Clinical Evidence of a Photoreceptor Origin in Diabetic Retinal Disease.

Clinical Relevance: Although diabetes is associated with a classic microvascular disease of the retina, it is also increasingly being recognized as a cause of retinal neuropathy. Preclinical evidence suggests that retinal neuropathy in diabetes manifests in part as photoreceptor dysfunction, preceding the development of vascular features in experimental models. It remains unknown whether such findings are relevant to patients with diabetes. Methods: Here, we review 4 lines of clinical evidence suggesting that diabetes-associated photoreceptor pathology is linked to the development of retinal microvascular disease. Results: First, a major population-based investigation of susceptibility loci for diabetic retinopathy (DR) implicated a photoreceptor protein product as a protective factor. Next, electroretinography and other studies of visual function collectively show that rod and/or cone-derived abnormalities occur decades before the development of vascular features of DR. Third, protection from DR seemingly develops in patients with coincident retinitis pigmentosa, as suggested by several case series. Finally, based on anatomic features, we propose that the beneficial effect of macular laser in DR occurs via ablation of diseased photoreceptors. Conclusions: The evidence we present is limited due to the small patient populations used in the studies we cite and due to the lack of methodologies that allow causative relationships to be inferred. Collectively, however, these clinical observations suggest that photoreceptors are involved in early diabetic retinal disease and may in fact give rise to the classic features of DR. Financial Disclosures: Proprietary or commercial disclosures may be found in the Footnotes and Disclosures at the end of this article.

Severity Scale of Diabetic Macular Ischemia Based on the Distribution of Capillary Nonperfusion in OCT Angiography.

Purpose: To evaluate the severity scales of diabetic macular ischemia (DMI) by analyzing the quantity and distribution of capillary nonperfusion using OCT angiography (OCTA) images. Design: A single-center, prospective case series. Participants: Three hundred one eyes from 301 patients with diabetic retinopathy. Methods: We acquired 3 × 3-mm swept-source OCTA images and created en face images within a central 2.5-mm circle. The circle was divided into 15 × 15-pixel squares and nonperfusion squares (NPSs) were defined as those without retinal vessels. Eyes with high-dimensional spatial data were arranged on a 2-dimensional space using the uniform manifold approximation and projection (UMAP) algorithm and classified by clustering into 5 groups: Initial, Mild, Superficial, Moderate, and Severe. Main Outcome Measures: Development of a severity scale for DMI. Results: Eyes arranged on a 2-dimensional UMAP space were divided into 5 clusters, based on the similarity of nonperfusion area distribution. Nonperfusion square counts in the deep layer increased in eyes of the Initial, Mild, Moderate, and Severe groups in a stepwise manner. In contrast, there were no significant changes in superficial NPS counts between eyes of the Initial and Mild groups. In the intermediate stage, eyes of the Superficial group exhibited higher NPS counts in the central sector of the superficial layer compared with those of the Moderate group. The foveal avascular zone extended into the temporal subfield of the deep layer in eyes of the Moderate group. Eyes of the Severe group had significantly poorer visual acuity that was more frequently accompanied with proliferative diabetic retinopathy. Conclusions: The application of dimensionality reduction and clustering has facilitated the development of a novel severity scale for DMI based on the distribution of capillary nonperfusion in OCTA images. Financial Disclosures: The authors have no proprietary or commercial interest in any materials discussed in this article.

Comparison of Machine Learning Models to a Novel Score in the Identification of Patients at Low Risk for Diabetic Retinopathy.

Purpose: To develop an easily applicable predictor of patients at low risk for diabetic retinopathy (DR). Design: An experimental study on the development and validation of machine learning models (MLMs) and a novel retinopathy risk score (RRS) to detect patients at low risk for DR. Subjects: All individuals aged ≥18 years of age who participated in the telemedicine retinal screening initiative through Temple University Health Systems from October 1, 2016 through December 31, 2020. The subjects must have documented evidence of their diabetes mellitus (DM) diagnosis as well as a documented glycosylated hemoglobin (HbA1c) recorded in their chart within 6 months of the retinal screening photograph. Methods: The charts of 1930 subjects (1590 evaluable) undergoing telemedicine screening for DR were reviewed, and 30 demographic and clinical parameters were collected. Diabetic retinopathy is a dichotomous variable where low risk is defined as no or mild retinopathy using the International Clinical Diabetic Retinopathy severity score. Five MLMs were trained to predict patients at low risk for DR using 1050 subjects and further underwent 10-fold cross validation to maximize its performance indicated by the area under the receiver operator characteristic curve (AUC). Additionally, a novel RRS is defined as the product of HbA1c closest to screening and years with DM. Retinopathy risk score was also applied to generate a predictive model. Main Outcome Measures: The performance of the trained MLMs and the RRS model was compared using DeLong's test. The models were further validated using a separate unseen test set of 540 subjects. The performance of the validation models were compared using DeLong's test and chi-square tests. Results: Using the test set, the AUC for the RRS was not statistically different from 4 out of 5 MLM. The error rate for predicting low-risk patients using the RRS was significantly lower than the naive rate (0.097 vs. 0.19; P < 0.0001), and it was comparable to the error rates of the MLMs. Conclusions: This novel RRS is a potentially useful and easily deployable predictor of patients at low risk for DR. Financial Disclosures: Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Syzygium cumini (L.) skeels mitigate diabetic nephropathy by regulating Nrf2 pathway and mitocyhondrial dysfunction: In vitro and in vivo studies.

ETHNOPHARMACOLOGICAL PREVALENCE: Hyperglycemia in diabetes increases the generation of advanced glycation end products (AGEs) through non-enzymatic reactions. The interaction between AGEs and their receptors (RAGE) leads to oxidative and inflammatory stress, which plays a pivotal role in developing diabetic nephropathy. Syzygium cumini (SC) L. (DC.) homeopathic preparations viz. 200C, 30C, and mother tincture [MT] are used to treat diabetes. This study aimed to elucidate the regulatory effects of SC preparations (200C, 30C, and MT) on the nuclear factor erythroid 2-related factor 2 (Nrf2) - nuclear factor-κB (NF-κB) pathways and mitochondrial dysfunction in mitigating diabetic nephropathy (DN). MATERIALS AND METHODS: Streptozotocin-induced diabetic rats were treated with SC preparations (200C, 30C, MT; 1:20 dilution in distilled water; 600 µL/kg body weight) and metformin (45 mg/kg body weight) twice daily for 40 days. DN was evaluated through biochemical parameters and histological examination. Renal tissue lysates were analyzed for glycation markers. Protein and gene levels of Nrf2, NF-κB, and mitochondrial dysfunctional signaling were determined via western blotting and RT-qPCR. An immunohistochemical analysis of the kidneys was performed. In vitro, human serum albumin (HSA - 10 mg/ml) was glycated with methylglyoxal (MGO - 55 mM) in the presence of SC preparations (200C, 30C, MT) for eight days. Glycated samples (400 µg/mL) were incubated with renal cells (HEK-293) for 24 h. Further reactive oxygen species production, Nrf2 nuclear translocation, and protein or gene expression of Nrf2 and apoptosis markers were analyzed by western blotting, RT-qPCR, and flow cytometry. Molecular docking of gallic and ellagic acid with the HSA-MGO complex was performed. RESULT: In vivo experiments using streptozotocin-induced diabetic rats treated with SC preparations exhibited improved biochemical parameters, preserved kidney function, and reduced glycation adduct formation in a dose-dependent manner. Furthermore, SC preparations downregulated inflammatory mediators such as RAGE, NF-κB, vascular endothelial growth factor (VEGF), and Tumor necrosis factor α (TNF-α) while upregulating the Nrf2-dependent antioxidant and detoxification pathways. They downregulated B-cell lymphoma 2 (Bcl-2) associated X-protein (BAX), C/EBP homologous protein (CHOP), Dynamin-related protein 1 (DRP1), and upregulated BCL 2 gene expression. Notably, SC preparations facilitated nuclear translocation of Nrf2, leading to the upregulation of antioxidant enzymes and the downregulation of oxidative stress markers. Molecular docking studies revealed favorable interactions between gallic (-5.26 kcal/mol) and ellagic acid (-4.71 kcal/mol) with the HSA-MGO complex. CONCLUSION: SC preparations mitigate renal cell apoptosis and mitochondrial dysfunction through Nrf2-dependent mechanisms.

In silico Profiling and Pharmacokinetic Modelling of Olivetol: Evaluating its Potential as a Therapeutic Agent for Diabetic Wound Healing.

BACKGROUND: Diabetic wound healing poses a significant challenge due to the intricate disruptions in cellular and molecular processes induced by hyperglycaemia, leading to delayed or impaired tissue repair. Computational techniques offer a promising avenue for unravelling the complexities of diabetic wound healing by elucidating the molecular mechanisms involved. METHODOLOGY: This study utilized in silico molecular docking and dynamics simulations to explore the potential therapeutic effectiveness of olivetol, a phenolic compound, in the context of diabetic wound healing. Furthermore, computational methodologies, encompassing pkCSM, Swiss ADME, OSIRIS® property explorer, PASS online web resource, and MOLINSPIRATION® software, were employed to forecast the pharmacokinetic properties, biological actions, and in vitro analyses, such as MTT and scratch assays, to evaluate the therapeutic effectiveness of olivetol in wound healing. RESULTS AND DISCUSSION: Our findings have revealed olivetol to be a promising candidate for targeting multiple pathways implicated in diabetic wound healing. Its ability to modulate inflammation, oxidative stress, extracellular matrix remodeling, angiogenesis, and cell signaling suggests a multifaceted approach to promoting effective wound repair. Moreover, olivetol has been found to demonstrate strong binding affinity with key MRSA target proteins, indicating its potential as an antimicrobial agent against MRSA infections in diabetic wounds. The in vitro MTT assay demonstrated cell viability with an IC50 value of 40.80 µM, highlighting its cytotoxicity potential. Additionally, the scratch assay confirmed promising wound healing activity, showcasing its effectiveness in promoting cell migration and closure. CONCLUSION: Olivetol emerges as a promising candidate for targeted interventions in non-healing diabetic wounds, particularly due to its ability to address prolonged inflammation, a common obstacle in diabetic wound healing.

α-Glucosidase Inhibiting Chromene Derivatives from Ageratum conyzoides L. Essential Oil Extracted via NADES-Assisted Hydrodistillation.

This work employed a green approach utilizing natural deep eutectic solvent (NADES)-assisted hydrodistillation for EO extraction from the aerial part of Ageratum conyzoides. Out of seven eutectic combinations used, glycerol-lactic acid (GLY:LA) (1:1) mixture significantly enhanced the yield from 0.78 mg/g (water as extraction media) to 1.00 mg/g. GC and GC-MS analysis revealed that EOs mainly contain (E)-ß-caryophyllene (15.2-25.3%), (E)-ß-farnesene (2.7-8.2 %), and notably, precocene-I (8.5-18.0 %) and precocene-II (31.8-51.4 %), which varied significantly across different extraction media. Further column chromatography-based purification of EO led to the isolation of two known chromene derivatives precocene-I (1) and precocene-II (2). Precocene-I exhibited potent anti-diabetic activity (IC50 0.26 mg/mL) compared to the standard drug acarbose. Among the EO samples, USK-N7, which had the highest percentage of precocene-I, showed the highest activity. The present study demonstrated the potential use of this weed plant as an anti-diabetic agent.

Analog Spiking U-Net integrating CBAM&ViT for medical image segmentation.

SNNs are gaining popularity in AI research as a low-power alternative in deep learning due to their sparse properties and biological interpretability. Using SNNs for dense prediction tasks is becoming an important research area. In this paper, we firstly proposed a novel modification on the conventional Spiking U-Net architecture by adjusting the firing positions of neurons. The modified network model, named Analog Spiking U-Net (AS U-Net), is capable of incorporating the Convolutional Block Attention Module (CBAM) into the domain of SNNs. This is the first successful implementation of CBAM in SNNs, which has the potential to improve SNN model's segmentation performance while decreasing information loss. Then, the proposed AS U-Net (with CBAM&ViT) is trained by direct encoding on a comprehensive dataset obtained by merging several diabetic retinal vessel segmentation datasets. Based on the experimental results, the provided SNN model achieves the highest segmentation accuracy in retinal vessel segmentation for diabetes mellitus, surpassing other SNN-based models and most ANN-based related models. In addition, under the same structure, our model demonstrates comparable performance to the ANN model. And then, the novel model achieves state-of-the-art(SOTA) results in comparative experiments when both accuracy and energy consumption are considered (Fig. 1). At the same time, the ablative analysis of CBAM further confirms its feasibility and effectiveness in SNNs, which means that a novel approach could be provided for subsequent deployment and hardware chip application. In the end, we conduct extensive generalization experiments on the same type of segmentation task (ISBI and ISIC), the more complex multi-segmentation task (Synapse), and a series of image generation tasks (MNIST, Day2night, Maps, Facades) in order to visually demonstrate the generality of the proposed method.

Near-infrared microscopy reveals diabetic nephropathy in ob/ob mice.

Diabetic nephropathy (DN) is a major cause of global kidney failure. While histological kidney biopsy is the gold standard for diagnosis, it primarily reveals tissue morphology. In contrast, near-infrared (NIR) microscopy offers a label-free method for detailed molecular characterization of kidney tissue. Hematoxylin and eosin-stained kidney tissue samples from 17 ob/ob mice with DN and 14 healthy mice were examined using Fourier transform-NIR microscopy. Four different spectra were obtained from both the mesangium and tubulus. NIR spectral analysis unveiled distinct differences in wavenumbers between DN-affected and healthy kidneys, notably in the carbohydrate and protein-associated region (5500-4200 cm-1). In the mesangium, DN tissue samples exhibited higher median values at 4235 cm-1, 4659 cm-1, 4844 cm-1, 4906 cm-1, and 5222 cm-1 compared to controls (P < 0.05, P < 0.01, P < 0.05, P < 0.05 and P < 0.001, respectively). In tubular spectra, higher median values were found at 4258 cm-1, 4659 cm-1, 5222 cm-1, and 5346 cm-1 in the DN group (P < 0.01, P < 0.05, P < 0.05 and P < 0.01, respectively). These spectral differences strongly correlated with metabolic, histologic, and urinary parameters, providing valuable DN progression insights. The classification model achieved a visible clustering between the control and DN group for both the mesangial and tubular measurements. NIR microscopy demonstrated significant spectral differences between DN and healthy kidney tissues in mice, hinting at its potential for providing chemical insights, aiding in more accurate diagnoses, and offering a foundation for further clinical exploration and potential therapeutic advancements in DN.

Systematic review and meta-analysis of the diagnostic accuracy of inflammatory markers for infected diabetic foot ulcer.

BACKGROUND: The aim was to evaluate the diagnostic value of ESR, CPR, PCT, and WBC in patients with infected diabetic foot ulcer (DFU). METHODS: The MEDLINE, Embase, BIOSIS, Cochrane databases, and Web of Knowledge databases were searched, without language restriction, to July 2023. Original studies were selected that reported the performance of ESR, CPR, PCT, and WBC in diagnosing infected DFU. To assess the diagnostic value of biomarkers for infected DFU, pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), and area under the summary receiver operating characteristic curve (ROC-AUC) were calculated. RESULTS: Ten studies with 765 patients were identified in our meta-analysis. The pooled sensitivity and specificity of ESR was 0.82 (95 % CI: 0.68-0.91) and 0.83 (95 % CI: 0.69-0.91) respectively. The pooled sensitivity and specificity of CRP was 0.81 (95 % CI: 0.65-0.91) and 0.91 (95 % CI: 0.79-0.96) respectively. The pooled sensitivity and specificity of PCT was 0.76 (95 % CI: 0.65-0.85) and 0.89 (95 % CI: 0.78-0.95) respectively. The pooled sensitivity and specificity of WBC was 0.75 (95 % CI: 0.64-0.83) and 0.79 (95 % CI: 0.67-0.88) respectively. CRP showed the best diagnostic accuracy at distinguishing infected DFU from noninfected DFU with an AUC of 0.93, followed by PCT (AUC of 0.89), ESR (AUC of 0.89), and WBC (AUC of 0.84). CONCLUSION: CPR levels had high efficiency in distinguishing infected DFU from noninfected DFU, followed by PCT, ESR and WBC. All of these biomarkers could be helpful for early diagnosis of infected DFU. New biomarkers for improving medical decision in diagnosis of infected DFU are highly desirable.

Diminished nuclear-localized ß-adrenoceptor signalling activates YAP to promote kidney fibrosis in diabetic nephropathy.

BACKGROUND AND PURPOSE: Diabetic nephropathy (DN) is a leading cause of chronic kidney disease (CKD), which is characterized by mesangial matrix expansion that involves dysfunctional mesangial cells (MCs). However, the underlying mechanisms remain unclear. This study aims to delineate the spatiotemporal contribution of adrenergic signalling in diabetic kidney fibrosis to reveal potential therapeutic targets. EXPERIMENTAL APPROACH: A model of diabetic nephropathy was induced by in db/db mice. Gene expression in kidneys was profiled by RNA-seq analyses, western blot and immunostaining. Subcellular-localized fluorescence resonance energy transfer (FRET) biosensors determined adrenergic signalling microdomains in MCs. Effects of oral rolipram, a phosphodiesterase 4 (PDE4) inhibitor, on the model were measured. KEY RESULTS: Our model exhibited impaired kidney function with elevated expression of adrenergic and fibrotic genes, including Adrb1, PDEs, Acta2 and Tgfß. RNA-seq analysis revealed that MCs with dysregulated YAP pathway were crucial to the extracellular matrix secretion in kidneys from diabetic nephropathy patients. In cultured MCs, TGF-ß promoted profibrotic gene transcription, which was regulated by nuclear-localized ß-adrenoceptor signalling. Mechanistically, TGF-ß treatment diminished nuclear-specific cAMP signalling in MCs and reduced PKA-dependent phosphorylation of YAP, leading to its activation. In parallel, db/db mouse kidneys showed increased expressions of PDE4B and PDE4D. Treatment with oral rolipram alleviated kidney fibrosis in db/db mice. CONCLUSION AND IMPLICATIONS: Diabetic nephropathy impaired nuclear-localized ß1-adrenoceptor-cAMP signalling microdomain through upregulating PDE4 expression, promoting fibrosis in MCs via PKA dephosphorylation-dependent YAP activation. Our results suggest PDE4 inhibition as a promising strategy for alleviating kidney fibrosis in diabetic nephropathy.

Multifunctional Hydrogel Microneedle Patches Modulating Oxi-inflamm-aging for Diabetic Wound Healing.

Oxidative stress, chronic inflammation, and immune senescence are important pathologic factors in diabetic wound nonhealing. This study loads taurine (Tau) into cerium dioxide (CeO2) to develop CeO2@Tau nanoparticles with excellent antioxidant, anti-inflammatory, and anti-aging properties. To enhance the drug penetration efficiency in wounds, CeO2@Tau is encapsulated in gelatin methacryloyl (GelMA) hydrogel to prepare CeO2@Tau@Hydrogel@Microneedle (CTH@MN) patch system. Microneedle technology achieves precise and efficient delivery of CeO2@Tau, ensuring their deep penetration into the wound tissue for optimal efficacy. Rigorous in vitro and in vivo tests have confirmed the satisfactory therapeutic effect of CTH@MN patch on diabetic wound healing. Mechanistically, CTH@MN attenuates oxidative damage and inflammatory responses in macrophages by inhibiting the ROS/NF-κB signaling pathway. Meanwhile, CTH@MN activated autophagy-mediated anti-aging activity, creating a favorable immune microenvironment for tissue repair. Notably, in a diabetic mouse wound model, the multifunctional CTH@MN patch significantly promotes wound healing by systematically regulating the oxidation-inflammation-aging (oxi-inflamm-aging) pathological axis. In conclusion, the in-depth exploration of the CTH@MN system in this study provides new strategies and perspectives for treating diabetic non-healing wounds.

Optimal tactics for surgical revascularisation in diabetic angiopathy of the lower limbs.

OBJECTIVE: Aim: This study aims to compare the efficacy of conservative treatment methods versus advanced surgical interventions, including revascularising automyelotransplantation and stem cell therapy, in improving vascular patency and the quality of life in patients with diabetic angiopathy. PATIENTS AND METHODS: Materials and Methods: The research analyzed 68 patients with angiopathies under medical supervision from January 2007 to December 2017 at the National Scientific Center of Surgery named after A.N. Syzganov. Participants, aged 4 to 49, were divided into two groups based on angiographic blood flow characteristics: one with accelerated and another with delayed blood flow. A comprehensive participant selection process was implemented to ensure a representative sample. Sensitivity analysis was conducted to validate the findings' robustness. RESULTS: Results: The main group demonstrated notable success in limb salvage, with 90.9% avoiding high limb amputation post-revascularising automyelotransplantation. Moreover, 16.7% of patients experienced healing of trophic ulcers and toe necrosis. The use of stem cells from adipose tissue and fetal tissue progenitor cells showed promising results in reducing pain and increasing pain-free walking distance, alongside the formation of collateral vascular networks. CONCLUSION: Conclusions: The study concludes that advanced surgical interventions and stem cell therapies significantly enhance treatment outcomes in patients with diabetic angiopathy compared to conventional conservative treatments. These findings highlight the potential of personalized and innovative approaches in managing vascular complications associated with diabetes, offering new avenues for reducing disability and improving patient quality of life. Future research should focus on further refining these therapeutic strategies and exploring their integration into clinical practice.

Mechanical Force on Hydrogel Implication on Enhanced Drug Release, Antibacterial, and M2 Macrophage Polarization: New Insights Alleviate Diabetic Wound Healing.

Diabetic foot ulcers/chronic wounds are difficult to treat because of dysfunctional macrophage response and decreased phenotype transition from the M1 to M2 status. This causes severe inflammation, less angiogenesis, microbial infections, and small deformation in wound beds, affecting the healing process. The commercial wound dressing material has limited efficacy, poor mechanical strength, extra pain, and new granulated tissue formed in a mesh of gauze. It is desired to create tough, skin-adhesive, antifouling, sustainable M2 phenotype-enabling, and mechanoresponsive drug-releasing hydrogel. To resolve this, zwitterionic poly(sulfobetaine methacrylate) (SB) incorporated with keratin-exfoliated MoS2 and bee-wax nanoparticles were developed to deliver phenytoin upon application of mechanical forces. Human hair keratin was used for exfoliation of MoS2, and bee-wax nanoparticles loaded with phenytoin were used as cross-linkers of SB hydrogel. The cross-linked SB-MO15-B hydrogel has high mechanical properties, with more tensile strength and strain of 118 kPa and 1485%. Under external mechanical force, hydrogel deformed to release phenytoin of 38% (tensile) and 24% (compressive), which was higher compared to static condition (12%). The penetration of phenytoin into skin tissue was also improved by the mechanical force applied to the hydrogel. SB-MO15-B hydrogel effectively activates the polarization of macrophages toward the M2 phenotype, promotes cell proliferation, and also shows superior antibacterial properties. In vivo results demonstrate that hydrogel rapidly promotes diabetic wound repair through fast antiinflammation and M2 macrophage polarization. Therefore, a robust mechanoresponsive hydrogel would provide a new strategy to deliver the drug and also tune the M2 macrophage polarization for chronic wound healing.

Role of EYP-1901 in neovascular age-related macular degeneration and diabetic eye diseases: review of Phase I/II trials.

EYP-1901 (Duravyu) has demonstrated promising outcomes in Phases I and II clinical trials for the treatment of neovascular age-related macular degeneration (nAMD) and diabetic macular edema (DME)/diabetic retinopathy. This innovative treatment capitalizes on the potent anti-angiogenic properties of vorolanib, an inhibitor that targets all isoforms of VEGF, effectively mitigating the pathological neovascularization and vascular permeability that underpin these retinal conditions. EYP-1901 is integrated with the Durasert drug delivery system to administer a sustained release of vorolanib directly to the posterior segment of the eye. This delivery system ensures a consistent therapeutic effect over an extended period and significantly reduces the frequency of clinical interventions required, offering a more convenient treatment regimen while maintaining patient safety.

Neovascular age-related macular degeneration (nAMD) and diabetic retinopathy (DR) are eye problems that can make you lose your sight. These eye problems happen when blood vessels in the eye do not work right. Right now, people need lots of shots in their eyes to treat it. EYP-1901 (Duravyu) is a new medicine that helps people with fewer shots in their eyes. It has two parts: one that helps the medicine last longer, and another that helps stop the problem in the eye. Early tests show it works well and helps people keep their sight with fewer treatments.

A biphasic drug-releasing microneedle with ROS scavenging and angiogenesis for the treatment of diabetic ulcers.

Diabetic ulcers are one of the common complications in diabetic patients. Delayed wound healing is associated with persistent pro-inflammatory M1 polarization, reduced angiogenesis and increased reactive oxygen species (ROS) in the microenvironment. Wound healing consists of multiple phases and therefore requires treatment tailored to each phase. In this study, a biphasic drug-releasing microneedle (MN) was fabricated to achieve early ROS scavenging and late accelerated angiogenesis to promote wound healing. Vascular endothelial growth factor (VEGF) was first encapsulated in methacryloylated sulfonated chitosan (SCSMA) microspheres (V@MP), and then V@MP was loaded into hyaluronic acid (HA) microneedles along with cerium dioxide nanoparticles (CONPs). Rapid dissolution of HA rapidly releases the CONPs to clear ROS, whereas the V@MP stays in the wound. SCSMA slow degradation prolongs the release of VEGF, thereby promoting angiogenesis. In vitro and in vivo studies have shown that this biphasic drug-releasing smart microneedle improves cell proliferation and migration, effectively scavenges ROS, promotes angiogenesis and tissue regeneration, and synergistically promotes M2 macrophage polarization. It provides a new delivery mode for nano-enzymes and growth factors that could be multifunctional and synergistic in the treatment of diabetic ulcers. STATEMENT OF SIGNIFICANCE: In our study, we present a microneedle (V@MP/C@MN) that can release drugs biphasically, which showed good repair ability in diabetic ulcer model. Large amounts of CONPs were rapidly released to alleviate oxidative stress during the inflammation of the wound, and V@MP stayed in the wound for a long period of time to release VEGF and promote angiogenesis in the late stage of wound healing. The results indicated that V@MP/C@MN could promote cell proliferation and migration, effectively scavenge ROS, promote angiogenesis and tissue regeneration, and synergistically promote M2 macrophage polarization, which could play a multifunctional and synergistic role in the treatment of diabetic ulcers.

Umbelliferone alleviates impaired wound healing and skin barrier dysfunction in high glucose-exposed dermal fibroblasts and diabetic skins.

Skin wound healing is a complex process involving various cellular and molecular events. However, chronic wounds, particularly in individuals with diabetes, often experience delayed wound healing, potentially leading to diabetic skin complications. In this study, we examined the effects of umbelliferone on skin wound healing using dermal fibroblasts and skin tissues from a type 2 diabetic mouse model. Our results demonstrate that umbelliferone enhances several crucial aspects of wound healing. It increases the synthesis of key extracellular matrix components such as collagen I and fibronectin, as well as proteins involved in cell migration like EVL and Fascin-1. Additionally, umbelliferone boosts the secretion of angiogenesis factors VEGF and HIF-1α, enhances the expression of cell adhesion proteins including E-cadherin, ZO-1, and Occludin, and elevates levels of skin hydration-related proteins like HAS2 and AQP3. Notably, umbelliferone reduces the expression of HYAL, thereby potentially decreasing tissue permeability. As a result, it promotes extracellular matrix deposition, activates cell migration and proliferation, and stimulates pro-angiogenic factors while maintaining skin barrier functions. In summary, these findings underscore the therapeutic potential of umbelliferone in diabetic wound care, suggesting its promise as a treatment for diabetic skin complications. KEY MESSAGES: Umbelliferone suppressed the breakdown of extracellular matrix components in the skin dermis while promoting their synthesis. Umbelliferone augmented the migratory and proliferative capacities of fibroblasts. Umbelliferone activated the release of angiogenic factors in diabetic wounds, leading to accelerated wound healing. Umbelliferone bolstered intercellular adhesion and reinforced the skin barrier by preventing moisture loss and preserving skin hydration.

New insight for SS­31 in treating diabetic cardiomyopathy: Activation of mitoGPX4 and alleviation of mitochondria­dependent ferroptosis.

SS­31 is a mitochondria­targeting antioxidant that exhibits promising therapeutic potential for various diseases; however, its protective effect on diabetic cardiomyopathy (DCM) remains to be elucidated. At present, SS­31 is considered not only to mitigate cardiolipin oxidative damage, but also to alleviate ferroptosis. The present study aimed to explore SS­31 as a potential therapeutic strategy for improving DCM by alleviating mitochondria­dependent ferroptosis. In vitro, H9C2 cells were exposed to 35 mM glucose for 24 h to induce high glucose damage, then were simultaneously treated with 10, 20 or 50 µM SS­31. In addition, in vivo studies were conducted on diabeticC57BL/6J mice, which were induced to develop DCM over 4 weeks, followed by intraperitoneal injections with 2.5 mg/kg/day SS­31 for a further 4 weeks. The elevation of serum lactate dehydrogenase and creatine kinase isoenzymes, the reduction of fractional shortening and ejection fraction, the rupture of myocardial fibers and the deposition of collagen indicated the establishment of the DCM mouse model. The results of the present study indicated that SS­31 effectively alleviated these pathological changes and exhibited significant efficacy in ameliorating mitochondrial dysfunction, such as by promoting adenosine triphosphate generation, improving mitochondrial membrane potential and restoring the mitochondrial ultrastructure. Further experiments suggested that activation of the mitochondrial glutathione (mitoGSH)/mitochondrial glutathione peroxidase 4 (mitoGPX4) pathway and the elimination of mitochondrial ferrous ions may constitute the mechanisms by which SS­31 treats DCM. Therefore, the present study revealed that mitochondria­dependent ferroptosis could serve as a pathogenic mechanism of DCM and highlighted that the cardioprotective effects of SS­31 against DCM involves activation of the mitoGSH/mitoGPX4 pathway. Due to the safety profile and cardiac protective effects of SS­31, SS­31 was considered a promising strategy for treating DCM.

'Whatever the GP says, is what I'll do'-A qualitative study of patient perspectives in accessing primary eye care for type 2 diabetes.

INTRODUCTION: To investigate the perspectives of people accessing a general medical practitioner (GP)-optometry model of collaborative care that was established to increase access to diabetes eye care. METHODS: Qualitative study of patient barriers and facilitators to accessing primary diabetes eye care located in a metropolitan area in Australia. One-on-one interviews were recorded, transcribed and thematically analysed using a determinant framework on patient-centred access to health care. RESULTS: Twenty-four people with type 2 diabetes, including 15 males and 9 females, who accessed the service between September 2021 and June 2022 agreed to participate. Mean (SD) age of the participants was 52 (12) years and 50% had been diagnosed with diabetes for <2 years. Facilitators to accessing diabetes eye care included a referral from a GP or GP nurse, fee-free consultations, availability of after-hours appointments and short waiting times. Barriers to access included perceived out-of-pocket costs, competing responsibilities and lack of awareness of diabetic retinopathy screening recommendations. CONCLUSION: Considering diabetic retinopathy may present asymptomatically, primary health practitioners (optometrists and GPs) are well positioned to raise patient awareness of the importance of routine eye examinations. In Australia, access to routine screening could be facilitated by fee-free eye checks and personalised text message reminders implemented at a health system level.

Gallic Acid Alleviates Glucolipotoxicity-Induced Nephropathy by miR-709-NFE2L2 Pathway in db/db Mice on a High-Fat Diet.

BACKGROUND: Type 2 diabetes mellitus (T2DM) has become a major global issue, with diabetic nephropathy (DN) ranking as one of its most serious complications. The involvement of microRNAs (miRNAs) in the progression of T2DM and DN is an area of active research, yet the molecular mechanisms remain only partially elucidated. Gallic acid (GA), a naturally occurring polyphenolic compound found in various plants such as bearberry leaves, pomegranate root bark, tea leaves, and oak bark, has demonstrated antioxidant properties that may offer therapeutic benefits in DN. METHODS AND RESULTS: The study aimed to investigate the therapeutic potential of GA in mitigating kidney fibrosis, oxidative stress and inflammation, within a glucolipotoxicity-induced diabetic model using db/db mice. The mice were subjected to a high-fat diet to induce glucolipotoxicity, a condition that mimics the metabolic stress experienced in T2DM. Through microarray data analysis, we identified a significant upregulation of renal miR-709a-5p in the diabetic mice, linking this miRNA to the pathological processes underlying DN. GA treatment was shown to boost the activity of including catalase, essential antioxidant enzymes, glutathione peroxidase and superoxide dismutase, while also reducing lipid accumulation in the kidneys, indicating a protective effect against HFD-induced steatosis. In vitro experiments further revealed that silencing miR-709a-5p in MES-13 renal cells led to a reduction in oxidative stress markers, notably lowering lipid peroxidation markers, and significantly boosting the activity of antioxidant defenses. Additionally, NFE2L2, a crucial transcription factor involved in the antioxidant response, was identified as a direct target of miR-709a-5p. The downregulation of miR-709a-5p by GA suggests that this polyphenol mitigates glucolipotoxicity-induced lipogenesis and oxidative stress, potentially offering a novel therapeutic avenue for managing diabetic fatty liver disease and DN. CONCLUSION: Our findings indicate that GA exerts a protective effect in DN by downregulating miR-709a-5p, thereby alleviating oxidative stress through the suppression of NFE2L2. The results highlight the potential of GA and NFE2L2-activating agents as promising therapeutic strategies in the treatment of DN.

Short pulse grid and subthreshold micropulse laser (the sandwich grid) plus intravitreal ranibizumab for the treatment of diabetic macular edema.

OBJECTIVE: To investigate the effects of two laser treatment procedures combined, short pulse grid laser (SP) and subthreshold micropulse laser (MP) (the sandwich grid [SWG] technique), plus intravitreal ranibizumab (IVR) on central subfield thickness (CSFT), best-corrected visual acuity (BCVA) and macular sensitivity in patients with diabetic macular edema (DME). METHODS: Forty-five eyes (of 33 patients) with center-involving DME were treated with the SWG laser technique plus IVR and followed for 12 months. Laser treatment was performed at baseline: SP laser spots were placed in a grid pattern in the macular area (500 µm from the fovea) according to the extension of DME; subsequently, MP laser was delivered up to the edge of the fovea. MP laser re-treatment sessions could be performed every 3 months if DME was present and CSFT was ≥ 300 µm on SD-OCT. IVR injection was performed at baseline and repeated monthly if CSFT > 300µm. Preoperatively and monthly, ophthalmological examination was performed including measurements of BCVA, CSFT, and macular sensitivity. RESULTS: One-year follow-up data is available for 37 eyes of 27 patients. Mean ± SE CSFT (µm) was 509.36 ± 25.14 and 325.76 ± 15.34 at baseline and 12 months, respectively. A significant reduction in mean CSFT was observed at all study visits compared to baseline (p < 0.001). Mean ± SE BCVA (logMAR) was 0.62 ± 0.04 and 0.45 ± 0.04 at baseline and 12 months, respectively. A significant improvement in mean BCVA was observed at all study visits compared to baseline (p < 0.001). Mean ± SE macular sensitivity (dB) was 17.85 ± 0.80 and improved to 19.05 ± 0.59 after one year of follow-up (p = 0.006). The mean number of IVR injections was 8.29 ± 0.63. The mean number of MP laser procedures including the initial SWG laser session was 3.67 ± 0.22. No ocular or systemic adverse effects were observed. CONCLUSION: The SWG laser technique plus IVR was associated with significant improvement in macular edema, BCVA, and macular sensitivity in patients with center-involving DME. CLINICAL TRIAL NUMBER (CAAE): 22969019.4.0000.5440.