However, as a heavy metal, excessive intake or abnormal accumulation of copper in the body can cause inevitable damage to the organism because copper can result in direct injury to various cell components or disruption of the redox balance, eventually leading to cell death. Interestingly, a growing body of research reports that diverse cancers have raised serum and tumor copper levels. Tumor cells depend on more copper for their metabolism than normal cells, and a decrease in copper or copper overload can have a detrimental effect on tumor cells. New modalities for identifying and characterizing copper-dependent signals offer translational opportunities for tumor therapy, but their mechanisms remain unclear. Therefore, this article summarizes what we currently know about the correlation between copper and cancer and describes the characteristics of copper metabolism in tumor cells and the prospective application of copper-derived therapeutics.

Identification of cuproptosis-associated subtypes and signature genes for diagnosis and risk prediction of Ulcerative colitis based on machine learning

Background

Ulcerative colitis (UC) is a chronic and debilitating inflammatory bowel disease that impairs quality of life. Cuproptosis, a recently discovered form of cell death, has been linked to many inflammatory diseases, including UC. This study aimed to examine the biological and clinical significance of cuproptosis-related genes in UC.

Methods

Three gene expression profiles of UC were obtained from the Gene Expression Omnibus (GEO) database to form the combined dataset. Differential analysis was performed based on the combined dataset to identify differentially expressed genes, which were intersected with cuproptosis-related genes to obtain differentially expressed cuproptosis-related genes (DECRGs). Machine learning was conducted based on DECRGs to identify signature genes. The prediction model of UC was established using signature genes, and the molecular subtypes related to cuproptosis of UC were identified. Functional enrichment analysis and immune infiltration analysis were used to evaluate the biological characteristics and immune infiltration landscape of signature genes and molecular subtypes.

Results

Seven signature genes (ABCB1, AQP1, BACE1, CA3, COX5A, DAPK2, and LDHD) were identified through the machine learning algorithms, and the nomogram built from these genes had excellent predictive performance. The 298 UC samples were divided into two subtypes through consensus cluster analysis. The results of the functional enrichment analysis and immune infiltration analysis revealed significant differences in gene expression patterns, biological functions, and enrichment pathways between the cuproptosis-related molecular subtypes of UC. The immune infiltration analysis also showed that the immune cell infiltration in cluster A was significantly higher than that of cluster B, and six of the characteristic genes (excluding BACE1) had higher expression levels in subtype B than in subtype A.

Conclusions

This study identified several promising signature genes and developed a nomogram with strong predictive capabilities. The identification of distinct subtypes of UC enhances our current understanding of UC's underlying pathogenesis and provides a foundation for personalized diagnosis and treatment in the future.

Targeting cell death pathways for cancer therapy: recent developments in necroptosis, pyroptosis, ferroptosis, and cuproptosis research

Many types of human cells self-destruct to maintain biological homeostasis and defend the body against pathogenic substances. This process, called regulated cell death (RCD), is important for various biological activities, including the clearance of aberrant cells. Thus, RCD pathways represented by apoptosis have increased in importance as a target for the development of cancer medications in recent years. However, because tumor cells show avoidance to apoptosis, which causes treatment resistance and recurrence, numerous studies have been devoted to alternative cancer cell mortality processes, namely necroptosis, pyroptosis, ferroptosis, and cuproptosis; these RCD modalities have been extensively studied and shown to be crucial to cancer therapy effectiveness. Furthermore, evidence suggests that tumor cells undergoing regulated death may alter the immunogenicity of the tumor microenvironment (TME) to some extent, rendering it more suitable for inhibiting cancer progression and metastasis. In addition, other types of cells and components in the TME undergo the abovementioned forms of death and induce immune attacks on tumor cells, resulting in enhanced antitumor responses. Hence, this review discusses the molecular processes and features of necroptosis, pyroptosis, ferroptosis, and cuproptosis and the effects of these novel RCD modalities on tumor cell proliferation and cancer metastasis. Importantly, it introduces the complex effects of novel forms of tumor cell death on the TME and the regulated death of other cells in the TME that affect tumor biology. It also summarizes the potential agents and nanoparticles that induce or inhibit novel RCD pathways and their therapeutic effects on cancer based on evidence from in vivo and in vitro studies and reports clinical trials in which RCD inducers have been evaluated as treatments for cancer patients. Lastly, we also summarized the impact of modulating the RCD processes on cancer drug resistance and the advantages of adding RCD modulators to cancer treatment over conventional treatments.

Comprehensive analysis of cuproptosis-related genes in immune infiltration and diagnosis in ulcerative colitis

Objectives

Cuproptosis is a recently discovered form of programmed cell death; however, its role in ulcerative colitis (UC) remains a void.

Methods

Three gene expression profiles were acquired from the GEO database. Subsequently, the single sample gene set enrichment analysis (ssGSEA) was performed to identify the immune infiltration characteristics of UC. Correlation analysis between cuproptosis and immune infiltration was further conducted, and the cuproptosis-related genes were applied to construct a UC diagnostic model. Subsequently, analysis results of microarray data were experimentally validated by DSS-induced colitis in mice. Finally, therapeutic agents for the cuproptosis-related genes were screened owing to the gaping field of therapeutic agents on cuproptosis.

Results

Three gene expression profiles with 343 samples (290 UC and 53 healthy samples) were included. Immune infiltration revealed that UC patients had a higher level of DCs, B cells, CD8⁺ T cells, iDCs, Macrophages, neutrophils, pDCs, T helper cells, Tfh, Th1 cells, Th2 cells, TIL and Treg than normal subjects. Moreover, almost all cuproptosis-related genes were significantly negatively associated with immune infiltration in UC patients. The risk prediction model based on cuproptosis-related genes showed an excellent discrimination for UC. Animal experiments revealed significant alterations in genes essential for cuproptosis between DSS-induced colitis mice and healthy controls, providing experimental validation for the analysis results of microarray data. Further analysis revealed that latamoxef, vitinoin, clomipramine, chlorzoxazone, glibenclamide, pyruvic acid, clindamycin, medrysone, caspan, and flavin adenine dinucleotide might be the target agents for cuproptosis-related genes.

Conclusions

In conclusion, cuproptosis was significantly associated with immune infiltration in UC, and the cuproptosis-related genes showed an excellent discrimination for UC.

Bioinformatics analysis identified immune infiltration, risk and drug prediction models of copper-induced death genes involved in salivary glands damage of primary Sjögren's syndrome

This study aimed to identify copper-induced death genes in primary Sjögren's syndrome (pSS) and explore immune infiltration, risk and drug prediction models for salivary glands (SGs) damage. The 3 datasets, including GSE40611, GSE23117, and GSE7451 from the Gene Expression Omnibus database were downloaded. The datasets were processed using the affy in R (version 4.0.3). In immune cells, copper-induced death genes were strongly expressed in "activated" dendritic cells (aDCs), macrophages and regulatory T cells (Treg). In immune functions, copper-induced death genes were strongly expressed in major histocompatibility complex (MHC) class I, human leukocyte antigen (HLA) and type I interferon (IFN) response. Correlation analysis showed that 5 genes including SLC31A1, PDHA1, DLD, ATP7B, and ATP7A were significantly correlated with immune infiltration. The nomogram suggested that the low expression of PDHA1 was significant for predicting the risk of pSS and the area under curve was 0.678. Drug model suggested that "Bathocuproine disulfonate CTD 00001350," "Vitinoin CTD 00007069," and "Resveratrol CTD 00002483" were the drugs most strongly associated with copper-induced death genes. In summary, copper-induced death genes are associated with SGs injury in pSS, which is worthy of clinicians' attention.

Recent advances of natural and bioengineered extracellular vesicles and their application in vascular regeneration

The progression of cardiovascular diseases such as atherosclerosis and myocardial infarction leads to serious vascular injury, highlighting the urgent need for targeted regenerative therapy. Extracellular vesicles (EVs) composed of a lipid bilayer containing nuclear and cytosolic materials are relevant to the progression of cardiovascular diseases. Moreover, EVs can deliver bioactive cargo in pathological cardiovascular and regulate the biological function of recipient cells, such as inflammation, proliferation, angiogenesis and polarization. However, because the targeting and bioactivity of natural EVs are subject to several limitations, bioengineered EVs have achieved wide advancements in biomedicine. Bioengineered EVs involve three main ways to acquire including (i) modification of the EVs after isolation; (ii) modification of producer cells before EVs’ isolation; (iii) synthesize EVs using natural or modified cell membranes, and encapsulating drugs or bioactive molecules into EVs. In this review, we first summarize the cardiovascular injury-related disease and describe the role of different cells and EVs in vascular regeneration. We also discuss the application of bioengineered EVs from different producer cells to cardiovascular diseases. Finally, we summarize the surface modification on EVs which can specifically target abnormal cells in injured vascular.

The Roles of Exosomes upon Metallic Ions Stimulation in Bone Regeneration

Metallic ions have been widely investigated and incorporated into bone substitutes for bone regeneration owing to their superior capacity to induce angiogenesis and osteogenesis. Exosomes are key paracrine mediators that play a crucial role in cell-to-cell communication. However, the role of exosomes in metallic ion-induced bone formation and their underlying mechanisms remain unclear. Thus, this review systematically analyzes the effects of metallic ions and metallic ion-incorporated biomaterials on exosome secretion from mesenchymal stem cells (MSCs) and macrophages, as well as the effects of secreted exosomes on inflammation, angiogenesis, and osteogenesis. In addition, possible signaling pathways involved in metallic ion-mediated exosomes, followed by bone regeneration, are discussed. Despite limited investigation, metallic ions have been confirmed to regulate exosome production and function, affecting immune response, angiogenesis, and osteogenesis. Although the underlying mechanism is not yet clear, these insights enrich our understanding of the mechanisms of the metallic ion-induced microenvironment for bone regeneration, benefiting the design of metallic ion-incorporated implants.

Copper-containing titanium alloys promote angiogenesis in irradiated bone through releasing copper ions and regulating immune microenvironment

Poor vascularization was demonstrated as a factor inhibiting bone regeneration in patients receiving radiotherapy. Various copper-containing materials have been reported to increase angiogenesis, therefore might improve bone formation. In this study, a Ti6Al4V-1.5Cu alloy was prepared using selective laser melting (SLM) technology. The immunomodulatory and pro-angiogenic effects of the Ti6Al4V-1.5Cu alloys were examined. In vitro, Ti6Al4V-1.5Cu stimulated vascular formation by restraining inflammatory factors and provoking angiogenic factors in non-irradiated and irradiated macrophages. In vivo, the angiogenic effects of the Ti6Al4V-1.5Cu alloy were confirmed using an irradiated rat femur defect model. Moreover, we found that the biological effects of the Ti6Al4V-1.5Cu alloy were partially due to the release of copper ions and associated with PI3K-Akt signaling pathway. In conclusion, this study indicated the potential of the Ti6Al4V-1.5Cu alloy to promote angiogenesis by releasing copper ions and inhibiting inflammation in normal and irradiated tissues.

Resveratrol promotes osteogenesis and angiogenesis through mediating immunology of senescent macrophages

Orthopedic implants have been used clinically to restore the functions of the compromised bone tissues, but there is still a relatively high risk of failure for elderly people. A critical reason is pro-inflammatory immune microenvironment created by senescent macrophages with homeostasis imbalance impairs osteogenesis and angiogenesis, two major processes involved in implant osseointegration. The present work proposes to use resveratrol as an autophagy inducing agent to upregulate the autophagy level of senescent macrophages to restore homeostasis, consequently generating a favorable immune microenvironment. The results show 0.1-1 µM of resveratrol can induce autophagy of senescent macrophages, promote cell viability and proliferation, reduce intracellular reactive oxygen species (ROS) level, and polarize the cells to pro-healing M2 phenotype. The immune microenvironment created by senescent macrophages upon resveratrol stimulation can promote osteogenesis and angiogenesis, as manifested by upregulated proliferation, alkaline phosphatase activity, type I collagen secretion, and extracellular matrix mineralization of senescent osteoblasts as well as nitric oxide production, migration, and in vitro angiogenesis of senescent endothelial cells. In addition, resveratrol-loaded silk fibroin coatings can be fabricated on titanium surface through electrophoretic co-deposition and the coatings show beneficial effects on the functions of senescent macrophages. Our results suggest resveratrol can be used as surface additive of titanium implants to promote osseointegration of elderly people though regulating immunology of senescent macrophages.

Multifunctional role of exosomes in viral diseases: From transmission to diagnosis and therapy

Efforts to discover antiviral drugs and diagnostic platforms have intensified to an unprecedented level since the outbreak of COVID-19. Nano-sized endosomal vesicles called exosomes have gained considerable attention from researchers due to their role in intracellular communication to regulate the biological activity of target cells through cargo proteins, nucleic acids, and lipids. According to recent studies, exosomes play a vital role in viral diseases including covid-19, with their interaction with the host immune system opening the door to effective antiviral treatments. Utilizing the intrinsic nature of exosomes, it is imperative to elucidate how exosomes exert their effect on the immune system or boost viral infectivity. Exosome biogenesis machinery is hijacked by viruses to initiate replication, spread infection, and evade the immune response. Exosomes, however, also participate in protective mechanisms by triggering the innate immune system. Besides that, exosomes released from the cells can carry a robust amount of information about the diseased state, serving as a potential biomarker for detecting viral diseases. This review describes how exosomes increase virus infectivity, act as immunomodulators, and function as a potential drug delivery carrier and diagnostic biomarker for diseases caused by HIV, Hepatitis, Ebola, and Epstein-Barr viruses. Furthermore, the review analyzes various applications of exosomes within the context of COVID-19, including its management.

Exosomes derived from magnesium ion-stimulated macrophages inhibit angiogenesis

Angiogenesis, an essential prerequisite to osteogenesis in bone repair and regeneration, can be mediated by immunoregulation of macrophages. Magnesium and its alloys are promising biodegradable bone implant materials and can affect immunoregulation of macrophages by the degradation products (magnesium ions. Nevertheless, the mechanism of macrophage-derived exosomes stimulated by Mg ions in immunoregulation is still not well understood. Herein, 10-50 mM magnesium ions are shown to inhibit the macrophage viability and proliferation in a dose-dependent manner, but a high concentration results in macrophage apoptosis. The exosomes secreted by macrophages from magnesium ion stimulation inhibit angiogenesis of endothelial cells, as manifested by the suppressed cell viability, proliferation, migration, and tube formation, which arise at least partially from exosome-mediated downregulation of endothelial nitric oxide and the vascular endothelial growth factor. The findings reported in this paper suggest that the bio-functionality of biodegradable magnesium alloys must be considered from the perspective of immunoregulation of macrophage-derived exosomes. Our results also suggest potential cancer therapy by inhibiting tumor-associated angiogenesis.

Surface functionalization with copper endows carbonate apatite honeycomb scaffold with antibacterial, proangiogenic, and pro-osteogenic activities

Osteomyelitis is a potentially devastating inflammatory bone disease that leads to bone destruction and loss. Treatment of osteomyelitis requires the removal of residual bacteria as well as osteogenesis with angiogenesis at the site of treatment. Use of an appropriate amount of copper (Cu) in treatment scaffolds may achieve these goals without the risk of toxicity. In this study, the surface of the carbonate apatite honeycomb scaffold was functionalized with Cu through a dissolution-precipitation reaction. The resulting scaffolds retained the honeycomb structure after immersion in CuCl₂ solution, and Cu was precipitated on the surface as libethenite [Cu₂(OH)PO₄]. The surface Cu concentration was controlled by the concentration of the CuCl₂ solution. Scaffolds with a surface Cu concentration of 23.8 wt% exhibited antibacterial and cytotoxic effects, whereas those with concentrations of ≤4.6 wt% exerted antibacterial effects without negatively affecting the cellular adhesion, proliferation, differentiation, and calcification of osteoblast-like cells. Furthermore, scaffolds with a surface Cu concentration of 4.6 wt% Cu inhibited bacterial growth for at least 28 days and displayed proangiogenic and pro-osteogenic activities in vivo. These data confirm the success in functionalizing scaffolds with Cu that may be utilized as an innovative osteomyelitis therapy.

Copper stress impairs angiogenesis and lymphangiogenesis during zebrafish embryogenesis by down-regulating pERK1/2-foxm1-MMP2/9 axis and epigenetically regulating ccbe1 expression

Molecular transport and cell circulation between tissues and organs through blood and lymphatic vessels are essential for physiological homeostasis in vertebrates. Despite the report of its association with vessel formation in solid tumors, the biological effects of Copper (Cu) accumulation on angiogenesis and lymphangiogenesis during embryogenesis are still unknown. In this study, we unveiled that intersegmental blood circulation was partially blocked in Cu²⁺-stressed zebrafish embryos and cell migration and tube formation were impaired in Cu²⁺-stressed mammalian HUVECs. Specifically, Cu²⁺-stressed embryos showed down-regulation in the expression of amotl2 and its downstream pERK1/2-foxm1-MMP2/9 regulatory axis, and knockdown/knockout of foxm1 in zebrafish embryos phenocopied angiogenesis defects, while FOXM1 knockdown HUVECs phenocopied cell migration and tube formation defects, indicating that excessive Cu²⁺-induced angiogenesis defects and blocked cell migration via down-regulating amotl2-pERK1/2-foxm1-MMP2/9 regulatory axis in both embryos and mammalian cells. Additionally, thoracic duct was revealed to be partially absent in Cu²⁺-stressed zebrafish embryos. Specifically, Cu²⁺-stressed embryos showed down-regulation in the expression of ccbe1 (a gene with pivotal function in lymphangiogenesis) due to the hypermethylation of the E2F7/8 binding sites on ccbe1 promoter to reduce their binding enrichment on the promoter, contributing to the potential mechanisms for down-regulation of ccbe1 and the formation of lymphangiogenesis defects in Cu²⁺-stressed embryos and mammalian cells. These integrated data demonstrate that Cu²⁺ stress impairs angiogenesis and lymphangiogenesis via down-regulation of pERK1/2-foxm1-MMP2/9 axis and epigenetic regulation of E2F7/8 transcriptional activity on ccbe1 expression, respectively.

Peptide-modified substrate enhances cell migration and migrasome formation

Extracellular vesicles (EVs) are cell-to-cell communication tools. Migrasomes are recently discovered microscale EVs formed at the rear ends of migrating cells, and thus are suggested to be involved in communicating with neighboring cells. In cell culture, peptide scaffolds on substrates have been used to demonstrate cellular function for regenerative medicine. In this study, we evaluated peptide scaffolds, including cell penetrating, virus fusion, and integrin-binding peptides, for their potential to enable the formation of migrasome-like vesicles. Through structural and functional analyses, we confirmed that the EVs formed on these peptide-modified substrates were migrasomes. We further noted that the peptide interface comprising cell-penetrating peptides (pVEC and R9) and virus fusion peptide (SIV) have superior properties for enabling cell migration and migrasome formation than fibronectin protein, integrin-binding peptide (RGD), or bare substrate. This is the first report of migrasome formation on peptide-modified substrates. Additionally, the combination of 95% RGD and 5% pVEC peptides provided a functional interface for effective migrasome formation and desorption of cells from the substrate via a simple ethylenediaminetetraacetic acid treatment. These results provide a functional substrate for the enhancement of migrasome formation and functional analysis.