Inflammation: The Link between Neural and Vascular Impairment in the Diabetic Retina and Therapeutic Implications

Immunomodulatory effects of Kaempferol on microglial and Macrophage cells during the progression of diabetic retinopathy

BACKGROUND

Diabetic retinopathy (DR) stands as a prevalent secondary complication of diabetes, notably Type 1 Diabetes Mellitus (T1D), characterized by immune system involvement potentially impacting the retinal immune response mediated by microglia. Early stages of DR witness blood-retinal barrier permeabilization, facilitating peripheral immune cell interaction with the retinal immune system. Kaempferol (Kae), known for its potent anti-inflammatory activity, presents a promising avenue in DR treatment by targeting the immune mechanisms underlying its onset and progression. Our investigation delves into the molecular intricacies of innate immune cell interaction during DR progression and the attenuation of inflammatory processes pivotal to its pathology.

METHODS

Employing in vitro studies, we exposed HAPI microglial and J774.A1 macrophage cells to pro-inflammatory stimuli in the presence or absence of Kae. Ex vivo and in vivo experiments utilized BB rats, a T1D animal model. Retinal explants from BB rats were cultured with Kae, while intraperitoneal Kae injections were administered to BB rats for 15 days. Quantitative PCR, Western blotting, immunofluorescence, and Spectral Domain - Optical Coherence Tomography (SD-OCT) facilitated survival assessment, cellular signaling analysis, and inflammatory marker determination.

RESULTS

Results demonstrate Kae significantly mitigates inflammatory processes across in vitro, ex vivo, and in vivo DR models, primarily targeting immune cell responses. Kae administration notably inhibits proinflammatory responses during DR progression while promoting an anti-inflammatory milieu, chiefly through microglia-mediated synthesis of Arginase-1 and Hemeoxygenase-1(HO-1). In vivo, Kae administration effectively preserves retinal integrity amid DR progression.

CONCLUSIONS

Our findings elucidate the interplay between retinal and systemic immune cells in DR progression, underscoring a differential treatment response predominantly orchestrated by microglia's anti-inflammatory action. Kae treatment induces a phenotypic and functional shift in immune cells, delaying DR progression, thereby spotlighting microglial cells as a promising therapeutic target in DR management.

In Silico Design, Synthesis, and Evaluation of Novel Enantiopure Isoxazolidines as Promising Dual Inhibitors of α-Amylase and α-Glucosidase

Isoxazolidine derivatives were designed, synthesized, and characterized using different spectroscopic techniques and elemental analysis and then evaluated for their ability to inhibit both α-amylase and α-glucosidase enzymes to treat diabetes. All synthesized derivatives demonstrated a varying range of activity, with IC50 values ranging from 53.03 ± 0.106 to 232.8 ± 0.517 μM (α-amylase) and from 94.33 ± 0.282 to 258.7 ± 0.521 μM (α-glucosidase), revealing their high potency compared to the reference drug, acarbose (IC50 = 296.6 ± 0.825 µM and 780.4 ± 0.346 µM), respectively. Specifically, in vitro results revealed that compound 5d achieved the most inhibitory activity with IC50 values of 5.59-fold and 8.27-fold, respectively, toward both enzymes, followed by 5b. Kinetic studies revealed that compound 5d inhibits both enzymes in a competitive mode. Based on the structure-activity relationship (SAR) study, it was concluded that various substitution patterns of the substituent(s) influenced the inhibitory activities of both enzymes. The server pkCSM was used to predict the pharmacokinetics and drug-likeness properties for 5d, which afforded good oral bioavailability. Additionally, compound 5d was subjected to molecular docking to gain insights into its binding mode interactions with the target enzymes. Moreover, via molecular dynamics (MD) simulation analysis, it maintained stability throughout 100 ns. This suggests that 5d possesses the potential to simultaneously target both enzymes effectively, making it advantageous for the development of antidiabetic medications.

Exploring the Correlation Between the Systemic Immune Inflammation Index (SII), Systemic Inflammatory Response Index (SIRI), and Type 2 Diabetic Retinopathy

Purpose

Systemic immune inflammation index (SII), systemic inflammatory response index (SIRI) are new inflammation indicators calculated after integrating multiple indicators in blood routine. This study aims to investigate the correlation between the SII, SIRI and type 2 diabetic retinopathy (T2DR) and the diagnostic significance of these indices in T2DR.

Patients and Methods

A retrospective analysis involved 500 patients diagnosed with type 2 diabetes (T2DM), categorized into two groups based on fundus examination results: the non-diabetic retinopathy group (NDR, n=256) and the diabetic retinopathy group (DR, n=244). We calculated SII and SIRI, and analyzed their associations with T2DR.

Results

The DR group exhibited significantly higher SII and SIRI values compared to the NDR group (P<0.001). Mantel-Haenszel's chi-square trend analysis revealed a notable linear trend (P<0.001) between SII, SIRI, and DR. SII and SIRI exhibited moderate positive correlations with DR, (r=0.354, P<0.001; r=0.469, P<0.001), respectively. Binary logistic regression analysis identified SII and SIRI as independent risk factors for DR. Restrictive cubic spline analysis demonstrated a significant linear relationship between SII and DR (P total trend <0.001, P nonlinear = 0.0657). Stratification by gender indicated that SII is more sensitive to the onset of DR in men. A significant nonlinear relationship was observed between SIRI and DR (P total trend <0.001, P nonlinear = 0.0025), with no gender-related differences in SIRI's association with DR. ROC curve analysis demonstrated that the combined use of SII and SIRI achieved the highest diagnostic accuracy for DR, with an AUC of 0.782, 74.6% sensitivity, and 69.9% specificity.

Conclusion

Our findings suggested that SII and SIRI as independent risk factors for DR. The high accuracy of SII combined with SIRI in diagnosing DR underscores their potential as early biological indicators for DR diagnosis.