Keratinocyte Function in Normal and Diabetic Wounds and Modulation by FOXO1

Phytoconstituents as modulators of NF-κB signalling: Investigating therapeutic potential for diabetic wound healing

The NF-κB pathway plays a pivotal role in impeding the diabetic wound healing process, contributing to prolonged inflammation, diminished angiogenesis, and reduced proliferation. In contrast to modern synthetic therapies, naturally occurring phytoconstituents are well-studied inhibitors of the NF-κB pathway that are now attracting increased attention in the context of diabetic wound healing because of lower toxicity, better safety and efficacy, and cost-effectiveness. This study explores recent research on phytoconstituent-based therapies and delve into their action mechanisms targeting the NF-κB pathway and potential for assisting effective healing of diabetic wounds. For this purpose, we have carried out surveys of recent literature and analyzed studies from prominent databases such as Science Direct, Scopus, PubMed, Google Scholar, EMBASE, and Web of Science. The classification of phytoconstituents into various categorie such as: alkaloids, triterpenoids, phenolics, polyphenols, flavonoids, monoterpene glycosides, naphthoquinones and tocopherols. Noteworthy phytoconstituents, including Neferine, Plumbagin, Boswellic acid, Genistein, Luteolin, Kirenol, Rutin, Vicenin-2, Gamma-tocopherol, Icariin, Resveratrol, Mangiferin, Betulinic acid, Berberine, Syringic acid, Gallocatechin, Curcumin, Loureirin-A, Loureirin-B, Lupeol, Paeoniflorin, and Puerarin emerge from these studies as promising agents for diabetic wound healing through the inhibition of the NF-κB pathway. Extensive research on various phytoconstituents has revealed how they modulate signalling pathways, including NF-κB, studies that demonstrate the potential for development of therapeutic phytoconstituents to assist healing of chronic diabetic wounds.

Melatonin supplementation counteracts fiber loss in knee ligaments of diabetes-induced rats

Diabetes mellitus (DM) is a prevalent metabolic disease. The clinical impact of sustained hyperglycemia on ligament healing has not been well characterized. Diabetes is a known cause of macro-, microvascular, and diabetic ulcer healing difficulties among tissues. Therefore, we aimed to investigate the healing potential occurring in injured and healthy ligaments among diabetic and healthy individuals using a rat model. We hypothesize that DM may contribute to altering the knee medial collateral ligament (MCL), thus its morphology, biochemical fitness, and functionality. The study cohort consisted of 40 rats. The animals were randomized into four equal groups. Groups I and II (20 rats) received saline subcutaneously and served as controls. Groups III and IV (20 rats) were injected with a single dose of streptozotocin (STZ). All animals underwent surgery to cut the left tibial collateral ligament in the hind limb and suture it. The access site was sutured to create inflammation and study the regenerative capacities of animals with normal carbohydrate metabolism and pharmacologically induced diabetes. Each animal then underwent sham surgery to access and suture the right tibial collateral ligament in the hind limb without ligament intervention. After the animals had undergone surgeries, groups II and IV were given melatonin supplementation for 4 weeks. Rats with DM presented with more fibrosis and calcification of the MCL and decreased healing potential. Treatment with melatonin in diabetic rats mitigated alterations and improved the antioxidant status of ligaments from the diabetic group.

Directed Differentiation of Adipose-Derived Stem Cells Using Imprinted Cell-Like Topographies as a Growth Factor-Free Approach

The influence of surface topography on stem cell behavior and differentiation has garnered significant attention in regenerative medicine and tissue engineering. The cell-imprinting method has been introduced as a promising approach to mimic the geometry and topography of cells. The cell-imprinted substrates are designed to replicate the topographies and dimensions of target cells, enabling tailored interactions that promote the differentiation of stem cells towards desired specialized cell types. In fact, by replicating the size and shape of cells, biomimetic substrates provide physical cues that profoundly impact stem cell differentiation. These cues play a pivotal role in directing cell morphology, cytoskeletal organization, and gene expression, ultimately influencing lineage commitment. The biomimetic substrates' ability to emulate the native cellular microenvironment supports the creation of platforms capable of steering stem cell fate with high precision. This review discusses the role of mechanical factors that impact stem cell fate. It also provides an overview of the design and fabrication principles of cell-imprinted substrates. Furthermore, the paper delves into the use of cell-imprinted polydimethylsiloxane (PDMS) substrates to direct adipose-derived stem cells (ADSCs) differentiation into a variety of specialized cells for tissue engineering and regenerative medicine applications. Additionally, the review discusses the limitations of cell-imprinted PDMS substrates and highlights the efforts made to overcome these limitations.

Shengjihuayu formula ameliorates the oxidative injury in human keratinocytes via blocking JNK/c-Jun/MMPs signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

The reactive oxygen species (ROS) surge in the chronic wound tissue of diabetic ulcers (DUs) aggravates the inflammatory response. The oxidative stress state during inflammation will exacerbate inflammation and cause tissue damage, resulting in prolonged wound healing. Shengjihuayu Formula (SJHYF) is a renowned Chinese medicine prescription for treating chronic wounds in diabetic ulcers. Growing clinical evidence has demonstrated that SJHYF exhibits superior therapeutic efficacy and has a favorable safety profile. However, the underlying mechanisms by which SJHYF ameliorates oxidative damage under pathological conditions of DUs remain unclear.

OBJECTIVE

To investigate the cytoprotective properties of SJHYF on hydrogen peroxide (H2O2)-induced cell damage in human HaCaT keratinocytes and to explore its potential targets and molecular pathways in treating DUs using RNA-seq.

METHODS

HaCaT cells were incubated with H2O2 for 24 h to construct an oxidative stress cell model. Cell viability and proliferation were measured using the MTT and EdU assays, respectively. Cell migration was assessed using the scratch assay, and the fluorescence intensity of ROS was measured using the DCFH-DA probe. The chemical components of SJHYF were analyzed by UPLC-Q-TOF/MS, while the therapeutic effects of SJHYF on H2O2-induced HaCaT cells were analyzed using RNA-Seq. The potential target genes were validated using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). At the same time, the pathway phenotype expression of SJHYF on the protection of H2O2-induced HaCaT cells was explored using Western Blot.

RESULTS

The application of SJHY at a concentration of 0.25 mg/mL promoted cell proliferation, cell migration, and reduced ROS production. In addition, SJHYF was detected to have a total of 93 active compounds, including key components such as Galloyl-beta-D-glucose, Danshensu, Procyanidin B2, Catechin, and Alkannin. The RNA-seq analysis identified several core targets namely KRT17, TGM1, JUNB, PRDX5, TXNIP, PRDX1, HSP90AA1, HSP90AB1, HSPA8, and TNF-α. Western blot revealed the presence of the JNK/c-Jun/MMPs pathway and its related transcription factors.

CONCLUSION

SJHYF displays significant protective effects on H2O2-induced oxidative cell damage in HaCaT cells via blocking the JNK/c-Jun/MMPs pathway.

Panthenol Citrate Biomaterials Accelerate Wound Healing and Restore Tissue Integrity

Impaired wound healing is a common complication for diabetic patients and effective diabetic wound management remains a clinical challenge. Furthermore, a significant problem that contributes to patient morbidity is the suboptimal quality of healed skin, which often leads to reoccurring chronic skin wounds. Herein, a novel compound and biomaterial building block, panthenol citrate (PC), is developed. It has interesting fluorescence and absorbance properties, and it is shown that PC can be used in soluble form as a wash solution and as a hydrogel dressing to address impaired wound healing in diabetes. PC exhibits antioxidant, antibacterial, anti-inflammatory, and pro-angiogenic properties, and promotes keratinocyte and dermal fibroblast migration and proliferation. When applied in a splinted excisional wound diabetic rodent model, PC improves re-epithelialization, granulation tissue formation, and neovascularization. It also reduces inflammation and oxidative stress in the wound environment. Most importantly, it improves the regenerated tissue quality with enhanced mechanical strength and electrical properties. Therefore, PC could potentially improve wound care management for diabetic patients and play a beneficial role in other tissue regeneration applications.

The epithelial barrier: The gateway to allergic, autoimmune, and metabolic diseases and chronic neuropsychiatric conditions

Since the 1960 s, our health has been compromised by exposure to over 350,000 newly introduced toxic substances, contributing to the current pandemic in allergic, autoimmune and metabolic diseases. The "Epithelial Barrier Theory" postulates that these diseases are exacerbated by persistent periepithelial inflammation (epithelitis) triggered by exposure to a wide range of epithelial barrier-damaging substances as well as genetic susceptibility. The epithelial barrier serves as the body's primary physical, chemical, and immunological barrier against external stimuli. A leaky epithelial barrier facilitates the translocation of the microbiome from the surface of the afflicted tissues to interepithelial and even deeper subepithelial locations. In turn, opportunistic bacterial colonization, microbiota dysbiosis, local inflammation and impaired tissue regeneration and remodelling follow. Migration of inflammatory cells to susceptible tissues contributes to damage and inflammation, initiating and aggravating many chronic inflammatory diseases. The objective of this review is to highlight and evaluate recent studies on epithelial physiology and its role in the pathogenesis of chronic diseases in light of the epithelial barrier theory.

Gintonin-Induced Wound-Healing-Related Responses Involve Epidermal-Growth-Factor-like Effects in Keratinocytes

Epidermal growth factor (EGF) receptor activation and related downstream signaling pathways are known to be one of the major mechanisms of the proliferation and migration of keratinocytes. The heparin-binding EGF-like growth factor (HB-EGF) binds to EGF receptors and stimulates keratinocyte proliferation and migration. Gintonin, a novel ginseng compound, is a lysophosphatidic acid (LPA) receptor ligand. Gintonin has skin-wound-healing effects. However, the underlying mechanisms for these gintonin actions remain unclear. In this study, we aimed to elucidate the involvement of EGFRs in gintonin-induced wound repair in HaCaT keratinocytes. In this study, a water-soluble tetrazolium salt-based assay, a modified Boyden chamber migration assay, and immunoblotting were performed. Gintonin increased EGF receptor activation in HaCaT cells. However, the gintonin-induced phosphorylation of the EGF receptor was markedly reduced via treatment with the LPA inhibitor Ki16425 or the EGF receptor inhibitor erlotinib. Gintonin-enhanced proliferation and migration were blocked by the EGF receptor inhibitors (erlotinib and AG1478). Additionally, gintonin stimulated the expression and release of HB-EGF in HaCaT cells. EGF receptor inhibitors blocked gintonin-enhanced HB-EGF expression. These results indicate that the wound-healing effects of gintonin are closely related to the collaboration between EGF receptor activation and HB-EGF release-mediated downstream signaling pathways.

Metrnl deficiency retards skin wound healing in mice by inhibiting AKT/eNOS signaling and angiogenesis

Meteorin-like (Metrnl) is a novel secreted protein with various biological activities. In this study, we investigated whether and how Metrnl regulated skin wound healing in mice. Global Metrnl gene knockout mice (Metrnl-/-) and endothelial cell-specific Metrnl gene knockout mice (EC-Metrnl-/-) were generated. Eight-mm-diameter full-thickness excisional wound was made on the dorsum of each mouse. The skin wounds were photographed and analyzed. In C57BL/6 mice, we observed that Metrnl expression levels were markedly increased in skin wound tissues. We found that both global and endothelial cell-specific Metrnl gene knockout significantly retarded mouse skin wound healing, and endothelial Metrnl was the key factor affecting wound healing and angiogenesis. The proliferation, migration and tube formation ability of primary human umbilical vein endothelial cells (HUVECs) were inhibited by Metrnl knockdown, but significantly promoted by addition of recombinant Metrnl (10 ng/mL). Metrnl knockdown abolished the proliferation of endothelial cells stimulated by recombinant VEGFA (10 ng/mL) but not by recombinant bFGF (10 ng/mL). We further revealed that Metrnl deficiency impaired VEGFA downstream AKT/eNOS activation in vitro and in vivo. The damaged angiogenetic activity in Metrnl knockdown HUVECs was partly rescued by addition of AKT activator SC79 (10 μM). In conclusion, Metrnl deficiency retards skin wound healing in mice, which is related to impaired endothelial Metrnl-mediated angiogenesis. Metrnl deficiency impairs angiogenesis by inhibiting AKT/eNOS signaling pathway.

Diabetes impairs fracture healing through Foxo1 mediated disruption of ciliogenesis

Foxo1 upregulation is linked to defective fracture healing under diabetic conditions. Previous studies demonstrated that diabetes upregulates Foxo1 expression and activation and diabetes impairs ciliogenesis resulting in defective fracture repair. However, the mechanism by which diabetes causes cilia loss during fracture healing remains elusive. We report here that streptozotocin (STZ)-induced type 1 diabetes mellitus (T1DM) dramatically increased Foxo1 expression in femoral fracture calluses, which thereby caused a significant decrease in the expression of IFT80 and primary cilia number. Ablation of Foxo1 in osteoblasts in OSXcretTAFoxo1f/f mice rescued IFT80 expression and ciliogenesis and restored bone formation and mechanical strength in diabetic fracture calluses. In vitro, advanced glycation end products (AGEs) impaired cilia formation in osteoblasts and reduced the production of a mineralizing matrix, which were rescued by Foxo1 deletion. Mechanistically, AGEs increased Foxo1 expression and transcriptional activity to inhibit IFT80 expression causing impaired cilia formation. Thus, our findings demonstrate that diabetes impairs fracture healing through Foxo1 mediated inhibition of ciliary IFT80 expression and primary cilia formation, resulting in impaired osteogenesis. Inhibition of Foxo1 and/or restoration of cilia formation has the potential to promote diabetes-impaired fracture healing.

Human Keratinocytes and Fibroblasts Co-Cultured on Silk Fibroin Scaffolds Exosomally Overrelease Angiogenic and Growth Factors

Objectives: The optimal healing of skin wounds, deep burns, and chronic ulcers is an important clinical problem. Attempts to solve it have been driving the search for skin equivalents based on synthetic or natural polymers. Methods: Consistent with this endeavor, we used regenerated silk fibroin (SF) from Bombyx mori to produce a novel compound scaffold by welding a 3D carded/hydroentangled SF-microfiber-based nonwoven layer (C/H-3D-SFnw; to support dermis engineering) to an electrospun 2D SF nanofiber layer (ESFN; a basal lamina surrogate). Next, we assessed-via scanning electron microscopy, attenuated total reflectance Fourier transform infrared spectroscopy, differential scanning calorimetry, mono- and co-cultures of HaCaT keratinocytes and adult human dermal fibroblasts (HDFs), dsDNA assays, exosome isolation, double-antibody arrays, and angiogenesis assays-whether the C/H-3D-SFnws/ESFNs would allow the reconstitution of a functional human skin analog in vitro. Results: Physical analyses proved that the C/H-3D-SFnws/ESFNs met the requirements for human soft-tissue-like implants. dsDNA assays revealed that co-cultures of HaCaTs (on the 2D ESFN surface) and HDFs (inside the 3D C/H-3D-SFnws) grew more intensely than did the respective monocultures. Double-antibody arrays showed that the CD9⁺/CD81⁺ exosomes isolated from the 14-day pooled growth media of HDF and/or HaCaT mono- or co-cultures conveyed 35 distinct angiogenic/growth factors (AGFs). However, versus monocultures' exosomes, HaCaT/HDF co-cultures' exosomes (i) transported larger amounts of 15 AGFs, i.e., PIGF, ANGPT-1, bFGF, Tie-2, Angiogenin, VEGF-A, VEGF-D, TIMP-1/-2, GRO-α/-β/-γ, IL-1β, IL-6, IL-8, MMP-9, and MCP-1, and (ii) significantly more strongly stimulated human dermal microvascular endothelial cells to migrate and assemble tubes/nodes in vitro. Conclusions: Our results showed that both cell-cell and cell-SF interactions boosted the exosomal release of AGFs from HaCaTs/HDFs co-cultured on C/H-3D-SFnws/ESFNs. Hence, such exosomes are an asset for prospective clinical applications as they advance cell growth and neoangiogenesis and consequently graft take and skin healing. Moreover, this new integument analog could be instrumental in preclinical and translational studies on human skin pathophysiology and regeneration.

D-beta-hydroxybutyrate reduced the enhanced cardiac microvascular endothelial FoxO1 to play protective roles in diabetic rats and high glucose-stimulated human cardiac microvascular endothelial cells

The O subfamily of forkhead (FoxO) 1 may participate in the pathogenesis of diabetic microvascular endothelial injury. However, it is unknown whether D-beta-hydroxybutyrate (BHB) regulates cardiac microvascular endothelial FoxO1 to play protective roles in diabetes. In the study, limb microvascular morphological changes, endothelial distribution of the tight junction protein Claudin-5 and FoxO1, and FoxO1 content in limb tissue from clinical patients were evaluated. Then the effects of BHB on cardiac microvascular morphological changes, cardiac FoxO1 generation and its microvascular distribution in diabetic rats were measured. And the effects of BHB on FoxO1 generation in high glucose (HG)-stimulated human cardiac microvascular endothelial cells (HCMECs) were further analyzed. The results firstly confirmed the enhanced limb microvascular FoxO1 distribution, with reduced Claudin-5 and endothelial injury in clinical patients. Then the elevated FoxO1 generation and its enhanced cardiac microvascular distribution were verified in diabetic rats and HG-stimulated HCMECs. However, BHB inhibited the enhanced cardiac FoxO1 generation and its microvascular distribution with attenuation of endothelial injury in diabetic rats. Furthermore, BHB reduced the HG-stimulated mRNA expression and protein content of FoxO1 in HCMECs. In conclusion, BHB reduced the enhanced cardiac microvascular endothelial FoxO1 to play protective roles in diabetic rats and HG-stimulated HCMECs.

Antioxidant Biomaterials in Cutaneous Wound Healing and Tissue Regeneration: A Critical Review

Natural-based biomaterials play an important role in developing new products for medical applications, primarily in cutaneous injuries. A large panel of biomaterials with antioxidant properties has revealed an advancement in supporting and expediting tissue regeneration. However, their low bioavailability in preventing cellular oxidative stress through the delivery system limits their therapeutic activity at the injury site. The integration of antioxidant compounds in the implanted biomaterial should be able to maintain their antioxidant activity while facilitating skin tissue recovery. This review summarises the recent literature that reported the role of natural antioxidant-incorporated biomaterials in promoting skin wound healing and tissue regeneration, which is supported by evidence from in vitro, in vivo, and clinical studies. Antioxidant-based therapies for wound healing have shown promising evidence in numerous animal studies, even though clinical studies remain very limited. We also described the underlying mechanism of reactive oxygen species (ROS) generation and provided a comprehensive review of ROS-scavenging biomaterials found in the literature in the last six years.

The Epidermal Keratinocyte as a Therapeutic Target for Management of Diabetic Wounds

Diabetes mellitus (DM) is an important cause of chronic wounds and non-traumatic amputation. The prevalence and number of cases of diabetic mellitus are increasing worldwide. Keratinocytes, the outermost layer of the epidermis, play an important role in wound healing. A high glucose environment may disrupt the physiologic functions of keratinocytes, resulting in prolonged inflammation, impaired proliferation, and the migration of keratinocytes and impaired angiogenesis. This review provides an overview of keratinocyte dysfunctions in a high glucose environment. Effective and safe therapeutic approaches for promoting diabetic wound healing can be developed if molecular mechanisms responsible for keratinocyte dysfunction in high glucose environments are elucidated.

Acceleration of Oral Wound Healing under Diabetes Mellitus Conditions Using Bioadhesive Hydrogel

Oral wounds under diabetic conditions display a significant delay during the healing process, mainly due to oxidative stress-induced inflammatory status and abnormal immune responses. Besides, the wet and complicated dynamic environment of the oral cavity impedes stable treatment of oral wounds. To overcome these, a biomimetic hydrogel adhesive was innovatively developed based on a mussel-inspired multifunctional structure. The adhesive displays efficient adhesion and mechanical harmony on the oral mucosa through enhanced bonding in an acidic proinflammatory environment. The bioadhesive hydrogel exhibits excellent antioxidative properties by mimicking antioxidative enzymatic activities to reverse reactive oxygen species (ROS)-mediated immune disorders. Experiments on oral wounds of diabetic rats showed that this hydrogel adhesive could effectively protect against mucosal wounds and obviously shorten the inflammatory phase, thus promoting the wound-healing process. Therefore, this study offers a promising therapeutic choice with the potential to advance the clinical treatment of diabetic oral wounds.

Antimicrobial efficacy, mode of action and in vivo use of hypochlorous acid (HOCl) for prevention or therapeutic support of infections

The objective is to provide a comprehensive overview of the rapidly developing field of the current state of research on in vivo use of hypochlorous acid (HOCl) to aid infection prevention and control, including naso-pharyngeal, alveolar, topical, and systemic HOCl applications. Also, examples are provided of dedicated applications in COVID-19. A brief background of HOCl's biological and chemical specifics and its physiological role in the innate immune system is provided to understand the effect of in vivo applications in the context of the body's own physiological defense mechanisms.

Icariin Treatment Rescues Diabetes Induced Bone Loss via Scavenging ROS and Activating Primary Cilia/Gli2/Osteocalcin Signaling Pathway

Diabetes-associated bone complications lead to fragile bone mechanical strength and osteoporosis, aggravating the disease burden of patients. Advanced evidence shows that chronic hyperglycemia and metabolic intermediates, such as inflammatory factor, reactive oxygen species (ROS), and advanced glycation end products (AGEs), are regarded as dominant hazardous factors of bone complications, whereas the pathophysiological mechanisms are complex and controversial. By establishing a diabetic Sprague-Dawley (SD) rat model and diabetic bone loss cell model in vitro, we confirmed that diabetes impaired primary cilia and led to bone loss, while adding Icariin (ICA) could relieve the inhibitions. Mechanistically, ICA could scavenge ROS to maintain the mitochondrial and primary cilia homeostasis of osteoblasts. Intact primary cilia acted as anchoring and modifying sites of Gli2, thereby activating the primary cilia/Gli2/osteocalcin signaling pathway to promote osteoblast differentiation. All results suggest that ICA has potential as a therapeutic drug targeting bone loss induced by diabetes.

High Glucose Induces Late Differentiation and Death of Human Oral Keratinocytes

Keratinocytes are essential cells for wound repair. Impaired oral wound healing is common in diabetic patients with periodontal disease. High glucose, or hyperglycemia, impairs the cellular function of different cell types. However, it is unknown whether high glucose has a detrimental effect on the functions of oral keratinocytes. In the current study, a human gingival keratinocyte cell line, telomerase immortalized gingival keratinocytes (TIGK), was treated with high glucose (24 and 48 mM) for up to 120 h. Proliferation, migration, cell viability, and production of markers of differentiation, growth factors and enzymatic antioxidants were assessed after high glucose treatment. The results showed that high glucose significantly inhibited TIGK proliferation and migration. High glucose also induced significant cell death through apoptosis and necrosis as determined by flow cytometry, especially at 120 h after high glucose treatment. Necrosis was the dominant form of cell death induced. Real-time PCR showed that high glucose treatment upregulated mRNA expression of late keratinocyte differentiation makers, such as keratin 1, 10, 13 and loricrin, and downregulated enzymatic antioxidants, including superoxide dismutase 1, catalase, nuclear factor erythroid 2 -related factor 2, heme oxygenase 1. In conclusion, high glucose impairs the proliferation and migration of oral keratinocytes and likely induces cell death through the promotion of late cell differentiation and down-regulation of enzymatic antioxidants.

Anti-Oxidant and Anti-Aging Activities of Callus Culture from Three Rice Varieties

The aims of this study were to induce calli from the seeds of three rice varieties (Hommali 105, Munpu, and Niawdum) and investigate their anti-aging potential. First, rice seeds were cultured on a Murashige and Skoog medium (MS medium) supplemented with 2 mg/L of 2,4-Dichlorophenoxyacetic acid (2,4-D), 1 mg/L of 1-Naphthalene acetic acid (NAA), and 1 mg/L of 6-Benzylaminopurine (BAP). After three weeks, the calli were extracted with ethanol. Then, their phenolic contents were determined by spectrophotometer and the amino acids were identified by ultra-performance liquid chromatography (UPLC). Their cytotoxicity, anti-oxidant (potassium ferricyanide reducing power assay (PFRAP), DPPH radical scavenging assay (DPPH), lipid peroxidation inhibition (LPO), and superoxide dismutase activity (SOD)), and anti-aging (keratinocyte proliferation, anti-collagenase, anti-inflammation, and anti-tyrosinase) activities were also investigated. Munpu callus (385%) was obtained with a higher yield than Hommali (322%) and Niawdum (297%) calli. The results revealed that the phenolic and amino acid contents were enhanced in the calli. Moreover, the calli were rich in glutamic acid, alanine, and gamma aminobutyric acid (GABA). The callus extracts showed no cytotoxic effects at a concentration of equal to or lower than 0.25 mg/mL. The highest anti-oxidant activities (PFRAP (0.81 mg AAE/mL), DPPH (68.22%), LPO (52.21%), and SOD (67.16%)) was found in Munpu callus extract. This extract also had the highest keratinocyte proliferation (43.32%), anti-collagenase (53.83%), anti-inflammation (85.40%), and anti-tyrosinase (64.77%) activities. The experimental results suggest that the amounts of bioactive compounds and anti-aging activities of rice seeds can be enhanced by the induction of callus formation.

Role of Primary Cilia in Bone and Cartilage

The primary cilium is a nonmotile microtubule-based organelle in most vertebrate cell types. The primary cilium plays a critical role in tissue development and homeostasis by sensing and transducing various signaling pathways. Ciliary proteins such as intraflagellar transport (IFT) proteins as well as ciliary motor proteins, kinesin and dynein, comprise a bidirectional intraflagellar transport system needed for cilia formation and function. Mutations in ciliary proteins that lead to loss or dysfunction of primary cilia cause ciliopathies such as Jeune syndrome and Ellis-van Creveld syndrome and cause abnormalities in tooth development. These diseases exhibit severe skeletal and craniofacial dysplasia, highlighting the significance of primary cilia in skeletal development. Cilia are necessary for the propagation of hedgehog, transforming growth factor β, platelet-derived growth factor, and fibroblast growth factor signaling during osteogenesis and chondrogenesis. Ablation of ciliary proteins such as IFT80 or IFT20 blocks cilia formation, which inhibits osteoblast differentiation, osteoblast polarity, and alignment and reduces bone formation. Similarly, cilia facilitate chondrocyte differentiation and production of a cartilage matrix. Cilia also play a key role in mechanosensing and are needed for increased bone formation in response to mechanical forces.

Paclitaxel-Induced Epidermal Alterations: An In Vitro Preclinical Assessment in Primary Keratinocytes and in a 3D Epidermis Model

Paclitaxel is a microtubule-stabilizing chemotherapeutic agent approved for the treatment of ovarian, non-small cell lung, head, neck, and breast cancers. Despite its beneficial effects on cancer and widespread use, paclitaxel also damages healthy tissues, including the skin. However, the mechanisms that drive these skin adverse events are not clearly understood. In the present study, we demonstrated, by using both primary epidermal keratinocytes (NHEK) and a 3D epidermis model, that paclitaxel impairs different cellular processes: paclitaxel increased the release of IL-1α, IL-6, and IL-8 inflammatory cytokines, produced reactive oxygen species (ROS) release and apoptosis, and reduced the endothelial tube formation in the dermal microvascular endothelial cells (HDMEC). Some of the mechanisms driving these adverse skin events in vitro are mediated by the activation of toll-like receptor 4 (TLR-4), which phosphorylate transcription of nuclear factor kappa B (NF-κb). This is the first study analyzing paclitaxel effects on healthy human epidermal cells with an epidermis 3D model, and will help in understanding paclitaxel's effects on the skin.

The role of CXCL8 in chronic nonhealing diabetic foot ulcers and phenotypic changes in fibroblasts: a molecular perspective

INTRODUCTION

A persistent inflammation is perpetuated by infiltrating immune cells and cytokines secreted from these immune cells. Additionally, apoptotic keratinocytes and adipocytes in diabetes causes diabetic foot ulcer (DFU) to arrest in an inflammatory phase without progressing to the resolution phase. This leads to a nonhealing DFU and, despite advanced treatments consisting of wound debridement, off-loading the ulcer of necrotic tissue, wound dressings to keep it moist and control exudate, medication, and preventing infection, DFUs remain a clinical problem. Nonhealing DFUs pose not only an economic burden but also increased morbidity and mortality in the form of psychological stress with and increased chance of amputation, and even death. Thus, investigating the complicated underlying molecular mechanism responsible for nonhealing patterns and designing better therapeutics is warranted. This review article focuses on the role of IL-8-mediated persistent inflammation and phenotypic change of fibroblasts due to this inflammatory cascade. We have discussed various sources of interleukin (IL)-8 secretion and the possible association of IL8-fibroblast plasticity as a cause of nonhealing DFUs.

MATERIAL AND METHODS

A literature search on PubMed, Google Scholar, and PMC was done including the terms diabetic foot ulcer, diabetes, diabetic ulcer, chronic inflammation, interleukin 8, diabetic wound, and nonhealing diabetic foot ulcers. The articles in the English language and published in last 10 years were selected. From the pool of these, the articles describing the relationship between IL-8 and nonhealing diabetic foot ulcer and diabetic ulcer were used sorted out and used for this review article following PRISMA guidelines.

CONCLUSION

Increased infiltration of inflammatory immune cells, secretion of pro-inflammatory cytokines, altered keratinocyte-fibroblast function, and phenotypic changes of fibroblasts in DFUs seem to be critical to the nonhealing of DFUs. Thus, inhibiting IL-8 secretion and downstream signaling seems to be a goal of potential therapeutics.

An overview on the manufacturing of functional and mature cellular skin substitutes

There are different types of skin diseases due to chronic injuries that impede the natural healing process of the skin. Tissue engineering (TE) has focused on the development of bioengineered skin or skin substitutes that cover the wound, providing the necessary care to restore the functionality of injured skin. There are two types of substitutes: acellular skin substitutes (ASSs), which offer a low response of the body, and cellular skin substitutes (CSSs), which incorporate living cells and appear as a great alternative in the treatment of skin injuries due to them presenting a greater interaction and integration with the rest of the body. For the development of a CSS, it is necessary to select the most suitable biomaterials, cell components, and methodology of biofabrication for the wound to be treated. Moreover, these CSSs are immature substitutes that must undergo a maturing process in specific bioreactors, guaranteeing their functionality. The bioreactor simulates the natural state of maturation of the skin by controlling parameters such as temperature, pressure, or humidity, allowing a homogeneous maturation of the CSSs in an aseptic environment. The use of bioreactors not only contributes to the maturation of the CSSs, but also offers a new way of obtaining large sections of skin substitutes or natural skin from small portions acquired from the patient, donor, or substitute. Based on the innovation of this technology and the need to develop efficient CSSs, this work offers an update on bioreactor technology in the field of skin regeneration.

Diabetic wound healing in soft and hard oral tissues

There is significant interest in understanding the cellular mechanisms responsible for expedited healing response in various oral tissues and how they are impacted by systemic diseases. Depending upon the types of oral tissue, wound healing may occur by predominantly re-eptihelialization, by re-epithelialization with substantial new connective tissue formation, or by a a combination of both plus new bone formation. As a result, the cells involved differ and are impacted by systemic diaseses in various ways. Diabetes mellitus is a prevalent metabolic disorder that impairs barrier function and healing responses throughout the human body. In the oral cavity, diabetes is a known risk factor for exacerbated periodontal disease and delayed wound healing, which includes both soft and hard tissue components. Here, we review the mechanisms of diabetic oral wound healing, particularly on impaired keratinocyte proliferation and migration, altered level of inflammation, and reduced formation of new connective tissue and bone. In particular, diabetes inhibits the expression of mitogenic growth factors whereas that of pro-inflammatory cytokines is elevated through epigenetic mechanisms. Moreover, hyperglycemia and oxidative stress induced by diabetes prevents the expansion of mesengenic cells that are involved in both soft and hard tissue oral wounds. A better understanding of how diabetes influences the healing processes is crucial for the prevention and treatment of diabetes-associated oral complications.

Microplasma Treatment versus Negative Pressure Therapy for Promoting Wound Healing in Diabetic Mice

The delayed healing response of diabetic wounds is a major challenge for treatment. Negative pressure wound therapy (NPWT) has been widely used to treat chronic wounds. However, it usually requires a long treatment time and results in directional growth of wound healing skin tissue. We investigated whether nonthermal microplasma (MP) treatment can promote the healing of skin wounds in diabetic mice. Splint excision wounds were created on diabetic mice, and various wound healing parameters were compared among MP treatment, NPWT, and control groups. Quantitative analysis of the re-epithelialization percentage by detecting Ki67 and DSG1 expression in the extending epidermal tongue (EET) of the wound area and the epidermal proliferation index (EPI) was subsequently performed. Both treatments promoted wound healing by enhancing wound closure kinetics and wound bed blood flow; this was confirmed through histological analysis and optical coherence tomography. Both treatments also increased Ki67 and DSG1 expression in the EET of the wound area and the EPI to enhance re-epithelialization. Increased Smad2/3/4 mRNA expression was observed in the epidermis layer of wounds, particularly after MP treatment. The results suggest that the Smad-dependent transforming growth factor β signaling contributes to the enhancement of re-epithelialization after MP treatment with an appropriate exposure time. Overall, a short-term MP treatment (applied for 30 s twice a day) demonstrated comparable or better efficacy to conventional NPWT (applied for 4 h once a day) in promoting wound healing in diabetic mice. Thus, MP treatment exhibits promise for treating diabetic wounds clinically.

Wound Healing Effect of Gintonin Involves Lysophosphatidic Acid Receptor/Vascular Endothelial Growth Factor Signaling Pathway in Keratinocytes

Gintonin, a novel compound of ginseng, is a ligand of the lysophosphatidic acid (LPA) receptor. The in vitro and in vivo skin wound healing effects of gintonin remain unknown. Therefore, the objective of this study was to investigate the effects of gintonin on wound healing-linked responses, especially migration and proliferation, in skin keratinocytes HaCaT. In this study, 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide assay, Boyden chamber migration assay, scratch wound healing assay, and Western blot assay were performed. A tail wound mouse model was used for the in vivo test. Gintonin increased proliferation, migration, and scratch closure in HaCaT cells. It also increased the release of vascular endothelial growth factor (VEGF) in HaCaT cells. However, these increases, induced by gintonin, were markedly blocked by treatment with Ki16425, an LPA inhibitor, PD98059, an ERK inhibitor, 1,2-Bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid tetrakis (acetoxymethyl ester), a calcium chelator, and U73122, a PLC inhibitor. The VEGF receptor inhibitor axitinib also attenuated gintonin-enhanced HaCaT cell proliferation. Gintonin increased the phosphorylation of AKT and ERK1/2 in HaCaT cells. In addition, gintonin improved tail wound healing in mice. These results indicate that gintonin may promote wound healing through LPA receptor activation and/or VEGF release-mediated downstream signaling pathways. Thus, gintonin could be a beneficial substance to facilitate skin wound healing.

Microbiological effects in patients with leg ulcers and diabetic foot treated with Lucilia sericata larvae

Lucilia sericata bottle fly worms can be used to heal infected, chronic, or necrotic wounds, including those associated with ulceration and diabetic foot. The study aimed to evaluate changes in the microflora in patients treated with L sericata larvae due to leg ulcers and diabetic foot. One hundred twenty-nine patients diagnosed with lower limb ulceration and diabetic foot were enrolled in the study, of which 80 of them met the eligibility criteria for maggot debridement therapy (MDT). On the contrary, 49 unqualified patients were offered ozone therapy (22 with leg ulcers; 27 with diabetic foot). In each of these patients, a microbiological swab was performed before and after the start of therapy. The group of 80 patients was further divided into four equal groups in terms of the treated area (lower leg vs foot) and the number of larvae/cm² (5 vs 10). Twenty-three particular species of bacteria in the infected wound were studied microbiologically in terms of presence/absence within the wound environment before and after treatment of patients with diabetic foot and lower limb ulceration. It was noted that there was a more intensive bacterial accumulation in the feet of patients compared to legs; furthermore, this applies to almost all analysed species. Diabetes status is also a clinical factor that generates a lower chance of bacterial appearance in the wound environment. Densification of MDT larvae per wound area unit also reduced the chance of the presence of Corynebacterium species, Enterobacteriaceae, Pseudomonas aeruginosa, Staphylococcus aureus MSSA, and Streptococcus coagulase negativa; however, it increased the likelihood of occurrence for Proteus mirabilis and the Proteus species. A microbiological analysis in this non-reference study shows the efficacy of larval therapy for leg and foot ulcers. Rearrangement of the microflora within the wound has been reported as a result of the therapy.

Clinical application of a FOXO1 inhibitor improves connective tissue healing in a diabetic minipig model

The forkhead box O1 (FOXO1) transcription factor plays a key role in wound healing process. Recently it has been reported that lineage-specific genetic ablation of FOXO1 significantly improves diabetic wound healing in a mouse model. To investigate the clinical usefulness of these findings, translational preclinical studies with a large animal model are needed. We report for the first time that the local application of a FOXO1 inhibitor (AS1842856) significantly improves connective tissue healing in a preclinical T2DM minipig model, reflected by increased collagen matrix formation, increased myofibroblast numbers, improved angiogenesis, and a shift in cell populations from pro-inflammatory (IL-1β⁺, TNF-α⁺ and iNOS⁺) to pro-healing (CD163⁺). Our results set up the basis for the clinical application of a FOXO1 antagonist in early diabetic wounds where there is impaired connective tissue healing.