Anti-Protease Activity Deficient Secretory Leukocyte Protease Inhibitor (SLPI) Exerts Cardioprotective Effect against Myocardial Ischaemia/Reperfusion

The secretory leukocyte protease inhibitor (SLPI) in pathophysiology of non-communicable diseases: Evidence from experimental studies to clinical applications

Non-communicable diseases (NCDs) are a worldwide health issue because of their prevalence, negative impacts on human welfare, and economic costs. Protease enzymes play important roles in viral and NCD diseases. Slowing disease progression by inhibiting proteases using small-molecule inhibitors or endogenous inhibitory peptides appears to be crucial. Secretory leukocyte protease inhibitor (SLPI), an inflammatory serine protease inhibitor, maintains protease/antiprotease balance. SLPI is produced by host defense effector cells during inflammation to prevent proteolytic enzyme-induced tissue damage. The etiology of noncommunicable illnesses is linked to SLPI's immunomodulatory and tissue regeneration roles. Disease phases are associated with SLPI levels and activity changes in regional tissue and circulation. SLPI has been extensively evaluated in inflammation, but rarely in NCDs. Unfortunately, the thorough evaluation of SLPI's pathophysiological functions in NCDs in multiple research models has not been published elsewhere. In this review, data from PubMed from 2014 to 2023 was collected, analysed, and categorized into in vitro, in vivo, and clinical studies. According to the review, serine protease inhibitor (SLPI) activity control is linked to non-communicable diseases (NCDs) and other illnesses. Overexpression of the SLPI gene and protein may be a viable diagnostic and therapeutic target for non-communicable diseases (NCDs). SLPI is also cytoprotective, making it a unique treatment. These findings suggest that future research should focus on these pathways using advanced methods, reliable biomarkers, and therapy approaches to assess susceptibility and illness progression. Implications from this review will help pave the way for a new therapeutic target and diagnosis marker for non-communicable diseases.

Gelatin-coated silicon oxide nanoparticles encapsulated recombinant human secretory leukocyte protease inhibitor (rhSLPI) reduced cardiac cell death against an in vitro simulated ischaemia/reperfusion injury

Ischemic Heart Disease (IHD) is the main global cause of death. Previous studies indicated that recombinant human secretory leukocyte protease inhibitor (rhSLPI) exhibits a cardioprotective effect against myocardial ischaemia/reperfusion (I/R) injury. However, SLPI has a short half-life in vivo due to digestion by protease enzymes in circulation. The application of nanoparticle encapsulation could be beneficial for SLPI delivery. Several types of nanoparticles have been developed to encapsulate SLPI and applied in some disease models. However, silica nanoparticles for rhSLPI delivery, particularly on myocardial I/R injury, have never been studied. In this study, we aimed to fabricate gelatin-covered silica nanoparticles (GSNPs) to encapsulate rhSLPI and cardioprotective effect of GSNP-SLPI against an in vitro simulated ischaemia/reperfusion (sI/R). Silica dioxide nanoparticles (SNPs) were fabricated followed by incubation with 0.33 mg/mL of rhSLPI. Then, SNPs containing rhSLPI were coated with gelatin (GSNPs). The GSNPs and rhSLPI-GSNPs were characterized by particle size, zeta potential, and morphology scanning electron microscope (SEM). The concentration of rhSLPI in rhSLPI-GSNPs and drug release was determined by ELISA. Then, cytotoxicity and cardioprotective effect were determined by incubation of GSNPs or rhSLPI-GSNPs with rat cardiac myoblast cell line (H9c2) subjected to simulated ischaemia/reperfusion (sI/R). The results showed the particle size of SNPs, GSNPs, and rhSLPI-GSNPs was 273, 300, and 301 nm, with a zeta potential of -57.21, -22.40, and -24.50 mV, respectively. One milligram of rhSLPI-GSNPs contains 235 ng of rhSLPI. The rhSLPI-GSNPs showed no cytotoxicity on cardiac cells. Treatment with 10 μg/ml of rhSLPI-GSNPs could significantly reduce sI/R induced cardiac cell injury and death. In conclusion, this is the first study to show successful of fabricating novel rhSLPI-encapsulating gelatin-covered silica nanoparticles (rhSLPI-GSNPs) and the cardioprotective effects of rhSLPI-GSNPs against cardiac cell injury and death from myocardial ischaemia/reperfusion.