Macrophage-secreted TGF-β1 contributes to fibroblast activation and ureteral stricture after ablation injury

Advances in macrophage-derived exosomes as immunomodulators in disease progression and therapy

Most somatic cells secrete vesicles called exosomes, which contain a variety of biomolecules. Recent research indicates that macrophage-derived exosomes are strongly correlated with tumors, infectious diseases, chronic inflammation, and tissue fibrosis. Therefore, the purpose of this review is to delve into the mechanisms of pathological states and how macrophage-derived exosomes react to them. We also discuss the biological effects of exosomes and how they affect disease. In addition, we have examined the possible uses of exosomes in illness treatment, highlighting both the benefits and drawbacks of these applications.

Verapamil inhibits inflammation and promotes autophagy to alleviate ureteral scar by regulation of CaMK IIδ/STAT3 axis

BACKGROUND

Ureteral stricture (US) is a pathological stenosis in the urinary tract characterized by increased collagen synthesis and inflammation. Autophagy activation has been shown to ameliorate tissue fibrosis and protect against fibrotic diseases. Verapamil has beneficial therapeutic benefits on fibrotic disorders. The pharmacological effects of verapamil on fibroblast autophagy in US and the underlying mechanism need to be investigated further.

METHODS

US patients were recruited to isolate scar tissues, hematoxylin-eosin (HE) and Masson trichrome staining were performed to analyze histopathological changes. The US animal model was established and administered with verapamil (0.05 mg/kg) in the drinking water. Transforming growth factor (TGF)-β1 was adopted to facilitate collagen synthesis in fibroblasts. The mRNA and protein expressions were examined by qRT-PCR, western blot, immunofluorescence and immunohistochemistry. ELISA was adopted to measure interleukin (IL)-1β and IL-6 levels. Molecular interaction experiments like dual luciferase reporter and chromatin immunoprecipitation (ChIP) assays were performed to analyze the interaction between signal transducers and activators of transcription 3 (STAT3) and RNA polymerase II associated factor 1 (PAF1).

RESULTS

Herein, our results revealed that verapamil activated TGF-β1-treated fibroblast autophagy and inhibited inflammation and fibrosis by repressing Ca2+⁄calmodulin-dependent protein kinase II (CaMK II) δ-mediated STAT3 activation. Our following tests revealed that STAT3 activated PAF1 transcription. PAF1 upregulation abrogated the regulatory effect of verapamil on fibroblast autophagy and fibrosis during US progression. Finally, verapamil mitigated US in vivo by activating fibroblast autophagy.

CONCLUSION

Taken together, verapamil activated TGF-β1-treated fibroblast autophagy and inhibited fibrosis by repressing the CaMK IIδ/STAT3/PAF1 axis.

The role of M1 (CD11c) and M2 (CD163) interplay in the pathogenesis of oral submucous fibrosis and its malignant transformation: An immunohistochemical analysis

OBJECTIVES

The M1/M2 macrophage framework is crucial in organ fibrosis and its progression to malignancy. This study investigated the possible role of M1/M2 macrophage interplay in the pathogenesis of oral submucous fibrosis (OSF) and its malignant transformation by analysing immunohistochemical expression of CD11c (M1) and CD163 (M2) markers.

METHODS

Immunohistochemistry was performed using primary antibodies against CD11c and CD163 on ten formalin-fixed paraffin-embedded tissue blocks for each group: (i) Stage 1 OSF, (ii) Stage 2 OSF, (iii) Stage 3 OSF, (iv) Stage 4 OSF, (v) well-differentiated squamous cell carcinoma (WDSCC) with OSF, and (vi) WDSCC without OSF. Ten cases of healthy buccal mucosa (NOM) served as controls.

RESULTS

Epithelial quick scores of M1 (CD11c) in NOM, Stages 1-4 OSF, and WDSCC with and without OSF were 0, 1.8, 2.9, 0.4, 0, 0, and 0, while connective tissue scores were 0, 3.2, 4.3, 2.7, 0.5, 1.2, and 2.4, respectively. Epithelial scores for M2 (CD163) were 0, 0.8, 0.8, 2.1, 0.6, 0.8, and 0.2, and connective tissue scores were 0, 1.8, 2.6, 3.9, 2.2, 5, and 4.4, respectively. Stages 3 and 4 OSF, WDSCC with and without OSF exhibited higher M2/M1 ratios compared to NOM and Stages 1-2 OSF.

CONCLUSION

The interaction between M1 (CD11c) and M2 (CD163) macrophages, leading to M2 polarisation, plays a crucial role in the pathogenesis of OSF and its potential malignant transformation.

Cellular and Molecular Mechanisms of Hypertrophy of Ligamentum Flavum

Hypertrophy of the ligamentum flavum (HLF) is a common contributor to lumbar spinal stenosis (LSS). Fibrosis is a core pathological factor of HLF resulting in degenerative LSS and associated low back pain. Although progress has been made in HLF research, the specific molecular mechanisms that promote HLF remain to be defined. The molecular factors involved in the onset of HLF include increases in inflammatory cytokines such as transforming growth factor (TGF)-β, matrix metalloproteinases, and pro-fibrotic growth factors. In this review, we discuss the current understanding of the mechanisms involved in HLF with a particular emphasis on aging and mechanical stress. We also discuss in detail how several pathomechanisms such as fibrosis, proliferation and apoptosis, macrophage infiltration, and autophagy, in addition to several molecular pathways involving TGF-β1, mitogen-activated protein kinase (MAPKs), and nuclear factor-κB (NF-κB) signaling, PI3K/AKT signaling, Wnt signaling, micro-RNAs, extracellular matrix proteins, reactive oxygen species (ROS), etc. are involved in fibrosis leading to HLF. We also present a summary of the current advancements in preclinical animal models for HLF research. In addition, we update the current and potential therapeutic targets/agents against HLF. An improved understanding of the molecular processes behind HLF and a novel animal model are key to developing effective LSS prevention and treatment strategies.

Emerging technologies in regenerative medicine: The future of wound care and therapy

Wound healing, an intricate biological process, comprises orderly phases of simple biological processed including hemostasis, inflammation, angiogenesis, cell proliferation, and ECM remodeling. The regulation of the shift in these phases can be influenced by systemic or environmental conditions. Any untimely transitions between these phases can lead to chronic wounds and scarring, imposing a significant socio-economic burden on patients. Current treatment modalities are largely supportive in nature and primarily involve the prevention of infection and controlling inflammation. This often results in delayed healing and wound complications. Recent strides in regenerative medicine and tissue engineering offer innovative and patient-specific solutions. Mesenchymal stem cells (MSCs) and their secretome have gained specific prominence in this regard. Additionally, technologies like tissue nano-transfection enable in situ gene editing, a need-specific approach without the requirement of complex laboratory procedures. Innovating approaches like 3D bioprinting and ECM bioscaffolds also hold the potential to address wounds at the molecular and cellular levels. These regenerative approaches target common healing obstacles, such as hyper-inflammation thereby promoting self-recovery through crucial signaling pathway stimulation. The rationale of this review is to examine the benefits and limitations of both current and emerging technologies in wound care and to offer insights into potential advancements in the field. The shift towards such patient-centric therapies reflects a paradigmatic change in wound care strategies.

Drug resistance and tumor immune microenvironment: An overview of current understandings (Review)

The use of antitumor drugs represents a reliable strategy for cancer therapy. Unfortunately, drug resistance has become increasingly common and contributes to tumor metastasis and local recurrence. The tumor immune microenvironment (TME) consists of immune cells, cytokines and immunomodulators, and collectively they influence the response to treatment. Epigenetic changes including DNA methylation and histone modification, as well as increased drug exportation have been reported to contribute to the development of drug resistance in cancers. In the past few years, the majority of studies on tumors have only focused on the development and progression of a tumor from a mechanistic standpoint; few studies have examined whether the changes in the TME can also affect tumor growth and drug resistance. Recently, emerging evidence have raised more concerns regarding the role of TME in the development of drug resistance. In the present review, it was discussed how the suppressive TME adapts to drug resistance characterized by the cooperation of immune cells, cytokines, immunomodulators, stromal cells and extracellular matrix. Furthermore, it was reviewed how these immunological or metabolic changes alter immuno‑surveillance and thus facilitate tumor drug resistance. In addition, potential targets present in the TME for developing novel therapeutic strategies to improve individualized therapy for cancer treatment were revealed.

Multimodal analyses of immune cells during bone repair identify macrophages as a therapeutic target in musculoskeletal trauma

Musculoskeletal traumatic injuries (MTI) involve soft tissue lesions adjacent to a bone fracture leading to fibrous nonunion. The impact of MTI on the inflammatory response to fracture and on the immunomodulation of skeletal stem/progenitor cells (SSPCs) remains unknown. Here, we used single-nucleus transcriptomic analyses to describe the immune cell dynamics after bone fracture and identified distinct macrophage subsets with successive pro-inflammatory, pro-repair and anti-inflammatory profiles. Concurrently, SSPCs transition via a pro- and anti-inflammatory fibrogenic phase of differentiation prior to osteochondrogenic differentiation. In a preclinical MTI mouse model, the injury response of immune cells and SSPCs is disrupted leading to a prolonged pro-inflammatory phase and delayed resolution of inflammation. Macrophage depletion improves bone regeneration in MTI demonstrating macrophage involvement in fibrous nonunion. Finally, pharmacological inhibition of macrophages using the CSF1R inhibitor Pexidartinib ameliorates healing. These findings reveal the coordinated immune response of macrophages and skeletal stem/progenitor cells as a driver of bone healing and as a primary target for the treatment of trauma-associated fibrosis.

Evidence of the Link between Stroma Remodeling and Prostate Cancer Prognosis

Prostate cancer (PCa), the most commonly diagnosed cancer in men worldwide, is particularly challenging for oncologists when a precise prognosis needs to be established. Indeed, the entire clinical management in PCa has important drawbacks, generating an intense debate concerning the possibility to individuate molecular biomarkers able to avoid overtreatment in patients with pathological indolent cancers. To date, the paradigmatic change in the view of cancer pathogenesis prompts to look for prognostic biomarkers not only in cancer epithelial cells but also in the tumor microenvironment. PCa ecology has been defined with increasing details in the last few years, and a number of promising key markers associated with the reactive stroma are now available. Here, we provide an updated description of the most biologically significant and cited prognosis-oriented microenvironment biomarkers derived from the main reactive processes during PCa pathogenesis: tissue adaptations, inflammatory response and metabolic reprogramming. Proposed biomarkers include factors involved in stromal cell differentiation, cancer-normal cell crosstalk, angiogenesis, extracellular matrix remodeling and energy metabolism.

A mechanobiological model of bone metastasis reveals that mechanical stimulation inhibits the pro-osteolytic effects of breast cancer cells

Bone is highly susceptible to cancer metastasis, and both tumor and bone cells enable tumor invasion through a "vicious cycle" of biochemical signaling. Tumor metastasis into bone also alters biophysical cues to both tumor and bone cells, which are highly sensitive to their mechanical environment. However, the mechanobiological feedback between these cells that perpetuate this cycle has not been studied. Here, we develop highly advanced in vitro and computational models to provide an advanced understanding of how tumor growth is regulated by the synergistic influence of tumor-bone cell signaling and mechanobiological cues. In particular, we develop a multicellular healthy and metastatic bone model that can account for physiological mechanical signals within a custom bioreactor. These models successfully recapitulated mineralization, mechanobiological responses, osteolysis, and metastatic activity. Ultimately, we demonstrate that mechanical stimulus provided protective effects against tumor-induced osteolysis, confirming the importance of mechanobiological factors in bone metastasis development.

Modulation of the tumor microenvironment and mechanism of immunotherapy-based drug resistance in breast cancer

Breast cancer, the most frequent female malignancy, is often curable when detected at an early stage. The treatment of metastatic breast cancer is more challenging and may be unresponsive to conventional therapy. Immunotherapy is crucial for treating metastatic breast cancer, but its resistance is a major limitation. The tumor microenvironment (TME) is vital in modulating the immunotherapy response. Various tumor microenvironmental components, such as cancer-associated fibroblasts (CAFs), tumor-associated macrophages (TAMs), and myeloid-derived suppressor cells (MDSCs), are involved in TME modulation to cause immunotherapy resistance. This review highlights the role of stromal cells in modulating the breast tumor microenvironment, including the involvement of CAF-TAM interaction, alteration of tumor metabolism leading to immunotherapy failure, and other latest strategies, including high throughput genomic screening, single-cell and spatial omics techniques for identifying tumor immune genes regulating immunotherapy response. This review emphasizes the therapeutic approach to overcome breast cancer immune resistance through CAF reprogramming, modulation of TAM polarization, tumor metabolism, and genomic alterations.

Cell type-specific transforming growth factor-β (TGF-β) signaling in the regulation of salivary gland fibrosis and regeneration

Salivary gland damage and hypofunction result from various disorders, including autoimmune Sjögren's disease (SjD) and IgG4-related disease (IgG4-RD), as well as a side effect of radiotherapy for treating head and neck cancers. There are no therapeutic strategies to prevent the loss of salivary gland function in these disorders nor facilitate functional salivary gland regeneration. However, ongoing aquaporin-1 gene therapy trials to restore saliva flow show promise. To identify and develop novel therapeutic targets, we must better understand the cell-specific signaling processes involved in salivary gland regeneration. Transforming growth factor-β (TGF-β) signaling is essential to tissue fibrosis, a major endpoint in salivary gland degeneration, which develops in the salivary glands of patients with SjD, IgG4-RD, and radiation-induced damage. Though the deposition and remodeling of extracellular matrix proteins are essential to repair salivary gland damage, pathological fibrosis results in tissue hardening and chronic salivary gland dysfunction orchestrated by multiple cell types, including fibroblasts, myofibroblasts, endothelial cells, stromal cells, and lymphocytes, macrophages, and other immune cell populations. This review is focused on the role of TGF-β signaling in the development of salivary gland fibrosis and the potential for targeting TGF-β as a novel therapeutic approach to regenerate functional salivary glands. The studies presented highlight the divergent roles of TGF-β signaling in salivary gland development and dysfunction and illuminate specific cell populations in damaged or diseased salivary glands that mediate the effects of TGF-β. Overall, these studies strongly support the premise that blocking TGF-β signaling holds promise for the regeneration of functional salivary glands.

Multimodal analyses of immune cells during bone repair identify macrophages as a therapeutic target in musculoskeletal trauma

Musculoskeletal traumatic injuries (MTI) involve soft tissue lesions adjacent to a bone fracture leading to fibrous nonunion. The impact of MTI on the inflammatory response to fracture and on the immunomodulation of skeletal stem/progenitor cells (SSPCs) remains unknown. Here, we used single cell transcriptomic analyses to describe the immune cell dynamics after bone fracture and identified distinct macrophage subsets with successive pro-inflammatory, pro-repair and anti-inflammatory profiles. Concurrently, SSPCs transition via a pro- and anti-inflammatory fibrogenic phase of differentiation prior to osteochondrogenic differentiation. In a preclinical MTI mouse model, the injury response of immune cells and SSPCs is disrupted leading to a prolonged pro-inflammatory phase and delayed resolution of inflammation. Macrophage depletion improves bone regeneration in MTI demonstrating macrophage involvement in fibrous nonunion. Finally, pharmacological inhibition of macrophages using the CSF1R inhibitor Pexidartinib ameliorates healing. These findings reveal the coordinated immune response of macrophages and skeletal stem/progenitor cells as driver of bone healing and as a primary target for the treatment of trauma-associated fibrosis.

Summary

Hachemi et al. report the immune cell atlas of bone repair revealing macrophages as pro-fibrotic regulators and a therapeutic target for musculoskeletal regeneration. Genetic depletion or pharmacological inhibition of macrophages improves bone healing in musculoskeletal trauma.

CDCA5 promoted cell invasion and migration by activating TGF-β1 pathway in human ovarian cancer cells

BACKGROUND

The gene cell division cycle associated 5 (CDCA5), also called sororin, has oncogenic characteristics and is upregulated in various carcinomas. Nevertheless, the involvement of CDCA5 in ovarian cancer (OC), a highly aggressive form of cancer, and the underlying mechanism of metastasis remain inadequately investigated.

RESULTS

The bioinformatics data revealed a negative correlation between the patient's survival and CDCA5 expression, which was overexpressed in OC. Functional assays also confirmed high expression levels of CDCA5 in OC tissues and cells. This suggests that CDCA5 may potentially enhance the motility, migration, and proliferation of OC cells invitro. It impedes DNA damage and apoptosis in OC cells, inhibiting xenograft development in nude mice. The RNA sequencing results suggest CDCA5 is majorly associated with biological functions related to the extracellular matrix (ECM) and influences the transforming growth factor (TGF) signaling pathway. Moreover, subsequent functional investigations elucidated that CDCA5 facilitated the migration and invasion of OC cells viathe TGF-β1/Smad2/3 signaling pathway activation.

CONCLUSIONS

CDCA5 may be a strong potential therapeutic target for the treatment and management of OC.

The pathogenic role of the immune system in erectile dysfunction and Peyronie's disease: focusing on immunopathophysiology and potential therapeutic strategies

INTRODUCTION

Erectile dysfunction (ED) represents the major cause of male sexual dysfunction, which is often associated with obesity, diabetes mellitus, atherosclerotic cardiovascular disease, and cigarette smoking. Peyronie's disease is a chronic disorder associated with irreversible fibrotic damage of the tunica albuginea leading to ED, painful erection, coital disturbance, and physical and social complaints. Both conditions are characterized by chronic inflammation, oxidative stress, and significant changes in intracavernous hydrodynamics. In this scenario, oxidized lipoproteins, M1-polarized macrophages, proinflammatory cytokines (such as the tumor necrosis factor α), endothelial nitric oxide synthase, penile smooth muscle cells, and toll-like receptors represent the main triggers of the inflammatory process in ED. Phosphodiesterase-5 inhibitors are the most common treatment for ED. This treatment is used intermittently, as it is conceived as a symptomatic and not curative therapy. Moreover, not all patients respond to phosphodiesterase-5 inhibitors (35%-85%), particularly those with dysmetabolic phenotypes. Additional or alternative treatments are therefore desirable, mostly in refractory cases.

OBJECTIVES

In this review, we describe the immune-mediated pathogenesis of ED and Peyronie's disease (PD). In our literature search we placed particular emphasis on potentially practical therapeutic approaches, including natural products (such as polyphenols), due to their anti-inflammatory and antioxidant activities, stem cell therapy, and platelet-derived preparations.

METHODS

We searched PubMed/MEDLINE, Web of Science, Scopus, Cochrane Library, Google Scholar, and institutional websites. Original studies, narrative reviews, systematic reviews, and meta-analyses written in English were searched, screened, and selected.

RESULTS

In animal models of ED and PD, therapeutic approaches, including anti-inflammatory and antioxidant agents, stem cell therapy, and platelet-derived preparations, have provided positive results, including improved penile function, reduced inflammation and oxidative stress, and promotion of tissue repair. However, clinical evidence of improvement in human patients is still insufficient.

CONCLUSION

Promising results for treating ED and PD have been shown in preclinical and pilot clinical studies, but specific clinical trials are needed to validate the efficacy of these therapeutic approaches in men with ED.

Unremitting pro-inflammatory T-cell phenotypes, and macrophage activity, following paediatric burn injury

Objectives

The aim of this study was to characterise the dynamic immune profile of paediatric burn patients for up to 18 months post-burn.

Methods

Flow cytometry was used to measure 25 cell markers, chemokines and cytokines which reflected both pro-inflammatory and anti-inflammatory immune profiles. Peripheral blood mononuclear cells from 6 paediatric burn patients who had returned for repeated burn and scar treatments for > 4 timepoints within 12 months post-burn were compared to four age-matched healthy controls.

Results

While overall proportions of T cells, NK cells and macrophages remained relatively constant, over time percentages of these immune cells differentiated into effector and proinflammatory cell phenotypes including Th17 and activated γδ T cells. Circulating proportions of γδ T cells increased their expression of pro-inflammatory mediators throughout the burn recovery, with a 3-6 fold increase of IL-17 at 1-3 weeks, and NFκβ 9-18 months post-burn. T-regulatory cell plasticity was also observed, and Treg phenotype proportions changed from systemically reduced skin-homing T-regs (CCR4+) and increased inflammatory (CCR6+) at 1-month post-burn, to double-positive cell types (CCR4+CCR6+) elevated in circulation for 18 months post-burn. Furthermore, Tregs were observed to proportionally express less IL-10 but increased TNF-α over 18 months.

Conclusion

Overall, these results indicate the circulating percentages of immune cells do not increase or decrease over time post-burn, instead they become highly specialised, inflammatory and skin-homing. In this patient population, these changes persisted for at least 18 months post-burn, this 'immune distraction' may limit the ability of immune cells to prioritise other threats post-burn, such as respiratory infections.

M2a macrophages regulate fibrosis and affect the outcome after stroke via PU.1/mTOR pathway in fibroblasts

The moderate formation of the fibrotic scar plays an important role in functional recovery after stroke. M2a macrophages have been identified as an important source of early fibrosis after cerebral ischemia. However, the underlying mechanisms by which macrophages interact with fibroblasts in this context remain largely unknown. Therefore, our study aimed to further investigate the potential mechanisms underlying the effects of macrophages on fibroblasts following ischemic stroke. In vitro and in vivo, recombinant rat interleukin 4 (IL4) was used to induce macrophages to polarize into M2a macrophages. In vitro, primary Sprague-Dawley newborn rat meningeal-derived fibroblasts were treated with PU.1 knockdown, the PU.1 inhibitor DB1976 or the mTOR inhibitor rapamycin, which were then co-cultured with M2a macrophage conditioned medium (MCM). In vivo, Sprague-Dawley adult rats were infected with negative control adenoviruses or PU.1-shRNA adenoviruses. Ten days after infection, an injury model of middle cerebral artery occlusion/reperfusion (MCAO/R) was constructed. Subsequently, IL4 was injected intracerebroventricularly to induce M2a macrophages polarization. In vitro, M2a MCM upregulated PU.1 expression and promoted the differentiation, proliferation, migration and extracellular matrix generation of fibroblasts, which could be reversed by treatment with the PU.1 inhibitor DB1976 or PU.1 knockdown. In vivo, PU.1 expression in fibroblasts was increased within ischemic core following MCAO/R, and this upregulation was further enhanced by exposure to IL4. Treatment with IL4 promoted fibrosis, increased angiogenesis, reduced apoptosis and infarct volume, as well as mitigated neurological deficits after MCAO/R, and these effects could be reversed by PU.1 knockdown. Furthermore, both in vivo and in vitro studies showed that IL4 treatment increased the levels of phosphorylated Akt and mTOR proteins, which were markedly decreased by PU.1 knockdown. Additionally, the use of an mTOR inhibitor rapamycin obviously suppressed the migration and differentiation of fibroblasts, and Col1 synthesis. In conclusion, our findings suggest for the first time that M2a macrophages, at least in part, regulate fibrosis and affect the outcome after cerebral ischemic stroke via the PU.1/mTOR signaling pathway in fibroblasts.

Quercetin inhibits mesothelial-mesenchymal transition and alleviates postoperative peritoneal adhesions by blocking the TGF-β1/PI3K/AKT pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Carthami flos is a dried flower of the Asteraceae plant Carthamus tinctorius (L.). Danhong injection, composed of Carthami flos and Danshen can prevent the formation of postoperative peritoneal adhesions. Quercetin (QUE), an active compound of Carthami flos, has also been proved to prevent postoperative abdominal and uterine cavity adhesions. However, whether QUE is the key component in Carthami flos and the mechanism in preventing postoperative peritoneal adhesions has not been studied.

AIM OF THE STUDY

To predict whether QUE is the key molecule in Carthami flos and explore the effect and mechanism of QUE in preventing postoperative peritoneal adhesions.

MATERIALS AND METHODS

Drug composition and target analysis was used to predict the key component in Carthami flos. The method of cecum-sidewall abrasion was used to establish adhesion models, and the antiadhesion effect of QUE was evaluated with the adhesion scoring system. Network pharmacology was used to predict the targets and potential mechanism of QUE in preventing adhesion. The mechanism was further verified by immunofluorescence, Western blot, wound healing experiment, and molecular docking.

RESULTS

Quercetin was predicted to be the key to preventing postoperative peritoneal adhesions in Carthami flos. Animal experiments revealed that QUE effectively ameliorated adhesions and reduced the expression of mesothelial-mesenchymal transition (MMT) related markers and TGF-β1. Moreover, the TGF-β1/PI3K/AKT pathway was predicted via protein-protein interaction and Kyoto encyclopedia of Genes and Genomes enrichment analysis to play a crucial part in preventing adhesion by QUE. Furthermore, in vitro experiments and molecular docking demonstrated that QUE could block the TGF-β1/PI3K/AKT pathway through forming a stable combination with TβR-II, thereby inhibiting MMT and ameliorating peritoneal adhesion.

CONCLUSIONS

QUE can not only reduce postoperative TGF-β1 but also block the TGF-β1/PI3K/AKT pathway to inhibit MMT of mesothelial cells, and finally alleviate postoperative peritoneal adhesions. These findings may provide insights towards development of a safe and effective anti-adhesive drug for prevention of postoperative peritoneal adhesions.

Role of TGF-β and p38 MAPK in TSG-6 Expression in Adipose Tissue-Derived Stem Cells In Vitro and In Vivo

Mesenchymal stem cells (MSCs) regulate immune cell activity by expressing tumor necrosis factor-α (TNF-α)-stimulated gene 6 (TSG-6) in inflammatory environments; however, whether anti-inflammatory responses affect TSG-6 expression in MSCs is not well understood. Therefore, we investigated whether transforming growth factor-β (TGF-β) regulates TSG-6 expression in adipose tissue-derived stem cells (ASCs) and whether effective immunosuppression can be achieved using ASCs and TGF-β signaling inhibitor A83-01. TGF-β significantly decreased TSG-6 expression in ASCs, but A83-01 and the p38 inhibitor SB202190 significantly increased it. However, in septic C57BL/6 mice, A83-01 further reduced the survival rate of the lipopolysaccharide (LPS)-treated group and ASC transplantation did not improve the severity induced by LPS. ASC transplantation alleviated the severity of sepsis induced by LPS+A83-01. In co-culture of macrophages and ASCs, A83-01 decreased TSG-6 expression whereas A83-01 and SB202190 reduced Cox-2 and IDO-2 expression in ASCs. These results suggest that TSG-6 expression in ASCs can be regulated by high concentrations of pro-inflammatory cytokines in vitro and in vivo, and that A83-01 and SB202190 can reduce the expression of immunomodulators in ASCs. Therefore, our data suggest that co-treatment of ASCs with TGF-β or p38 inhibitors is not adequate to modulate inflammation.

Efficacy of Robot-Assisted Ureteroureterostomy in Patients with Complex Ureteral Stricture after Ureteroscopic Lithotripsy

BACKGROUND

Ureteral stricture (US) postureteroscopic lithotripsy (URSL) has emerged as a severe complication with the widespread use of laser technology. Furthermore, managing a complex US is challenging. Therefore, this study evaluated the efficacy of robot-assisted ureteroureterostomy (RAUU) in addressing US post-URSL and analyzed the pathology of transected ureteral tissues to identify the risk factors for US.

METHODS

we conducted a prospective cohort study on patients who underwent RAUU for URSL-induced US from April 2021 to May 2023.

RESULTS

A total of 14 patients with a mean age of 49.8 years were included in this study. The mean stricture length on radiography was 22.66 ± 7.38 mm. Nine (64.2%) patients had experienced failure with previous interventions. The overall success rate was 92.9%, both clinically and radiographically, without major complications, at a mean follow-up of 12.8 months. The pathological findings revealed microcalcifications and a loss of ureteral mucosa in 57.1% and 28.6% of patients, respectively.

CONCLUSIONS

The RAUU technique shows promise as a viable option for US post-URSL in appropriately selected patients despite severe pathological changes in the ureter. Therefore, the migration of microcalcifications to the site of ureteral perforation may be a significant factor contributing to US development.

In vitro and in vivo assessment of a bilayered degradable rapamycin-eluting stent for ureteral stricture caused by holmium: YAG laser lithotripsy

Ureteral stricture caused by holmium: YAG laser lithotripsy is one of the most challenging issues for urologists. Currently, evidence for rapamycin application in reducing ureterostenosis is not sufficient. This study aimed to assess the inhibition of ureteral stricture of rapamycin-eluting stents in vitro and in vivo. A bilayered drug-eluting ureteral stent consisted of drug blending with poly (lactic-co-glycolic acid) (PU/drug stent), which was over-layered by polycaprolactone (PCL) by ultrasonic atomizing spraying. Stent morphology was observed by scanning electron microscope. A kidney-ureter-bladder model was established to simulate the stents-releasing condition, and high-performance liquid chromatography was used to measure the drug release rate. The inhibitory proliferation was detected by CCK-8. The bladder of rats was injured through electro tome, and stents were implanted for 7, 14, and 28 days. The effects of drug-eluting stents was investigated by hematoxylin-eosin staining, immunofluorescence staining, real-time quantitative polymerase chain reaction and western blot. The bilayered stents could block the burst loss of the drug and maintained a sustained delivery period because of the 5.3 μm thickness of the PCL layer. The relative growth rates of cells plotted inhibitory effect on the proliferation of human urethral scar fibroblast cells. For in vivo results of 28 days, the bilayered stent maintained structural integrity and induced less deposition of crystals, thinner and less lamina propria connective tissues were formed, and α-SMA and TGF-β1 were downregulated. Bilayered rapamycin-eluting stent is significantly effective in alleviating fibrosis in in vitro and in vivo models. STATEMENT OF SIGNIFICANCE: The occurrence of ureteral stricture resulting from holmium: YAG laser lithotripsy presents a significant challenge for urologists. Traditional double J stents have not been proven to offer a shorter indwelling time or improved inhibition of tissue blocking. While drug-eluting stents containing rapamycin, paclitaxel, and other substances have been extensively used in treating artery stenosis, there is insufficient evidence supporting their application in reducing ureterostenosis. Consequently, a biodegradable polymer ureteric scaffold incorporating rapamycin was fabricated in this study, employing ultrasonic atomization spraying technology to optimize the bilayers composed of 75/25 poly (lactic-co-glycolic acid) (PLGA) and polycaprolactone (PCL). The efficacy of the scaffold was subsequently confirmed through in vitro and in vivo experiments.

Precisely Regulating M2 Subtype Macrophages for Renal Fibrosis Resolution

Macrophages are central to the pathogenesis of kidney disease and serve as an effective therapeutic target for kidney injury and fibrosis. Among them, M2-type macrophages have double-edged effects regarding anti-inflammatory effects and tissue repair. Depending on the polarization of the M2 subtypes (M2a or M2c) in the diseased microenvironment, they can either mediate normal tissue repair or drive tissue fibrosis. In renal fibrosis, M2a promotes disease progression through macrophage-to-myofibroblast transition (MMT) cells, while M2c possesses potent anti-inflammatory functions and promotes tissue repair, and is inhibited. The mechanisms underlying this differentiation are complex and are currently not well understood. Therefore, in this study, we first confirmed that M2a-derived MMT cells are responsible for the development of renal fibrosis and demonstrated that the intensity of TGF-β signaling is a major factor determining the differential polarization of M2a and M2c. Under excessive TGF-β stimulation, M2a undergoes a process known as MMT cells, whereas moderate TGF-β stimulation favors the polarization of M2c phenotype macrophages. Based on these findings, we employed targeted nanotechnology to codeliver endoplasmic reticulum stress (ERS) inhibitor (Ceapin 7, Cea or C) and conventional glucocorticoids (Dexamethasone, Dex or D), precisely modulating the ATF6/TGF-β/Smad3 signaling axis within macrophages. This approach calibrated the level of TGF-β stimulation on macrophages, promoting their polarization toward the M2c phenotype and suppressing excessive MMT polarization. The study indicates that the combination of ERS inhibitor and a first-line anti-inflammatory drug holds promise as an effective therapeutic approach for renal fibrosis resolution.

Microenvironmental regulation in tumor progression: Interactions between cancer-associated fibroblasts and immune cells

The tumor microenvironment (TME), the "soil" on which tumor cells grow, has an important role in regulating the proliferation and metastasis of tumor cells as well as their response to treatment. Cancer-associated fibroblasts (CAFs), as the most abundant stromal cells of the TME, can not only directly alter the immunosuppressive effect of the TME through their own metabolism, but also influence the aggregation and function of immune cells by secreting a large number of cytokines and chemokines, reducing the body's immune surveillance of tumor cells and making them more prone to immune escape. Our study provides a comprehensive review of fibroblast chemotaxis, malignant transformation, metabolic characteristics, and interactions with immune cells. In addition, the current small molecule drugs targeting CAFs have been summarized, including both natural small molecules and targeted drugs for current clinical therapeutic applications. A complete review of the role of fibroblasts in TME from an immune perspective is presented, which has important implications in improving the efficiency of immunotherapy by targeting fibroblasts.

Galectin-12 modulates Kupffer cell polarization to alter the progression of nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease is caused by an imbalance in lipid metabolism and immune response to pose a risk factor for liver fibrosis. Recent evidence indicates that M2 macrophages secrete transforming growth factor-β1, which contributes to liver fibrosis. Galectin-12 has been demonstrated to regulate lipid metabolism and macrophage polarization. The purpose of this study is to investigate the role of galectin-12 in the development of nonalcoholic fatty liver disease and fibrosis. Liver tissue from wild-type C57BL/6 mice fed with a high-fat diet containing cholesterol and cholic acid for 4-12 weeks was used to examine galectin-12 expression and its correlation with nonalcoholic fatty liver disease. Furthermore, the effects of galectin-12 on M2 macrophages during the progression of nonalcoholic fatty liver disease were investigated by studying Kupffer cells from galectin-12 knockout mice and doxycycline-inducible Gal12-/-THP-1 cells. Ablation of galectin-12 promoted M2 polarization of Kupffer cells, as indicated by higher levels of M2 markers, such as arginase I and chitinase 3-like protein 3. Furthermore, the activation of signal transducer and activator of transcription 6 was significantly higher in Gal12-/- macrophages activated by interleukin-4, which was correlated with higher levels of transforming growth factor-β1. Moreover, Gal12-/- macrophage-conditioned medium promoted hepatic stellate cells myofibroblast differentiation, which was indicated by higher α-smooth muscle actin expression levels compared with those treated with LacZ control medium. Finally, we demonstrated that galectin-12 knockdown negatively regulated the suppressor of cytokine signaling 3 levels. These findings suggested that galectin-12 balances M1/M2 polarization of Kupffer cells to prevent nonalcoholic fatty liver disease progression.

Macrophages and fibroblasts in foreign body reactions: How mechanical cues drive cell functions?

Biomaterials, when implanted in the human body, can induce a series of cell- and cytokine-related reactions termed foreign body reactions (FBRs). In the progression of FBRs, macrophages regulate inflammation and healing by polarizing to either a pro-inflammatory or pro-healing phenotype and recruit fibroblasts by secreting cytokines. Stimulated by the biomaterials, fibrotic capsule is formed eventually. The implant, along with its newly formed capsule, introduces various mechanical cues that influence cellular functions. Mechanosensing proteins, such as integrins or ion channels, transduce extracellular mechanical signals into cytoplasm biochemical signals in response to mechanical stimuli. Consequently, the morphology, migration mode, function, and polarization state of the cells are affected. Modulated by different intracellular signaling pathways and their crosstalk, the expression of fibrotic genes increases with fibroblast activation and fibroblast to myofibroblast transition under stiff or force stimuli. However, summarized in most current studies, the outcomes of macrophage polarization in the effect of different mechanical cues are inconsistent. The underlying mechanisms should be investigated with more advanced technology and considering more interfering aspects. Further research is needed to determine how to modulate the progression of fibrotic capsule formation in FBR artificially.

Fibroblast diversity and plasticity in the tumor microenvironment: roles in immunity and relevant therapies

Cancer-associated fibroblasts (CAFs), enriched in the tumor stroma, have received increasing attention because of their multifaceted effects on tumorigenesis, development, metastasis, and treatment resistance in malignancies. CAFs contributed to suppressive microenvironment via different mechanisms, while CAFs also exerted some antitumor effects. Therefore, CAFs have been considered promising therapeutic targets for their remarkable roles in malignant tumors. However, patients with malignancies failed to benefit from current CAFs-targeted drugs in many clinical trials, which suggests that further in-depth investigation into CAFs is necessary. Here, we summarize and outline the heterogeneity and plasticity of CAFs mainly by exploring their origin and activation, highlighting the regulation of CAFs in the tumor microenvironment during tumor evolution, as well as the critical roles performed by CAFs in tumor immunity. In addition, we summarize the current immunotherapies targeting CAFs, and conclude with a brief overview of some prospects for the future of CAFs research in the end. Video Abstract.

Intricacies of TGF-β signaling in Treg and Th17 cell biology

Balanced immunity is pivotal for health and homeostasis. CD4+ helper T (Th) cells are central to the balance between immune tolerance and immune rejection. Th cells adopt distinct functions to maintain tolerance and clear pathogens. Dysregulation of Th cell function often leads to maladies, including autoimmunity, inflammatory disease, cancer, and infection. Regulatory T (Treg) and Th17 cells are critical Th cell types involved in immune tolerance, homeostasis, pathogenicity, and pathogen clearance. It is therefore critical to understand how Treg and Th17 cells are regulated in health and disease. Cytokines are instrumental in directing Treg and Th17 cell function. The evolutionarily conserved TGF-β (transforming growth factor-β) cytokine superfamily is of particular interest because it is central to the biology of both Treg cells that are predominantly immunosuppressive and Th17 cells that can be proinflammatory, pathogenic, and immune regulatory. How TGF-β superfamily members and their intricate signaling pathways regulate Treg and Th17 cell function is a question that has been intensely investigated for two decades. Here, we introduce the fundamental biology of TGF-β superfamily signaling, Treg cells, and Th17 cells and discuss in detail how the TGF-β superfamily contributes to Treg and Th17 cell biology through complex yet ordered and cooperative signaling networks.

Cancer-associated fibroblasts: Just on the opposite side of antitumour immunity?

The tumour microenvironment (TME) is critical for the initiation, progression, and metastasis of tumours, and cancer-associated fibroblasts (CAFs) are the most dominant cells and have attracted interest as targets for cancer therapy among the stromal components within the TME. Currently, most of the identified CAF subpopulations are believed to exhibit suppressive effects on antitumour immunity. However, accumulating evidence indicates the presence of immunostimulatory CAF subpopulations, which play an important role in the maintenance and amplification of antitumour immunity, in the TME. Undoubtedly, these findings provide novel insights into CAF heterogeneity. Herein, we focus on summarizing CAF subpopulations that promote antitumour immunity, the surface markers of these populations, and possible immunostimulatory mechanisms in the context of recent advances in research on CAF subpopulations. In addition, we discuss the possibility of new therapies targeting CAF subpopulations and conclude with a brief description of some prospective avenues for CAF research.

Fibrotic Diseases of the Human Urinary and Genital Tract: Current Understanding and Potential Strategies for Treatment

Fibrosis is a disease condition characterized by abnormalities of the extracellular matrix, such as accumulation of the transforming growth factor β, infiltration by myofibroblasts, deposition of collagen, and a generalized dysregulation of collagen maturation. It can severely impair the function of organs by replacing normal tissue with a highly collagenized matrix, thereby reducing the elasticity and compliance of tissues. Fibrotic diseases of the genitourinary tract present relevant problems in healthcare, and their principles of pathophysiology remain unclarified; hence, the armamentarium for prevention and treatment is limited. These diseases include renal fibrosis, Peyronie's disease and ureteral and urethral strictures due to perturbations in the process of wound healing in response to injuries. Such deteriorations may contribute to obstructive uropathies or sexual dysfunction. This review provides a brief overview of the most frequent fibrotic diseases of the genitourinary system and of how the pathophysiology is related to symptoms, and also highlights potential therapeutic strategies to address the abnormal deposition of collagen. Although the understanding of factors associated with fibrotic conditions of the urinary and genital tract is still limited, some beneficial advances have been made. Further research will serve to provide a more comprehensive insight into factors responsible for the development of fibrotic tissue deposition.

Semi-autonomous wound invasion via matrix-deposited, haptotactic cues

Proper wound healing relies on invasion of fibroblasts via directed migration. While the related experimental and mathematical modeling literature has mainly focused on cell migration directed by soluble cues (chemotaxis), there is ample evidence that fibroblast migration is also directed by insoluble, matrix-bound cues (haptotaxis). Furthermore, numerous studies indicate that fibronectin (FN), a haptotactic ligand for fibroblasts, is present and dynamic in the provisional matrix throughout the proliferative phase of wound healing. In the present work, we show the plausibility of a hypothesis that fibroblasts themselves form and maintain haptotactic gradients in a semi-autonomous fashion. As a precursor to this, we examine the positive control scenario where FN is pre-deposited in the wound matrix, and fibroblasts maintain haptotaxis by removing FN at an appropriate rate. After developing conceptual and quantitative understanding of this scenario, we consider two cases in which fibroblasts activate the latent form of a matrix-loaded cytokine, TGFβ, which upregulates the fibroblasts' own secretion of FN. In the first of these, the latent cytokine is pre-patterned and released by the fibroblasts. In the second, fibroblasts in the wound produce the latent TGFβ, with the presence of the wound providing the only instruction. In all cases, wound invasion is more effective than a negative control model with haptotaxis disabled; however, there is a trade-off between the degree of fibroblast autonomy and the rate of invasion.

Rectifying disorder of extracellular matrix to suppress urethral stricture by protein nanofilm-controlled drug delivery from urinary catheter

Urethral stricture secondary to urethral injury, afflicting both patients and urologists, is initiated by excessive deposition of extracellular matrix in the submucosal and periurethral tissues. Although various anti-fibrotic drugs have been applied to urethral stricture by irrigation or submucosal injection, their clinical feasibility and effectiveness are limited. Here, to target the pathological state of the extracellular matrix, we design a protein-based nanofilm-controlled drug delivery system and assemble it on the catheter. This approach, which integrates excellent anti-biofilm properties with stable and controlled drug delivery for tens of days in one step, ensures optimal efficacy and negligible side effects while preventing biofilm-related infections. In a rabbit model of urethral injury, the anti-fibrotic catheter maintains extracellular matrix homeostasis by reducing fibroblast-derived collagen production and enhancing metalloproteinase 1-induced collagen degradation, resulting in a greater improvement in lumen stenosis than other topical therapies for urethral stricture prevention. Such facilely fabricated biocompatible coating with antibacterial contamination and sustained-drug-release functionality could not only benefit populations at high risk of urethral stricture but also serve as an advanced paradigm for a range of biomedical applications.

The Influence of Apremilast-Induced Macrophage Polarization on Intestinal Wound Healing

There is compelling evidence suggesting a pivotal role played by macrophages in orchestrating intestinal wound healing. Since macrophages display significant plasticity and heterogeneity, exhibiting an either classically activated (M1-like) or alternatively activated (M2-like) phenotype, they can aggravate or attenuate intestinal wound healing. Growing evidence also demonstrates a causal link between impaired mucosal healing in inflammatory bowel disease (IBD) and defects in the polarization of pro-resolving macrophages. By targeting the switch from M1 to M2 macrophages, the phosphodiesterase-4 inhibitor Apremilast has gained recent attention as a potential IBD drug. However, there is a gap in our current knowledge regarding the impact of Apremilast-induced macrophages' polarization on intestinal wound healing. The THP-1 cells were differentiated and polarized into M1 and M2 macrophages, and subsequently treated with Apremilast. Gene expression analysis was performed to characterize macrophage M1 and M2 phenotypes, and to identify possible target genes of Apremilast and the involved pathways. Next, intestinal fibroblast (CCD-18) and epithelial (CaCo-2) cell lines were scratch-wounded and exposed to a conditioned medium of Apremilast-treated macrophages. Apremilast had a clear effect on macrophage polarization, inducing an M1 to M2 phenotype switch, which was associated with NF-κB signaling. In addition, the wound-healing assays revealed an indirect influence of Apremilast on fibroblast migration. Our results support the hypothesis of Apremilast acting through the NF-κB-pathway and provide new insights into the interaction with fibroblast during intestinal wound healing.

The role of macrophages-mediated communications among cell compositions of tumor microenvironment in cancer progression

Recent studies have revealed that tumor-associated macrophages are the most abundant stromal cells in the tumor microenvironment and play an important role in tumor initiation and progression. Furthermore, the proportion of macrophages in the tumor microenvironment is associated with the prognosis of patients with cancer. Tumor-associated macrophages can polarize into anti-tumorigenic phenotype (M1) and pro-tumorigenic phenotype (M2) by the stimulation of T-helper 1 and T-helper 2 cells respectively, and then exert opposite effects on tumor progression. Besides, there also is wide communication between tumor-associated macrophages and other immune compositions, such as cytotoxic T cells, regulatory T cells, cancer-associated fibroblasts, neutrophils and so on. Furthermore, the crosstalk between tumor-associated macrophages and other immune cells greatly influences tumor development and treatment outcomes. Notably, many functional molecules and signaling pathways have been found to participate in the interactions between tumor-associated macrophages and other immune cells and can be targeted to regulate tumor progression. Therefore, regulating these interactions and CAR-M therapy are considered to be novel immunotherapeutic pathways for the treatment of malignant tumors. In this review, we summarized the interactions between tumor-associated macrophages and other immune compositions in the tumor microenvironment and the underlying molecular mechanisms and analyzed the possibility to block or eradicate cancer by regulating tumor-associated macrophage-related tumor immune microenvironment.

Cancer-associated fibroblasts: The chief architect in the tumor microenvironment

Stromal heterogeneity of tumor microenvironment (TME) plays a crucial role in malignancy and therapeutic resistance. Cancer-associated fibroblasts (CAFs) are one of the major players in tumor stroma. The heterogeneous sources of origin and subsequent impacts of crosstalk with breast cancer cells flaunt serious challenges before current therapies to cure triple-negative breast cancer (TNBC) and other cancers. The positive and reciprocal feedback of CAFs to induce cancer cells dictates their mutual synergy in establishing malignancy. Their substantial role in creating a tumor-promoting niche has reduced the efficacy of several anti-cancer treatments, including radiation, chemotherapy, immunotherapy, and endocrine therapy. Over the years, there has been an emphasis on understanding CAF-induced therapeutic resistance in order to enhance cancer therapy results. CAFs, in the majority of cases, employ crosstalk, stromal management, and other strategies to generate resilience in surrounding tumor cells. This emphasizes the significance of developing novel strategies that target particular tumor-promoting CAF subpopulations, which will improve treatment sensitivity and impede tumor growth. In this review, we discuss the current understanding of the origin and heterogeneity of CAFs, their role in tumor progression, and altering the tumor response to therapeutic agents in breast cancer. In addition, we also discuss the potential and possible approaches for CAF-mediated therapies.

Macrophage activity at the site of tumor ablation can promote murine urothelial cancer via transforming growth factor-β1

Cell death and injury at the site of tumor ablation attracts macrophages. We sought to understand the status and activity of these cells while focusing on transforming growth factor-β1 (TGF-β1), a potent immunosuppressive and tumorigenic cytokine. Patients with urothelial cancer who underwent ablation using electrocautery or laser demonstrated increased infiltration and numbers of CD8+ T cells, along with FoxP3+ regulatory T cells, CD68+ macrophages and elevated levels of TGF-β1 in recurrent tumors. Similar findings were reproduced in a mouse model of urothelial cancer (MB49) by partial tumor ablation with irreversible electroporation (IRE). Stimulation of bone marrow derived macrophages with MB49 cell debris produced using IRE elicited strong M2 polarization, with exuberant secretion of TGF-β1. The motility, phenotypic markers and cytokine secretion by macrophages could be muted by treatment with Pirfenidone (PFD), a clinically approved drug targeting TGF-β1 signaling. MB49 cancer cells exposed to TGF-β1 exhibited increased migration, invasiveness and upregulation of epithelial-mesenchymal transition markers α-Smooth Muscle Actin and Vimentin. Such changes in MB49 cells were reduced by treatment with PFD even during stimulation with TGF-β1. IRE alone yielded better local tumor control when compared with control or PFD alone, while also reducing the overall number of lung metastases. Adjuvant PFD treatment did not provide additional benefit under in vivo conditions.

Aluminum exposure induces nephrotoxicity via fibrosis and apoptosis through the TGF-β1/Smads pathway in vivo and in vitro

Aluminum (Al), the most common element in nature, can enter the body through various routes. Unfortunately, excessive accumulation of Al in the body can cause chronic toxicity. In this study, rats were randomly allocated to 4 groups and intraperitoneally injected with AlCl₃ solution at 0, 5, 10, and 20 mg/(kg·d), respectively, for 4 weeks. The kidney function of rats and Al contents in the kidney were measured, and the pathological structural changes and apoptosis of the kidney were observed. Meanwhile, the expression of fibrosis- and apoptosis-related proteins was detected with western blot. For the in vitro assay, HK-2 cells were used to construct a model to evaluate the effects of Al exposure on cell viability, cell apoptosis, and the expression of fibrosis- and apoptosis-related proteins. Additionally, the TGF-β1/Smads pathway was also altered in HK-2 cells, followed by the measurement of changes in apoptosis and fibrosis-related proteins. The results revealed that Al could accumulate in kidney tissues, then leading to histopathological changes and kidney function impairment, promoting renal tubular cell apoptosis and renal collagen fiber deposition, and also elevating the expression of TGF-β1/Smads pathway-related proteins. In vitro experiments also exhibited that Al exposure increased apoptosis and the expression of fibrosis-related factors in HK-2 cells, accompanied by activation of the TGF-β1/Smads pathway. Further modulation of the TGF-β1/Smads pathway manifested that activation of the TGF-β1/Smads pathway facilitated Al-induced apoptosis and fibrosis-related factor expression, while inhibition of the pathway negated this effect of Al. In conclusion, the findings of the present study illustrate that Al exposure damages kidney function and facilitate apoptosis and kidney fibrosis, which may be achieved through the activation of the TGF-β1/Smads pathway. This study provides a new theoretical basis for the study of nephrotoxicity induced by excessive Al exposure.

Metformin Improves Burn Wound Healing by Modulating Microenvironmental Fibroblasts and Macrophages

Metformin, a biguanide, exerts different functions through various signaling pathways. In order to investigate the function and mechanism of metformin in burn wounds, we established burn rat models, subcutaneously injected metformin to treat the wounds, and observed the morphologies and the expression of collagen I, collagen III, fibronectin, and pro-inflammatory markers. In vitro experiments were performed to investigate the effects of metformin on the proliferation, migration, and collagen I synthesis of the mouse embryonic fibroblast (NIH 3T3) cell line and on the proliferation, apoptosis, and immune response of the mouse mononuclear macrophage (RAW 264.7) cell line. Finally, we studied the regulatory effects of metformin on a co-culture of RAW 264.7/NIH 3T3 cells. We found that 100 mM of metformin reduced dermal thickness, collagen I deposition, and mRNA expression of IL1β and CCL2 in rat burn wounds. In vitro experiments revealed that metformin inhibited the proliferation of NIH 3T3 and RAW 264.7 cells. Metformin attenuated NIH 3T3 cell migration via the AMPK/mTOR pathway and attenuated collagen I synthesis through the TGFβ1/Smad3 pathway. Metformin inhibited the apoptosis of RAW 264.7 cells induced by 10 μg/mL LPS. Metformin downregulated the mRNA expression of IL1β and CCL2 in RAW 264.7 cells under 1 μg/mL LPS induction by inhibiting NF-κB p65 phosphorylation. In a RAW 264.7/NIH 3T3 co-culture, metformin attenuated collagen I synthesis in NIH 3T3 cells by inhibiting RAW 264.7 paracrine secretion of TGF-β1. This provides new evidence related to the development of metformin for potentially improving burn wound healing.

Macrophages in intestinal fibrosis and regression

Intestinal macrophages are heterogenous cell populations with different developmental ontogeny and tissue anatomy. The concerted actions of intestinal macrophage subsets are critical to maintaining tissue homeostasis. However, the dysregulation of macrophages following tissue injury or chronic inflammation could also lead to intestinal fibrosis, with few treatment options in the clinic. In this review, we will characterize the features of intestinal macrophages in light of the latest advances in lineage tracing and single-cell sequencing technology. The roles of macrophages in distinct stages of intestinal fibrosis would be also elaborated. Finally, based on the reciprocal interaction between macrophages and intestinal fibrosis, we will propose the potential macrophage targeting anti-intestinal fibrosis therapies.

The potential of functionalized dressing releasing flavonoids facilitates scar-free healing

Scars are pathological marks left after an injury heals that inflict physical and psychological harm, especially the great threat to development and aesthetics posed by oral and maxillofacial scars. The differential expression of genes such as transforming growth factor-β, local adherent plaque kinase, and yes-related transcriptional regulators at infancy or the oral mucosa is thought to be the reason of scarless regenerative capacity after tissue defects. Currently, tissue engineering products for defect repair frequently overlook the management of postoperative scars, and inhibitors of important genes alone have negative consequences for the organism. Natural flavonoids have hemostatic, anti-inflammatory, antioxidant, and antibacterial properties, which promote wound healing and have anti-scar properties by interfering with the transmission of key signaling pathways involved in scar formation. The combination of flavonoid-rich drug dressings provides a platform for clinical translation of compounds that aid in drug disintegration, prolonged release, and targeted delivery. Therefore, we present a review of the mechanisms and effects of flavonoids in promoting scar-free regeneration and the application of flavonoid-laden dressings.

Macrophage-mediated extracellular matrix remodeling after fat grafting in nude mice

Clinical unpredictability and variability following fat grafting remain non-negligible problems due to the unknown mechanism of grafted fat retention. The role of the extracellular matrix (ECM), which renders cells with structural and biochemical support, has been ignored. This study aimed to clarify the ECM remodeling process, related cellular events, and the spatiotemporal relationship between ECM remodeling and adipocyte survival and adipogenesis after fat grafting. Labeled Coleman fat by the matrix-tracing technique was grafted in nude mice. The ECM remodeling process and cellular events were assessed in vivo. The related cytokines were evaluated by qRT-PCR. An in vitro cell migration assay was performed to verify the chemotactic effect of M2-like macrophages on fibroblasts. The results demonstrated that in the periphery, most of the adipocytes of the graft survived or regenerated, and the graft-derived ECM was gradually replaced by the newly-formed ECM. In the central parts, most adipocytes in the grafts died shortly after, and a small part of the graft-derived and newly-formed ECM was expressed with irregular morphology. Adipose ECM remodeling is associated with increased infiltration of macrophages and fibroblasts, as well as up-regulated expression of cytokines in the adipose tissue. To sum up, our results describe the various preservation mode of fat grafts after transplantation and underscore the importance of macrophage-mediated ECM remodeling in graft preservation after fat grafting. The appreciation and manipulation of underlying mechanisms that are operant in this setting stand to explore new therapeutic approaches and improve clinical outcomes of fat grafting.

The emerging roles of interstitial macrophages in pulmonary fibrosis: A perspective from scRNA-seq analyses

Pulmonary fibrosis is an irreversible and progressive disease affecting the lungs, and the etiology remains poorly understood. This disease can be lethal and currently has no specific clinical therapeutic regimen. Macrophages, the most common type of immune cell in the lungs, have been reported to play a key role in the pathogenesis of fibrotic disease. The lung macrophage population is mostly composed of alveolar macrophages and interstitial macrophages, both of which have not been thoroughly studied in the pathogenesis of lung fibrosis. Interstitial macrophages have recently been recognised for their participation in lung fibrosis due to new technology arising from a combination of bioinformatics and single-cell RNA sequencing analysis. This paper reviews recent developments regarding lung macrophage classification and summarizes the origin and replenishment of interstitial macrophages and their function in pulmonary fibrosis.

Plasma Kallikrein-Activated TGF-β Is Prognostic for Poor Overall Survival in Patients with Pancreatic Ductal Adenocarcinoma and Associates with Increased Fibrogenesis

Pancreatic ductal adenocarcinoma (PDAC) is a hard-to-treat cancer due to the collagen-rich (fibrotic) and immune-suppressed microenvironment. A major driver of this phenomenon is transforming growth factor beta (TGF-β). TGF-β is produced in an inactive complex with a latency-associated protein (LAP) that can be cleaved by plasma kallikrein (PLK), hereby releasing active TGF-β. The aim of this study was to evaluate LAP cleaved by PLK as a non-invasive biomarker for PDAC and tumor fibrosis. An ELISA was developed for the quantification of PLK-cleaved LAP-TGF-β in the serum of 34 patients with PDAC (stage 1−4) and 20 healthy individuals. Biomarker levels were correlated with overall survival (OS) and compared to serum type III collagen (PRO-C3) and type VI collagen (PRO-C6) pro-peptides. PLK-cleaved LAP-TGF-β was higher in patients with PDAC compared to healthy individuals (p < 0.0001). High levels (>median) of PLK-cleaved LAP-TGF-β were associated with poor OS in patients with PDAC independent of age and stage (HR 2.57, 95% CI: 1.22−5.44, p = 0.0135). High levels of PLK-cleaved LAP-TGF-β were associated with high PRO-C3 and PRO-C6, indicating a relationship between the PLK-cleaved LAP-TGF-β fragment, TGF-β activity, and tumor fibrosis. If these preliminary results are validated, circulating PLK-cleaved LAP-TGF-β may be a biomarker for future clinical trials.

Metabolic reprogramming and crosstalk of cancer-related fibroblasts and immune cells in the tumor microenvironment

It is notorious that cancer cells alter their metabolism to adjust to harsh environments of hypoxia and nutritional starvation. Metabolic reprogramming most often occurs in the tumor microenvironment (TME). TME is defined as the cellular environment in which the tumor resides. This includes surrounding blood vessels, fibroblasts, immune cells, signaling molecules and the extracellular matrix (ECM). It is increasingly recognized that cancer cells, fibroblasts and immune cells within TME can regulate tumor progression through metabolic reprogramming. As the most significant proportion of cells among all the stromal cells that constitute TME, cancer-associated fibroblasts (CAFs) are closely associated with tumorigenesis and progression. Multitudinous studies have shown that CAFs participate in and promote tumor metabolic reprogramming and exert regulatory effects via the dysregulation of metabolic pathways. Previous studies have demonstrated that curbing the substance exchange between CAFs and tumor cells can dramatically restrain tumor growth. Emerging studies suggest that CAFs within the TME have emerged as important determinants of metabolic reprogramming. Metabolic reprogramming also occurs in the metabolic pattern of immune cells. In the meanwhile, immune cell phenotype and functions are metabolically regulated. Notably, immune cell functions influenced by metabolic programs may ultimately lead to alterations in tumor immunity. Despite the fact that multiple previous researches have been devoted to studying the interplays between different cells in the tumor microenvironment, the complicated relationship between CAFs and immune cells and implications of metabolic reprogramming remains unknown and requires further investigation. In this review, we discuss our current comprehension of metabolic reprogramming of CAFs and immune cells (mainly glucose, amino acid, and lipid metabolism) and crosstalk between them that induces immune responses, and we also highlight their contributions to tumorigenesis and progression. Furthermore, we underscore potential therapeutic opportunities arising from metabolism dysregulation and metabolic crosstalk, focusing on strategies targeting CAFs and immune cell metabolic crosstalk in cancer immunotherapy.

TIM-4 in macrophages contributes to nasal polyp formation through the TGF-β1–mediated epithelial to mesenchymal transition in nasal epithelial cells

Chronic rhinosinusitis with nasal polyps (CRSwNP) is caused by prolonged inflammation of the paranasal sinus mucosa. The epithelial to mesenchymal transition (EMT) is involved in the occurrence and development of CRSwNP. The T-cell immunoglobulin domain and the mucin domain 4 (TIM-4) is closely related to chronic inflammation, but its mechanism in CRSwNP is poorly understood. In our study, we found that TIM-4 was increased in the sinonasal mucosa of CRSwNP patients and, especially, in macrophages. TIM-4 was positively correlated with α-SMA but negatively correlated with E-cadherin in CRS. Moreover, we confirmed that TIM-4 was positively correlated with the clinical parameters of the Lund-Mackay and Lund-Kennedy scores. In the NP mouse model, administration of TIM-4 neutralizing antibody significantly reduced the polypoid lesions and inhibited the EMT process. TIM-4 activation by stimulating with tissue extracts of CRSwNP led to a significant increase of TGF-β1 expression in macrophages in vitro. Furthermore, coculture of macrophages and human nasal epithelial cells (hNECs) results suggested that the overexpression of TIM-4 in macrophages made a contribution to the EMT process in hNECs. Mechanistically, TIM-4 upregulated TGF-β1 expression in macrophages via the ROS/p38 MAPK/Egr-1 pathway. In conclusion, TIM-4 contributes to the EMT process and aggravates the development of CRSwNP by facilitating the production of TGF-β1 in macrophages. Inhibition of TIM-4 expression suppresses nasal polyp formation, which might provide a new therapeutic approach for CRSwNP.

Verapamil inhibited the development of ureteral stricture by blocking CaMK II-mediated STAT3 and Smad3/JunD pathways

BACKGROUND

Ureteral stricture (US) is a fibrotic process that leads to urinary tract obstruction and even kidney damage, with the characteristic of reduced extracellular matrix (ECM) degradation and increased collagen synthesis. Verapamil, as a calcium channel blocker, was reported to prevent scar formation. Our work aimed to investigate the biological effects and mechanism of verapamil in US.

METHODS

Fibroblasts were subjected to transforming growth factor-beta 1 (TGF-β1) to stimulate collagen synthesis, and the messenger ribonucleic acid (mRNA) and protein expressions in fibroblasts were assessed using quantitative real-time polymerase chain reaction (qRT-PCR) and western blot. The location of phosphorylation-signal transducer and activator of transcription 3 (p-STAT3) and Jund proto-oncogene subunit (JunD) in fibroblasts were determined by immunofluorescence (IF). The binding relationship between signal transducer and activator of transcription 3 (STAT3) and collagen type I alpha1 (COL1A1)/collagen type III alpha 1 chain (COL3A1) and the binding relationship between JunD and tissue inhibitor of metalloproteinases-1 (TIMP-1) were verified by dual luciferase reporter gene and chromatin Immunoprecipitation (ChIP) assays.

RESULTS

Herein, we found that verapamil could inhibit TGF-β1/Ca2 + ⁄calmodulin-dependent protein kinase II (CaMK II)-mediated STAT3 activation in fibroblasts, and STAT3 inhibition repressed collagen production. In addition, verapamil could inhibit TGF-β1/CaMK II-mediated Mothers against DPP homolog 3 (Smad3)/JunD pathway activation in fibroblasts, and JunD silencing inhibited TIMP1 (a matrix metalloproteinase inhibitor) expression. Our subsequent experiments revealed that STAT3 bound with COL1A1 promoter and COL3A1 promoter and activated their transcription, and JunD bound with TIMP1 promoter and activated its transcription. Moreover, as expected, STAT3 activation could eliminate the inhibitory effect of verapamil treatment on TGF-β1-induced collagen production in fibroblasts, and JunD overexpression reversed the inhibitory effect of verapamil treatment on TGF-β1-induced TIMP1 expression in fibroblasts.

CONCLUSION

Verapamil inhibited collagen production and TIMP-1 expression in US by blocking CaMK II-mediated STAT3 and Smad3/JunD pathways.

Interstitial lung disease progression in patients with anti-aminoacyl transfer-RNA-synthetase autoantibodies is characterized by higher levels of sCD163

BACKGROUND

Patients with anti-tRNA autoantibodies are characterized by arthritis, mechanic´s hands, fever, Raynaud´s phenomenon, and interstitial lung disease (ILD), in at least two clinical scenarios: the antisynthetase syndrome (ASSD) and interstitial pneumonia with autoimmune features (IPAF). The anti-tRNA-ILD treatment is centered on the administration of corticosteroids and a wide variety of immunosuppressive drugs; however, the effectiveness of the treatment depends on factors not fully understood. This research work aimed to quantify the serum levels of two molecules related to pulmonary fibrosis and explore their relationship with the progression of ILD associated with ASSD METHODOLOGY: Serum levels of sCD163 and TGF-β1 from baseline and after six months of treatment of ILD patients' positives to anti-tRNA were included in the current study. At six months, patients were classified as with or without ILD progression RESULTS: Forty patients were included (anti-Jo1, anti-PL7, anti-PL12, and anti-Ej). Five patients (12.5%) had ILD progression and were characterized by higher levels of sCD163 at baseline. Baseline sCD163 serum levels showed good discriminatory capacity in patients with ILD progression. On the other hand, at follow-up, serum TGF-β1 levels significantly increased in both patients' groups, with and without progression CONCLUSION: Basal levels of sCD163 were higher in patients who later developed ILD progression and kinetics of both molecules suggests the participation of M2 macrophages in the development of ILD.

Macrophages evoke autophagy of hepatic stellate cells to promote liver fibrosis in NAFLD mice via the PGE2/EP4 pathway

The pathogenesis of liver fibrosis in nonalcoholic fatty liver disease (NAFLD) remains unclear and the effective treatments have not been explored yet. The activation of hepatic stellate cells (HSCs) is considered as the most critical factor in the progression of liver fibrosis and cirrhosis. Autophagy has recently been identified as a new mechanism to regulate HSC activation. Here, we found that liver macrophages were polarized toward type 2 (M2) during the progression of nonalcoholic steatohepatitis (NASH) and liver fibrosis in both patients and NAFLD mice. Using the methionine-choline-deficient (MCD) diet NAFLD murine model and the in vitro cell culture system, we identified that the M2 macrophages promoted HSC autophagy by secreting prostaglandin E2 (PGE2) and binding its receptor EP4 on the surface of HSCs, which consequently enhanced HSC activation, extracellular matrix deposition, and liver fibrosis. Mechanistically, PGE2/EP4 signals enhanced HSC autophagy through the Erk pathway. A specific PGE2/EP4 antagonist E7046 significantly inhibited M2 macrophage-mediated HSC autophagy and improved liver fibrosis and histopathology in NAFLD mice. Our study provides novel mechanistic insights into the regulation of HSC activation and liver fibrosis. Our findings suggest that the PGE2/EP4 pathway is a promising therapeutic target to prevent NASH progression into cirrhosis.

The contribution of the immune system to genitourinary fibrosis

Fibrotic diseases of the genitourinary tract are devastating and incompletely understood pathologies. These diseases include urethral and ureteral strictures, retroperitoneal fibrosis, and Peyronie's disease. They can contribute to obstructive uropathy and sexual dysfunction. Poor understanding of the pathophysiology of these diseases severely limits our ability to prevent and treat them. Genitourinary fibrotic diseases likely represent related pathologies that share common underlying mechanisms involving wound healing in response to injury. These diseases share the common feature of extracellular matrix abnormalities-such as collagen deposition, transforming growth factor-β accumulation, and dysregulation of collagen maturation-leading to abnormal tissue stiffness. Given the association of many of these diseases with autoimmunity, a systemic pro-inflammatory state likely contributes to their associated fibrogenesis. Herein, we explore the immunologic contribution to fibrogenesis in several fibrotic diseases of the genitourinary system. Better understanding how the immune system contributes to fibrosis in these diseases may improve prevention and therapeutic strategies and elucidate the functions of immunologic contributors to fibrosis in general.

Dual Relationship Between Stromal Cells and Immune Cells in the Tumor Microenvironment

The tumor microenvironment (TME) plays a critical role in tumorigenesis and is comprised of different components, including tumor cells, stromal cells, and immune cells. Among them, the relationship between each mediator involved in the construction of the TME can be understood by focusing on the secreting or expressing factors from each cells. Therefore, understanding the various interactions between each cellular component of the TME is necessary for precise therapeutic approaches. In carcinoma, stromal cells are well known to influence extracellular matrix (ECM) formation and tumor progression through multiple mediators. Immune cells respond to tumor cells by causing cytotoxicity or inflammatory responses. However, they are involved in tumor escape through immunoregulatory mechanisms. In general, anti-cancer therapy has mainly been focused on cancer cells themselves or the interactions between cancer cells and specific cell components. However, cancer cells directly or indirectly influence other TME partners, and members such as stromal cells and immune cells also participate in TME organization through their mutual communication. In this review, we summarized the relationship between stromal cells and immune cells in the TME and discussed the positive and negative relationships from the point of view of tumor development for use in research applications and therapeutic strategies.

Role of macrophages in tumor progression and therapy (Review)

The number and phenotype of macrophages are closely related to tumor growth and prognosis. Macrophages are recruited to (and polarized at) the tumor site thereby promoting tumor growth, stimulating tumor angiogenesis, facilitating tumor cell migration, and creating a favorable environment for subsequent colonization by (and survival of) tumor cells. These phenomena contribute to the formation of an immunosuppressive tumor microenvironment (TME) and therefore speed up tumor cell proliferation and metastasis and reduce the efficacy of antitumor factors and therapies. The ability of macrophages to remodel the TME through interactions with other cells and corresponding changes in their number, activity, and phenotype during conventional therapies, as well as the association between these changes and drug resistance, make tumor-associated macrophages a new target for antitumor therapies. In this review, advantages and limitations of the existing antitumor strategies targeting macrophages in Traditional Chinese and Western medicine were analyzed, starting with the effect of macrophages on tumors and their interactions with other cells and then the role of macrophages in conventional treatments was explored. Possible directions of future developments in this field from an all-around multitarget standpoint were also examined.