The alarm secretory leukocyte protease inhibitor increases with progressive metabolic dysfunction

Long-Term Dietary Consumption of Grapes Alters Phenotypic Expression in Skeletal Muscle of Aged Male and Female Mice

(1) Background: Nutrigenomics investigates how diet influences gene expression and how genetic variation impacts dietary responses. Grapes, rich in phytochemicals, exhibit potential disease-preventive properties through nutrigenomic mechanisms rather than direct chemical interactions. This study aimed to explore the modulation of gene expression in muscle tissue resulting from long-term grape consumption. (2) Methods: A mouse model was employed to assess gene expression in the skeletal muscles of males and females fed a grape-enriched diet versus a bland diet over 2.5 years. Heatmaps and principal component analyses were performed to identify patterns, and pathway analyses using KEGG, GO, and Reactome were conducted. (3) Results: Significant sex-specific gene expression changes were observed, with female phenotypes showing greater alterations and converging toward male-like characteristics. Twenty-five differentially expressed genes associated with muscle health were identified. Up-regulated genes such as Ahsg, Alb, Apoa1, and Arg1, and down-regulated genes including Camp, Lcn2, and Irf4, suggest improved muscle function. (4) Conclusions: Long-term grape consumption appears to enhance female muscle traits toward a male-like phenotype, potentially indicating broader health benefits. Further studies and clinical trials are needed to confirm human applicability and the physiological implications of these findings. Nonetheless, this research underscores the role of nutrigenomics in understanding dietary influences on gene expression and sex-specific responses.

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

Background

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.

Methods

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.

Results

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.

Conclusions

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.

Consumption of ultra-processed foods is associated with depression, mesocorticolimbic volume, and inflammation

BACKGROUND

The consumption of ultra-processed foods and drinks (UPF) has been associated with depression and inflammation and preclinical studies showed that some UPF components disrupt the amygdala-hippocampal complex. We combine diet, clinical and brain imaging data to investigate the relationship between the UPF consumption, depressive symptoms, and brain volumes in humans, considering interactions with obesity, and the mediation effect of inflammation biomarkers.

METHODS

One-hundred fifty-two adults underwent diet, depressive symptoms, anatomic magnetic resonance imaging assessments and laboratory tests. Relationships between the % of UPF consumption (in grams) of the total diet, depressive symptoms, and gray matter brain volumes were explored using several adjusted regression models, and in interaction with the presence of obesity. Whether inflammatory biomarkers (i.e., white blood cell count, lipopolysaccharide-binding protein, c-reactive protein) mediate the previous associations was investigated using R mediation package.

RESULTS

High UPF consumption was associated with higher depressive symptoms in all participants (β = 0.178, CI = 0.008-0.261) and in those with obesity (β = 0.214, CI = -0.004-0.333). Higher consumption was also associated with lower volumes in the posterior cingulate cortex and the left amygdala, which in the participants with obesity also encompassed the left ventral putamen and the dorsal frontal cortex. White blood count levels mediated the association between UPF consumption and depressive symptoms (p = 0.022).

LIMITATIONS

The present study precludes any causal conclusions.

CONCLUSIONS

UPF consumption is associated with depressive symptoms and lower volumes within the mesocorticolimbic brain network implicated in reward processes and conflict monitoring. Associations were partially dependent on obesity and white blood cell count.

Analysis of potential hub genes involved in the pathogenesis of Chinese type 1 diabetic patients

Background

Type 1 diabetes is an autoimmune disease strongly related to genetic factors. Although studies on T1D susceptibility genes have achieved great progress, the molecular mechanism of T1D remains to be explained.

Methods

To explore the underlying mechanisms of T1D, bioinformatic analysis based on a microarray database was used to determine the key biomarkers of T1D as well as their biofunctions and interactions. The microarray database GSE55100 was downloaded from the Gene Expression Omnibus (GEO). Differentially expressed genes (DEGs) were processed by packages in R Software. The database for Annotation, Visualization, and Integrated Discovery (DAVID, version 6.8) was used to conduct gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses. The protein-protein interaction network was analyzed with the Search Tool for the Retrieval of Interacting Genes (STRING), and the module analysis was performed using Cytoscape.

Results

Seventy-eight DEGs and 13 hub genes were identified. The biofunctions and pathways of these DEGs were enriched in immune response, extracellular exosome, cytokine activity and antigen processing and presentation. Thirteen DEGs with MCODE score ≥2 were selected as hub genes including MMP9, ARG1, CAMP, CHI3L1, CRISP3, SLPI, LCN2, PGLYRP1, LTF, RETN, CEACAM1, CEACAM8 and MS4A3.

Conclusions

The identification and analyses of the DEGs and hub genes from database GSE55100 provide novel prospectives of the pathogenesis of T1D.

Secretory Leukocyte Protease Inhibitor (SLPI)-A Novel Predictive Biomarker of Acute Kidney Injury after Cardiac Surgery: A Prospective Observational Study

Acute kidney injury (AKI) is one of the most frequent complications after cardiac surgery and is associated with poor outcomes. Biomarkers of AKI are crucial for the early diagnosis of this condition. Secretory leukocyte protease inhibitor (SLPI) is an alarm anti-protease that has been implicated in the pathogenesis of AKI but has not yet been studied as a diagnostic biomarker of AKI. Using two independent cohorts (development cohort (DC), n = 60; validation cohort (VC), n = 148), we investigated the performance of SLPI as a diagnostic marker of AKI after cardiac surgery. Serum and urinary levels of SLPI were quantified by ELISA. SLPI was significantly elevated in AKI patients compared with non-AKI patients (6 h, DC: 102.1 vs. 64.9 ng/mL, p < 0.001). The area under the receiver operating characteristic curve of serum SLPI 6 h after surgery was 0.87 ((0.76–0.97); DC). The addition of SLPI to standard clinical predictors significantly improved the predictive accuracy of AKI (24 h, VC: odds ratio (OR) = 3.91 (1.44–12.13)). In a subgroup, the increase in serum SLPI was evident before AKI was diagnosed on the basis of serum creatinine or urine output (24 h, VC: OR = 4.89 (1.54–19.92)). In this study, SLPI was identified as a novel candidate biomarker for the early diagnosis of AKI after cardiac surgery.

Blood pathway analyses reveal differences between prediabetic subjects with or without dyslipidaemia. The Cardiovascular Risk in Young Finns Study

BACKGROUND

Prediabetes often occurs together with dyslipidaemia, which is paradoxically treated with statins predisposing to type 2 diabetes mellitus. We examined peripheral blood pathway profiles in prediabetic subjects with (PR_D ) and without dyslipidaemia (PR₀ ) and compared these to nonprediabetic controls without dyslipidaemia (C₀ ).

METHODS

The participants were from the Cardiovascular Risk in Young Finns Study, including 1240 subjects aged 34 to 49 years. Genome-wide expression data of peripheral blood and gene set enrichment analysis were used to investigate the differentially expressed genes and enriched pathways between different subtypes of prediabetes.

RESULTS

Pathways for cholesterol synthesis, interleukin-12-mediated signalling events, and downstream signalling in naïve CD8+ T-cells were upregulated in the PR₀ group in comparison with controls (C₀ ). The upregulation of these pathways was independent of waist circumference, blood pressure, smoking status, and insulin. Adjustment for CRP left the CD8+ T-cell signalling and interleukin-12-mediated signalling event pathway upregulated. The cholesterol synthesis pathway was also upregulated when all prediabetic subjects (PR₀ and PR_D ) were compared with the nonprediabetic control group. No pathways were upregulated or downregulated when the PR_D group was compared with the C₀ group. Five genes in the PR₀ group and 1 in the PR_D group were significantly differentially expressed in comparison with the C₀ group.

CONCLUSIONS

Blood cell gene expression profiles differ significantly between prediabetic subjects with and without dyslipidaemia. Whether this classification may be used in detection of prediabetic individuals at a high risk of cardiovascular complications remains to be examined.

Secretory leukocyte protease inhibitor promising protective roles in obesity-associated atherosclerosis

Secretory leukocyte protease inhibitor (SLPI), a serine protease inhibitor, which was most commonly examined in mucosal fluids such as saliva, is a versatile molecule and plays non-redundant roles. In addition to its anti-protease activity, SLPI has been shown to express anti-bacterial, anti-viral, anti-fungal, and anti-inflammatory properties as well as participating in innate and adaptive immune responses, most of which has been well documented. Recently, it is reported that SLPI is expressed in adipocytes and adipose tissue where it could play an important feedback role in the resolution of inflammation. Furthermore, circulating SLPI has been shown to correlate with progressive metabolic dysfunction. Moreover, adenoviral gene delivery of elafin and SLPI attenuates nuclear factor-κB-dependent inflammatory responses of human endothelial cells and macrophages to atherogenic stimuli. This review contributes to unraveling the protective role of SLPI in obesity-related atherosclerosis development, and the potential role in preventing arterial plaque rupture.

Biofluid proteases profiling in diabetes mellitus

The investigation of protease relevance in biologic systems beyond catabolism of proteins and peptides to amino acids has stimulated interest as to their role in the pathogenesis of several disorders including diabetes mellitus (DM). Evaluation of proteases and the assessment of their activity in biofluids are fundamental to elucidate these proteolytic systems in DM and its related complications. In contrast to traditional immunoassay or substrate based approaches that targeted specific proteases and their inhibitors, the field of degradomics has provided a comprehensive approach to study these enzymes. Although the degradome contains over 500 proteases, very few have been associated with DM and its micro- and macrovascular complications. In this paper, we review these proteases and their respective inhibitors with emphasis on DM. It is likely that future research will expand these initial studies and look to develop high throughput automated technologies to identify and characterize biofluid proteases of diagnostic and prognostic value in other pathologies.

Lard-based high-fat diet increases secretory leukocyte protease inhibitor expression and attenuates the inflammatory response of acute lung injury in endotoxemic rats

BACKGROUND & AIMS

Acute lung injury (ALI) is less severe in obese than in nonobese patients, but the mechanism is unclear. Secretory leukocyte protease inhibitor (SLPI) is the key anti-inflammatory protein in various lung diseases. We have previously reported changes of the surgical stress in obese rats using lard-based high-fat diet (HFD). The purpose of this study was to elucidate the effect of lard-based HFD on the pathophysiology of lipopolysaccharide (LPS)-induced ALI, and the role of SLPI expression.

METHODS

Male Wistar rats were fed lard-based HFD (60 kcal% fat) or control diet (CD) for either 4 or 12 weeks and were killed after intraperitoneal LPS injection. Analyses included messenger RNA expression of TNF-α, macrophage inflammatory protein (MIP)-2, inducible nitric oxide synthase (iNOS), IL-10 and SLPI in the lung tissue and bronchoalveolar lavage fluid, and histology of the lungs.

RESULTS

Rats fed HFD for 12 weeks showed suppression of the lung injury and oxidative stress after LPS injection, as indicated by reduction of pulmonary TNF-α, MIP-2 and iNOS mRNA expression and 8-hydroxy-2'-deoxyguanosine immunostaining. The increased pulmonary SLPI caused by lard was associated with decreased pro-inflammatory cytokines and oxidative stress, which eventually resulted in the prevention of ALI. Those effects of lard on LPS-induced ALI were greater after 12 weeks than after 4 weeks feeding, as indicated by the reduction of TNF-α, MIP-2 and iNOS levels.

CONCLUSIONS

Feeding lard-based HFD for 12 weeks attenuated LPS-induced ALI with increased pulmonary SLPI expression in rats.

The effect of proatherogenic pathogens on adipose tissue transcriptome and fatty acid distribution in apolipoprotein E-deficient mice

Background

Chronic infections have been demonstrated to maintain low-grade systemic inflammation and associate with atherosclerosis. We studied the inflammation- and lipid homeostasis-related effects of Aggregatibacter actinomycetemcomitans (Aa) and Chlamydia pneumoniae (Cpn) infections on the epididymal and inguinal adipose tissue (AT) transcriptomes and fatty acid distribution in apolipoprotein (apo) E-deficient mice. Chow-fed apoE-deficient mice were exposed to 1) chronic intranasal infection with C. pneumoniae (Cpn group), 2) recurrent intravenous infection with A. actinomycetemcomitans (Aa group), 3) a combination of both types of infection (Cpn + Aa group), or 4) infection with the vehicle (control group). Epididymal and inguinal AT gene expression was analyzed using an Illumina Mouse WG-6 v2.0 platform and quantitative PCR (QPCR). Microarray data were analyzed using Gene Ontology enrichment analysis. AT fatty acid analysis was performed using gas–liquid chromatography.

Results

The transcriptomics data revealed significant enrichment in inflammation-associated biological pathways in both AT depots derived from the Aa and Cpn + Aa treated mice compared with the control group. The proportion of saturated fatty acids was higher in the inguinal AT in Aa (p = 0.027) and Cpn + Aa (p = 0.009) groups and in the epididymal AT in Aa group (p = 0.003). The proportion of polyunsaturated fatty acids was significantly lower among all Aa-infected groups in both depots. Chronic Cpn infection displayed only minor effects on transcriptomics and fatty acids of the AT depots.

Conclusions

Systemic infection with A. actinomycetemcomitans activates inflammation-related biological pathways and modulates cellular lipid homeostasis. The adverse changes in adipose tissues during chronic infection may promote atherosclerosis.

Serum and urinary concentrations of calprotectin as markers of insulin resistance and type 2 diabetes

OBJECTIVE

Increased circulating calprotectin has been reported in obese subjects but not in association with measures of insulin resistance and type 2 diabetes (T2D). The main aim of this study was to determine whether calprotectins in plasma and urine are associated with insulin resistance.

DESIGN

We performed both cross-sectional and longitudinal (diet-induced weight loss) studies.

METHODS

Circulating calprotectin concentrations (ELISA), other inflammatory markers, homeostasis model assessment of insulin resistance (HOMA-IR), and parameters of glucose and lipid metabolism were evaluated in 298 subjects (185 with normal (NGT) and 62 with impaired (IGT) glucose tolerance and 51 T2D subjects). Calprotectin was also evaluated in urine samples from 71 participants (50 NGT and 21 subjects with IGT). Insulin sensitivity (S(I), Minimal Model) was determined in a subset of 156 subjects, and the effects of weight loss were investigated in an independent cohort of obese subjects (n=19).

RESULTS

Circulating calprotectin was significantly increased in IGT-T2D (independently of BMI) and positively associated with HOMA-IR, obesity measures, inflammatory markers, and parameters of glucose and lipid metabolism. Similar findings were reported for calprotectin concentrations in urine. In the subset of subjects, the association of calprotectin with S(I) was independent of BMI and age. In fact, S(I) together with C-reactive protein contributed to 27.4% of calprotectin variance after controlling for age and blood neutrophils count. Otherwise, weight loss led to decreased circulating calprotectin in parallel to fasting glucose and HOMA-IR.

CONCLUSION

These findings suggest that circulating and urinary concentrations of calprotectin are linked to chronic low-grade inflammation and insulin resistance beyond obesity.

Using gene expression to predict differences in the secretome of human omental vs. subcutaneous adipose tissue

The objective of this study was to characterize differences in the secretome of human omental compared with subcutaneous adipose tissue using global gene expression profiling. Gene expression was measured using Affymetrix microarrays (Affymetrix, Santa Clara, CA) in subcutaneous and omental adipose tissue in two independent experiments (n = 5 and n = 3 independent subjects; n = 16 arrays in total, 2 for each subject). Predictive bioinformatic algorithms were employed to identify secreted proteins. Microarray analysis identified 22 gene probe sets whose expression was significantly different with a fold change (FC) greater than 5 in expression in both experiments between omental and subcutaneous adipose tissue. Using bioinformatic predictive programs 11 of these 22 probe sets potentially coded for secreted proteins. Pathway network analysis of the secreted proteins showed that three of the proteins are part of a common pathway network. These proteins gremlin 1 (GREM1), pleiotrophin (PTN), and secretory leukocyte peptidase inhibitor (SLPI) are expressed respectively 43×, 23×, and 5× in omental adipose tissue relative to subcutaneous adipose tissue as determined by real-time PCR. The presence of GREM1, PTN, and SLPI protein in human adipose tissue was confirmed by western blotting. All three proteins are expressed in the human Simpson-Golabi-Behmel syndrome (SGBS) preadipocyte cell line. The expression of GREM1, PTN, and SLPI changed with the differentiation of the preadipocytes into mature adipocytes. Gene expression coupled with predictive bioinformatic algorithms have identified several genes coding for secreted proteins which are expressed differently in omental adipose tissue compared to subcutaneous adipose tissue proving a valid alternative approach to help further define the adipocyte secretome.