Mechanical Stretch Promotes Macrophage Polarization and Inflammation via the RhoA-ROCK/NF-κB Pathway

Myofibrillogenesis Regulator-1 in Smooth Muscle Cells Modulates Inflammation Signaling Pathways via Regulating ROCK1 Ubiquitination and Degradation to Impact Aortic Dissection

Background

Aortic dissection (AD) is a life-threatening cardiovascular emergency and currently lacks effective drug treatment. Inflammation is a critical mechanism in the development of AD, and identifying specific molecular targets to regulate inflammation is crucial for stopping its progression. This study aimed to investigate the role of MR-1 and ROCK1 in the regulation of inflammation in AD and their potentialities as therapeutic targets.

Methods

Researchers performed protein immunoblotting on aortic wall tissue from 10 patients who underwent aortic arch replacement and 10 patients who underwent coronary artery bypass grafting to examine the expression levels of MR-1, ROCK1, and inflammatory pathways in the aortas. In vitro experiments, human aortic smooth muscle cells were extracted, and an in vitro dissection model was constructed with angiotensin II. siRNA silencing studies were performed to investigate the effects of MR-1 and ROCK1 on the development of AD and their interconnections.

Results

Analysis of aortic tissues revealed significantly elevated levels of MR-1 and ROCK1 in AD patients, and meanwhile the inflammatory indexes showed the same trend. Furthermore, it was observed that overexpression of MR-1 and ROCK1 facilitated smooth muscle cell phenotypic transformation and augmented matrix metalloproteinase release in in vitro settings through inflammatory pathway activation. The relationship between MR-1 and ROCK1 was elucidated, too.

Conclusion

MR-1 and ROCK1 overexpression is associated with the occurrence and development of AD through inflammation. This study highlights the role of inflammation in AD development and tap the potentiality of using MR-1 and ROCK1 as targets to alleviate AD development.

In Situ Proefferocytosis Microspheres as Macrophage Polarity Converters Accelerate Osteoarthritis Treatment

Efferocytosis in macrophages typically engages an anti-inflammatory positive feedback regulatory mechanism. In osteoarthritis (OA), characterized by imbalanced inflammatory homeostasis, the proinflammatory state of macrophages in the immune microenvironment can be reversed through enhanced efferocytosis. This study develops an in situ proefferocytosis hydrogel microsphere (macrophage polarity converter, H-C@IL) for OA treatment. Immunoliposomes (IL), CD16/32 antibody-modified clodronate liposomes, are initially prepared using the Re-emulsion method. Then, the IL is loaded into CCL19-modified HAMA microspheres through microfluidic technology. In vitro, H-C@IL can specifically recruit M0 and M1 macrophages via CCL19, induce apoptosis in M1 macrophages through secondary targeting with IL, and provide "Find/Eat-me" signals to enhance in situ efferocytosis. Additionally, it promotes macrophage polarization toward the M2 phenotype. In vivo, behavioral, imaging, and histological analyses demonstrate that H-C@IL effectively facilitates macrophage polarization toward M2, inhibits inflammation, and promotes cartilage regeneration. Mechanistically, H-C@IL enhances efferocytosis by activating proteins such as PROS1 and TIMD4 in M0 macrophages. Concurrently, signaling pathways, including PQLC2-Arg-Rac1 and Pbx1/IL-10, are activated to drive the polarization of macrophages from M0 to M2. In summary, H-C@IL promotes M0 macrophage efferocytosis in situ, facilitates macrophage polarization toward M2, restores inflammatory homeostasis, and promotes cartilage regeneration, offering a comprehensive treatment strategy for OA.

Synergetic role of TRPV4 inhibitor and mechanical loading on reducing inflammation

Resolution of inflammation is essential for normal tissue healing and regeneration, with macrophages playing a key role in regulating this process through phenotypic changes from a pro-inflammatory to an anti-inflammatory state. Pharmacological and mechanical (mechanotherapy) techniques can be employed to polarize macrophages toward an anti-inflammatory phenotype, thereby diminishing inflammation. One clinically relevant pharmacological approach is the inhibition of Transient Receptor Potential Vanilloid 4 (TRPV4). This study investigates the effects of various mechanical loading amplitudes (0%, 3%, and 6%) and TRPV4 inhibition (10 µM RN-1734) on the phenotypic commitments of pro-inflammatory (M1) macrophages within three-dimensional (3D) collagen matrices. M1 macrophages exposed to 3% mechanical strain exhibited upregulated pro-inflammatory responses, including increased pro-inflammatory gene expression and enhanced proteolytic activity within the extracellular matrix. TRPV4 inhibition partially mitigated this inflammation. Notably, 6% mechanical strain combined with TRPV4 inhibition suppressed Mitogen-Activated Protein Kinase (MAPK) expression, leading to reduced pro-inflammatory gene expression and increased anti-inflammatory markers such as CD206. Gene expression analysis further demonstrated significant reductions in pro-inflammatory gene expression and a synergistic promotion of anti-inflammatory phenotypes under TRPV4 inhibition at 6% mechanical strain. Surface protein analysis via immunohistochemistry confirmed these phenotypic shifts, highlighting changes in the expression of CD80 (pro-inflammatory) and CD206 (anti-inflammatory) markers, alongside F-actin and nuclear staining. This research suggests that TRPV4 inhibition, combined with specific mechanical loading (6%), can drive macrophages toward an anti-inflammatory state, thereby may promote inflammation resolution and tissue repair.

Daphnetin ameliorates intervertebral disc degeneration via the Keap1/Nrf2/NF-κB axis in vitro and in vivo

Intervertebral disc degeneration (IVDD) is the primary cause of low back pain (LBP). Enhanced inflammation and reactive oxygen species (ROS) levels can cause apoptosis, which is one of the initial factors of IVDD. Our previous study showed that daphnetin (DAP) alleviates IVDD; however, the underlying mechanisms remain unknown. An IVDD mouse model was established by lumbar disc puncture to investigate the mechanisms of DAP regulation, and DAP was injected intraperitoneally. Moreover, nucleus pulposus cells (NPCs) were challenged with tumor necrosis factor-alpha (TNF-α)/H2O2 to mimic IVDD. Additionally, NPC apoptosis, ROS, and the expression of proinflammatory cytokines were comprehensively assessed. We found that DAP can reverse H2O2-induced ROS and play an anti-inflammatory role by inhibiting Nuclear factor-kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) pathways. Moreover, we found that DAP inhibits the apoptosis of NPCs induced by H2O2/TNF-α. DAP may regulate ROS production and apoptosis via the Kelch-like ECH-associated protein 1/NF-E2-related factor 2/heme oxygenase-1 (Keap1/Nrf2/HO-1) pathway. These findings were confirmed by in vivo results. The comprehensive nature of our research provides a strong foundation for the potential use of DAP as a therapeutic agent to alleviate IVDD.

A study of the role of androgen receptor and androgen receptor variant 7 in TNBC patients and the effect of their targeting by Enzalutamide and EPI-001 in MDA-MB-231

The lack of targeted therapy for triple-negative breast cancer (TNBC) is among the mainsprings of its poor prognosis. This study aimed to elucidate the role of the androgen receptor (AR) and its splice variant 7 (ARv7) in TNBC patients. Further, the molecular impact of their blockers, Enzalutamide and EPI-001, on the TNBC cell line MDA-MB-231 was investigated. Thereby, immunohistochemical expression of AR/ARv7 was assessed for TNBC Egyptian patients. Moreover, bioinformatics analysis of AR/ARv7 RNA status was carried out on TNBC patients from The Cancer Genome Atlas Breast Carcinoma project (TCGA-BRCA). Data from both groups was correlated with patients' clinicopathological features. Besides, scratch wound healing assay and ELISA were employed to assess the effect of AR/ARv7 blockers on several metastasis markers in MDA-MB-231 cell line. In the Egyptian-TNBC patients, AR expression was associated with worse 7-year DFS (40.6 ± 18.6 %). In addition, ARv7 showed cytoplasmic and nuclear patterns, and both cytoplasmic and nuclear ARv7+ patients demonstrated a worse 7-year DFS (22.7 ± 17.7 % and 20 ± 17.9 %) and overall survival (63.6 ± 14.5 % and 40 ± 21.8 %). Importantly, 80 % of the nuclear ARv7+ patients developed distant metastasis. The data of the TCGA-TNBC patients showed a tendency for poor outcomes in the high ARv7-expressing patients. Molecularly, in MDA-MB-231, both inhibitors modulated metastasis and epithelial to mesenchymal transition (EMT) markers ROCK1, ROCK2, c-Myc, E-cadherin and N-cadherin, with EPI-001 downregulating NF-ĸB level as well. We concluded that ARv7 indicated poor prognosis in the studied cohorts and that blocking of AR/ARv7 abated metastasis and key regulators of EMT in MDA-MB-231, at least in part by targeting ROCK/NF-ĸB/c-Myc axis.

Role of STIM1 in stretch-induced signaling in human airway smooth muscle

Alteration in the normal mechanical forces of breathing can contribute to changes in contractility and remodeling characteristic of airway diseases, but the mechanisms that mediate these effects in airway cells are still under investigation. Airway smooth muscle (ASM) cells contribute to both contractility and extracellular matrix (ECM) remodeling. In this study, we explored ASM mechanisms activated by mechanical stretch, focusing on mechanosensitive piezo channels and the key Ca2+ regulatory protein stromal interaction molecule 1 (STIM1). Expression of Ca2+ regulatory proteins, including STIM1, Orai1, and caveolin-1, mechanosensitive ion channels Piezo-1 and Piezo-2, and NLRP3 inflammasomes were upregulated by 10% static stretch superimposed on 5% cyclic stretch. These effects were blunted by STIM1 siRNA. Histamine-induced [Ca2+]i responses and inflammasome activation were similarly blunted by STIM1 knockdown. These data show that the effects of mechanical stretch in human ASM cells are mediated through STIM1, which activates multiple pathways, including Piezo channels and the inflammasome, leading to potential downstream changes in contractility and ECM remodeling.NEW & NOTEWORTHY Mechanical forces on the airway can contribute to altered contractility and remodeling in airway diseases, but the mechanisms are not clearly understood. Using human airway smooth muscle cells exposed to cyclic forces with static stretch to mimic breathing and static pressure, we found that the effects of stretch are mediated through STIM1, resulting in the activation of multiple pathways, including Piezo channels and the inflammasome, with potential downstream influences on contractility and remodeling.

The Roles of RhoA/ROCK/NF-κB Pathway in Microglia Polarization Following Ischemic Stroke

Ischemic stroke is the leading cause of death and disability worldwide. Nevertheless, there still lacks the effective therapies for ischemic stroke. Microglia are resident macrophages of the central nervous system (CNS) and can initiate immune responses and monitor the microenvironment. Microglia are activated and polarize into proinflammatory or anti‑inflammatory phenotype in response to various brain injuries, including ischemic stroke. Proinflammatory microglia could generate immunomodulatory mediators, containing cytokines and chemokines, these mediators are closely associated with secondary brain damage following ischemic stroke. On the contrary, anti-inflammatory microglia facilitate recovery following stroke. Regulating the activation and the function of microglia is crucial in exploring the novel treatments for ischemic stroke patients. Accumulating studies have revealed that RhoA/ROCK pathway and NF-κB are famous modulators in the process of microglia activation and polarization. Inhibiting these key modulators can promote the polarization of microglia to anti-inflammatory phenotype. In this review, we aimed to provide a comprehensive overview on the role of RhoA/ROCK pathway and NF-κB in the microglia activation and polarization, reveal the relationship between RhoA/ROCK pathway and NF-κB in the pathological process of ischemic stroke. In addition, we likewise discussed the drug modulators targeting microglia polarization.

NF-ĸB axis in diabetic neuropathy, cardiomyopathy and nephropathy: A roadmap from molecular intervention to therapeutic strategies

Diabetes mellitus (DM) is a metabolic illness defined by elevated blood glucose levels, mediating various tissue alterations, including the dysfunction of vital organs. Diabetes mellitus (DM) can lead to many consequences that specifically affect the brain, heart, and kidneys. These issues are known as neuropathy, cardiomyopathy, and nephropathy, respectively. Inflammation is acknowledged as a pivotal biological mechanism that contributes to the development of various diabetes consequences. NF-κB modulates inflammation and the immune system at the cellular level. Its abnormal regulation has been identified in several clinical situations, including cancer, inflammatory bowel illnesses, cardiovascular diseases, and Diabetes Mellitus (DM). The purpose of this review is to evaluate the potential impact of NF-κB on complications associated with DM. Enhanced NF-κB activity promotes inflammation, resulting in cellular harm and compromised organ performance. Phytochemicals, which are therapeutic molecules, can potentially decline the NF-κB level, therefore alleviating inflammation and the progression of problems correlated with DM. More importantly, the regulation of NF-κB can be influenced by various factors, such as TLR4 in DM. Highlighting these factors can facilitate the development of novel therapies in the future.

Evaluation of nanoparticle albumin-bound paclitaxel loaded macrophages for glioblastoma treatment based on a microfluidic chip

Introduction: Glioblastoma (GBM) is a primary brain malignancy with a dismal prognosis and remains incurable at present. In this study, macrophages (MΦ) were developed to carry nanoparticle albumin-bound paclitaxel (nab-PTX) to form nab-PTX/MΦ. The aim of this study is to use a GBM-on-a-chip to evaluate the anti-GBM effects of nab-PTX/MΦ. Methods: In this study, we constructed nab-PTX/MΦ by incubating live MΦ with nab-PTX. We developed a microfluidic chip to co-culture GBM cells and human umbilical vein endothelial cells, mimicking the simplified blood-brain barrier and GBM. Using a syringe pump, we perform sustainable perfusion of nutrient media. To evaluate the anti-GBM effects nab-PTX/MΦ, we treated the GBM-on-a-chip model with nab-PTX/MΦ and investigated GBM cell proliferation, migration, and spheroid formation. Results: At the chosen concentration, nab-PTX did not significantly affect the viability, chemotaxis and migration of MΦ. The uptake of nab-PTX by MΦ occurred within 1 h of incubation and almost reached saturation at 6 h. Additionally, nab-PTX/MΦ exhibited the M1 phenotype, which inhibits tumor progression. Following phagocytosis, MΦ were able to release nab-PTX, and the release of nab-PTX by MΦ had nearly reached its limit at 48 h. Compared with control group and blank MΦ group, individual nab-PTX group and nab-PTX/MΦ group could inhibit tumor proliferation, invasion and spheroid formation. Meanwhile, the anti-GBM effect of nab-PTX/MΦ was more significant than nab-PTX. Discussion: Our findings demonstrate that nab-PTX/MΦ has a significant anti-GBM effect compared to individual nab-PTX or MΦ administration, suggesting MΦ as potential drug delivery vectors for GBM therapy. Furthermore, the developed GBM-on-a-chip model provides a potential ex vivo platform for innovative cell-based therapies and tailored therapeutic strategies for GBM.

High Stretch Associated with Mechanical Ventilation Promotes Piezo1-Mediated Migration of Airway Smooth Muscle Cells

Ventilator-induced lung injury (VILI) during mechanical ventilation (MV) has been attributed to airway remodeling involving increased airway smooth muscle cells (ASMCs), but the underlying mechanism is not fully understood. Thus, we aimed to investigate whether MV-associated high stretch (>10% strain) could modulate mechanosensitive Piezo1 expression and thereby alter cell migration of ASMCs as a potential pathway to increased ASMCs in VILI. C57BL/6 mice and ASMCs were subjected to MV at high tidal volume (VT, 18 mL/kg, 3 h) and high stretch (13% strain, 0.5 Hz, 72 h), respectively. Subsequently, the mice or cells were evaluated for Piezo1 and integrin mRNA expression by immunohistochemical staining and quantitative PCR (qPCR), and cell migration and adhesion by transwell and cell adhesion assays. Cells were either treated or not with Piezo1 siRNA, Piezo1-eGFP, Piezo1 knockin, Y27632, or blebbistatin to regulate Piezo1 mRNA expression or inhibit Rho-associated kinase (ROCK) signaling prior to migration or adhesion assessment. We found that expression of Piezo1 in in situ lung tissue, mRNA expression of Piezo1 and integrin αVβ1 and cell adhesion of ASMCs isolated from mice with MV were all reduced but the cell migration of primary ASMCs (pASMCs) isolated from mice with MV was greatly enhanced. Similarly, cell line mouse ASMCs (mASMCs) cultured in vitro with high stretch showed that mRNA expression of Piezo1 and integrin αVβ1 and cell adhesion were all reduced but cell migration was greatly enhanced. Interestingly, such effects of MV or high stretch on ASMCs could be either induced or abolished/reversed by down/up-regulation of Piezo1 mRNA expression and inhibition of ROCK signaling. High stretch associated with MV appears to be a mechanical modulator of Piezo1 mRNA expression and can, thus, promote cell migration of ASMCs during therapeutic MV. This may be a novel mechanism of detrimental airway remodeling associated with MV, and, therefore, a potential intervention target to treat VILI.

Matrix stiffness affects tumor-associated macrophage functional polarization and its potential in tumor therapy

The extracellular matrix (ECM) plays critical roles in cytoskeletal support, biomechanical transduction and biochemical signal transformation. Tumor-associated macrophage (TAM) function is regulated by matrix stiffness in solid tumors and is often associated with poor prognosis. ECM stiffness-induced mechanical cues can activate cell membrane mechanoreceptors and corresponding mechanotransducers in the cytoplasm, modulating the phenotype of TAMs. Currently, tuning TAM polarization through matrix stiffness-induced mechanical stimulation has received increasing attention, whereas its effect on TAM fate has rarely been summarized. A better understanding of the relationship between matrix stiffness and macrophage function will contribute to the development of new strategies for cancer therapy. In this review, we first introduced the overall relationship between macrophage polarization and matrix stiffness, analyzed the changes in mechanoreceptors and mechanotransducers mediated by matrix stiffness on macrophage function and tumor progression, and finally summarized the effects of targeting ECM stiffness on tumor prognosis to provide insight into this new field.

Current status and development direction of immunomodulatory therapy for intervertebral disk degeneration

Intervertebral disk (IVD) degeneration (IVDD) is a main factor in lower back pain, and immunomodulation plays a vital role in disease progression. The IVD is an immune privileged organ, and immunosuppressive molecules in tissues reduce immune cell (mainly monocytes/macrophages and mast cells) infiltration, and these cells can release proinflammatory cytokines and chemokines, disrupting the IVD microenvironment and leading to disease progression. Improving the inflammatory microenvironment in the IVD through immunomodulation during IVDD may be a promising therapeutic strategy. This article reviews the normal physiology of the IVD and its degenerative mechanisms, focusing on IVDD-related immunomodulation, including innate immune responses involving Toll-like receptors, NOD-like receptors and the complement system and adaptive immune responses that regulate cellular and humoral immunity, as well as IVDD-associated immunomodulatory therapies, which mainly include mesenchymal stem cell therapies, small molecule therapies, growth factor therapies, scaffolds, and gene therapy, to provide new strategies for the treatment of IVDD.

Navigating the landscape of Rho GTPase signalling system in autoimmunity: A bibliometric analysis spanning over three decades (1990 to 2023)

Ras-homologous (Rho) guanosine triphosphatases (GTPases) are considered a central player in regulating various biological processes, extending to immune regulation. Perturbations in Rho GTPase signalling have been implicated in immune-related dysregulation, contributing to the development of autoimmunity. This study presents a scientometric analysis exploring the interlink between the Rho GTPase signalling system and autoimmunity, while also delving into the trends of past studies. A total of 967 relevant publications from 1990 to 2023 were retrieved from the Web of Science Core Collection database after throrough manual filtering of irrelevant articles. The findings show an upward trajectory in publications related to this field since 2006. Over the past three decades, the United States of America (41.68%) emerged as the primary contributor in advancing our understanding of the association between the Rho GTPase signalling system and autoimmunity. Research in autoimmunity has mainly centered around therapeutic interventions, with an emphasis on studying leukocyte (macrophage) and endothelial remodelling. Interestingly, within the domains of multiple sclerosis and rheumatoid arthritis, the current focus has been directed towards comprehending the role of RhoA, Rac1, and Cdc42. Notably, certain subfamilies of Rho (such as RhoB and RhoC), Rac (including Rac2 and RhoG), Cdc42 (specifically RhoJ), and other atypical Rho GTPases (like RhoE and RhoH) consistently demonstrating compelling link with autoimmunity, but still warrants emphasis in the future study. Hence, strategic manipulation of the Rho signalling system holds immense promise as a pivotal approach to addressing the global challenge of autoimmunity.

Hydroxyfasudil regulates immune balance and suppresses inflammatory responses in the treatment of experimental autoimmune encephalomyelitis

Multiple sclerosis (MS) is a central nervous system (CNS) disease with complicated etiology. Multifocal demyelination and invasion of inflammatory cells are its primary pathological features. Fasudil has been confirmed to improve experimental autoimmune encephalomyelitis (EAE), an animal model of MS. However, Fasudil is accompanied by several shortcomings in the clinical practice. Hydroxyfasudil is a metabolite of Fasudil in the body with better pharmaceutical properties. Therefore, we attempted to study the influence of Hydroxyfasudil upon EAE mice. The results demonstrated that Hydroxyfasudil relieved the symptoms of EAE and the associated pathological damage, reduced the adhesion molecules and chemokines, decreased the invasion of peripheral immune cells. Simultaneously, Hydroxyfasudil modified the rebalance of peripheral T cells. Moreover, Hydroxyfasudil shifted the M1 phenotype to M2 polarization, inhibited inflammatory signaling cascades as well as inflammatory factors, and promoted anti-inflammatory factors in the CNS. In the end, mice in the Hydroxyfasudil group expressed more tight junction proteins, indirectly indicating that the blood-brain barrier (BBB) was protected. Our results indicate that Hydroxyfasudil may be a prospective treatment for MS.

The Role of the Piezo1 Mechanosensitive Channel in Heart Failure

Mechanotransduction (MT) is inseparable from the pathobiology of heart failure (HF). However, the effects of mechanical forces on HF remain unclear. This review briefly describes how Piezo1 functions in HF-affected cells, including endothelial cells (ECs), cardiac fibroblasts (CFs), cardiomyocytes (CMs), and immune cells. Piezo1 is a mechanosensitive ion channel that has been extensively studied in recent years. Piezo1 responds to different mechanical forces and converts them into intracellular signals. The pathways that modulate the Piezo1 switch have also been briefly described. Experimental drugs that specifically activate Piezo1-like proteins, such as Yoda1, Jedi1, and Jedi2, are available for clinical studies to treat Piezo1-related diseases. The only mechanosensitive ion-channel-specific inhibitor available is GsMTx4, which can turn off Piezo1 by modulating the local membrane tension. Ultrasound waves can modulate Piezo1 switching in vitro with the assistance of microbubbles. This review provides new possible targets for heart failure therapy by exploring the cellular functions of Piezo1 that are involved in the progression of the disease. Modulation of Piezo1 activity may, therefore, effectively delay the progression of heart failure.

Corydalis decumbens Alleviates the Migration, Phagocytosis, and Inflammatory Response of Macrophages

Background

The role of Corydalis decumbens (CD) in macrophage activation remains unclear, particularly in the Ras homolog family member A (RhoA) signaling pathway. Therefore, the present study aimed to investigate the effect of CD on the viability, proliferation, morphological changes, migration, phagocytosis, differentiation, and release of inflammatory factors and signaling pathways in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages.

Methods

Cell counting kit-8 and water-soluble tetrazolium salt assays were used to evaluate the viability and proliferation of RAW264.7 macrophages. A transwell assay was examined to assess cell migration. The ingestion of lumisphere assay was employed to detect the phagocytic capacity of macrophages. Phalloidin staining was performed to observe morphological changes in the macrophages. An enzyme-linked immunosorbent assay was performed to quantify inflammation-related cytokines in cell culture supernatants. Cellular immunofluorescence and western blotting were adopted to show the expression of inflammation-related factors, biomarkers of M1/M2 subset macrophages, and factors of the RhoA signaling pathway.

Results

We found that CD increased the viability and proliferation of RAW264.7 macrophages. CD also impaired the migration and phagocytic capacity of macrophages, induced anti-inflammatory M2 macrophage polarization, such as M2-like morphological changes, and upregulated M2 macrophage biomarkers and anti-inflammatory factors. We also observed that CD inactivated the RhoA signaling pathway.

Conclusions

CD mediates the activation of LPS-stimulated macrophages, alleviates the inflammatory responses of macrophages, and activates related signaling pathways induced by LPS.