Current topics in membranes最新文献

Parasitic helminths display remarkable plasticity in their interactions with the host immune system. Zoonotic species can elicit markedly different immune profiles depending on the host, ranging from balanced responses that allow long-term parasite persistence with minimal pathology to concomitant responses leading to rapid clearance accompanied by varying degrees of inflammation and/or fibrosis. Central to this host-specific immunomodulation are helminth-derived excretory/secretory products (ESPs) and extracellular vesicles (EVs), which carry a diverse repertoire of bioactive molecules capable of modulating key immune pathways. These mediators influence both innate and adaptive immunity, promoting regulatory, type 2, or mixed inflammatory responses according to the host context. This review synthesizes current evidence on how zoonotic helminths employ ESPs and EVs to fine-tune immune outcomes across natural, accidental, and experimental hosts. Elucidating these host-dependent dynamics offers valuable insights into parasite adaptation, the clinical manifestations of zoonotic infections, and the potential use of helminth-derived molecules as innovative immunotherapeutics.

Objective: To evaluate the relationship between the changes in condylar volume and maxillofacial skeletal morphology according to sex as well as the relationship between condylar volume reduction and skeletal relapse in patients who underwent orthognathic surgery.

Methods: Ninety-five patients were categorized into skeletal Class III, Class II, and facial asymmetry groups. Computed tomography scans taken preoperatively and at 1 year postoperatively were used for quantitative measurement.

Results: Postoperative condylar volume was reduced in both the Class II group and the deviated side of the asymmetry group. Both female and Class II deformity were significant predictors of postoperative reduction in the condylar volume. There was a significant correlation between skeletal relapse and postoperative change in condylar volume in the Class II group.

Conclusion: Postoperative condylar resorption may be associated with preoperative maxillofacial skeletal morphology and sex and also with skeletal relapse in the Class II group.

The plasma membrane (PM) of Leishmania spp. is a highly specialized structure that plays a crucial role in the parasite's survival and adaptation as it transitions between its invertebrate and vertebrate hosts. The unique composition of lipids, sterols, and surface proteins in the Leishmania PM is essential for parasite's ability to thrive and cause disease. This chapter provides an in-depth exploration of the molecular structure and functions of the Leishmania PM, integrating the latest research on its composition and biological roles. It highlights the differences between the two infective forms, promastigotes and amastigotes, which exhibit distinct surface molecule profiles and membrane adaptations suited to life in the sand fly vector and the mammalian host. Key molecules, such as ergosterol, GPI-anchored lipophosphoglycan (LPG), metalloprotease GP63, and other PM molecules, are discussed in the context of immune evasion, host cell entry, intracellular survival, and vaccine development. The chapter emphasizes how understanding the structure and function of the Leishmania plasma membrane can lead to the development of new strategies for treating and preventing leishmaniases.

A key event in Leishmania pathogenesis is the interaction between parasite surface molecules and host immune cells. Among these, lipophosphoglycan (LPG), the dominant surface glycoconjugate of Leishmania promastigotes, plays a central role in establishing infection and evading immune responses. Beyond mediating adhesion and protection, LPG actively modulates host membrane receptors and intracellular signaling pathways. This chapter explores the multifaceted strategies by which LPG alters host cell membrane organization to promote parasite survival. By engaging various surface receptors, LPG facilitates parasite uptake while simultaneously inhibiting classical activation pathways. It redirects intracellular signaling toward anti-inflammatory responses, suppressing the production of key molecules required for parasite elimination. Unraveling these interactions provides critical insight into the mechanisms of immune evasion and persistent infection, and opens new avenues for therapeutic intervention.

Extracellular vesicles (EVs) have emerged as key mediators in cancer biology, playing critical roles in intercellular communication within the tumor microenvironment. These nano-sized particles carry diverse molecular cargos, including proteins, lipids, DNA, and various RNA species, which reflect the biological state of their cells of origin. This chapter provides a comprehensive overview of the diagnostic and prognostic potential of EVs across a wide spectrum of tumor types, following the World Health Organization (WHO) tumor classification. We discuss the contribution of EVs in genetic tumor syndromes, solid tumors (such as skin, breast, digestive, and thoracic cancers), hematolymphoid malignancies, and pediatric cancers. Special emphasis is placed on the utility of EVs in liquid biopsy applications, offering minimally invasive alternatives for early diagnosis, monitoring of disease progression, treatment response, and detection of relapse. Furthermore, the chapter highlights specific EV-associated biomarkers, including proteins, microRNAs, long non-coding RNAs, and circular RNAs, identified in various biofluids such as blood, urine, saliva, and cerebrospinal fluid. Despite the promising potential of EVs as clinical tools, several challenges remain, including standardization of isolation and characterization methods, biological heterogeneity of EV populations, and the need for large-scale validation studies. Addressing these hurdles will be critical for the successful translation of EV-based biomarkers into routine oncology practice.

Sphingolipids are unique among cellular lipids inasmuch as their biosynthesis is compartmentalized between the endoplasmic reticulum (ER) and the Golgi apparatus. This compartmentalization was first recognized about thirty years ago, and the current review not only updates studies on the compartmentalization of sphingolipid biosynthesis, but also discusses the ramifications of this feature for our understanding of how the pathway could have evolved. Thus, we augment some of our recent studies by inclusion of two further molecular pathways that need to be considered when analyzing the evolutionary requirements for generation of sphingolipids, namely contact sites between the ER and the Golgi apparatus, and the mechanism(s) of vesicular transport between these two organelles. Along with evolution of the individual enzymes of the pathway, their subcellular localization, and the supply of essential metabolites via the anteome, it becomes apparent that current models to describe evolution of the sphingolipid biosynthetic pathway may need substantial refinement.

Lysosomes are more than just cellular recycling bins; they play a crucial role in regulating key cellular functions. Proper lysosomal function is essential for growth pathway regulation, cell proliferation, and metabolic homeostasis. Impaired lysosomal function is associated with lipid storage disorders and neurodegenerative diseases. Lysosomes form extensive and dynamic close contacts with the membranes of other organelles, including the endoplasmic reticulum, mitochondria, peroxisomes, and lipid droplets. These membrane contacts sites (MCSs) are vital for many lysosomal functions. In this chapter, we will explore lysosomal MCSs focusing on the machinery that mediates these contacts, how they are regulated, and their functional implications on physiology and pathology.

This chapter focuses on the interplay between Leishmania parasites and their host, particularly on Leishmania RNA virus (LRVs) and extracellular vesicles (EVs) in modulating host-pathogen interactions. Leishmania EVs have been shown to facilitate gene transfer, including drug-resistance genes, enhancing the parasites' survival and resistance to antileishmanial therapeutics. These EVs also play a significant role in host immune modulation by altering cytokine production in macrophages and promoting an anti-inflammatory environment that favours parasitic persistence. The presence of virulence factors such as GP63 within these EVs further underscores their role in the parasite's immunopathogenesis. Over the last few decades, LRVs have been established as drivers of the severity and persistence of leishmaniasis by exacerbating inflammatory responses and potentially influencing treatment outcomes. This chapter discusses the evolutionary origins and classification of these viruses, and explores their role in parasitic pathogenicity, highlighting their ubiquity across protozoan parasites and their impact on disease progression.

Toxoplasma gondii, the causative agent of toxoplasmosis, is widely distributed. This protozoan parasite is one of the best adapted, being able to infect innumerous species of animals and different types of cells. This chapter reviews current literature on extracellular vesicles secreted by T. gondii and by its hosts. The topics describe the life cycle and transmission (1); toxoplasmosis epidemiology (2); laboratorial diagnosis approach (3); The T. gondii interaction with extracellular vesicles and miRNAs (4); and the perspectives on T. gondii infection. Each topic emphases the host immune responses to the parasite antigens and the interaction with the extracellular vesicles and miRNAs.

The genomic sequences attributed to the coat protein play a pivotal role in the evolutionary trajectory of plant viruses. The coat protein region, particularly scrutinized in the genus of Ilarvirus phylogroups, actively shapes the regional and host-specific dispersion. Within this chapter, assorted insights pertaining to the roles undertaken by coat proteins of frequently encountered Ilarviruses in their evolutionary processes are consolidated. Nonetheless, it is discerned that the availability of genomic data for RNA1 and RNA2 remains markedly limited, impeding the provision of lucid elucidations in this domain. Hence, to comprehensively delineate the evolution of Ilarviruses, a requisite exists for supplementary nucleotide sequence data, with a particular emphasis on taxa that have received lesser attention in research endeavors.