Periodontitis (PD) is a degenerative, bacteria-induced chronic disease of periodontium causing bone resorption and teeth loss. It includes a strong reaction of immune cells through the secretion of proinflammatory factors such as Interleukin-17 (IL-17). PD treatment may consider systemic oral antibiotics application, including doxycycline (Dox), exhibiting antibacterial and anti-inflammatory properties along with supportive activity in wound healing, thus affecting alveolar bone metabolism. In the present study, we aimed to determine whether Dox can affect the regenerative potential of periodontal ligament mesenchymal stem cells (PDLSCs) modulated by IL-17 in terms of cell migration, osteogenic potential, bioenergetics and expression of extracellular matrix metalloproteinase 2 (MMP-2). Our findings indicate that Dox reduces the stimulatory effect of IL-17 on migration and MMP-2 expression in PDLSCs. Furthermore, Dox stimulates osteogenic differentiation of PDLSCs, annulling the inhibitory effect of IL-17 on PDLSCs osteogenesis. In addition, analyses of mitochondrial respiration reveal that Dox decreases oxygen consumption rate in PDLSCs exposed to IL-17, suggesting that changes in metabolic performance can be involved in Dox-mediated effects on PDLSCs. The pro-regenerative properties of Dox in inflammatory microenvironment candidates Dox in terms of regenerative therapy of PD-affected periodontium are observed.

Macrophages are a heterogenous population of cells that adopt specific phenotypes in response to signals from their dynamic microenvironment. Apart from being key players in innate immunity and in the maintenance of tissue homeostasis, macrophages are also important drivers of low-grade inflammation, which is associated with different chronic conditions including stress and cancer. The activation of macrophages during chronic stress and cancer results in their multifaceted pathogenic roles. Macrophages residing in the tumor microenvironment are commonly known as tumor-associated macrophages and favor or inhibit tumor growth depending on the microenvironmental cues and their activation state. Activated macrophages display a continuum of properties rather than a distinct proinflammatory or anti-inflammatory dichotomy. Emerging evidence suggests that prolonged tissue residency restricts the plasticity of macrophages, while recruited monocytes are more plastic and their differentiation into tumor-associated macrophages during stress can result in a dual imprinting from both the existing stress-induced inflammation and the tumor microenvironment. In addition, the immunomodulation of the tumor microenvironment and reprogramming of tumor-associated macrophages toward the anti-tumor phenotypes have emerged as promising therapeutic approaches. In this review, we will focus on how the persistent inflammatory state underlying chronic stress affects macrophages as well as the macrophages’ contribution to various aspects of tumor growth and progression, highlighting a therapeutic potential of modulation of the macrophage-mediated immunosuppressive tumor microenvironment.

Psychological stress is a significant contributor to various chronic diseases and affects multiple physiological processes including erythropoiesis. This study aimed to examine the tissue-specific contributions of macrophages and extracellular ATP, as a signal of disturbed tissue homeostasis, to erythropoiesis under conditions of repeated psychological stress. Adult male BALB/c mice were subjected to 2 h daily restraint stress for seven consecutive days. Clodronate-liposomes were used to deplete resident macrophages from the bone marrow and spleen two days prior to the first restraint procedure, as well as newly recruited macrophages, every third day for the duration of the experiment. Repeated stress induced a considerable increase in the number of erythroid progenitor cells as well as in the percentage of CD71+/Ter119+ and CD71−/Ter119+ cells in the bone marrow and spleen. Macrophage depletion completely abolished the stimulative effect of repeated stress on immature erythroid cells, and prevented stress-induced increases in ATP levels, P2X7 receptor (P2X7R) expression, and ectonucleotidase CD39 activity and expression in the bone marrow and spleen. The obtained results demonstrate the stimulative effects of repeated stress on erythroid cells, extracellular ATP levels, P2X7R expression, CD39 activity and expression within the bone marrow and spleen, as well as the essential role of macrophages in stress-induced changes.

Chronic stress is increasingly recognized as a major contributor to systemic disease. Prolonged or repeated activation of the hypothalamic–pituitary–adrenal (HPA) axis and sympathoadrenal systems may contribute to glucocorticoid receptor resistance and chronic low-grade inflammation, although stress-related responses vary depending on stressor characteristics, population, age, sex, health status, and study design. Elevated levels of pro-inflammatory cytokines (IL-6, IL-1β, TNF-α), oxidative stress, and NF-κB activation contribute to immune dysfunction, neuroinflammation, metabolic disturbances, reproductive and endocrine imbalance, as well as structural and functional alterations in stress-sensitive brain regions. Prolonged exposure to stress may contribute to the development of neuropsychiatric, cardiovascular, metabolic, neurodegenerative, and malignant diseases, highlighting the need for effective strategies to mitigate the detrimental consequences of chronic stress. Given the limitations and adverse effects associated with conventional pharmacological approaches, increasing attention has been directed toward natural bioactive compounds. Terpenes represent a diverse class of phytochemicals with reported anti-inflammatory, antioxidant, and neuromodulatory properties. Terpenes such as limonene and β-caryophyllene, as well as terpenoids such as linalool, may modulate NF-κB, MAPK, and Nrf2 signaling pathways and interact with the endocannabinoid system, thereby attenuating neuroinflammation, oxidative stress, and stress-induced immune dysregulation. This review summarizes current evidence regarding the mechanisms linking chronic stress, HPA axis dysfunction, and systemic disease, with particular emphasis on endocrine, immune, and nervous system alterations. In addition, it critically evaluates the mechanistic and translational potential of terpenes as possible indirect neuroimmune and redox modulators of stress-related pathophysiology.

Human placenta-derived amniotic membrane (hAM) and its derivatives have attracted growing interest as bioactive materials for tissue engineering, regenerative medicine, and biomaterial design. This review summarizes the anatomical and cellular characteristics of hAM and examines the interplay between its regenerative and immunomodulatory properties. Key hAM-derived biomolecules are discussed, with an emphasis on their roles in immune regulation, angiogenesis, extracellular matrix remodeling, and tissue repair across diverse regenerative contexts. Current applications of hAM-based materials in tissue engineering and regenerative biomaterials are reviewed, including emerging studies involving soft tissue applications. In addition, recent efforts to integrate hAM derivatives into 3D bioprinting approaches are examined, including their use as bioink components or biofunctional additives to hydrogel-based systems. Although studies involving hAM-based bioprinted constructs remain limited, the available findings suggest promising regenerative, proangiogenic, and bioactive effects. Challenges related to material processing, printability, standardization, and reproducibility are also discussed. Overall, this review highlights the biomaterial potential of hAM derivatives and their emerging relevance to biofabrication strategies aimed at developing biologically instructive constructs for regenerative medicine.

Erythropoiesis under basal conditions involves the continuous production of new erythrocytes at a constant rate. During the adult period, erythropoiesis takes place primarily in the bone marrow and has a substantial capacity. The regulation of this process is achieved through a multitude of cellular and molecular mechanisms that synergistically act to ensure adequate tissue oxygenation while avoiding viscosity-related issues associated with excessive production. Therefore, this process is regulated through both positive and negative feedback mechanisms. In contrast to the continuous renewal of erythrocytes under basal conditions, disruptions in homeostasis such as bleeding, stress, inflammation, etc., lead to the activation of a process known as stress erythropoiesis. Stress erythropoiesis is a unique process that, in addition to the bone marrow, also occurs extramedullary. Extramedullary erythropoiesis primarily takes place in the red pulp of the spleen, where, under the influence of specific signals within its microenvironment, there is an extensive expansion of immature erythroid cell populations. This process ensures an adequate response to the increased demands for erythropoiesis. This paper elucidates the fundamental molecular mechanisms involved in regulating erythropoiesis under basal conditions and stress erythropoiesis. It highlights the dependency of these molecular mechanisms on the microenvironment in which these processes occur. Understanding the molecular mechanisms that govern erythropoiesis and stress erythropoiesis is crucial for advancing therapeutic strategies for hematological disorders.