A Synthetic Curcuminoid Analog, (2E,6E)-2,6-bis(2-(trifluoromethyl)benzylidene)cyclohexanone, Ameliorates Impaired Wound Healing in Streptozotocin-Induced Diabetic Mice by Increasing miR-146a

Monocarbonyl analogs of curcumin C66 and B2BrBC modulate oxidative stress, JNK activity, and pancreatic gene expression in rats with streptozotocin-induced diabetes

The pathogenesis of type 1 diabetes mellitus (T1DM) involves oxidative stress and inflammation. Curcumin, a natural polyphenolic compound found in turmeric, known to exhibit antioxidative and anti-inflammatory properties, is characterized by poor chemical stability, low bioavailability, and rapid metabolism. Monocarbonyl analogs of curcumin (MACs) with a structural absence of β-diketone and enhanced stability and bioavailability present a potential solution to the challenges associated with the use of curcumin. This study aimed to evaluate the effect of two MACs, C66 and B2BrBC, on oxidative stress markers, antioxidant enzyme activity, expression of diabetes-associated genes, and signaling pathway proteins in the context of T1DM. Streptozotocin (STZ)-induced male Wistar rats or rat pancreatic RIN-m cells were used for in vivo and in vitro experiments, respectively. C66 or B2BrBC were given either before or after STZ treatment. Oxidative stress markers and antioxidant enzyme activities were determined in various tissues. Expression of diabetes-associated genes was assessed using RT-qPCR, and the activity of signaling pathway proteins in the pancreas was determined through Western blot analysis. Treatment with C66 and B2BrBC significantly reduced oxidative stress markers and positively influenced antioxidant enzyme activities. Moreover, both compounds inhibited JNK activity in the pancreas while enhancing the expression of genes crucial for β-cell survival and glucose and redox homeostasis. The findings highlight the multifaceted potential of C66 and B2BrBC in ameliorating oxidative stress, influencing gene expression patterns linked to diabetes, and modulating key signaling pathways in the pancreas. The findings suggest that these compounds can potentially address diabetes-related pathological processes.

The emerging modulators of non-coding RNAs in diabetic wound healing

Diabetic wound healing is a complex physiological process often hindered by the underlying metabolic dysfunctions associated with diabetes. Despite existing treatments, there remains a critical need to explore innovative therapeutic strategies to improve patient outcomes. This article comprehensively examines the roles of non-coding RNAs (ncRNAs), specifically microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs), in regulating key phases of the wound healing process: inflammation, angiogenesis, re-epithelialization, and tissue remodeling. Through a deep review of current literature, we discuss recent discoveries of ncRNAs that have been shown to either promote or impair the wound healing process in diabetic wound healing, which were not covered in earlier reviews. This review highlights the specific mechanisms by which these ncRNAs impact cellular behaviors and pathways critical to each healing stage. Our findings indicate that understanding these recently identified ncRNAs provides new insights into their potential roles in diabetic wound healing, thereby contributing valuable knowledge for future research directions in this field.

Study on chitosan/gelatin hydrogels containing ceria nanoparticles for promoting the healing of diabetic wound

Chronic inflammation at diabetic wound sites results in the uncontrolled accumulation of pro-inflammatory factors and reactive oxygen species (ROS), which impedes cell proliferation and delays wound healing. To promote the healing of diabetic wounds, chitosan/gelatin hydrogels containing ceria nanoparticles (CNPs) of various sizes were created in the current study. CNPs' efficacy in removingO 2 • - , •OH, and H2O2 was demonstrated, and the scavenging ability of CNPs of varying sizes was compared. The in vitro experiments demonstrated that hydrogels containing CNPs could effectively protect cells from ROS-induced damage and facilitate mouse fibroblast migration. Furthermore, during the treatment of diabetic wounds in vivo, hydrogels containing CNPs exhibited anti-inflammatory activity and could reduce the expression of the pro-inflammatory factors TNF-α (above 30%), IL-6 (above 90%), and IL-1β (above 80%), and effectively promote wound closure (above 80%) by inducing re-epithelialization, collagen deposition, and angiogenesis. In addition, the biological properties and therapeutic effects of hydrogels containing CNPs of various sizes were compared and discussed. The finding revealed that hydrogels with 4 nm CNPs exhibited more significant biological properties and had implications for diabetic wound treatment.

Molecular pathways of NF-ĸB and NLRP3 inflammasome as potential targets in the treatment of inflammation in diabetic wounds: A review

Diabetic wounds are slow healing wounds characterized by disordered healing processes and frequently take longer than three months to heal. One of the defining characteristics of impaired diabetic wound healing is an abnormal and unresolved inflammatory response, which is primarily brought on by abnormal macrophage innate immune signaling activation. The persistent inflammatory state in a diabetic wound may be attributed to inflammatory pathways such as nuclear factor kappa B (NF-ĸB) and nod-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome, which have long been associated with inflammatory diseases. Despite the available treatments for diabetic foot ulcers (DFUs) that include debridement, growth factor therapy, and topical anti-bacterial agents, successful wound healing is still hampered. Further understanding of the molecular mechanism of these pathways could be useful in designing potential therapeutic targets for diabetic wound healing. This review provides an update and novel insights into the roles of NF-ĸB and NLRP3 pathways in the molecular mechanism of diabetic wound inflammation and their potential as therapeutic targets in diabetic wound healing.

Effect of MicroRNA-146a Modified Adipose-Derived Stem Cell Exosomes on Rat Back Wound Healing

Objective: To investigate the effect of MicroRNA-146a modified adipose-derived stem cell exosomes on the proliferation and migration of fibroblasts and the therapeutic effect on wound healing. Methods: Culture and identification of human adipose-derived stem cells (hASCs), miRNA-146a minic vector was constructed and transfected into hASCs, the exosomes of the empty group and overexpression group were extracted, identified, and quantitatively analyzed after 24 h of successful transfection. The exosomes were added into National Institute of Health Mouse Embryonic Fibroblasts (NIH/3T3) and cultured for 48 h, the proliferation and migration ability of NIH/3T3 fibroblasts was detected. The expression of serpin family H member 1 (SERPINH1) and phosphorylated extracellular regulated protein kinase (p-ERK) was detected by Western blot. The model of back wound was established. The exosomes were injected into 4 different sites with the shape of "cross" around the wound, and the scar diameter of the skin defect was measured at 3, 7, and 11 days, the skin of the defect was taken on the 14th day. platelet endothelial cell adhesion molecule-1 (CD31) was detected by immunofluorescence staining to evaluate angiogenesis, and Western blot was used to detect the expression of SERPINH1 and p-ERK. Results: The miR-146a mimic-exosome promoted the proliferation and migration of fibroblasts, and the expression of SERPINH1 and p-ERK2 was up-regulated. After the rats were treated with exosomes, the wound area decreased rapidly, neovascularization was promoted, and the expression of SERPINH1 and p-ERK2 was up-regulated. Conclusions: MicroRNA-146a modified adipose stem cell exosomes could regulate the expression of SERPINH1 and p-ERK, promote the migration and proliferation of fibroblasts, and neovascularization to promote the wound healing of rat back.

Exploring the Complex Relationship between Diabetes and Cardiovascular Complications: Understanding Diabetic Cardiomyopathy and Promising Therapies

Diabetes mellitus (DM) and cardiovascular complications are two unmet medical emergencies that can occur together. The rising incidence of heart failure in diabetic populations, in addition to apparent coronary heart disease, ischemia, and hypertension-related complications, has created a more challenging situation. Diabetes, as a predominant cardio-renal metabolic syndrome, is related to severe vascular risk factors, and it underlies various complex pathophysiological pathways at the metabolic and molecular level that progress and converge toward the development of diabetic cardiomyopathy (DCM). DCM involves several downstream cascades that cause structural and functional alterations of the diabetic heart, such as diastolic dysfunction progressing into systolic dysfunction, cardiomyocyte hypertrophy, myocardial fibrosis, and subsequent heart failure over time. The effects of glucagon-like peptide-1 (GLP-1) analogues and sodium-glucose cotransporter-2 (SGLT-2) inhibitors on cardiovascular (CV) outcomes in diabetes have shown promising results, including improved contractile bioenergetics and significant cardiovascular benefits. The purpose of this article is to highlight the various pathophysiological, metabolic, and molecular pathways that contribute to the development of DCM and its significant effects on cardiac morphology and functioning. Additionally, this article will discuss the potential therapies that may be available in the future.

Association of MicroRNA-146a with Type 1 and 2 Diabetes and their Related Complications

Most medical investigations have found a reduced blood level of miR-146a in type 2 diabetes (T2D) patients, suggesting an important role for miR-146a (microRNA-146a) in the etiology of diabetes mellitus (DM) and its consequences. Furthermore, injection of miR-146a mimic has been confirmed to alleviate diabetes mellitus in diabetic animal models. In this line, deregulation of miR-146a expression has been linked to the progression of nephropathy, neuropathy, wound healing, olfactory dysfunction, cardiovascular disorders, and retinopathy in diabetic patients. In this review, besides a comprehensive review of the function of miR-146a in DM, we discussed new findings on type 1 (T1MD) and type 2 (T2DM) diabetes mellitus, highlighting the discrepancies between clinical and preclinical investigations and elucidating the biological pathways regulated through miR-146a in DM-affected tissues.

Efficacy of the monocarbonyl curcumin analog C66 in the reduction of diabetes-associated cardiovascular and kidney complications

Curcumin is a polyphenolic compound derived from turmeric that has potential beneficial properties for cardiovascular and renal diseases and is relatively safe and inexpensive. However, the application of curcumin is rather problematic due to its chemical instability and low bioavailability. The experimental results showed improved chemical stability and potent pharmacokinetics of one of its analogs – (2E,6E)-2,6-bis[(2-trifluoromethyl)benzylidene]cyclohexanone (C66). There are several advantages of C66, like its synthetic accessibility, structural simplicity, improved chemical stability (in vitro and in vivo), presence of two reactive electrophilic centers, and good electron-accepting capacity. Considering these characteristics, we reviewed the literature on the application of C66 in resolving diabetes-associated cardiovascular and renal complications in animal models. We also summarized the mechanisms by which C66 is preventing the release of pro-oxidative and pro-inflammatory molecules in the priming and in activation stage of cardiomyopathy, renal fibrosis, and diabetic nephropathy. The cardiovascular protective effect of C66 against diabetes-induced oxidative damage is Nrf2 mediated but mainly dependent on JNK2. In general, C66 causes inhibition of JNK2, which reduces cardiac inflammation, fibrosis, oxidative stress, and apoptosis in the settings of diabetic cardiomyopathy. C66 exerts a powerful antifibrotic effect by reducing inflammation-related factors (MCP-1, NF-κB, TNF-α, IL-1β, COX-2, and CAV-1) and inducing the expression of anti-inflammatory factors (HO-1 and NEDD4), as well as targeting TGF-β/SMADs, MAPK/ERK, and PPAR-γ pathways in animal models of diabetic nephropathy. Based on the available evidence, C66 is becoming a promising drug candidate for improving cardiovascular and renal health.

Polyphenols target miRNAs as a therapeutic strategy for diabetic complications

MiRNAs are a large group of non-coding RNAs which participate in different cellular pathways like inflammation and oxidation through transcriptional, post-transcriptional, and epigenetic regulation. In the post-transcriptional regulation, miRNA interacts with the 3'-UTR of mRNAs and prevents their translation. This prevention or dysregulation can be a cause of pathological conditions like diabetic complications. A huge number of studies have revealed the association between miRNAs and diabetic complications, including diabetic nephropathy, cardiomyopathy, neuropathy, retinopathy, and delayed wound healing. To address this issue, recent studies have focused on the use of polyphenols as selective and safe drugs in the treatment of diabetes complications. In this article, we will review the involvement of miRNAs in diabetic complications' occurrence or development. Finally, we will review the latest findings on targeting miRNAs by polyphenols like curcumin, resveratrol, and quercetin for diabetic complications therapy.

Anti-Inflammatory microRNAs for Treating Inflammatory Skin Diseases

Skin inflammation occurs due to immune dysregulation because of internal disorders, infections, and allergic reactions. The inflammation of the skin is a major sign of chronic autoimmune inflammatory diseases, such as psoriasis, atopic dermatitis (AD), and lupus erythematosus. Although there are many therapies for treating these cutaneous inflammation diseases, their recurrence rates are high due to incomplete resolution. MicroRNA (miRNA) plays a critical role in skin inflammation by regulating the expression of protein-coding genes at the posttranscriptional level during pathogenesis and homeostasis maintenance. Some miRNAs possess anti-inflammatory features, which are beneficial for mitigating the inflammatory response. miRNAs that are reduced in inflammatory skin diseases can be supplied transiently using miRNA mimics and agomir. miRNA-based therapies that can target multiple genes in a given pathway are potential candidates for the treatment of skin inflammation. This review article offers an overview of the function of miRNA in skin inflammation regulation, with a focus on psoriasis, AD, and cutaneous wounds. Some bioactive molecules can target and modulate miRNAs to achieve the objective of inflammation suppression. This review also reports the anti-inflammatory efficacy of these molecules through modulating miRNA expression. The main limitations of miRNA-based therapies are rapid biodegradation and poor skin and cell penetration. Consideration was given to improving these drawbacks using the approaches of cell-penetrating peptides (CPPs), nanocarriers, exosomes, and low-frequency ultrasound. A formulation design for successful miRNA delivery into skin and target cells is also described in this review. The possible use of miRNAs as biomarkers and therapeutic modalities could open a novel opportunity for the diagnosis and treatment of inflammation-associated skin diseases.

Curcumin and Its Analogs as Potential Epigenetic Modulators: Prevention of Diabetes and Its Complications

BACKGROUND

The pathobiology of diabetes and associated complications has been widely researched in various countries, but effective prevention and treatment methods are still insufficient. Diabetes is a metabolic disorder of carbohydrates, fats, and proteins caused by an absence of insulin or insulin resistance, which mediates an increase of oxidative stress, release of inflammatory factors, and macro- or micro-circulation dysfunctions, ultimately developing into diverse complications.

SUMMARY

In the last decade through pathogenesis research, epigenetics has been found to affect metabolic diseases. Particularly, DNA methylation, histone acetylation, and miRNAs promote or inhibit diabetes and complications by regulating the expression of related factors. Curcumin has a wide range of beneficial pharmacological activities, including anti-inflammatory, anti-oxidation, anticancer, anti-diabetes, anti-rheumatism, and increased immunity. Key Messages: In this review, we discuss the effects of curcumin and analogs on diabetes and associated complications through epigenetics, and we summarize the preclinical and clinical researches for curcumin and its analogs in terms of management of diabetes and associated complications, which may provide an insight into the development of targeted therapy of endocrine diseases.

Tailored Functionalization of Natural Phenols to Improve Biological Activity

Phenols are widespread in nature, being the major components of several plants and essential oils. Natural phenols' anti-microbial, anti-bacterial, anti-oxidant, pharmacological and nutritional properties are, nowadays, well established. Hence, given their peculiar biological role, numerous studies are currently ongoing to overcome their limitations, as well as to enhance their activity. In this review, the functionalization of selected natural phenols is critically examined, mainly highlighting their improved bioactivity after the proper chemical transformations. In particular, functionalization of the most abundant naturally occurring monophenols, diphenols, lipidic phenols, phenolic acids, polyphenols and curcumin derivatives is explored.

Immunology of Acute and Chronic Wound Healing

Skin wounds greatly affect the global healthcare system, creating a substantial burden on the economy and society. Moreover, the situation is exacerbated by low healing rates, which in fact are overestimated in reports. Cutaneous wounds are generally classified into acute and chronic. The immune response plays an important role during acute wound healing. The activation of immune cells and factors initiate the inflammatory process, facilitate wound cleansing and promote subsequent tissue healing. However, dysregulation of the immune system during the wound healing process leads to persistent inflammation and delayed healing, which ultimately result in chronic wounds. The microenvironment of a chronic wound is characterized by high quantities of pro-inflammatory macrophages, overexpression of inflammatory mediators such as TNF-α and IL-1β, increased activity of matrix metalloproteinases and abundance of reactive oxygen species. Moreover, chronic wounds are frequently complicated by bacterial biofilms, which perpetuate the inflammatory phase. Continuous inflammation and microbial biofilms make it very difficult for the chronic wounds to heal. In this review, we discuss the role of innate and adaptive immunity in the pathogenesis of acute and chronic wounds. Furthermore, we review the latest immunomodulatory therapeutic strategies, including modifying macrophage phenotype, regulating miRNA expression and targeting pro- and anti-inflammatory factors to improve wound healing.

Curcumin-primed human BMSC-derived extracellular vesicles reverse IL-1β-induced catabolic responses of OA chondrocytes by upregulating miR-126-3p

BACKGROUND

Curcumin has anti-inflammatory effects and qualifies as a potential candidate for the treatment of osteoarthritis (OA). However, curcumin has limited bioavailability. Extracellular vesicles (EVs) are released by multiple cell types and act as molecule carrier during intercellular communication. We assume that EVs can maintain bioavailability and stability of curcumin after encapsulation. Here, we evaluated modulatory effects of curcumin-primed human (h)BMSC-derived EVs (Cur-EVs) on IL-1β stimulated human osteoarthritic chondrocytes (OA-CH).

METHODS

CellTiter-Blue Viability- (CTB), Caspase 3/7-, and live/dead assays were used to determine range of cytotoxic curcumin concentrations for hBMSC and OA-CH. Cur-EVs and control EVs were harvested from cell culture supernatants of hBMSC by ultracentrifugation. Western blotting (WB), transmission electron microscopy, and nanoparticle tracking analysis were performed to characterize the EVs. The intracellular incorporation of EVs derived from PHK26 labeled and curcumin-primed or control hBMSC was tested by adding the labeled EVs to OA-CH cultures. OA-CH were pre-stimulated with IL-1β, followed by Cur-EV and control EV treatment for 24 h and subsequent analysis of viability, apoptosis, and migration (scratch assay). Relative expression of selected anabolic and catabolic genes was assessed with qRT-PCR. Furthermore, WB was performed to evaluate phosphorylation of Erk1/2, PI3K/Akt, and p38MAPK in OA-CH. The effect of hsa-miR-126-3p expression on IL-1β-induced OA-CH was determined using CTB-, Caspase 3/7-, live/dead assays, and WB.

RESULTS

Cur-EVs promoted viability and reduced apoptosis of IL-1β-stimulated OA-CH and attenuated IL-1β-induced inhibition of migration. Furthermore, Cur-EVs increased gene expression of BCL2, ACAN, SOX9, and COL2A1 and decreased gene expression of IL1B, IL6, MMP13, and COL10A1 in IL-1β-stimulated OA-CH. In addition, phosphorylation of Erk1/2, PI3K/Akt, and p38 MAPK, induced by IL-1β, is prevented by Cur-EVs. Cur-EVs increased IL-1β-reduced expression of hsa-miR-126-3p and hsa-miR-126-3p mimic reversed the effects of IL-1β.

CONCLUSION

Cur-EVs alleviated IL-1β-induced catabolic effects on OA-CH by promoting viability and migration, reducing apoptosis and phosphorylation of Erk1/2, PI3K/Akt, and p38 MAPK thereby modulating pro-inflammatory signaling pathways. Treatment of OA-CH with Cur-EVs is followed by upregulation of expression of hsa-miR-126-3p which is involved in modulation of anabolic response of OA-CH. EVs may be considered as promising drug delivery vehicles of curcumin helping to alleviate OA.

Plasma endothelial cells-derived extracellular vesicles promote wound healing in diabetes through YAP and the PI3K/Akt/mTOR pathway

Extracellular vesicles are involved in skin wound healing and diabetes. After enrichment and identification, plasma endothelial cells-derived-extracellular vesicles were cocultured with skin fibroblasts or HaCaT. The gain-and loss-of functions were performed to measure fibroblast proliferation, senescence, and reactive oxygen species. Levels of senescence-related proteins, senescence-associated secretory phenotypes, vascular markers, YAP and the PI3K/Akt/mTOR pathway-related proteins were determined. Diabetic mice were induced to establish skin wound model. After endothelial cells-derived-extracellular vesicles were injected into skin wound modeling mice, skin wound healing was evaluated. Endothelial cells-derived-extracellular vesicles treatment enhanced fibroblast proliferation, and decreased senescence through the elevation of YAP nuclear translocation and activation the PI3K/Akt/mTOR pathway. YAP inhibition reversed the effect of plasma endothelial cells-derived-extracellular vesicles on fibroblast proliferation. Endothelial cells-derived-extracellular vesicles also promoted wound healing in diabetic mice, increased microvascular density, collagen deposition, macrophage infiltration and positive rates of vascular markers, and inhibited YAP phosphorylation and senescence. Plasma endothelial cells-derived-extracellular vesicles prevent fibroblast senescence and accelerate skin wound healing in diabetic mice by reducing YAP phosphorylation and activating the PI3K/Akt/mTOR pathway. This study may provide novel insights for skin disorders in diabetic mice.