Secretory Leukocyte Protease Inhibitor Research Articles

Levels of Lysozyme and SLPI in Bronchoalveolar Lavage: Exploring Their Role in Interstitial Lung Disease.

Interstitial lung diseases (ILDs) are characterized by inflammation or fibrosis of the pulmonary parenchyma. Despite the involvement of immune cells and soluble mediators in pulmonary fibrosis, the influence of antimicrobial peptides (AMPs) remains underexplored. These effector molecules display a range of activities, which include immunomodulation and wound repair. Here, we investigate the role of AMPs in the development of fibrosis in ILD. We compare the concentration of different AMPs and different cytokines in 46 fibrotic (F-ILD) and 17 non-fibrotic (NF-ILD) patients by ELISA and using peripheral blood mononuclear cells from in vitro stimulation in the presence of lysozyme or secretory leukocyte protease inhibitor (SLPI) from 10 healthy donors. We observed that bronchoalveolar lavage (BAL) levels of AMPs were decreased in F-ILD patients (lysozyme: p < 0.001; SLPI: p < 0.001; LL-37: p < 0.001; lactoferrin: p = 0.47) and were negatively correlated with levels of TGF-β (lysozyme: p = 0.02; SLPI: p < 0.001) and IL-17 (lysozyme: p < 0.001; SLPI: p < 0.001). We observed that lysozyme increased the percentage of CD86+ macrophages (p < 0.001) and the production of TNF-α (p < 0.001). We showed that lysozyme and SLPI were associated with clinical parameters (lysozyme: p < 0.001; SLPI: p < 0.001) and disease progression (lysozyme: p < 0.001; SLPI: p = 0.01). These results suggest that AMPs may play an important role in the anti-fibrotic response, regulating the effect of pro-fibrotic cytokines. In addition, levels of lysozyme in BAL may be a potential biomarker to predict the progression in F-ILD patients.

Synthesis of secretory leukocyte protease inhibitor using cell-free protein synthesis system.

Secretory leukocyte protease inhibitor (SLPI) functions as a protease inhibitor that modulates excessive proteolysis in the body, exhibits broad-spectrum antimicrobial activity, regulates inflammatory responses, and plays an important role in the innate immunity. The purpose of the study was to artificially synthesize a SLPI, an antimicrobial peptide, and investigate its effect on antimicrobial activity against Porphyromonas gingivalis and interleukin-6 (IL-6) production. SLPI protein with a molecular weight of approximately 13kDa was artificially synthesized using a cell-free protein synthesis (CFPS) system and investigated by western blotting and enzyme-linked immunosorbent assay (ELISA). Disulfide bond isomerase in the protein synthesis mixture increased the amount of SLPI synthesized. The synthesized SLPI (sSLPI) protein was purified and its antimicrobial activity was investigated based on the growth of Porphyromonas gingivalis and bacterial adhesion to oral epithelial cells. The effect of sSLPI on IL-6 production in human periodontal ligament fibroblasts (HPLFs) was examined by ELISA. Our results showed that sSLPI significantly inhibited the growth of Porphyromonas gingivalis and bacterial adhesion to oral epithelial cells and further inhibited IL-6 production by HPLFs. These results suggested that SLPI artificially synthesized using the CFPS system may play a role in the prevention of periodontal diseases through its antimicrobial and anti-inflammatory effects.

Exploration of immune cell heterogeneity by single-cell RNA sequencing and identification of secretory leukocyte protease inhibitor as an oncogene in pancreatic cancer.

Clinical outcomes remain unsatisfactory in patients with pancreatic cancer (PAC). In this study, through single-cell sequencing, we identified eight cell subpopulations in the tumor microenvironment (TME). Redimensional clustering of epithelial cells, myeloid cells, and cancer-associated fibroblasts (CAFs) revealed heterogeneity in the TME of PAC. Intercellular communication analysis showed strong direct interactions between matrix CAFs, inflammatory CAFs, and epithelial cells. Additionally, we found that the SPP1-associated pathway was activated in monocytes, whereas the vascular endothelial growth factor-associated pathway was activated in epithelial cells. These results improve the understanding of the TME of pancreatic cancer and provide a foundation for further studies on intratumoral heterogeneity. In addition, differentially expressed gene secretory leukocyte protease inhibitor (SLPI) was identified in pancreatic cancer, and functional experiments showed that SLPI had a strong impact on cell viability and apoptosis, which offers a potential therapy target for pancreatic cancer.

Secretory leukocyte protease inhibitor as a novel predictive biomarker in patients with diabetic kidney disease.

Secretory leukocyte protease inhibitor (SLPI) is a multifunctional protein involved in the chronic inflammatory process, implicated in the pathogenesis of diabetic kidney disease (DKD). However, its potential as a diagnostic and prognostic biomarker of DKD has yet to be evaluated. This study explored the clinical utility of SLPI in the diagnosis and prognosis of renal endpoint events in patients with DKD. A multi-center cross-sectional study comprised of 266 patients with DKD and a predictive cohort study comprised of 120 patients with stage IV DKD conducted between December 2016 and January 2022. The clinical parameters were collected for statistical analysis, a multivariate Cox proportional hazards model was used to evaluate the independent risk factors for renal endpoints. Serum SLPI levels gradually increased with DKD progression (p<0.01). A significant correlation was observed between serum SLPI levels and renal function in patients with DKD. The mean follow-up duration in this cohort study was 2.32 ± 1.30 years. Multivariate Cox regression analysis showed SLPI levels≥51.61ng/mL (HR=2.95, 95% CI[1.55, 5.60], p<0.01), 24h urinary protein levels≥3500 mg/24h (HR=3.02, 95% CI[1.66, 5.52], p<0.01), Alb levels<30g/l (HR=2.19, 95% CI[1.12, 4.28], p<0.05), HGB levels<13g/dl (HR=3.18, 95% CI[1.49, 6.80], p<0.01), and urea levels≥7.1 mmol/L (HR=8.27, 95% CI[1.96, 34.93], p<0.01) were the independent risk factors for renal endpoint events in DKD patients. Serum SLPI levels increased with DKD progression and were associated with clinical parameters of DKD. Moreover, elevated SLPI levels showed potential prognostic value for renal endpoint events in individuals with DKD. These findings validate the results of previous studies on SLPI in patients with DKD and provide new insights into the role of SLPI as a biomarker for the diagnosis and prognosis of DKD that require validation.

Secretory leukocyte protease inhibitor protects against severe urinary tract infection in mice.

Millions suffer from urinary tract infections (UTIs) worldwide every year with women accounting for the majority of cases. Uropathogenic Escherichia coli (UPEC) causes most of these primary infections and leads to 25% becoming recurrent or chronic. To repel invading pathogens, the urinary tract mounts a vigorous innate immune response that includes the secretion of antimicrobial peptides (AMPs), rapid recruitment of phagocytes, and exfoliation of superficial umbrella cells. Here, we investigate secretory leukocyte protease inhibitor (SLPI), an AMP with antiprotease, antimicrobial, and immunomodulatory functions, known to play protective roles at other mucosal sites, but not well characterized in UTIs. Using a preclinical model of UPEC-caused UTI, we show that urine SLPI increases in infected mice and that SLPI is localized to bladder epithelial cells. UPEC-infected SLPI-deficient (Slpi-/-) mice suffer from higher urine bacterial burdens, prolonged bladder inflammation, and elevated urine neutrophil elastase (NE) levels compared to wild-type (Slpi+/+) controls. Combined with bulk bladder RNA sequencing, our data indicate that Slpi-/- mice have a dysregulated immune and tissue repair response following UTI. We also measure SLPI in urine samples from a small group of female subjects 18-49 years old and find that SLPI tends to be higher in the presence of a uropathogen, except in patients with a history of recent or recurrent UTI, suggesting a dysregulation of SLPI expression in these women. Taken together, our findings show SLPI promotes clearance of UPEC in mice and provides preliminary evidence that SLPI is likewise regulated in response to uropathogen exposure in women.IMPORTANCEAnnually, millions of people suffer from urinary tract infections (UTIs) and more than $3 billion are spent on work absences and treatment of these patients. While the early response to UTI is known to be important in combating urinary pathogens, knowledge of host factors that help curb infection is still limited. Here, we use a preclinical model of UTI to study secretory leukocyte protease inhibitor (SLPI), an antimicrobial protein, to determine how it protects the bladder against infection. We find that SLPI is increased during UTI, accelerates the clearance of bacteriuria, and upregulates genes and pathways needed to fight an infection while preventing prolonged bladder inflammation. In a small clinical study, we show SLPI is readily detectable in human urine and is associated with the presence of a uropathogen in patients without a previous history of UTI, suggesting SLPI may play an important role in protecting from bacterial cystitis.

Recombinant human secretory leukocyte protease inhibitor (rhSLPI) coated titanium enhanced human osteoblast adhesion and differentiation

Osseointegration is vital to success in orthopedic and dental reconstructions with implanted materials. The bone matrix or cells—particularly osteoblasts—are required to achieve functional contact on the implant surface. Osteoblast induction is therefore essential for osteogenesis to occur. Enhancement of osteoblast adhesion, proliferation, and differentiation, particularly by implant surface modifications, have been found challenging to develop. Secretory Leukocyte Protease Inhibitor (SLPI), a cation ionic protein with anti-inflammatory and anti-bacterial activities, showed activation in osteoblast proliferation and differentiation. However, the effects of coating recombinant human (rh) SLPI on a titanium alloy surface on human osteoblast adhesion, proliferation, and differentiation has never been investigated. In this study, titanium alloys (Ti–6Al–4V) were coated with rhSLPI, while human osteoblast adhesion, proliferation, differentiation, actin cytoskeletal organization, and gene expressions involved in cell adhesion and differentiation were investigated. The results indicate that coating titanium with 10–100 µg/ml rhSLPI enhanced the physical properties of the Ti surface and enhanced human osteoblast (hFOB 1.19) cell adhesion, activated actin dynamic, enhanced adhesive forces, upregulated integrins α1, α2, and α5, enhanced cell proliferation, mineralization, alkaline phosphatase activity, and upregulated ALP, OCN, and Runx2. This is the first study to demonstrate that coating SLPI on titanium surfaces enhances osseointegration and could be a candidate molecule for surface modification in medical implants.

Salivary concentrations of secretory leukocyte protease inhibitor and matrix metallopeptidase-9 following a single bout of exercise are associated with intensity and hydration status.

To investigate the effects of exercise on salivary concentrations of inflammatory markers by analyzing a panel of 25 inflammatory markers in subjects who had participated in bicycle ergometer tests varying in workload and hydration status. Fifteen healthy young men (20-35 years) had performed 4 different exercise protocols of 1 hour duration in a randomly assigned cross-over design, preceded by a rest protocol. Individual workloads depended on participant's pre-assessed individual maximum workload (Wmax): rest (protocol 1), 70% Wmax in hydrated (protocol 2) and dehydrated (protocol 3) state, 50% Wmax (protocol 4) and intermittent 85%/55% Wmax in 2 min blocks (protocol 5). Saliva samples were collected before (T0) and immediately after exercise (T1), and at several time points after exercise (2 hours (T3), 3 hours (T4), 6 hours (T5) and 24 hours (T6)). Secretory Leukocyte Protease Inhibitor (SLPI), Matrix Metallopeptidase-9 (MMP-9) and lactoferrin was analyzed using a commercial ELISA kit, a panel of 22 cytokines and chemokines were analyzed using a commercial multiplex immunoassay. Data was analyzed using a multilevel mixed linear model, with multiple test correction. Among a panel of 25 inflammatory markers, SLPI concentrations were significantly elevated immediately after exercise in all protocols compared to rest and higher concentrations reflected the intensity of exercise and hydration status. MMP-9 showed a significant increase in the 70% Wmax dehydrated, 50% Wmax and intermittent protocols. Salivary concentrations of SLPI and MMP-9 seem associated with exercise intensity and hydration status and may offer non-invasive biomarkers to study (local) inflammatory responses to different exercise intensities in human studies.

Стан локального цервікального імунітету в жінок із непліддям

Purpose - to study certain indicators of local immunity in women with infertility of various origins and early cervical lesions Materials and methods. The state of local cervical immunity was examined in 496 women, who were divided into groups depending on the cause of infertility, and each group was divided into subgroups A and B depending on the presence of cervical epithelial lesions. 128 women in the Group I had an endocrine cause, 122 patients in the Group II had a tubal-peritoneal factor of infertility, and 121 patients in the Group III had a male factor of fertility disorder. 125 healthy women formed the control group (CG). Subgroup A included women with NILM liquid cytology results: IA - 100 women, IIA - 70, IIIA - 68, GCA - 88. Subgroups B included women with ASC-US (atypical squamous cells of undetermined significance), LSIL (low-grade squamous intraepithelial lesion) and HSIL (high-grade squamous intraepithelial lesion): IB - 28 patients, IIB - 52, IIIB - 53, CGB - 37. In all patients, the content of interleukin-8 and -6 (IL-8, IL-6), lactoferrin and secretory leukocyte proteinase inhibitor in the material obtained for liquid cytology was determined by polymerase chain reaction. Results. In all patients with infertility, an increased concentration of secretory leukocyte proteinase inhibitor (from 314.1 to 398.7 pg/ml) and a decreased lactoferrin content (from 13.6 to 28.6 pg/ml) were found compared to the group of healthy women (114.8 and 64.8 pg/ml, respectively). In women with tubal and peritoneal infertility and male infertility, higher concentrations of IL-8 were found (659.9 to 878.8 pg/ml) than in the group of endocrine infertility (302.9 pg/ml) and in the group of healthy women (282.4 pg/ml). Conclusions. IL-8 content in cervical mucus is probably higher in women with tubal-peritoneal infertility (838 pg/ml) and male infertility (659.9 pg/ml) than in healthy women (289.4 pg/ml) and in women with endocrine infertility (302.3 pg/ml). The content of secretory inhibitor of leukocyte proteinase in cervical mucus was increased in all patients with infertility, regardless of its cause (from 314.1 pg/ml to 398.9 pg/ml), in the group of healthy women - 144.8 pg/ml. 3. The content of lactoferrin in the mucus of the cervical canal was reduced in all patients with impaired fertility (from 13.6 pg/ml to 28.6 pg/ml), in the group of healthy women - 64.8 pg/ml. The research was carried out in accordance with the principles of the Helsinki Declaration. The study protocol was approved by the Local Ethics Committee of the participating institution. The informed consent of the patient was obtained for conducting the studies. No conflict of interests was declared by the author.

Decoding the endometrial niche of Asherman’s Syndrome at single-cell resolution

Asherman’s Syndrome is characterized by intrauterine adhesions or scarring, which cause infertility, menstrual abnormalities, and recurrent pregnancy loss. The pathophysiology of this syndrome remains unknown, with treatment restricted to recurrent surgical removal of intrauterine scarring, which has limited success. Here, we decode the Asherman’s Syndrome endometrial cell niche by analyzing data from over 200,000 cells with single-cell RNA-sequencing in patients with this condition and through in vitro analyses of Asherman’s Syndrome patient-derived endometrial organoids. Our endometrial atlas highlights the loss of the endometrial epithelium, alterations to epithelial differentiation signaling pathways such as Wnt and Notch, and the appearance of characteristic epithelium expressing secretory leukocyte protease inhibitor during the window of implantation. We describe syndrome-associated alterations in cell-to-cell communication and gene expression profiles that support a dysfunctional pro-fibrotic, pro-inflammatory, and anti-angiogenic environment.

Secretory leucocyte protease inhibitor (SLPI) as an adjunct prognostic biomarker for canine pyometra.

Pyometra is a potentially life-threatening condition that affects intact female dogs in their middle to advance age. Timely diagnosis and appropriate treatment are critical for the survival of patients, especially when pyometra advances to sepsis. This study aimed to investigate the prognostic potential of certain haematology, serum biochemical and inflammatory biomarker, secretory leucocyte protease inhibitor (SLPI) for pyometra in bitches (n = 41). Blood samples were collected after clinical diagnosis of pyometra for haematology and serum biochemistry. Based on the prognosis following medical/surgical treatment, animals were retrospectively categorized into survivor (n = 29) and dead (n = 12). Endometrial tissue sections were obtained from the bitches undergoing ovariohysterectomy (n = 21). Serum concentration of SLPI was quantified using sandwich ELISA and its expression in the endometrium was investigated using RT-qPCR. A marked increase in the total leucocyte count (TLC), neutrophils, blood urea nitrogen (BUN) and serum creatinine was observed in the female dogs that did not survive. Significant elevation in the serum SLPI concentration (3.49 ± 0.44 vs. 2.38 ± 0.13 ng/mL) was observed in the bitches those died after the treatment, in comparison to those survived (p < .01). Additionally, there was a notable upregulation of SLPI in the endometrium in the bitches those died due to pyometra. Based on the ROC analysis results, it was observed that a cut-off concentration of 2.93 ng/mL for SLPI, 27.77 mg/dL for BUN and 16.3 × 103 /μL for TLC could effectively distinguish the prognosis of pyometra-affected dogs. From this study, it can be concluded that upregulation of SLPI in the endometrium and its elevated concentration in peripheral circulation along with TLC and BUN concentration could serve as valuable indicators for predicting the prognosis of pyometra in bitches.

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.

A novel immune modulator IM33 mediates a glia-gut-neuronal axis that controls lifespan

Aging is a complex process involving various systems and behavioral changes. Altered immune regulation, dysbiosis, oxidative stress, and sleep decline are common features of aging, but their interconnection is poorly understood. Using Drosophila, we discover that IM33, a novel immune modulator, and its mammalian homolog, secretory leukocyte protease inhibitor (SLPI), are upregulated in old flies and old mice, respectively. Knockdown of IM33 in glia elevates the gut reactive oxygen species (ROS) level and alters gut microbiota composition, including increased Lactiplantibacillus plantarum abundance, leading to a shortened lifespan. Additionally, dysbiosis induces sleep fragmentation through the activation of insulin-producing cells in the brain, which is mediated by the binding of Lactiplantibacillus plantarum-produced DAP-type peptidoglycan to the peptidoglycan recognition protein LE (PGRP-LE) receptor. Therefore, IM33 plays a role in the glia-microbiota-neuronal axis, connecting neuroinflammation, dysbiosis, and sleep decline during aging. Identifying molecular mediators of these processes could lead to the development of innovative strategies for extending lifespan.

Salivary Antiviral and Antibacterial Properties in the Encounter of SARS-CoV-2.

Due to the high mortality rate of COVID-19 and its high variability and mutability, it is essential to know the body's defense mechanisms against this virus. Saliva has numerous functions, such as digestion, protection, and antimicrobial effects. Salivary diagnostic tests for many oral and systemic diseases will be available soon because saliva is a pool of biological markers. The most important antiviral and antibacterial compounds identified in saliva include lysozyme, lactoferrin (LF), mucins, cathelicidin, salivary secretory immunoglobulin (SIgA), chromogranin A, cathelicidin, salivary agglutinin (SAG) (gp340, DMBT1), α, β defensins, cystatin, histatins, secretory leukocyte protease inhibitor (SLPI), heat shock protein (HSP), adrenomedullin and microRNA (miRNAs). Antimicrobial peptides (AMPs) in saliva could be used in the future as models for designing effective oral microbial antibiotics. The antiviral properties of the peptides in saliva may be one of the future treatments for the COVID-19 virus. In this review, we investigate compounds with antiviral and antibacterial properties in saliva and the importance of these compounds in saliva in exposure to the COVID-19 virus. Due to the transmission route of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) into the oral cavity in the lower and upper respiratory tract, studies of salivary antiviral properties in these patients are very important. Some of the antiviral effects of saliva, especially mucin, α, β-defensins, IgA, IgG, IgM, lysozyme, SAG, SLPI, and histatins, may play a greater role in neutralizing or eliminating COVID-19.

Secretory leukocyte protease inhibitor modulates FcεRI-dependent but not Mrgprb2-dependent mastocyte function in psoriasis

Psoriasis, which involves mast cells, is a chronic inflammatory skin disorder whose pathophysiology is still not fully understood. We investigated the role of secretory leukocyte protease inhibitor (SLPI), a potential inhibitor of mastocyte serine proteases, on mast cell-dependent processes of relevance to the skin barrier defense in psoriasis. Here, we demonstrate that the dermal mast cells of patients with psoriasis express SLPI but not those of healthy donors. Moreover, SLPI transcripts were found to be markedly upregulated in murine mast cells by mediators derived from psoriasis skin explant cultures. Using mast cells from SLPI-deficient mice and their SLPI+ wild-type controls, we show that SLPI inhibits the activity of serine protease chymase in mastocytes. SLPI was also found to enhance the degranulation of mast cells activated via anti-IgE Abs but not Mrgprb2 ligands. Finally, we demonstrate that the expression and function of Mrgprb2 in mast cells are suppressed by a normal and, to a larger extent, psoriatic skin environment. Together, these findings reveal mechanisms underlying FcεRI– and Mrgprb2-dependent mast cell function that have not been described previously.

Dietary iron modulates gut microbiota and induces SLPI secretion to promote colorectal tumorigenesis

ABSTRACT Dietary iron intake is closely related to the incidence of colorectal cancer. However, the interactions among dietary iron, gut microbiota, and epithelial cells in promoting tumorigenesis have rarely been discussed. Here, we report that gut microbiota plays a crucial role in promoting colorectal tumorigenesis in multiple mice models under excessive dietary iron intake. Gut microbiota modulated by excessive dietary iron are pathogenic, irritating the permeability of the gut barrier and causing leakage of lumen bacteria. Mechanistically, epithelial cells released more secretory leukocyte protease inhibitor (SLPI) to combat the leaked bacteria and limit inflammation. The upregulated SLPI acted as a pro-tumorigenic factor and promoted colorectal tumorigenesis by activating the MAPK signaling pathway. Moreover, excessive dietary iron significantly depleted Akkermansiaceae in the gut microbiota; while supplementation with Akkermansia muciniphila could successfully attenuate the tumorigenic effect from excessive dietary iron. Overall, excessive dietary iron perturbs diet – microbiome–epithelium interactions, which contributes to intestinal tumor initiation.

Afterbirth oral fluid secretory leukocyte protease inhibitor decreased in acute histologic chorioamnionitis in preterm birth.

Secretory leukocyte protease inhibitor (SLPI) is an innate anti-inflammatory and anti-microbial peptide and produced in amnion of fetal membranes during pregnancy. However, studies on the association between SLPI levels in amniotic fluid and acute chorioamnionitis are limited. Afterbirth oral fluid (AOF) of the baby could be useful for representing the intra-amniotic environment precisely just before delivery. This study aimed to determine the relationship between SLPI levels in AOF and acute histologic chorioamnionitis (HC). AOF of the baby was obtained during delivery from 24(0/7) to 36(6/7) weeks of gestational age (preterm group, n=94) and from 37(0/7) to 41(6/7) weeks of gestational age (term group, n=27) just after birth. SLPI expression levels among five classifications were compared to the intensity of acute HC as follows: no inflammation, acute subchorionitis, acute chorionitis, acute chorioamnionitis, and funisits. The SLPI and matrix metalloproteinase-8 (MMP-8) concentrations of AOF were determined using Enzyme Linked Immunosorbent Assay. Histologic examination of the placenta and membranes was performed after delivery. SLPI concentrations in AOF inversely decreased according to the intensity of acute HC (161.62ng/mL in funisitis, 134.83ng/mL in acute chorioamnionitis, 749.35ng/mL in acute chorionitis, 953.05ng/mL in acute subchorionitis, and 1126.77ng/mL in no inflammation [p=.021]). The MMP-8 concentrations in AOF and maternal serum C-reactive protein were the highest in funisitis. The SLPI/ MMP-8 ratio was low in subgroup with acute chorioamnionitis and funisitis. Along with increased MMP-8 levels, decreased SLPI levels in AOF of the baby could be an additional factor in predicting acute HC immediately after birth.

Canine umbilical cord tissue derived mesenchymal stem cells naturally express mRNAs of some antimicrobial peptides.

Antimicrobial peptides (AMPs) are naturally produced by all living organisms at a constitutive rate. They represent the first line of active defence systems against invading microorganisms, helping in innate immunity. Besides their therapeutic applications, great attention has also been given to the mesenchymal stem cells (MSCs) due to their antimicrobial activities. The study aimed to observe the mRNA expression profile of few antimicrobial peptides (AMPs) in canine MSCs during standard in vitro culture. MSCs were isolated from canine umbilical cord tissue, propagated and characterized by morphology, surface markers and tri-lineage differentiation capability. The mRNA expression of eleven commonly known antimicrobial peptides was checked by Reverse Transcriptase PCR. It has been found for the first time that canine MSCs naturally express the mRNAs of AMPs like C-X-C motif chemokine ligand 8 (CXCL8), Elafin (PI3), Hepcidin (HAMP), Lipocalin 2 (LCN2) and Secretory leukocyte protease inhibitor (SLPI). However, their expressions at protein level and, relation with antimicrobial effect of canine MSCs need to be explored.

Serum concentrations of secretory leukocyte protease inhibitor and IL6 can predict the onset of sepsis in pyometra bitches.

As onset of sepsis adversely affects the prognosis of canine pyometra, finding biomarkers that would distinguish sepsis status would be useful in the clinical management. Accordingly, we hypothesized that differential expression of endometrial transcripts and circulating concentration of certain inflammatory mediators would discriminate pyometra-led sepsis (P-sepsis+) from those of pyometra without sepsis (P-sepsis-). Bitches with pyometra (n = 52) were classified into P-sepsis+ (n = 28) and P-sepsis- (n = 24) based on vital clinical score and total leukocyte count. A group of non-pyometra bitches (n = 12) served as control. The relative fold changes in the transcripts of IL6, IL8, TNFα, IL10, PTGS2, mPGES1 and PGFS, SLPI, S100A8, S100A12 and eNOS were determined by quantitative polymerase chain reaction. Furthermore, the serumconcentrations of IL6, IL8, IL10, SLPI and prostaglandin F2α metabolite (PGFM) were assayed by ELISA. The relative fold changes in S100A12 and SLPI and mean concentrations of IL6 and SLPI were significantly (p < .05) higher in P-sepsis+ than that of P-sepsis- group. Receiver operating characteristic analysis revealed that serum IL6 had a diagnostic sensitivity of 78.6% and a positive likelihood ratio (LR+) of 2.09, at a cut-off value of 15.7 pg/mL to diagnose P-sepsis+ cases. Similarly, serum SLPI had a sensitivity of 84.6% and an LR+ of 2.23, at a cut-off value of 2.0 pg/mL. It was concluded that SLPI and IL6 would serve as putative biomarkers for pyometra-led sepsis in bitches. Monitoring SLPI and IL6would be a useful adjunct to the established haemato-biochemical parameters in customizing the treatment strategies and arriving at the decision for management of pyometra bitcheswith critical illness.

Development of nanoparticles for delivering recombinant human secretory leukocyte protease inhibitor (rhSLPI) for enhancing human osteoblast differentiation

The global number of elderly people has been increasing and the world can now be considered as an aging society. One of the most concerning health problems in the elderly is a musculoskeletal disease, in which fractures and osteoporosis are the most common problems. The deteriorating bone quality in the elderly is a limitation for treatment and for patient recovery. Several drugs and biomolecules have been studied for enhancing osteoblast properties and differentiation. The secretory leukocyte protease inhibitor (SLPI), which is a serine protease inhibitory protein, has been reported to enhance osteoblast cell adhesion, proliferation, and differentiation. However, the application of SLPI in real clinical settings is limited due to its short half-life in circulation and the fact that it can be destroyed by circulating protease enzymes. Therefore, the application of nanoparticle encapsulation might be of benefit for SLPI delivery. This study aims to fabricate the liposome nanoparticles encapsulating recombinant human SLPI or rhSLPI (rhSLPI-LNPs) for augmenting the half-life and enhancing human osteoblast differentiation. The liposome nanoparticles (LNPs) were fabricated by the thin film hydration method. Encapsulation of rhSLPI was performed by adding 0.33 µg/mL rhSLPI in ultrapure water to the thin film lipid and then rhSLPI-LNPs formed into vesicles. The size and zeta potential of blank-LNPs or rhSLPI-LNPs were measured by scanning electron microscopy (SEM) and dynamic light scattering (DLS). The results showed that the size of both blank-LNPs and rhSLPI-LNPs was approximately 200 nm, and the zeta potentials were −55.6 ± 16.90 mV and −64 ± 7.86 mV, respectively. The rhSLPI encapsulation was confirmed by ELISA. The results showed that liposome nanoparticles could encapsulate rhSLPI. For cytotoxicity, rhSLPI-LNPs treatment did not cause any toxicity to the human osteoblast cell line (hFOB 1.19). In addition, pre-incubation of hFOB 1.19 with rhSLPI-LNPs could significantly enhance osteoblast adhesion when compared with the untreated group.

Development of gelatin-silicon dioxide nanoparticles (GSNPs) encapsulating recombinant human secretory leukocyte protease inhibitor (rhSLPI) for reducing in vitro myocardial ischemia/reperfusion injury

Ischemic Heart Disease (IHD) is the main global cause of death. Previous studies indicate that recombinant human secretory leukocyte protease inhibitor (rhSLPI) exhibits a cardioprotection effect against myocardial ischemia and reperfusion (I/R) injury. However, SLPI has a short half-life in vivo due to protease enzymes in circulation. Application of nanoparticle encapsulation could be beneficial for SLPI delivery. Several types of nanoparticles have been used to encapsulate SLPI and applied in some disease models. However, silica nanoparticles for rhSLPI delivery, particularly on myocardial I/R injury, has never been studied. In this study, rhSLPI was encapsulated into Gelatin-Silica dioxide nanoparticles (GSNPs), which will be further used to determine an in vitro cardioprotective effect against simulated ischemia/reperfusion injury in cardiomyocytes. Silica dioxide nanoparticles (SNPs) were fabricated followed by incubation with 0.33 mg/mL of rhSLPI. Finally, 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 was determined by ELISA. Next, cytotoxicity was determined by incubation of GSNPs or rhSLPI-GSNPs with rat cardiac myoblast cell line (H9c2). The results show that SNPs, GSNPs, and rhSLPI-GSNPs are sized 280, 303, and 302 nm, respectively, and have a zeta potential of −27.8, −24.4, and −21.5 mV, respectively. SEM indicated a thin layer of gelatin covering SNPs, and the value of zeta potential of SNPs was changed when they were covered by gelatin, indicating a successful coating process. 20 μL of rhSLPI-GSNPs verified by ELISA showed the concentration of rhSLPI was 50.89 ng/mL. The cytotoxicity showed no significant difference between cardiac cells with or without rhSLPI-GSNPs. In conclusion, the researchers were able to fabricate Gelatin-Silica dioxide nanoparticles (GSNPs) to deliver rhSLPI which was used to study cardiomyocyte subjected to simulated ischemia/reperfusion (sI/R) injury.