Inflammation and metabolism in tissue repair and regeneration

Single-Cell Proteomics Uncovers Dual Traits of Dermal Sheath Cells in Wound Repair

Wound healing is a dynamic process involving multiple cell types and signaling pathways. Dermal sheath cells (DSCs), residing surrounding hair follicles, play a critical role in tissue repair, yet their regulatory mechanisms remain unclear. This study used single-cell proteomics with the AcanCreER;R26LSL-tdTomato-DTR mouse model to explore DSC function across different healing stages. All animal procedures were conducted in accordance with the Animal Research: Reporting of In Vivo Experiments guidelines. Gene set enrichment analysis (GSEA) and temporal clustering (Mfuzz) were employed to reveal dynamic functional shifts. GSEA identified enriched gene sets related to interferon-gamma response, inflammatory response, ultraviolet response, myogenesis, and xenobiotic metabolism. Temporal clustering revealed eight distinct clusters: clusters associated with the early contracting and proliferative phases were linked to metabolic activation and oxidative stress, while clusters from the later remodeling phase emphasized extracellular matrix remodeling and structural reorganization. The dynamic expression of epithelial-mesenchymal transition-related genes and keratins supported DSCs' dual epithelial and mesenchymal traits. Additionally, keratins, collagens, integrins, and actin proteins emerged as promising markers or signature molecules for DSCs. This study reveals DSCs' dual traits during wound repair, providing a basis for therapies to enhance healing.

NLRP3: a key regulator of skin wound healing and macrophage-fibroblast interactions in mice

Wound healing is a highly coordinated process driven by intricate molecular signaling and dynamic interactions between diverse cell types. Nod-like receptor pyrin domain-containing protein 3 (NLRP3) has been implicated in the regulation of inflammation and tissue repair; however, its specific role in skin wound healing remains unclear. This study highlights the pivotal role of NLRP3 in effective skin wound healing, as demonstrated by delayed wound closure and altered cellular and molecular responses in NLRP3-deficient (NLRP3-/-) mice. Histological analysis revealed impaired healing processes, accompanied by reduced expression of key inflammatory mediators, including interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and prostaglandin E2 (PGE2). Deficiencies in apoptosis were evident through altered expression of cysteine-aspartic acid protease 3 (Caspase-3), P53, and B-cell lymphoma-2 (Bcl-2). Furthermore, critical growth factors such as vascular endothelial growth factor (VEGF), epidermal growth factor (EGF), and matrix metalloproteinase-9 (MMP-9) were significantly decreased at the excisional skin wound sites. Furthermore, using co-culture systems, we found that NLRP3 mediated the interaction between macrophages and myofibroblasts. Wild-type fibroblast-conditioned media (MFbCM) enhanced nitric oxide (NO), IL-6, and tumor necrosis factor-α (TNF-α) production in M1 macrophages and arginase activity, chitinase 3-like protein 1 (Ym1), and IL-10 expression in M2 macrophages, effects significantly diminished with NLRP3-/- MFbCM. Similarly, conditioned media from wild-type M1 or M2 macrophages promoted the expression of FGF-2, VEGF, and MMP-2 expression in myofibroblasts, which was attenuated when using NLRP3-/- macrophage-conditioned media. PGE2 levels were reduced in both NLRP3-/- macrophages and myofibroblasts. Supplementing NLRP3-/- conditioned media with PGE2 partially restored the impaired functions, suggesting that PGE2 acts as a downstream mediator of NLRP3-regulated macrophage-myofibroblast interactions. These findings indicate that NLRP3 is a key regulator of skin wound healing, facilitating macrophage-myofibroblast communication.

Single cell approaches define neural stem cell niches and identify microglial ligands that can enhance precursor-mediated oligodendrogenesis

Here, we used single cell RNA sequencing and single cell spatial transcriptomics to characterize the forebrain neural stem cell (NSC) niche under homeostatic and injury conditions. We defined the dorsal and lateral ventricular-subventricular zones (V-SVZs) as two distinct neighborhoods and showed that, after white matter injury, NSCs are activated to make oligodendrocytes dorsally for remyelination. This activation is coincident with an increase in transcriptionally distinct microglia in the dorsal V-SVZ niche. We modeled ligand-receptor interactions within this changing niche and identified two remyelination-associated microglial ligands, insulin growth factor 1 and oncostatin M, that promote precursor proliferation and oligodendrogenesis in culture. Infusion of either ligand into the lateral ventricles also enhanced oligodendrogenesis, even in the lateral V-SVZ, where NSCs normally make neuroblasts. These data support a model where gliogenesis versus neurogenesis is determined by the local NSC neighborhood and where injury-induced niche alterations promote NSC activation, local oligodendrogenesis, and likely contribute to myelin repair.

Mesenchymal stem cells derived exosomes: a new era in cardiac regeneration

Despite significant strides in medical treatments and surgical procedures for cardiovascular diseases, these conditions continue to be a major global health concern. The persistent need for innovative therapeutic approaches to mend damaged heart tissue highlights the complexity and urgency of this medical challenge. In recent years, stem cells have emerged as a promising tool for tissue regeneration, but challenges such as graft rejection and tumor formation have limited their clinical application. Exosomes, extracellular vesicles containing a diverse array of biomolecules, have garnered significant attention for their potential in regenerative medicine. The cardioprotective and reparative properties of mesenchymal stem cell-derived exosomes hold promise for the treatment of heart diseases. These exosomes can modulate various cellular processes, including angiogenesis, apoptosis, and inflammation, thereby enhancing cardiac function. Despite the growing interest, there remains a lack of comprehensive reviews synthesizing the molecular mechanisms, preclinical, and clinical evidence related to the specific role of MSC-derived exosomes in cardiac therapies. This review aims to fill that gap by exploring the potential of MSC-derived exosomes as a therapeutic strategy for cardiac diseases. This review explores the potential of mesenchymal stem cell-derived exosomes as a therapeutic strategy for cardiac diseases. We discuss the molecular mechanisms underlying their cardioprotective effects, summarize preclinical and clinical studies investigating their efficacy, and address the challenges and future perspectives of exosome-based therapies. The collective evidence suggests that MSC-derived exosomes hold promise as a novel and effective therapeutic approach for cardiac diseases.

Herbal HuoXueTongFu Formula with anti-inflammatory and fibrinolytic activity regulation for the prevention of postoperative peritoneal adhesions

Background

The HuoXueTongFu Formula (HXTF) originates from the classic prescription "DaHuangMuDan Decoction" from the "Synopsis of the golden chamber". Our previous study revealed that HXTF has a positive effect on postoperative peritoneal adhesion (PPA). However, the specific mechanism of HXTF on PPA formation within the time-to-treatment window has not been fully elucidated. This study aimed to determine the critical roles of HXTF as a result of its specific anti-inflammatory and antifibrinolytic activities for PPA treatment.

Methods

The eight main bioactive components of HXTF were subjected to high-performance liquid chromatography-mass spectrometry. The core targets, critical biological processes, and underlying pathways of HXTF and PPA were identified via a series of network pharmacological methods. The specific anti-inflammatory function in the initial step of PPA formation was validated in peritoneal macrophages (PMs) isolated from PPA mice on Day 3 postsurgery. The potential anti-fibrinolytic activity in the next stage of PPA formation was subsequently explored in PPA mice on Day 7 postsurgery.

Results

Network pharmacology revealed 160 common targets between HXTF and PPA. Several core targets, i.e., matrix metalloproteinase 9 (MMP9), tissue-type plasminogen activator (tPA), and plasminogen activator inhibitor 1 (PAI-1), were annotated as important biological processes (extracellular matrix disassembly and the collagen catabolic process). Validation experiments revealed that HXTF could induce macrophage polarization-mediated anti-inflammatory reactions by increasing the phagocytic capacity of PMs and promoting the release of anti-inflammatory cytokines (IL-4 and IL-10). In addition, HXTF promoted fibrinogenolysis and improved fibrinolytic activity, thereby inhibiting collagen deposition and reducing adhesion development.

Conclusion

The ameliorative effects of herbal HXTF on PPA formation are attributable to the induction of macrophage polarization-mediated anti-inflammatory reactions in the early stage of PPA formation and the promotion of fibrinogenolysis and fibrinolytic activity in the middle stage of PPA formation. HXTF may be a promising alternative agent for the prevention and treatment of PPA.

The role of multiomics in revealing the mechanism of skin repair and regeneration

Skin repair and regeneration are crucial processes in restoring the integrity of the skin after injury, with significant implications for medical treatments and plastic surgery. Multiomics, an integrated approach combining genomics, transcriptomics, proteomics, and metabolomics, offers unprecedented insights into the complex molecular and cellular mechanisms involved in skin healing. This review explores the transformative role of multiomics in elucidating the mechanisms of skin repair and regeneration. While genomic studies identify the genetic basis of wound healing, transcriptomics and proteomics uncover the dynamic changes in gene and protein expression, and metabolomics provides a snapshot of metabolic alterations associated with wound healing. Integrative multiomics studies can also identify novel biomarkers and therapeutic targets for skin regeneration. Despite the technical and biological challenges, the future of multiomics in skin research holds great promise for advancing personalized medicine and improving wound healing strategies. Through interdisciplinary collaboration, multiomics has the potential to revolutionize our understanding of skin repair, paving the way for innovative treatments in plastic surgery and beyond.

m6A RNA modification pathway: orchestrating fibrotic mechanisms across multiple organs

Organ fibrosis, a common consequence of chronic tissue injury, presents a significant health challenge. Recent research has revealed the regulatory role of N6-methyladenosine (m6A) RNA modification in fibrosis of various organs, including the lung, liver, kidney, and heart. In this comprehensive review, we summarize the latest findings on the mechanisms and functions of m6A modification in organ fibrosis. By highlighting the potential of m6A modification as a therapeutic target, our goal is to encourage further research in this emerging field and support advancements in the clinical treatment of organ fibrosis.

3D nanofiber sponge based on natural insect quaternized chitosan/pullulan/citric acid for accelerating wound healing

Extensive traumatic injuries and difficult-to-heal wounds, induced by many circumstances, impose a significant social and economic burden on an annual basis. Thus, innovative wound dressings that encourage wound healing are greatly needed. In this work, we prepared a novel insect chitosan (MCS) using waste pupal shells from housefly (Musca domestica L.) culture. After conducting comparative investigations with commercially available chitosan, it was shown that MCS exhibited comparable qualities and may be used as a substitute source of commercial chitosan. A quaternized chitosan/pullulan/citric acid three-dimensional nanofiber sponge (3D-NS) of natural origin was prepared by electrostatic spinning and gas foaming techniques after MCS was quaternized. In vitro, tests showed that the 3D-NS had a higher liquid absorption capacity than the two-dimensional nanofibrous membrane (2D-NM). Additionally, the 3D-NS showed improved hemostatic, pro-cell proliferation, antibacterial, and anti-inflammatory qualities. In vitro, tests demonstrated that 3D-NS could inhibit the release of inflammatory factors, promote angiogenesis, accelerate collagen deposition, and promote wound contraction. These effects considerably facilitated the healing process of wounds in rats with full-thickness skin damage. In conclusion, the great bioactivity and physicochemical properties of 3D-NS render it an optimal candidate for developing novel wound dressings.

Single-cell and spatial transcriptomic profiling revealed niche interactions sustaining growth of endometriotic lesions

Endometriosis is a chronic condition with limited therapeutic options. The molecular aberrations promoting ectopic attachment and interactions with the local microenvironment sustaining lesion growth have been unclear, prohibiting development of targeted therapies. Here, we performed single-cell and spatial transcriptomic profiling of ectopic lesions and eutopic endometrium in endometriosis. We found that ectopic endometrial stromal (EnS) cells retained cyclical gene expression patterns of their eutopic counterparts while exhibiting unique gene expression that contributes to the pathogenesis of endometriosis. We identified two distinct ovarian stromal cells (OSCs) localized at different zones of the lesion, showing differential gene expression profiles associated with fibrosis and inflammation, respectively. We also identified WNT5A upregulation and aberrant activation of non-canonical WNT signaling in endometrial stromal cells that may contribute to the lesion establishment, offering novel targets for therapeutic intervention. These data will enhance our understanding of the molecular mechanisms underlying endometriosis and paves the way for developing non-hormonal treatments.

Intrinsic immunomodulatory hydrogels for chronic inflammation

The immune system plays a pivotal role in maintaining physiological homeostasis and influencing disease processes. Dysregulated immune responses drive chronic inflammation, which in turn results in a range of diseases that are among the leading causes of death globally. Traditional immune interventions, which aim to regulate either insufficient or excessive inflammation, frequently entail lifelong comorbidities and the risk of severe side effects. In this context, intrinsic immunomodulatory hydrogels, designed to precisely control the local immune microenvironment, have recently attracted increasing attention. In particular, these advanced hydrogels not only function as delivery mechanisms but also actively engage in immune modulation, optimizing interactions with the immune system for enhanced tissue repair, thereby providing a sophisticated strategy for managing chronic inflammation. In this tutorial review, we outline key elements of chronic inflammation and subsequently explore the strategic design principles of intrinsic immunomodulatory hydrogels based on these elements. Finally, we examine the challenges and prospects of such immunomodulatory hydrogels, which are expected to inspire further preclinical research and clinical translation in addressing chronic inflammation.

Clinical characteristics and impact of pseudo-lumen blood flow on long-term vessel dilatation in spontaneous isolated dissection of superior mesenteric/celiac artery

This study aimed to identify the clinical characteristics associated with spontaneous isolated dissection of superior mesenteric artery/celiac artery (SIDSMA/SIDCA). This observational study, conducted at Toranomon Hospital, Japan between 2009 and 2020, analyzed consecutive SIDSMA/SIDCA cases based on radiology data. The study compared clinical characteristics between symptomatic and asymptomatic patients with SIDSMA/SIDCA and investigated factors related to future vessel dilatation. Among 57 cases (44 SIDSMA, 17 SIDCA, and 4 both), the majority were male (87.7%), nearly half having hypertension (43.9%) and smokers (48.9%). Of those, 17 cases (29.8%) were symptomatic; abdominal pain (94.1%), back pain (23.5%), nausea (17.6%) and fever (5.9%). The symptomatic group was younger (52.6 ± 9.4 versus 67.2 ± 7.9 years, P < 0.001), had higher systolic and mean blood pressure (142.6 ± 20.0 versus 129.5 ± 16.5 mmHg, P = 0.017; 96.1 ± 14.6 versus 88.2 ± 17.7 mmHg, P = 0.038), a higher white blood cell count (9975 ± 5032 versus 6268 ± 1991 /µL, P = 0.012), and a higher LDL cholesterol level at diagnosis (129.7 ± 21.7 versus 87.2 ± 25.6 mg/dL, P = 0.002) than the asymptomatic group. The factors associated with future vessel dilatation included the presence of pseudo-lumen flow in the dissection vessel (73.9% versus 41.4%, p = 0.019) and a larger vessel diameter (13.5 ± 2.4 mm versus 11.5 ± 2.1 mm, p = 0.005) at diagnosis after multiple adjustments, pseudo-lumen flow was a predictor of future vessel dilatation (odds ratio, 4.80; 95% confidence interval, 1.11-20.75; p = 0.036). The study revealed that only 30% of SIDSMA/SIDCA cases were symptomatic. Symptomatic cases were generally younger and exhibited higher blood pressure and elevated white blood cell counts. These findings offer valuable insights for the acute diagnosis of SIDSMA/SIDCA.

A superelastic, biofluid-locking, and degradable dressing for wound healing

In medical field, light-weight, superelastic, and super-absorbing aerogels are highly desired for sensitive wounds with persistent exudations. Up to now, superelastic PU porous dressings are commonly employed, which impose environmental concerns both in their preparation and in their pollution after usage. Herein, carboxymethyl cellulose (CMC) was used to construct hierarchical aerogels via a dual-crosslinking and porogen leaching method. The hierarchical aerogel not only disperses stress at multiple scales, endowing the aerogel with superelasticity, but also deeply absorbs bioliquid through its hierarchical porous surfaces and strong wetting forces deriving from the abundant hydrophilic groups such as hydroxyl and carboxyl groups. Moreover, for practical use, the hierarchical CMC (H-CMC) dressing demonstrates superior absorbency than commercial elastic PU foam both in static and dynamic liquid absorption, faster wound healing than commercial CMC fiber dressing, and can fully degrade both in vivo and in soil. Thus, this research offers a universal approach to design hierarchical wound dressings using bio-based polyelectrolyte, presenting a wound dressing that is both environmentally-friendly and highly comfortable when applied in healing human sensitive injuries.

Causal relationship between inflammatory cytokines, metabolites, and ulcers of lower limb: A Mendelian randomization study

Inflammatory cytokines are key indicators affecting the development of ulcers of lower limb. The causal role of inflammatory cytokines in ulcers of lower limb and whether this can be mediated by metabolites remain unknown. We conducted a two-step, two-sample Mendelian randomization (MR) study to investigate the causal effect of inflammatory cytokines on ulcers of lower limb and the mediating role of metabolites in the association between inflammatory cytokines and ulcers of lower limb. MR analysis identified seven inflammatory cytokines (CCL19, IL-12β, MCP4, MIP1a, SCF, sirtuin2, and TNFSF9) that promote ulcers of lower limb. Additionally, 56 metabolites were found to be associated with ulcers of lower limb. Mediation MR indicated that the causal effect of sirtuin2 on ulcers of lower limb (total effect Inverse Variance Weighted [IVW]: odds ratio [OR] = 1.162, 95% confidence interval [CI] [1.051, 1.285], p = 0.003) is largely mediated by 4-hydroxyphenylacetate (0.0185, 95% CI [-0.00278, 0.0397], accounting for 11.1% of the total effect).

Thyroid hormone receptor- and stage-dependent transcriptome changes affect the initial period of Xenopus tropicalis tail regeneration

BACKGROUND

Thyroid hormone (T3) has an inhibitory effect on tissue/organ regeneration. It is still elusive how T3 regulates this process. It is well established that the developmental effects of T3 are primarily mediated through transcriptional regulation by thyroid hormone receptors (TRs). Here we have taken advantage of mutant tadpoles lacking both TRα and TRβ (TRDKO), the only receptor genes in vertebrates, for RNA-seq analyses to investigate the transcriptome changes underlying the initiation of tail regeneration, i.e., wound healing and blastema formation, because this crucial initial step determines the extent of the functional regeneration in the later phase of tissue regrowth.

RESULTS

We discovered that GO (gene ontology) terms related to inflammatory response, metabolic process, cell apoptosis, and epithelial cell migration were highly enriched among commonly regulated genes during wound healing at either stage 56 or 61 or with either wild type (WT) or TRDKO tadpoles, consistent with the morphological changes associated with wound healing occurring in both regenerative (WT stage 56, TRDKO stage 56, TRDKO stage 61) and nonregenerative (WT stage 61) animals. Interestingly, ECM-receptor interaction and cytokine-cytokine receptor interaction, which are essential for blastema formation and regeneration, were significantly enriched among regulated genes in the 3 regenerative groups but not the non-regenerative group at the blastema formation period. In addition, the regulated genes specific to the nonregenerative group were highly enriched with genes involved in cellular senescence. Finally, T3 treatment at stage 56, while not inducing any measurable tail resorption, inhibited tail regeneration in the wild type but not TRDKO tadpoles.

CONCLUSIONS

Our study suggests that TR-mediated, T3-induced gene regulation changed the permissive environment during the initial period of regeneration and affected the subsequent patterning/outgrowth period of the regeneration process. Specifically, T3 signaling via TRs inhibits the expression of ECM-related genes while promoting the expression of inflammation-related genes during the blastema formation period. Interestingly, our findings indicate that amputation-induced changes in DNA replication-related pathways can occur during this nonregenerative period. Further studies, particularly on the regenerative microenvironment that may depend on ECM-receptor interaction and cytokine-cytokine receptor interaction, should provide important insights on the regulation of regenerative capacity during vertebrate development.

Exosomes derived from umbilical cord mesenchymal stem cells promote healing of complex perianal fistulas in rats

BACKGROUND

Complex perianal fistulas, challenging to treat and prone to recurrence, often require surgical intervention that may cause fecal incontinence and lower quality of life due to large surgical wounds and potential sphincter damage. Human umbilical cord-derived MSCs (hUC-MSCs) and their exosomes (hUCMSCs-Exo) may promote wound healing.

METHODS

This study assessed the efficacy, mechanisms, and safety of these exosomes in treating complex perianal fistulas in SD rats. We established a rat model, divided rats with fistulas into the control and the exosome groups. We assessed treatment efficacy through ultrasound, clinical observations, and histopathological analysis. We also evaluated the activation of the HIF-1α/TGF-β/Smad signaling pathway via PCR and Western blot and assessed serological markers for HIF-1α and inflammatory indices through ELISA. We analyzed gut microbiota and the systemic metabolic environment via untargeted metabolomics.

RESULTS

The hUCMSCs-Exo effectively promoted healing of wound, regulated the immune balance enhanced collagen synthesis and angiogenesis in the perianal fistulas model of rats, and regulated the gut microbiota and metabolomic profiles. Results of PCR and Western blot analyses indicated that the exosomes activated HIF-1α/TGF-β/Smad signaling pathways. To the dosages tested, the 10ug/100ul concentration (medium dose) was found to be the most effective to the treatment of complex perianal fistulas.

CONCLUSIONS

The hUCMSCs-Exo significantly promoted the healing of wound in perianal fistulas of rats and demonstrated higher safety. The underlying mechanism facilitating the healing process was likely associated with the activation of the HIF-1α/TGF-β/Smad signaling pathway.

The Invertebrate Immunocyte: A Complex and Versatile Model for Immunological, Developmental, and Environmental Research

The knowledge of comparative and developmental immunobiology has grown over the years and has been strengthened by the contributions of multi-omics research. High-performance microscopy, flow cytometry, scRNA sequencing, and the increased capacity to handle complex data introduced by machine learning have allowed the uncovering of aspects of great complexity and diversity in invertebrate immunocytes, i.e., immune-related circulating cells, which until a few years ago could only be described in terms of morphology and basic cellular functions, such as phagocytosis or enzymatic activity. Today, invertebrate immunocytes are recognized as sophisticated biological entities, involved in host defense, stress response, wound healing, organ regeneration, but also in numerous functional aspects of organismal life not directly related to host defense, such as embryonic development, metamorphosis, and tissue homeostasis. The multiple functions of immunocytes do not always fit the description of invertebrate organisms as simplified biological systems compared to those represented by vertebrates. However, precisely the increasing complexity revealed by immunocytes makes invertebrate organisms increasingly suitable models for addressing biologically significant and specific questions, while continuing to present the undeniable advantages associated with their ethical and economic sustainability.

A Novel Scoring System to Predict Acute Radiation Enteritis Recovery in Cervical Cancer Patients Undergoing Concurrent Chemoradiotherapy: A Southwest China Cohort Study

Purpose

To establish a pragmatic and effective predictive model for monitoring the recovery of radiation enteritis (RE) in cervical cancer patients undergoing concurrent chemoradiotherapy (CCRT).

Methods

This study included 105 cervical cancer patients undergoing CCRT. We assessed baseline clinicopathologic characteristics, evaluated the effects of CCRT on circulating immune cells, tumor biomarkers, and inflammatory cytokines, and developed a predictive scoring system, the Immune-Tumor-Score (ITS), using the LASSO-Cox regression model. The model performance of LASSO-Cox and nomogram was compared via ROC curve and calibration curve.

Results

The median age of the patients was 55 years, with 53.3% having a normal BMI and 46.7% having positive lymph nodes. Post-CCRT, significant decreases were observed in lymphocyte counts, T-cell subpopulations, and tumor markers (CA125, TPA, SCCA, CYFRA21). The CD4/CD8 ratio and IL10 levels were significantly higher post-CCRT, while inflammation indexes (NLR, ELR) increased, and LMR decreased. The ITS, derived from 11 significant parameters, effectively predicted RE recovery, outperforming a traditional nomogram. Higher ITS scores correlated with shorter RE recovery times, as validated by Kaplan-Meier analyses and ROC curves (AUC = 0.822).

Conclusion

The ITS system provides a robust and reliable tool for predicting RE recovery in cervical cancer patients undergoing CCRT, surpassing traditional models in accuracy and reliability. This tool enables better patient management by allowing for timely interventions and personalized treatment strategies. Future research should focus on validating these findings in larger cohorts and integrating additional clinical parameters to enhance the predictive power of the ITS.

Ubiquitin proteasome system in cardiac fibrosis

BACKGROUND

Cardiac fibrosis, including reactive fibrosis and replacement fibrosis, is a common pathological process in most cardiovascular diseases. The ubiquitin proteasome system (UPS) plays an important role in the development of fibrosis by mediating the degradation and synthesis of proteins involved in transforming growth factor-β (TGF-β)-dependent and TGF-β-independent fibrous pathways.

AIM OF REVIEW

This review aims to provide an overview of ubiquitinated and deubiquitinated molecules that participating in cardiac fibrosis, with the ultimate purpose to identify promising targets for therapeutic strategies.

KEY SCIENTIFIC CONCEPTS OF REVIEW

The UPS primarily impacts cardiac fibrosis through modulation of the TGF-β signaling pathway targeting key molecules involved, including the TGF-β receptors, Smad2/3/4 complexes, and inhibitory Smad7, thereby influencing fibrotic processes. In addition to its effect on TGF-β signaling, UPS also regulates pro-fibrotic pathways independent of TGF-β, including p53, AKT1-p38, and JNK1/2. Understanding these pathways is critical due to their involvement in diverse fibrotic mechanisms. The interplay between ubiquitination and deubiquitination of crucial pathways and molecules is pivotal in cardiac fibrosis and represents a promising area for identifying novel therapeutic targets. Different types of cardiac fibrosis involve distinct fibrotic pathways, leading to differential effects of ubiquitin ligases (E3 ligases) and deubiquitinating enzymes (DUBs) across various cardiac fibrotic diseases. Insights into UPS-mediated regulation of cardiac fibrosis provide potential anti-fibrotic therapeutic strategies, emphasizing the importance of targeting UPS components specific to the heart for effective therapy against cardiac fibrosis.

Mefunidone Inhibits Inflammation, Oxidative Stress, and Epithelial-Mesenchymal Transition in Lens Epithelial Cells

Purpose

Inflammation, oxidative stress, and epithelial-mesenchymal transition (EMT) play crucial roles in forming posterior capsular opacification (PCO), particularly in fibrotic PCO. Here we investigated the protective effects of mefunidone (MFD), a novel compound with potent antifibrotic properties, which could be useful in preventing PCO.

Methods

We utilized an extracapsular lens extraction (ECLE) surgery in mice to simulate the development of PCO in vivo. Treatment was performed immediately postsurgery through the intracameral injection of MFD solution. Expression levels of EMT and inflammatory markers were analyzed using Western blot, qRT-PCR, immunofluorescence, and hematoxylin and eosin staining. Additionally, the oxidative stress indicator malondialdehyde and glutathione expression were monitored to assess the oxidative stress response. In vitro experiments, TGF-β2, and H2O2 were used to treat lens epithelial cells to induce EMT and oxidative stress models, respectively. These models were employed to explore the effects of MFD and investigate its underlying mechanisms.

Results

Compared to the model group, the group treated with anterior chamber MFD injection effectively suppressed inflammation, oxidative stress, and fibrotic responses within the capsular bag after ECLE and partially inhibited the downregulation of the epithelial marker E-cadherin. To further elucidate the underlying mechanisms, we discovered that MFD treatment in vitro remarkably reduced inflammation, decreased the production of reactive oxygen species, and suppressed the phosphorylation of TGF-β/SMAD as well as MAPK/ERK, thereby inhibiting the occurrence of EMT.

Conclusions

Our findings substantiate the efficacy of MFD in treating PCO and provide insights into its potential mechanisms of action.

Christensenellaceae minuta modulates epithelial healing via PI3K-AKT pathway and macrophage differentiation in the colitis

Ulcerative colitis (UC) is a chronic inflammatory disorder with an unsatisfactory cure rate and mucosal healing is a key treatment objective. Christensenellaceae minuta (C. minuta) has emerged as a next-generation of probiotic for maintaining intestinal health. We investigated the therapeutic efficacy of C. minuta in dextran sulfate sodium (DSS)-induced colitis, focusing on mucosal healing and the underlying mechanisms. C. minuta effectively alleviated colitis and promoted the regeneration of intestinal epithelial cells (IECs). Using 16S rRNA sequencing and metabolomics, we found that C. minuta administration increased beneficial bacteria, decreased pathogenic bacteria, and significantly elevated propionic acid levels. Additionally, C. minuta activated the PI3K-AKT pathway by upregulating systemic and local IGF-1 expression. Inhibiting the PI3K-AKT pathway reduced the therapeutic effects of C. minuta and impaired IEC regeneration. Furthermore, C. minuta promoted macrophage differentiation into the M2 phenotype and decreased proinflammatory factors. We propose that C. minuta alleviates colitis by regulating the gut microbiota, modulating macrophage differentiation, and enhancing mucosal healing by activating the PI3K-AKT pathway via IGF-1 secretion induced by short-chain fatty acids. Our findings provide evidence from animal experiments to support future clinical trials and the therapeutic translation of C. minuta.

PCSK9 inhibitor attenuates cardiac fibrosis in reperfusion injury rat by suppressing inflammatory response and TGF-β1/Smad3 pathway

Progressive cardiac fibrosis, a hallmark of heart failure, remains poorly understood regarding Proprotein convertase subtilisin/kexin type 9 (PCSK9) 's role. This study aims to elucidate PCSK9's involvement in cardiac fibrosis. After ischemia/reperfusion (I/R) injury surgery in rats, PCSK9 inhibitors were used to examine their effects on the transforming growth factor-β1 (TGF-β1)/small mother against decapentaplegic 3 (Smad3) pathway and inflammation. Elevated PCSK9, TGF-β1, and Smad3 levels were observed in cardiac tissues post-I/R injury, indicating fibrosis. PCSK9 inhibition reduced pro-fibrotic protein expression, protecting the heart and mitigating I/R-induced damage and fibrosis. Additionally, it ameliorated cardiac inflammation and reduced post-myocardial infarction (MI) size, improving cardiac function and slowing heart failure progression. PCSK9 inhibitors significantly attenuate myocardial fibrosis induced by I/R via the TGF-β1/Smad3 pathway.

An injectable epoxidized soybean oil/gelatin-based photothermal biogel with remarkable rapid hemostasis capability for wound repair

The development of wound dressings with rapid hemostasis, antibacterial activity without the addition of antibiotics and on-demand removability that effectively avoid secondary damage to the wound during replacement still faces significant challenges. Herein, injectable epoxidized soybean oil/gelatin-based photothermal biogel with outstanding tissue adhesion, on-demand removability, shape-adaptability, and antibacterial performance is prepared as a removable wound dressing for wound repair. The biogel is composed of two types of hydrophilic/hydrophobic three-dimensional network structures, which interweave together through dynamic imine bonds, coordination bonds and numerous hydrogen bonds to synergistically improve injectability, self-healing, tissue adhesion, and compressive performance of the biogel. Moreover, the prepared EG-02 biogel not only has excellent thermal stability, biodegradability, hemocompatibility, and RBCs and platelet adhesion properties, but also displays outstanding cytocompatibility and the ability to promote cell migration. Furthermore, the EG-02 biogel treated with a near-infrared (NIR) laser (808 nm, 0.2 W·cm-2) exhibits prominent photothermal cycling stability and antibacterial performance. Notably, the EG-02 biogel presents remarkable rapid hemostasis capability, with the hemostatic time greatly shortened to 40 s and the blood loss significantly reduced to 89.2 mg. Therefore, the injectable photothermal biogel, as a fascinating candidate for on-demand removable wound dressing, has shown promising application prospects in wound repair.

TREM2-mediated Macrophage Glycolysis Promotes Skin Wound Angiogenesis via the Akt/mTOR/HIF-1α Signaling Axis

OBJECTIVE

The trigger receptor expressed on myeloid cells-2 (TREM2) pathway in myeloid cells is a key disease-inducing immune signaling hub that is essential for detecting tissue damage and limiting its pathological spread. However, the role and potential mechanisms of TREM2 in wound repair remain unclear. The purpose of this study was to determine the role and mechanism of TREM2 in skin wound healing in mice.

METHODS

Immunofluorescence staining was used to determine the expression and cellular localization of TREM2 and test the effects of TREM2 knockout on angiogenesis, glycolysis, and lactylation in skin tissue. Western blotting was used to analyze the expression of the Akt/mTOR/HIF-1α signaling pathway in the wounded skin tissues of wild-type (WT) and TREM2 knockout mice. A coimmunoprecipitation assay was used to determine whether HIF-1α, which mediates angiogenesis, is modified by lactylation.

RESULTS

The number of TREM2+ macrophages was increased, and TREM2+ macrophages mediated angiogenesis after skin injury. TREM2 promoted glycolysis and lactylation in macrophages during wound healing. Mechanistically, TREM2 promoted macrophage glycolysis and angiogenesis in wounded skin tissues by activating the Akt/mTOR/HIF-1α signaling pathway. HIF-1α colocalized with Klac to mediate lactylation in macrophages, and lactate could stabilize the expression of the HIF-1α protein through lactylation. Lactate treatment ameliorated the impaired angiogenesis and delayed wound healing in wounded skin in TREM2 knockout mice.

CONCLUSION

TREM2+ macrophage-mediated glycolysis can promote angiogenesis and wound healing. Our findings provide an effective strategy and target for promoting skin wound healing.

Advances in proteins, polysaccharides, and composite biomaterials for enhanced wound healing via microenvironment management: A review

Wound management is crucial yet imposes substantial social and economic burdens on patients and healthcare systems. The recent rapid advancements in biomaterials and manufacturing technology have created favorable conditions for expediting wound healing. This review examines the latest developments in biomacromolecule-based wound dressings, with a particular focus on proteins and polysaccharides, and their role in modulating the wound microenvironment. The importance of extracellular matrix (ECM)-inspired materials, such as hydrogels and biomimetic dressings, is emphasized. Additionally, this review explores the functionalization of wound dressings, emphasizing properties such as hemostatic capabilities, pain relief, antimicrobial activity, and innovative smart functions like electroceuticals and wound condition monitoring. The study integrates discussions on both the macroscopic healing outcomes and the microscopic pathophysiological mechanisms, highlighting recent advances in managing wound environments to expedite healing. Finally, the review critically assesses the challenges associated with the clinical translation of these wound-healing materials in the future.

The correlation between chronic endometritis and Caesarean scar diverticulum

PURPOSE

To investigate the risk factors for Caesarean Scar Diverticulum (CSD) with Chronic Endometritis (CE) and the correlation between CE and clinical symptoms of CSD.

METHODS

The frequency of CE in 44 patients with CSD who underwent surgical treatment and 20 control women who underwent total hysterectomy was assessed and the clinical symptoms in the presence and absence of CE were compared. In accordance with the presence of one or more CD138-positive plasma cells per high-power field, CE was classified as mild or severe group.

RESULTS

According to multivariate analysis, the presence of mild CE (OR 8.963, 95 % CI 2.177-36.907, p = 0.002) or severe CE (OR 21.773, 95 % CI 2.285-207.419, p = 0.007) was significantly associated with CSD. Mild CE (OR 12.390, 95 % CI 1.158-132.511, p = 0.037) or severe CE (OR 22.463, 95 % CI 1.657-304.541, P = 0.019) or depth of diverticulum (OR 1.294, 95 % CI 1.003-1.668, p = 0.047) was associated with prolonged menstruation in patients with CSD. The degree of CE in patients with CSD was positively correlated with the days of prolonged menstruation (r = 0.552, p < 0.001) and negatively correlated with haemoglobin level (r = -0.408, p = 0.038).

CONCLUSIONS

CE was associated with CSD and its clinical symptoms, including prolonged menstruation and decreased haemoglobin. The severity of clinical symptoms of CSD is associated with endometrial inflammation.

Metabolic MRI With Hyperpolarized 13 C-Pyruvate for Early Detection of Fibrogenic Kidney Metabolism

OBJECTIVES

Fibrosis is the final common pathway for chronic kidney disease and the best predictor for disease progression. Besides invasive biopsies, biomarkers for its detection are lacking. To address this, we used hyperpolarized 13 C-pyruvate MRI to detect the metabolic changes associated with fibrogenic activity of myofibroblasts.

MATERIALS AND METHODS

Hyperpolarized 13 C-pyruvate MRI was performed in 2 pig models of kidney fibrosis (unilateral ureteral obstruction and ischemia-reperfusion injury). The imaging data were correlated with histology, biochemical, and genetic measures of metabolism and fibrosis. The porcine experiments were supplemented with cell-line experiments to inform the origins of metabolic changes in fibrogenesis. Lastly, healthy and fibrotic human kidneys were analyzed for the metabolic alterations accessible with hyperpolarized 13 C-pyruvate MRI.

RESULTS

In the 2 large animal models of kidney fibrosis, metabolic imaging revealed alterations in amino acid metabolism and glycolysis. Conversion from hyperpolarized 13 C-pyruvate to 13 C-alanine decreased, whereas conversion to 13 C-lactate increased. These changes were shown to reflect profibrotic activity in cultured epithelial cells, macrophages, and fibroblasts, which are important precursors of myofibroblasts. Importantly, metabolic MRI using hyperpolarized 13 C-pyruvate was able to detect these changes earlier than fibrosis-sensitive structural imaging. Lastly, we found that the same metabolic profile is present in fibrotic tissue from human kidneys. This affirms the translational potential of metabolic MRI as an early indicator of fibrogenesis associated metabolism.

CONCLUSIONS

Our findings demonstrate the promise of hyperpolarized 13 C-pyruvate MRI for noninvasive detection of fibrosis development, which could enable earlier diagnosis and intervention for patients at risk of kidney fibrosis.

Mesenchymal stem cells-derived exosomes alleviate liver fibrosis by targeting Hedgehog/SMO signaling

BACKGROUND & AIMS

Despite increasing knowledge regarding the cellular and molecular mechanisms of liver fibrogenesis, there is currently no approved drug for the treatment of liver fibrosis. Mesenchymal stem cells (MSCs) are multipotent progenitor cells representing an attractive therapeutic tool for tissue damage and inflammation. This study was designed to determine the protective effect and underlying mechanism of human umbilical cord-derived MSCs (UC-MSCs) on thioacetamide-induced liver fibrosis.

METHODS

Liver fibrosis was induced in mice by intraperitoneal injection of thioacetamide (TAA). Some mice were then given injection of UC-MSCs or UC-MSCs-derived exosomes (UC-MSCs-Exo) via the tail vein. Liver tissues were collected for histologic analysis.

RESULTS

We found that administration of UC-MSCs significantly reduced serum alanine aminotransferase and aspartate aminotransferase levels, and attenuated hepatic inflammation and fibrosis. Moreover, the therapeutic effect of UC-MSCs-derived exosomes was similar to that of UC-MSCs. Intriguingly, UC-MSCs-Exo treatment downregulated the expression of smoothened (SMO), a fundamental component of Hedgehog signaling which plays a critical role in fibrogenesis, and subsequently inhibited the activation of hepatic stellate cells, a central driver of fibrosis in experimental and human liver injury. Furthermore, the anti-inflammatory and anti-fibrotic effects of UCMSCs- Exo was reversed by the SMO agonist SAG treatment in mice.

CONCLUSION

Our findings suggest that UC-MSCs-Exo exert therapeutic effects on liver fibrosis, at least in part, through inhibiting the Hedgehog/SMO signaling pathway.

Concrete-Inspired Bionic Bone Glue Repairs Osteoporotic Bone Defects by Gluing and Remodeling Aging Macrophages

Osteoporotic fractures are characterized by abnormal inflammation, deterioration of the bone microenvironment, weakened mechanical properties, and difficulties in osteogenic differentiation. The chronic inflammatory state characterized by aging macrophages leads to delayed or non-healing of the fracture or even the formation of bone defects. The current bottleneck in clinical treatment is to achieve strong fixation of the comminuted bone fragments and effective regulation of the complex microenvironment of aging macrophages. Inspired by cement and gravel in concrete infrastructure, a biomimetic bone glue with poly(lactic-co-glycolic acid) microspheres is developed and levodopa/oxidized chitosan hydrogel stabilized on an organic-inorganic framework of nanohydroxyapatite, named DOPM. DOPM is characterized via morphological and mechanical characterization techniques, in vitro experiments with bone marrow mesenchymal stromal cells, and in vivo experiments with an aged SD rat model exhibiting osteoporotic bone defects. DOPM exhibited excellent adhesion properties, good biocompatibility, and significant osteogenic differentiation. Transcriptomic analysis revealed that DOPM improved the inflammatory microenvironment by inhibiting the NF-κB signaling pathway and promoting aging macrophage polarization toward M2 macrophages, thus significantly accelerating bone defect repair and regeneration. This biomimetic bone glue, which enhances osteointegration and reestablishes the homeostasis of aging macrophages, has potential applications in the treatment of osteoporotic bone defects.

Exploration of the Topical Nanoemulgel Bearing with Ferulic Acid and Essential Oil for Diabetic Wound Healing

Aim: To investigate the anti-inflammatory, antioxidant, and diabetic wound healing properties of the novel topical formulation [Ferulic acid-loaded nanoemulgel (DLMGO-G)]. Methods: Ferulic acid nanoemulsion developed with lemongrass oil is investigated in diabetic wound healing. Further nanoemulsion is incorporated into 1% carbopol® 934 to obtain the DLMGO-G. Nanoemulsion was characterized for particle size, and polydispersity index (PDI) was obtained by Malvern Zetasizer (Zetasizer Nano ZS, Malvern, AL, USA), and morphology by TEM (JEM 1400, JOEL, Akishima, Japan). Furthermore, in vitro cell line and in vivo studies were carried out. Results: The developed nanoemulsion showed a globule size of 28.04 ± 0.23 nm and PDI of 0.07 ± 0.01. The morphology of nanoformulations by TEM confirmed the spherical and uniform nature. Further, the nanoformulation in in vitro cell line experiments revealed that the IC50 value was increased by 1.52 times compared to the drug solution. The treatment groups have shown that fibroblast morphologies were spindle-shaped, suggesting that nanoformulation was compatible with the cells and developed normally on nanoformulation. It also reduced ROS with improved internalization more than the control group. The in vitro wound healing model also revealed that nanoformulation had better wound healing activity. In the in vivo diabetic wound studies on male SD rats, the levels of inflammatory markers such as TNF-α, IL-6, IL-22, and IL-1β declined significantly when treated with DLMGO-G. IL-10 levels significantly increased compared to the diseased group, and MMP-9 levels were remarkably decreased compared to the diseased group. Furthermore, histopathological studies showed the regeneration and granulation of tissues. Conclusions: Thus, these findings indicate that FA-loaded nanoemulgel greatly accelerates the healing of wounds in diabetic rats.

Fresh Hemorrhages in Intestinal Resection Margins Are Associated with Unfavorable Clinical Outcomes in Preterm Infants with Necrotizing Enterocolitis with Surgical Intervention

BACKGROUND

Necrotizing enterocolitis (NEC) is a common disease in premature infants. If conservative treatment does not respond, surgical removal of the necrotic section of bowel is common practice. This study investigates whether there is a correlation between the histopathological findings and the postoperative clinical course of the children who have undergone surgery. To date, only a few detailed studies on a possible correlation have been published.

METHODS

The surgical specimens of 49 infants diagnosed with NEC in the years 2010-2019 were re-evaluated. The histologic specimens were examined for tissue viability and hemorrhage of the resection margins, peritonitis or perforation of the central resection segment. The groups were divided according to the clinical outcome: death, postoperative complications and patients without complications.

RESULTS

5 of 49 (10.2%) children died, 22 children (44.9%) required reoperation, while 22 (44.9%) had no complications. Univariate and multivariate analyses showed a significant association between fresh hemorrhage in the resection margins and postoperative outcome. In our data, correlation between the vitality of the resection margins or the extent of necrosis and the postoperative course was not seen.

CONCLUSION

This retrospective study shows a significant correlation between a fresh hematoma in the tissue of the resection margin and the clinical prognosis. Fresh bleeding in the resection margins was associated with increased morbidity with stenosis and possibly another surgical intervention. In contrast, no further correlation was found between the vitality of the tunica mucosae, the tunica muscularis or peritonitis in the resection margin or central part of the NEC specimen and the clinical course. In summary, it can be said that the presence of a fresh hematoma at the resection margin is significantly linked to a poorer clinical outcome for the infants with NEC surgery. Other histopathological findings of the surgical specimen with regard to the clinical course show now significant correlation and, therefore, the histological examination mainly serves the medico-legal documentation and quality assurance of the NEC operation.

Relationship between immune cell traits, circulating inflammatory cytokines, and the risk of incisional hernia after gastric surgery

PURPOSE

The systemic and local inflammatory response in patients after surgical operation is closely related to the quality of the wound healing. Low-quality wound healing and defects in the suture technique lead to the occurrence of incisional hernia (IH). However, the causal relationship between human circulating inflammatory cytokines, immune cell traits, and the risk of IH remains unclear.

METHODS

We used summary data from genome-wide association studies to assess the causal relationship between 91 types of circulating inflammatory factors, 731 types of circulating immune cell traits, and the risk of IH. The outcome dataset was obtained from FinnGen, including 6,336 patients with IH and 232,612 controls. We performed Mendelian Randomization (MR) analysis to identify their causal relationship and immune cell phenotypes upstream of inflammatory factors. Inverse variance weighting is considered to be the main analysis method.

RESULTS

Among the identified cytokines, TNF-related activation-induced cytokine levels were associated with a lower risk of IH (OR: 0.89; 95% CI: 0.82-0.96; P = 0.003). In contrast, interleukin-5 levels were associated with an increased risk of IH (OR: 1.18; 95% CI: 1.06-1.31; P = 0.003). Additionally, a significant causal relationship was found between four immune cell traits and the risk of IH (P < 0.01). Through two-step MR analysis, we determined that interleukin-5 levels mediate the causal relationship between the relative count of CD25hi % CD4 + in Treg cells and the higher risk of IH.

CONCLUSION

This study found a causal relationship between specific inflammatory cytokines, immune cell traits, and risk of IH. These results can help surgeons predict the risk of IH and take preventive measures.

Cellular and molecular roles of reactive oxygen species in wound healing

Wound healing is a highly coordinated spatiotemporal sequence of events involving several cell types and tissues. The process of wound healing requires strict regulation, and its disruption can lead to the formation of chronic wounds, which can have a significant impact on an individual's health as well as on worldwide healthcare expenditure. One essential aspect within the cellular and molecular regulation of wound healing pathogenesis is that of reactive oxygen species (ROS) and oxidative stress. Wounding significantly elevates levels of ROS, and an array of various reactive species are involved in modulating the wound healing process, such as through antimicrobial activities and signal transduction. However, as in many pathologies, ROS play an antagonistic pleiotropic role in wound healing, and can be a pathogenic factor in the formation of chronic wounds. Whilst advances in targeting ROS and oxidative stress have led to the development of novel pre-clinical therapeutic methods, due to the complex nature of ROS in wound healing, gaps in knowledge remain concerning the specific cellular and molecular functions of ROS in wound healing. In this review, we highlight current knowledge of these functions, and discuss the potential future direction of new studies, and how these pathways may be targeted in future pre-clinical studies.

A dual αvβ1/αvβ6 integrin inhibitor Bexotegrast (PLN-74809) ameliorates organ injury and fibrogenesis in fibrotic kidney disease

Chronic kidney disease (CKD) is a global public health problem, involving about 10% of the global population. Unfortunately, there are currently no effective drugs. Kidney fibrosis is the main pathology of CKD, where integrins play crucial roles in renal fibrogenesis. Recently, Bexotegrast (PLN-74809) as a dual integrin αvβ1/αvβ6 inhibitor could reduce the degree of lung fibrosis in patients with idiopathic pulmonary fibrosis. However, the role of PLN-74809 remains unclear in fibrotic kidney disease. Here, we have revealed that PLN-74809 administration dose-dependently delayed the progression of renal fibrosis in both adenine diet- and unilateral ureteral obstruction (UUO)-induced mice. Mechanistically, PLN-74809 targeted integrin αvβ1/αvβ6 to inhibit FAK/Src/Akt/β-catenin cascade in fibrotic kidneys. In summary, our results for the first time highlighted the αvβ1/αvβ6 inhibitor PLN-74809 exerted potential therapeutic against kidney fibrosis.

Injectable Photocrosslinked Hydrogel Dressing Encapsulating Quercetin-Loaded Zeolitic Imidazolate Framework-8 for Skin Wound Healing

Background: Wound management is a critical component of clinical practice. Promoting timely healing of wounds is essential for patient recovery. Traditional treatments have limited efficacy due to prolonged healing times, excessive inflammatory responses, and susceptibility to infection. Methods: In this research, we created an injectable hydrogel wound dressing formulated from gelatin methacryloyl (GelMA) that encapsulates quercetin-loaded zeolitic imidazolate framework-8 (Qu@ZIF-8) nanoparticles. Next, its ability to promote skin wound healing was validated through in vitro experiments and animal studies. Results: Research conducted both in vitro and in vivo indicated that this hydrogel dressing effectively mitigates inflammation, inhibits bacterial growth, and promotes angiogenesis and collagen synthesis, thus facilitating a safe and efficient healing process for wounds. Conclusions: This cutting-edge scaffold system provides a novel strategy for wound repair and demonstrates significant potential for clinical applications.

Exposure to High Concentrations of Tetrabromobisphenol A Slows the Process of Tissue Regeneration and Induces an Imbalance of Metabolic Homeostasis in the Regenerated Intestines of Apostichopus japonicus

BACKGROUND

Tissue regenerative capacity following evisceration, potentially influenced by environmental contaminants and intestinal microflora, is essential for the financial success of Apostichopus japonicus farming. However, the morphological structure, gut microbiome composition, and genes expression pattern of the regenerated gut after exposure to high levels of TBBPA remain poorly unclear.

METHODS

In this research, the effect of TBBPA exposure on tissue regeneration in A. japonicus was investigated through a comprehensive multi-omics approach.

RESULTS

Our results showed that the integrity, the intestinal wall thickness, and the villi length of the regenerated intestines in A. japonicus decreased after treatment with high levels of TBBPA. The findings from PCoA and NMDS analyses revealed that the microbial community composition was significantly altered following exposure to high concentrations of TBBPA in the regenerated intestines of A. japonicus. The KEGG pathway enrichment analysis indicated that the DEGs (differentially expressed genes) were predominantly enriched on metabolism and immunity-related signaling pathways after exposure to high levels of TBBPA. These included pathways involved in the PPAR signaling pathway, ECM receptor interaction, glycerolipid metabolism, and fatty acid degradation. Interestingly, the results have demonstrated that there are 77 transcript factors that were significantly different after exposure to TBBPA.

CONCLUSIONS

These results suggested that high levels of exposure to TBBPA induces an imbalance of the metabolic homeostasis by regulating the expression levels of transcription factors in the regenerated intestines of A. japonicus.

Challenges in tendon-bone healing: emphasizing inflammatory modulation mechanisms and treatment

Tendons are fibrous connective tissues that transmit force from muscles to bones. Despite their ability to withstand various loads, tendons are susceptible to significant damage. The healing process of tendons and ligaments connected to bone surfaces after injury presents a clinical challenge due to the intricate structure, composition, cellular populations, and mechanics of the interface. Inflammation plays a pivotal role in tendon healing, creating an inflammatory microenvironment through cytokines and immune cells that aid in debris clearance, tendon cell proliferation, and collagen fiber formation. However, uncontrolled inflammation can lead to tissue damage, and adhesions, and impede proper tendon healing, culminating in scar tissue formation. Therefore, precise regulation of inflammation is crucial. This review offers insights into the impact of inflammation on tendon-bone healing and its underlying mechanisms. Understanding the inflammatory microenvironment, cellular interactions, and extracellular matrix dynamics is essential for promoting optimal healing of tendon-bone injuries. The roles of fibroblasts, inflammatory cytokines, chemokines, and growth factors in promoting healing, inhibiting scar formation, and facilitating tissue regeneration are discussed, highlighting the necessity of balancing the suppression of detrimental inflammatory responses with the promotion of beneficial aspects to enhance tendon healing outcomes. Additionally, the review explores the significant implications and translational potential of targeted inflammatory modulation therapies in refining strategies for tendon-bone healing treatments.

TRIM56 Modulates YBX1 Degradation to Ameliorate ZBP1-Mediated Neuronal PANoptosis in Spinal Cord Injury

Spinal cord injury (SCI) is a severe injury to the central nervous system, and its treatment is always a major medical challenge. Proinflammatory cell death is considered an important factor affecting neuroinflammation and the prognosis after injury. PANoptosis, a newly discovered type of proinflammatory cell death, regulates the activation of executioner molecules of apoptosis, pyroptosis and necroptosis through the PANoptosome, providing a new target for therapeutic intervention after SCI. However, its role and regulatory mechanism in SCI are not yet elucidated. Here, based on proteomic data, YBX1 expression is significantly increased in neurons after SCI. Guided by RIP-seq, subsequent experiments reveal that YBX1 promotes ZBP1 expression by stabilizing the Zbp1 mRNA, thereby aggravating ZBP1-mediated PANoptosis. Furthermore, the E3 ubiquitin ligase TRIM56 is identified as an endogenous inhibitor of YBX1 via molecular docking and IP/MS analysis. Mechanistically, TRIM56 bound to YBX1 and promoted its ubiquitination, thereby accelerating its degradation. Taken together, these findings reveal a novel function of YBX1 in regulating ZBP1-mediated PANoptosis in the pathogenesis of SCI and verified that TRIM56 functions as an endogenous inhibitor to promote the ubiquitin-proteasomal degradation of YBX1, providing new insights into SCI treatment strategies.

Bi-directional regulation between inflammation and stem cells in the respiratory tract

Inflammation plays a crucial role in tissue injury, repair and disease, orchestrating a complex interplay of immune responses and cellular processes. Recent studies have uncovered the intricate connection between inflammation and stem cell dynamics, shedding light on the central role of stem cells in tissue regeneration. This Review highlights the significance of inflammation in shaping epithelial stem cell dynamics and its implications for tissue repair, regeneration and aging. We explore the multifaceted interactions between inflammation and stem cells, focusing on how inflammatory signals affect stem cell behavior and fate as well as the remodeling of their niche in the respiratory tract. We also discuss the concept of 'inflammatory memory' in epithelial stem cells, where prior inflammatory stimuli endow these cells with enhanced regenerative potential and confer long-lasting protective mechanisms for maintaining tissue integrity and function. Furthermore, we review the impact of cell senescence induced by inflammation on tissue regeneration and aging, delving into the molecular mechanisms underlying the modulation of signaling pathways, epigenetic modifications and cellular crosstalk. Understanding these dynamic processes not only deepens our knowledge of tissue homeostasis and repair but also holds profound implications for regenerative medicine strategies aimed at preventing pulmonary diseases.

Metabolic regulation of intestinal homeostasis: molecular and cellular mechanisms and diseases

Metabolism serves not only as the organism's energy source but also yields metabolites crucial for maintaining tissue homeostasis and overall health. Intestinal stem cells (ISCs) maintain intestinal homeostasis through continuous self-renewal and differentiation divisions. The intricate relationship between metabolic pathways and intestinal homeostasis underscores their crucial interplay. Metabolic pathways have been shown to directly regulate ISC self-renewal and influence ISC fate decisions under homeostatic conditions, but the cellular and molecular mechanisms remain incompletely understood. Understanding the intricate involvement of various pathways in maintaining intestinal homeostasis holds promise for devising innovative strategies to address intestinal diseases. Here, we provide a comprehensive review of recent advances in the regulation of intestinal homeostasis. We describe the regulation of intestinal homeostasis from multiple perspectives, including the regulation of intestinal epithelial cells, the regulation of the tissue microenvironment, and the key role of nutrient metabolism. We highlight the regulation of intestinal homeostasis and ISC by nutrient metabolism. This review provides a multifaceted perspective on how intestinal homeostasis is regulated and provides ideas for intestinal diseases and repair of intestinal damage.

A wearable and stretchable dual-wavelength LED device for home care of chronic infected wounds

Phototherapy can offer a safe and non-invasive solution against infections, while promoting wound healing. Conventional phototherapeutic devices are bulky and limited to hospital use. To overcome these challenges, we developed a wearable, flexible red and blue LED (r&bLED) patch controlled by a mobile-connected system, enabling safe self-application at home. The patch exhibits excellent skin compatibility, flexibility, and comfort, with high safety under system supervision. Additionally, we synthesized a sprayable fibrin gel (F-gel) containing blue light-sensitive thymoquinone and red light-synergistic NADH. Combined with bLED, thymoquinone eradicated microbes and biofilms within minutes, regardless of antibiotic resistance. Furthermore, NADH and rLED synergistically improved macrophage and endothelial cell mitochondrial function, promoting wound healing, reducing inflammation, and enhancing angiogenesis, as validated in infected diabetic wounds in mice and minipigs. This innovative technology holds great promise for revolutionizing at-home phototherapy for chronic infected wounds.

Regulatory T cell-based therapy in type 1 diabetes: Latest breakthroughs and evidence

Autoimmune diseases (ADs) are among the most significant health complications, with their incidence rising in recent years. Type 1 diabetes (T1D), an AD, targets the insulin-producing β cells in the pancreas, leading to chronic insulin deficiency in genetically susceptible individuals. Regulatory immune cells, particularly T-cells (Tregs), have been shown to play a crucial role in the pathogenesis of diabetes by modulating immune responses. In diabetic patients, Tregs often exhibit diminished effectiveness due to various factors, such as instability in forkhead box P3 (Foxp3) expression or abnormal production of the proinflammatory cytokine interferon-gamma (IFN-γ) by autoreactive T-cells. Consequently, Tregs represent a potential therapeutic target for diabetes treatment. Building on the successful clinical outcomes of chimeric antigen receptor (CAR) T-cell therapy in cancer treatment, particularly in leukemias, the concept of designing and utilizing CAR Tregs for ADs has emerged. This review summarizes the findings on Treg targeting in T1D and discusses the benefits and limitations of this treatment approach for patients suffering from T1D.

Acute contact with profibrotic macrophages mechanically activates fibroblasts via αvβ3 integrin-mediated engagement of Piezo1

Fibrosis-excessive scarring after injury-causes >40% of disease-related deaths worldwide. In this misguided repair process, activated fibroblasts drive the destruction of organ architecture by accumulating and contracting extracellular matrix. The resulting stiff scar tissue, in turn, enhances fibroblast contraction-bearing the question of how this positive feedback loop begins. We show that direct contact with profibrotic but not proinflammatory macrophages triggers acute fibroblast contractions. The contractile response depends on αvβ3 integrin expression on macrophages and Piezo1 expression on fibroblasts. The touch of macrophages elevates fibroblast cytosolic calcium within seconds, followed by translocation of the transcription cofactors nuclear factor of activated T cells 1 and Yes-associated protein, which drive fibroblast activation within hours. Intriguingly, macrophages induce mechanical stress in fibroblasts on soft matrix that alone suppresses their spontaneous activation. We propose that acute contact with suitable macrophages mechanically kick-starts fibroblast activation in an otherwise nonpermissive soft environment. The molecular components mediating macrophage-fibroblast mechanotransduction are potential targets for antifibrosis strategies.

The Effect of Environmental Enrichment on Selected Physiological and Immunological Stress-Related Markers in Dairy Goats

Homeostasis preservation is essential for animal survival, and any event that causes a disturbance in homeostasis is defined as a stressor. Here, we aimed to evaluate the effect of scratch brushes and stages as an environmental enrichment to alleviate stress in dairy goats. Twenty-four mixed-breed goats were divided into two groups according to common physiological conditions in breeding farms: milking and dry (milk-producing and non-milk-producing, respectively). Ten days after exposure to environmental enrichment treatment or not (control), blood was sampled. Following the enrichment, we observed a reduction in reactive oxidative stress metabolites, advanced glycation end products (AGEs), and their binding protein (transferrin) in the dry goats, as determined by an ELISA. In contrast, no change in AGEs, along with an increase in transferrin levels, was observed in the milking goats. Moreover, oxytocin levels decreased in the dry and increased in the milking goats, while serotonin levels increased in the dry and remained unchanged in the milking goats. Additionally, gene expression of the cytokines, IL-6 and IL-1ß, and anti-oxidative proteins, lysozyme and transferrin (in peripheral blood leukocytes), as determined by qPCR, presented the same pattern: down-regulation in the dry or up-regulation in the milking goats. In conclusion, a reliable methodology was developed for measuring husbandry stress in goats and to improve dairy goats' husbandry practice. Current environmental enrichment produced different responsiveness in goats correlated to their physiological status: beneficial effect in dry goats, detrimental effect in milking goats.

Microenvironment-responsive nanomedicines: a promising direction for tissue regeneration

Severe tissue defects present formidable challenges to human health, persisting as major contributors to mortality rates. The complex pathological microenvironment, particularly the disrupted immune landscape within these defects, poses substantial hurdles to existing tissue regeneration strategies. However, the emergence of nanobiotechnology has opened a new direction in immunomodulatory nanomedicine, providing encouraging prospects for tissue regeneration and restoration. This review aims to gather recent advances in immunomodulatory nanomedicine to foster tissue regeneration. We begin by elucidating the distinctive features of the local immune microenvironment within defective tissues and its crucial role in tissue regeneration. Subsequently, we explore the design and functional properties of immunomodulatory nanosystems. Finally, we address the challenges and prospects of clinical translation in nanomedicine development, aiming to propose a potent approach to enhance tissue regeneration through synergistic immune modulation and nanomedicine integration.

SDIMMMER: A Proposed Clinical Approach to Optimize Cellular Physiology in Regenerative Medicine

SDIMMMER is an acronym intended for use in both clinical practice and medical research. It facilitates a comprehensive evaluation of a patient's metabolic profile and serves as a mnemonic for the following key assessment areas: Sleep, Diet, Microbiome, Metabolism, Medications, Exams, and Rehabilitation. In the clinical setting, SDIMMMER's primary objective is to monitor and manage the patient's metabolic status, particularly targeting low-grade chronic systemic inflammation, a hallmark of metabolic syndrome (MS). This inflammatory condition is characterized by elevated levels of circulating inflammatory cytokines and increased macrophage infiltration in peripheral tissues. SDIMMMER aims to enhance the effectiveness of ortho biological treatments by elevating growth factor levels, thereby enhancing patient outcomes. Additionally, SDIMMMER emphasizes guiding patients toward positive lifestyle changes to improve overall quality of life and foster a healthier metabolism. SDIMMMER introduces a patient metabolic profile quantification tool comprising 7 domains, totaling 35 items. Additionally, an instructional guide is provided to facilitate the application process. Its versatility spans various clinical and research domains, showcasing its potential to positively influence multiple fields.

An immunostimulatory liponanogel reveals immune activation-enhanced drug delivery and therapeutic efficacy in cancer

The clinical use of immunostimulatory polyinosinic:polycytidylic acid (pIC) for cancer therapy has been notably limited by its low tumor accumulation and poor cytosolic delivery to activate innate immune sensors. Here, we report a liponanogel (LNG)-based platform to address these challenges. The immunostimulatory LNG consists of an ionizable lipid shell coating a nanogel made of hyaluronic acid (HA), Mn2+ and pIC, which is denoted as LNG-Mn-pIC (LMP). The protonation of internal HA within acidic endosomes increases the endosomal membrane permeability and facilitates the cytosolic delivery of pIC. Moreover, Mn2+, previously reported to activate the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathway, synergizes with pIC to activate innate immune cells. Remarkably, intravenously injected LMP significantly induces tumor vasculature disruption and tumor cell apoptosis in an innate immune activation-dependent manner, facilitating the LMP delivery into tumors and leading to enhanced antitumor immunity that potently inhibits or even completely regresses the established tumors. In summary, this immunostimulatory LNG platform not only serves as a useful tool to uncover the immune activation-enhanced drug delivery profile but also represents a broadly applicable platform for effective cancer immunotherapy.

Characterization and Physiological Differences of Two Primary Cultures of Human Normal and Hypertrophic Scar Dermal Fibroblasts: A Pilot Study

Background/Objectives: Dermal fibroblasts (DFs) are key participants in skin hypertrophic scarring, and their properties are being studied to identify the molecular and cellular mechanisms underlying the pathogenesis of skin scarring. Methods: In the present work, we performed a comparative analysis of DFs isolated from normal skin (normal dermal fibroblasts, NDFs), and hypertrophic scar skin (hypertrophic scar fibroblasts, HTSFs). The fibroblasts were karyotyped and phenotyped, and experiments on growth rate, wound healing, and single-cell motility were conducted. Results: Comparative analysis revealed a minor karyotype difference between cells. However, HTSFs are characterized by higher proliferation level and motility compared to NDFs. These significant differences may be associated with quantitative and qualitative differences in the cell secretome. A proteomic comparison of NDF and HTSF found that differences were associated with metabolic proteins reflecting physiological differences between the two cells lines. Numerous unique proteins were found only in the vesicular phase of vHTSFs. Some proteins involved in cell proliferation (protein-glutamine gamma-glutamyltransferase K) and cell motility (catenin delta-1), which regulate gene transcription and the activity of Rho family GTPases and downstream cytoskeletal dynamics, were identified. A number of proteins which potentially play a role in fibrosis and inflammation (mucin-5B, CD97, adhesion G protein-coupled receptor E2, antileukoproteinase, protein S100-A8 and S100-A9, protein caspase recruitment domain-containing protein 14) were detected in vHTSFs. Conclusions: A comparative analysis of primary cell cultures revealed their various properties, especially in the cell secretome. These proteins may be considered promising target molecules for developing treatment or prevention strategies for pathological skin scarring.

The lncRNA SNHG26 drives the inflammatory-to-proliferative state transition of keratinocyte progenitor cells during wound healing

The cell transition from an inflammatory phase to a subsequent proliferative phase is crucial for wound healing, yet the driving mechanism remains unclear. By profiling lncRNA expression changes during human skin wound healing and screening lncRNA functions, we identify SNHG26 as a pivotal regulator in keratinocyte progenitors underpinning this phase transition. Snhg26-deficient mice exhibit impaired wound repair characterized by delayed re-epithelization accompanied by exacerbated inflammation. Single-cell transcriptome analysis combined with gain-of-function and loss-of-function of SNHG26 in vitro and ex vivo reveals its specific role in facilitating inflammatory-to-proliferative state transition of keratinocyte progenitors. A mechanistic study unravels that SNHG26 interacts with and relocates the transcription factor ILF2 from inflammatory genomic loci, such as JUN, IL6, IL8, and CCL20, to the genomic locus of LAMB3. Collectively, our findings suggest that lncRNAs play cardinal roles in expediting tissue repair and regeneration and may constitute an invaluable reservoir of therapeutic targets in reparative medicine.

Hydrogel Microneedle Patches Loaded with Stem Cell Mitochondria-Enriched Microvesicles Boost the Chronic Wound Healing

Rescuing or compensating mitochondrial function represents a promising therapeutic avenue for radiation-induced chronic wounds. Adult stem cell efficacies are primarily dependent on the paracrine secretion of mitochondria-containing extracellular vesicles (EVs). However, effective therapeutic strategies addressing the quantity of mitochondria and mitochondria-delivery system are lacking. Thus, in this study, we aimed to design an effective hydrogel microneedle patch (MNP) loaded with stem cell-derived mitochondria-rich EVs to gradually release and deliver mitochondria into the wound tissues and boost wound healing. We, first, used metformin to enhance mitochondrial biogenesis and thereby increasing the secretion of mitochondria-containing EVs (termed "Met-EVs") in adipose-derived stem cells. To verify the therapeutic effects of Met-EVs, we established an in vitro and an in vivo model of X-ray-induced mitochondrial dysfunction. The Met-EVs ameliorated the mitochondrial dysfunction by rescuing mitochondrial membrane potential, increasing adenosine 5'-triphosphate levels, and decreasing reactive oxygen species production by transferring active mitochondria. To sustain the release of EVs into damaged tissues, we constructed a Met-EVs@Decellularized Adipose Matrix (DAM)/Hyaluronic Acid Methacrylic Acid (HAMA)-MNP. Met-EVs@DAM/HAMA-MNP can load and gradually release Met-EVs and their contained mitochondria into wound tissues to alleviate mitochondrial dysfunction. Moreover, we found Met-EVs@DAM/HAMA-MNP can markedly promote macrophage polarization toward the M2 subtype with anti-inflammatory and regenerative functions, which can, in turn, enhance the healing process in mice with skin wounds combined radiation injuries. Collectively, we successfully fabricated a delivery system for EVs, Met-EVs@DAM/HAMA-MNP, to effectively deliver stem cell-derived mitochondria-rich EVs. The effectiveness of this system has been demonstrated, holding great potential for chronic wound treatments in clinic.

Viral infection induces inflammatory signals that coordinate YAP regulation of dysplastic cells in lung alveoli

Severe viral pneumonia can induce rapid expansion of KRT5+ basal-like cells in small airways and alveoli; this forms a scar-like structure that persists in the injured alveoli and impedes normal alveolar epithelium regeneration. In this study, we investigated the mechanism by which viral infection induced this remodeling response. Through comparing different lung-injury models, we demonstrated that infection induced strong IFN-γ signal-stimulated dysplastic KRT5+ cell formation. Inactivation of interferon receptor 1 (Ifngr1) reduced dysplastic cell formation, ameliorated lung fibrosis, and improved lung-function recovery. Mechanistically, IFN-γ regulated dysplastic cell formation via the focal adhesion kinase (FAK)/Yes-associated protein 1 (YAP) pathway. Inhibiting FAK/Src diminished IFN-γ-induced YAP nuclear translocation and dysplastic cell formation. Inhibiting YAP during viral infection prevented dysplastic cell formation, whereas inhibiting YAP in persistent KRT5+ cells led to their conversion into distal club cells. Importantly, human dysplastic cells exhibited elevated FAK and YAP activity, and IFN-γ treatment promoted the transformation of human alveolar progenitor cells into dysplastic cells. These findings uncover the role of infection-induced inflammatory response in alveolar remodeling and may provide potential therapeutic avenues for the treatment of alveolar remodeling in patients with severe viral pneumonia.