Histopathologic evaluation of gastrointestinal graft-versus-host disease: Opportunities for improvement based on a survey of practicing pathologists.

Hepatocyte apoptotic bodies (ApopBDs) are extracellular vesicles formed during hepatocyte apoptosis. Although they were initially recognized as cellular waste and vesicles that clear toxic substances and viral infections in the liver, they are now known to serve as key mediators of intercellular communication that influence key metabolic and immune responses, such as inflammation, regeneration, and fibrosis. While numerous functions of ApopBDs in the liver are emerging, this review will focus on discussing their biogenesis, characterization, and roles in different liver diseases, with an emphasis on intercellular communication with liver-resident cells. The mechanisms of liver injury are convoluted by series of injurious crosstalk between hepatocyte ApopBDs and surviving resident cells. A unique feature of liver injury is a constant cycle of hepatocyte apoptosis, which has been attributed to crosstalk between surviving hepatocytes and their ApopBDs. The progression of liver injury is also affected by the activation of proinflammatory and profibrotic pathways such as TLR9/NLRP3 and JAK-STAT3. Given the expression of hepatocyte-specific molecular signatures on these ApopBDs, their application as diagnostic tools may improve the treatment of liver diseases. Although the science of hepatocyte ApopBDs is fairly recent and still emerging, in-depth understanding of this aspect of liver biology may provide a novel therapeutic option for the progression of liver damage.

Amorphous silicon dioxide nanoparticles (SiO 2 NPs) are abundant within the earth’s crust and can be released into the air through industrial and manufacturing activities. Such materials are often used in industrial processes, in pharmaceutical and in the cosmetic industries. Amorphous SiO 2 NPs are pulmonary toxicants; however, the mechanism of toxicity is uncertain. In the current study, toxicity of SiO 2 NPs was assessed using inhalation exposure in an in vivo system to study a possible mechanism of pulmonary injury. Golden Syrian Hamsters were divided into 4 groups: 1- room air control, 2- vehicle control, 3- low concentration (6 mg/m 3 ) and 4- high concentration (12 mg/m 3 ). Hamsters were treated for 4 h a day for 8 days. Bronchoalveolar Lavage Fluid (BALF) analysis found increases in total cell counts (p < 0.0001), neutrophils (p < 0.0001), lymphocytes (p < 0.001), eosinophils (p < 0.01), multinucleated macrophages (p < 0.01), total protein (p < 0.0001), alkaline phosphatase (p < 0.0001), and lactate dehydrogenase (p < 0.001) in the high concentration group. Histopathological analysis found an increase in air space, quantified by Mean Linear Intercept (p < 0.0001), and a significant increase in TUNEL positive cells (p < 0.001), in the high concentration group. SEM and TEM found structural alterations to the lung tissue including increase in the number holes in the alveolar walls and in apoptotic bodies within tissue. Caspase 3 (p < 0.05), and 8 (p < 0.05), were significantly increased along with cellular inflammation markers TNF-α (p < 0.05), and HSP70 (p < 0.05) in the high concentration group. Results of the study indicate exposure to SiO 2 NPs may induce extrinsic apoptotic pathway, leading to tissue damage and significant airspace enlargement.

Circulating mRNA as an inflammatory biomarker in head and neck cancer.

Hematological malignancies like leukemia and lymphoma are severe cancers with high relapse rates. Duvelisib (DUV) is a selective dual phosphatidylinositol 3-kinase-delta and gamma inhibitor with good potential for treating hematological malignancies. However, its application is subsided by poor solubility, permeability and side effects. Herein, we have designed a human serum albumin shell and liquid-lipid core type of nanocapsule system (DUV-NCs) for effective drug loading, enhanced circulation and improved anticancer potential of DUV. The DUV-NCs were extensively optimized with DoE, resulting in a mean particle size of 188.2 ± 1.1nm, PDI of 0.238 ± 0.018 and entrapment efficiency of 86.99 ± 1.40%. Moreover, a sustained release behaviour with around 80% release up to 48h was observed. DUV-NCs showed an IC50of (12.78 ± 0.66µg/mL), which was significantly decreased (P < 0.001) than the free drug (IC50: 26.08 ± 4.04µg/mL) in the MOLT-4 cell line. Qualitative and quantitative cellular uptake studies in MOLT-4 cells revealed considerably higher internalization of FITC-NCs than free FITC. DUV-NC-treated groups also displayed higher ROS generation, which was also evident from the increase in apoptotic bodies in MOLT-4 cells. Pharmacokinetic studies showed a 2.07-fold increase in MRT with a 3.56-fold rise in AUC0-t from DUV-NCs compared to free DUV. The DUV-NCs were found to be safe in toxicity studies with no major alterations in biomarkers compared to the control. In conclusion, DUV-NCs is a promising strategy to deliver DUV in hematological malignancies with improved efficacy and safety.

Mature red blood cells (RBCs), the most abundant anucleate cells in humans, have long been overlooked as DNA carriers. Recent evidenceimplicates RBC-derived DNA (rbcDNA) as a potential biomarker for cancer diagnostics, yet itsorigin and how RBCs acquire tumor DNA remain poorly understood. Here, we find that mature RBCs harbor short DNA fragments distinct from genomic DNA. Both in vivo and in vitro experiments confirm that RBCs can internalize extracellular DNA and reflect tumor burden. Oxford Nanopore sequencing of rbcDNA reveals that short rbcDNA fragments are homologous to extracellular cell-free DNA (cfDNA). We identify apoptotic bodies (apoBDs) as key mediators of extracellular DNA uptake by RBCs, triggering RBC deformation, Heinz body formation, oxidative stress, and vesiculation. Tumor apoBD-treated RBCs are rapidly cleared in vivo via a partly macrophage-dependent effect, causing local immunosuppression in the spleen. Clinically, rbcDNA shows no advantage in detecting driver mutations compared with cfDNA, but its abundance significantly correlates with tumor burden and treatment response. Overall, our findings offer novel insights into RBC biology and support rbcDNA's clinical application in liquid biopsy.

ASFV p54 manipulates the secretory carrier membrane protein 3-dependent apoptotic bodies pathway to enhance cell-cell transmission.

Apoptotic-body-inspired nanoplatform targeting the lung-macrophage-mitochondrial axis for acute lung injury therapy.

A temporal relationship between liver enzyme derangement and an herbal remedy warrants further assessment for herb‐induced liver injury (HILI). Here, we describe the use of kava, a drink traditionally consumed in Pacific Island cultures, causing acute ALT and AST elevation as assessed by an updated RUCAM score of 7. The increasing use of kava in Western society should prompt clinicians to be more aware of this rare cause of HILI. A 46‐year‐old man was referred to the emergency department with a 3‐week history of fatigue, right upper quadrant pain, and profound transaminitis. He commenced kava 10 g daily 5 weeks prior to aid sleep, which was ceased 2 weeks prior due to his biochemical derangement. Blood tests revealed an ALT of 1546 U/L and an AST of 920 U/L. An autoimmune screen, viral serology, and liver ultrasound showed no abnormalities. A liver biopsy revealed foci of hepatocellular necrosis with scattered ballooning degeneration and apoptotic bodies in the parenchyma, but normal underlying hepatic parenchyma without steatosis. Following cessation of kava, the liver enzymes improved without any other intervention. He was monitored as an outpatient and had no recurrence. The incidence of kava HILI may increase with its marketing; its exact mechanism is unknown. Ultimately, further research is needed to identify the pathogenesis of kava HILI. HILI is a significant cause of transaminitis, and clinicians should remain vigilant in patients presenting with nonspecific symptoms and a negative liver screen.

Efferocytosis, the process by which macrophages clear apoptotic cells, plays a vital role in maintaining immune homeostasis. This study explores the influence of inflammatory cytokines—tumor necrosis factor-alpha (TNF-α) and transforming growth factor-beta (TGF-β)—on efferocytosis dysregulation in coronary artery disease (CAD). Peripheral blood samples were collected from 27 non-obstructive and 29 obstructive CAD patients to isolate monocytes, which were then differentiated into M1 and M2 macrophages using specific cytokine stimuli. These macrophages were transfected with TNF-α and TGF-β siRNA to assess cytokine impact on efferocytosis. Expression levels of the efferocytosis receptor MERTK and its regulatory protease ADAM17 were quantified via qPCR. Statistical analysis revealed significantly higher MERTK expression in M2 macrophages compared to M1 (p = 0.002). Notably, TNF-α silencing enhanced efferocytosis in M2 macrophages, with increased clearance of early apoptotic bodies in non-obstructive CAD and late apoptotic bodies in obstructive CAD (both p &lt; 0.001). These findings suggest that macrophage phenotype, apoptotic stage, and cytokine environment influence efferocytosis efficiency and may involve pathways beyond MERTK-ADAM17. They offer preliminary mechanistic insights into cytokine-mediated modulation of efferocytosis in CAD. Further in vivo studies are needed to confirm these observations and evaluate their relevance for future therapeutic strategies.

Phagocytosis of apoptotic cells maintains tissue homeostasis and regulates inflammation. A proposed facilitator of apoptotic cell clearance is the fragmentation of these cells into apoptotic bodies (ApoBDs) through cell-autonomous processes involving caspases and cytoskeletal rearrangement. Although this fragmentation process is considered a hallmark of apoptosis, its progression in tissue environments remains underexplored. Here, we examine the in vivo apoptotic dynamics of mouse thymocytes and pluripotent cells from zebrafish embryos. We show that the in vivo biogenesis of ApoBDs is independent of known cell-intrinsic regulators. Instead, fragmentation depends on actin-rich protrusions from neighboring resident phagocytes, which mechanically compress apoptotic cells to break them into smaller particles. Four-dimensional in vivo tracking of apoptotic cells reveals that both phagocyte-mediated fragmentation and phagocytosis are size sensitive, indicating that apoptotic size reduction mediated by phagocytes enhances their own clearance abilities. This non–cell-autonomous fragmentation ensures rapid apoptotic cell clearance, crucial for maintaining tissue homeostasis in physiological settings.

Apoptotic bodies (ABs), once considered mere cellular debris resulting from programmed cell death, are emerging as crucial mediators in translational medicine, bridging the gap between death signaling and regenerative processes. Recent advances have revealed their dual role: as natural carriers of bioactive molecules (nucleic acids, proteins, and organelles) and as engineerable platforms for precision therapy. This review systematically explores the biological essence of ABs, beginning with their biogenesis mechanisms, which are regulated by caspase-dependent and -independent pathways, along with microenvironmental cues, and extending to their functional heterogeneity in physiological homeostasis, pathological progression, and tissue repair. We highlight groundbreaking applications of ABs in drug delivery, where their inherent biocompatibility and targeting capacity surpass those of synthetic nanoparticles, and in regenerative engineering, where they facilitate stem cell differentiation and extracellular matrix remodeling. Engineering strategies, including membrane functionalization, cargo reprogramming, and biomimetic design, are critically evaluated for enhancing therapeutic precision. Despite challenges in standardization, scalability, and long-term safety evaluation, ABs represent a paradigm shift in "death-to-life" translational research. By integrating cutting-edge technologies such as CRISPR, AI-driven design, and organ-on-chip models, ABs are poised to revolutionize oncology, the treatment of degenerative diseases, and immune modulation. This review not only redefines the biological significance of apoptosis but also charts a roadmap for harnessing cell death derivatives as next-generation regenerative tools.

Extracellular vesicles (EVs) are implicated in various functions within the complex mechanisms of intercellular communication. There are several subpopulations of EVs, including apoptotic bodies, microvesicles and exosomes. These nanovesicles are capable of transferring functional proteins and genetic information to alter the phenotype and function of recipient cells. In animal reproduction, numerous studies have demonstrated that EVs are actively involved in the regulation of different physiological events, modulating a variety of processes such as follicular development, spermatogenesis, oocyte maturation, fertilization and embryo development, with results indicating improved gamete quality, embryo development and cryotolerance. Additionally, EVs showtherapeutic potential in restoring reproductive function and supporting maternal-embryonic communication in both domestic and wild species. Therefore, the present review aimed to describe the main studies conducted using EVs in the field of animal reproduction, highlighting their biological relevance, experimental applications and future prospects for clinical implementation in assisted reproductive technologies.

Chimeric antigen receptor T-cell (CAR-T) therapy targeting for B-cell maturation antigen (BCMA) is used to treat patients with multiple myeloma (MM). To investigate gastrointestinal changes associated with CAR-T therapy, we performed a retrospective study. A total of 10 patients with 26 gastrointestinal biopsy specimens who underwent CAR-T therapy for MM were identified. Except for one patient with residual multiple myeloma, all specimens demonstrated markedly reduced or absent plasma cells. The most prominent biopsy findings occurred in the small intestine, primarily the duodenum, and included lamina propria lymphocytic infiltration, villous atrophy, foveolar metaplasia, an absence of plasma cells, and an increase in intraepithelial lymphocytes. There was an average of 7 apoptotic bodies per 10 high-power fields (hpf). The terminal ileum was also notable for increase in apoptotic bodies (average of 9.5 apoptotic bodies/10 hpf), villous atrophy, and lamina propria lymphocytic infiltration. The stomach biopsies overall typically showed mild inflammation with no increase in apoptotic bodies. A few colonic specimens demonstrated active colitis and prominent apoptotic bodies, while the majority of the colonic biopsies did not have significant findings other than melanosis coli, and an absence or reduction of plasma cells. The disproportionately greater injury in the duodenum versus the colon highlights the importance of upper endoscopic evaluation in symptomatic patients after CAR-T therapy. The mechanisms for these patterns of injury and differential anatomic findings are unknown; however, an immune-mediated injury associated with CAR-T therapy is suspected. Our study identifies a unique pattern of intestinal injury in patients with MM who received BCMA-targeted CAR-T therapy; this encompasses histologic findings more profound in the small intestine, which include absence of plasma cells, an increase in apoptotic bodies, lymphocytic infiltration, and villous atrophy.

Osteoporosis therapies remain limited by non-specific osteoclast inhibition, which disrupts physiological bone remodeling and increases fracture risk. Here we show that selectively targeting mature osteoclasts via enzyme-responsive nanoparticles could eliminate pathological bone resorption while generating apoptotic bodies (ABs) to promote regeneration. We design OsteoSAVE, a peptide-based nanoparticle integrating a cathepsin K (CTSK)-cleavable linker, a bone-targeting motif, and a self-assembling biphenyl core. Upon CTSK-mediated hydrolysis, OsteoSAVE transforms into nanofibers within osteoclast lysosomes, inducing apoptosis and releasing ABs enriched with PDGF-BB. Mechanistic studies confirm CTSK-selective cleavage and charge-driven cellular specificity. In ovariectomized mice, OsteoSAVE restores bone density by coupling osteoclast elimination with ABs-mediated osteogenesis via PI3K/AKT activation in mesenchymal stem cells. This work establishes enzyme-triggered supramolecular self-assembly as a paradigm for dual-action therapies that recalibrate bone homeostasis without disrupting physiological processes.

Deciphering the contributions of extracellular vesicles to cancer metastasis: Mechanisms and therapeutic implications.

Establishment of a simple and novel method for contact-dependent intercellular interaction analysis using extracellular vesicles.

This study aimed to evaluate the pro-apoptotic effects of 5-fluorouracil (5-FU) on ameloblastoma (AM) through in vitro experiments and to explore its potential as a topical adjunctive therapy following surgery. Primary AM cells and freshly resected tumor tissues were treated with 5μM 5-FU for 48h. Apoptotic changes were assessed via transmission electron microscopy (TEM), TUNEL staining, and flow cytometry. Cell proliferation and viability were evaluated using EdU incorporation and CCK-8 assays. Transcriptomic profiling and Gene Ontology (GO) enrichment analyses were conducted to investigate underlying mechanisms. 5-FU treatment markedly induced apoptosis in AM tissues and cells. TEM revealed abundant apoptotic bodies, with a mean count 2.01-fold higher than controls (p<0.05). TUNEL staining demonstrated a 2.66-fold increase in apoptotic area (p<0.01). Flow cytometry showed a 4.70-fold rise in early apoptotic cells (Annexin V+/PI-) and a 25.5% decrease in viable cells (Annexin V-/PI-) (p<0.01 and p<0.05, respectively). EdU incorporation decreased by 35.0%, and CCK-8 assays indicated a 34.5% reduction in cell viability (p<0.01). Transcriptomic analysis revealed downregulation of cell cycle-related genes (CCNB1, CCNB2) and enrichment of pathways involved in cell cycle arrest and apoptosis. 5-FU effectively induces apoptosis and inhibits proliferation in AM cells, likely through disruption of cell cycle progression. These findings support the potential use of topical 5-FU as an adjunctive pharmacologic strategy in the post-surgical management of ameloblastoma.

Membrane-bound vesicles called apoptotic bodies (ApoBDs) formed during apoptosis are being recognized as non-invasive biomarkers for neurological diseases like dementia and ischemic stroke. Centrifugation-based isolation of these vesicles from blood was suggested in a recent paper by Serrano-Heras et al. (2020), which asserted their use for clinical diagnosis. This initial study provides a foundational methodology for ApoBD diagnostics. Albeit, centrifugation parameters employed present technical challenges that require optimization to ensure the purity and reproducibility of ApoBD preparations for clinical utility. Due to the use of improper centrifugation speeds (160×g and 700×g) not consistent with accepted norms for the separation of platelets (ideally 2,000-5,000×g), running the risk of being seriously contaminated by platelets and platelet-derived EVs (P-EVs), which make up 70-90% of EVs in circulation. Such contamination can render functional studies problematic, cloud proteomic and size-distribution analysis, and lower the specificity of ApoBDs enumeration on the basis of Annexin V/PI labeling. Even more extreme centrifugation has little chance to eliminate platelets completely, according to comparative literature data. Increased centrifugal pressure, density gradient separation, size-exclusion chromatography (SEC), and confirmation with platelet-specific markers are among some procedural changes recommended to improve sample purity in attempts to solve such problems. Even as the Serrano-Heras et al. study pinpoints the potential of ApoBDs as biomarkers, constraints to the procedure under consideration pose the threat of bias in future studies. Proper isolation of ApoBDs requires multimodal confirmation, optimized platelet removal protocols and clinically feasible methods like SEC are essential to enhance ApoBDs isolation for neurological disease diagnostics. Rectification of such issues enhance significantly the practicality of ApoBDs in clinical practice for the detection of neurological illnesses.

BackgroundMultiple sclerosis (MS) is an immune-mediated disorder characterized by demyelination, axonal damage, and neurodegeneration, leading to neurological disability in patients. It is considered a prototypic antigen-specific autoimmune disease, and therefore is a strong candidate for therapies aimed at restoring immune tolerance to self-antigens. However, the development of effective antigen-specific tolerization remains an important unmet medical need. In the present study, we administered phosphatidylserine (PS) liposomes, mimicking apoptotic bodies, containing a myelin antigen [35–55 myelin oligodendrocyte glycoprotein (MOG35 − 55) peptide] in the MOG35 − 55-induced experimental autoimmune encephalomyelitis (EAE), as a therapeutic strategy for the treatment of MS.MethodsMOG PS liposomes or empty PS liposomes were administered in a single administration before or after the appearance of EAE neurological symptoms. Intraperitoneal, intranasal, intradermal and intravenous administration routes were used. For mechanistic studies, peripheral T and B cell subpopulations of treated EAE mice were studied by flow cytometry. In addition, EAE mice treated with MOG PS liposomes received blocking antibodies to deplete Treg, B cells, and immunomodulatory mediators IL-10 and TGF-β. The efficacy of the therapy was compared with daily administration of fingolimod.ResultsWe demonstrated the therapeutic efficacy of the MOG-loaded PS liposomes when administered intraperitoneally before onset, and the mechanism of action of MOG-loaded PS liposomes involved Treg and B cells, since blocking these populations and their related molecules IL-10 and TGF-β, abrogated the tolerogenic effect of the therapy. We also demonstrated the therapeutic efficacy of the MOG-loaded PS liposomes when administered intraperitoneally after appearance of EAE neurological signs. Alternative routes of administration such as intravenous and intradermal, which are more suited for translation in clinical trials, were found to be efficacious before and after appearance of EAE neurological signs. Intravenous administration of MOG-loaded PS liposomes in established EAE reduced dendritic cell activation, decreased inflammatory cytokine secretion, induced T cell exhaustion and expanded regulatory B cells (Breg) and CD39+CD4+FoxP3+ T cells.ConclusionsOur findings indicate that antigen-specific therapy with PS liposomes mimicking apoptotic bodies downregulates the MOG-specific inflammatory immune response and expands Breg and Treg cells, offering a safe, versatile, and easily applicable approach that strongly supports its potential for near-future clinical translation in MS.Supplementary InformationThe online version contains supplementary material available at 10.1186/s12974-025-03618-w.