Cerulein-Induced Acute Pancreatitis Affects Sphingomyelin Signaling Pathway in Rats

Chaiqin chengqi decoction treatment mitigates hypertriglyceridemia-associated acute pancreatitis by modulating liver-mediated glycerophospholipid metabolism

BACKGROUND

The incidence of hypertriglyceridemia-associated acute pancreatitis (HTG-AP) is increasing globally and more so in China. The characteristics of liver-mediated metabolites and related key enzymes are rarely reported in HTG-AP. Chaiqin chengqi decoction (CQCQD) has been shown to protect against AP including HTG-AP in both patients and rodent models, but the underlying mechanisms in HTG-AP remain unexplored.

PURPOSE

To assess the characteristics of liver-mediated metabolism and the therapeutic mechanisms of CQCQD in HTG-AP.

METHODS

Male human apolipoprotein C3 transgenic (hApoC3-Tg; leading to HTG) mice or wild-type littermates received 7 intraperitoneal injections of cerulein (100 μg/kg) to establish HTG-AP and CER-AP, respectively. In HTG-AP, some mice received CQCQD (5.5 g/kg) gavage at 1, 5 or 9 h after disease induction. AP severity and related liver injury were determined by serological and histological parameters; and underlying mechanisms were identified by lipidomics and molecular biology. Molecular docking was used to identify key interactions between CQCQD compounds and metabolic enzymes, and subsequently validated in vitro in hepatocytes.

RESULTS

HTG-AP was associated with increased disease severity indices including augmented liver injury compared to CER-AP. CQCQD treatment reduced severity and liver injury of HTG-AP. Glycerophospholipid (GPL) metabolism was the most disturbed pathway in HTG-AP in comparison to HTG alone. In HTG-AP, the mRNA level of GPL enzymes involved in phosphocholine (PC) and phosphatidylethanolamine (PE) synthesis (Pcyt1a, Pcyt2, Pemt, and Lpcat) were markedly upregulated in the liver. Of the GPL metabolites, lysophosphatidylethanolamine LPE(16:0) in serum of HTG-AP was significantly elevated and positively correlated with the pancreas histopathology score (r = 0.65). In vitro, supernatant from Pcyt2-overexpressing hepatocytes co-incubated with LPE(16:0) or phospholipase A2 (a PC- and PE-hydrolyzing enzyme) alone induced pancreatic acinar cell death. CQCQD treatment downregulated PCYT1a and PCYT2 enzyme levels in the liver. Hesperidin and narirutin were identified top two CQCQD compounds with highest affinity docking to PCYT1a and PCYT2. Both hesperidin and narirutin reduced the level of some GPL metabolites in hepatocytes.

CONCLUSION

Liver-mediated GPL metabolism is excessively activated in HTG-AP with serum LPE(16:0) level correlating with disease severity. CQCQD reduces HTG-AP severity partially via modulating key enzymes in GPL metabolism pathway.

Genetic and biochemical analysis of severe hypertriglyceridemia complicated with acute pancreatitis or with low post-heparin lipoprotein lipase mass

Severe hypertriglyceridemia is a pathological condition caused by genetic factors alone or in combination with environmental factors, sometimes leading to acute pancreatitis (AP). In this study, exome sequencing and biochemical analyses were performed in 4 patients with hypertriglyceridemia complicated by obesity or diabetes with a history of AP or decreased post-heparin LPL mass. In a patient with a history of AP, SNP rs199953320 resulting in LMF1 nonsense mutation and APOE rs7412 causing apolipoprotein E2 were both found in heterozygous form. Three patients were homozygous for APOA5 rs2075291, and one was heterozygous. ELISA and Western blot analysis of the serum revealed the existence of apolipoprotein A-V in the lipoprotein-free fraction regardless of the presence or absence of rs2075291; furthermore, the molecular weight of apolipoprotein A-V was different depending on the class of lipoprotein or lipoprotein-free fraction. Lipidomics analysis showed increased serum levels of sphingomyelin and many classes of glycerophospholipid; however, when individual patients were compared, the degree of increase in each class of phospholipid among cases did not coincide with the increases seen in total cholesterol and triglycerides. Moreover, phosphatidylcholine, lysophosphatidylinositol, and sphingomyelin levels tended to be higher in patients who experienced AP than those who did not, suggesting that these phospholipids may contribute to the onset of AP. In summary, this study revealed a new disease-causing gene mutation in LMF1, confirmed an association between overlapping of multiple gene mutations and severe hypertriglyceridemia, and suggested that some classes of phospholipid may be involved in the pathogenesis of AP.

Identification of Differential Metabolites Between Type 2 Diabetes and Postchronic Pancreatitis Diabetes (Type 3c) Based on an Untargeted Metabolomics Approach

OBJECTIVE

A nontargeted metabolomics approach was established to characterize serum metabolic profile in type 3c diabetes mellitus (T3cDM) secondary to chronic pancreatitis and compare with T2DM.

METHODS

Forty patients were recruited for metabolite analysis based on liquid chromatography-mass spectrometry. Cluster heatmap and KEGG metabolic pathway enrichment analysis were used to analyze the specific and differential metabolites. The receiver operating characteristics (ROCs) were generated and correlation analysis with clinical data was conducted.

RESULTS

Metabolites including sphingosine, lipids, carnitine, bile acid, and hippuric acid were found to be different between T2DM and T3cDM, mainly enriched in bile acid biosynthesis, fatty acid biosynthesis, and sphingolipid metabolic pathways. The ROCs were generated with an area under the curve of 0.907 (95% confidence interval, 0.726-1) for the model with 15 metabolites.

CONCLUSION

T3cDM is characterized by increased sphingosine, carnitine, bile acid, and most lipids, providing novel biomarkers for clinical diagnosis and a future direction in research on pathophysiological mechanisms.

Serum metabolomics study for acute attack of chronic pancreatitis

BACKGROUND & AIMS

Chronic pancreatitis (CP) is an inflammatory disease characterized by irreversible changes. However, acute CP attacks can lead to various complications and affect patient prognosis. Therefore, this study aimed to identify reliable candidate metabolic biomarkers for diagnosing acute CP attacks and complement candidate diagnostic markers for CP.

METHODS

A total of 139 serum specimens were prospectively included in three consecutive exploratory, identification, and validation studies. All samples were analyzed for candidate diagnostic biomarkers and metabolic pathways using a liquid chromatography-mass spectrometer.

RESULTS

Serum metabolic profiles differed between patients with CP and non-pancreatic disease controls, and 239 potential metabolic biomarkers for diagnosing CP were identified. Based on identification and validation studies, Diacylglycerol(16:0/18:4), 16-F1-PhytoP, N-(hexacosanoyl)-tetradecasphing-4-enine, carnosic acid, and Auxin b were identified as biomarkers for distinguishing acute attacks from non-acute attacks in patients with CP. The area under the curve of the Diacylglycerol(16:0/18:4) was 0.969 (95% confidence interval, 0.869-1) in the validation study.

CONCLUSIONS

To the best of our knowledge, this is the first prospective cohort study to identify and validate a metabolomic signature in serum for diagnosing acute attacks of CP. In addition, our study identified 239 potential biomarkers for CP diagnosis.

Serum metabolomics identified metabolite biomarkers and distinguished maturity-onset diabetes of the young from type 1 diabetes in the Chinese population

BACKGROUND

Maturity-onset diabetes of the young (MODY) patients have unique clinical manifestations and need individualized treatments. We identified novel serum metabolic biomarkers to distinguish MODY and explore the possible mechanism of the clinical manifestation and complications of MODY.

METHODS

Fasting serum samples were collected from MODY3 (n = 17), MODY2 (n = 33), type 1 diabetes (T1DM) (n = 34) and healthy individuals (n = 30), and were analyzed using the ultra-performance liquid chromatography-mass spectrometry (UPLC-MS) metabolomic platform.

RESULTS

4 metabolites were found significantly fluctuated between groups, including glycerophosphocholine, LysoPC(18:2(9Z,12Z)), sphinganine and l-Phenylalanine. Glycerophosphocholine was selected as a diagnostic biomarker. The the area under the ROC curve (AUC) for distinguishing MODYs from healthy controls and differentiating MODY3 from T1DM reached 1.0. The combination of metabolites also gained good diagnostic value. The AUC of the combination of LysoPC(18:2(9Z,12Z)), sphinganine and l-Phenylalanine for discriminating MODY3 from T1DM was 0.983. Besides, the combination of clinical indices and metabolites helped to better differentiate the 2 MODY subtypes.

CONCLUSIONS

We identified the metabolic profiles of MODY2 and MODY3 and found promising biomarkers for distinguishing MODY from T1DM, which provides evidence for the pathogenesis and characteristic clinical manifestations of patients with MODY2 and MODY3.

Paper-Based Distance Sensor for the Detection of Lipase via a Phase Separation-Induced Viscosity Change

Human pancreatic lipase is a symbolic biomarker for the diagnosis of acute pancreatitis, which has profound significance for clinical detection and disease treatment. Herein, we first demonstrate a paper-based lipase sensor via a phase separation-induced viscosity change. Lipase catalyzes triolein to produce oleic acid and glycerol. Adding an excess of Ca²⁺ produces calcium oleate. The remaining Ca²⁺ binds with sodium alginate, triggering hydrogelation with an "egg-box" structure. The viscosity change of the aqueous solution induced by the phase separation process can be quantified by measuring the solution flow distance on a pH test paper. The paper-based lipase sensor has high sensitivity with a detection limit of 0.052 U/mL and also shows excellent specificity. Additionally, it is also utilized for quantitative lipase analysis in human serum samples to exhibit its potency in acute pancreatitis detection. This method overcomes the drawbacks of low sensitivity, slow response, and poor reproducibility caused by the nonuniform distribution of the highly viscous hydrogel on the sensing interface in existing approaches. In conclusion, thanks to the prominent characteristics of high portability, low cost, and easy operation, it is prospective for simple quantitative detection of lipase and has great potential for commercialization.

Correlation between metabolomic profile constituents and feline pancreatic lipase immunoreactivity

Background

Feline pancreatic lipase immunoreactivity (fPLI) is commonly used to diagnose pancreatitis in cats (FP). Untargeted metabolomics has been extensively applied in human and veterinary medicine, but no metabolomic studies regarding FP have been conducted.

Objectives

To identify metabolites significantly associated with increased fPLI.

Animals

Forty‐nine client‐owned cats: 11 clinically healthy and 38 with various clinical conditions.

Methods

Analytical cross‐sectional study with convenience sampling. A panel of 630 metabolites belonging to 26 biochemical classes was quantified in plasma using a commercial metabolomic assay. The correlation between plasma metabolite concentrations and serum fPLI was evaluated using Spearman's rank correlation coefficient (R_s) with Bonferroni correction. Multivariable analysis then was performed to control for glomerular filtration rate, liver damage, and blood glucose concentration. The accuracy of selected metabolites in discriminating between cats with normal (≤3.5 μg/L) and increased (>5.3 μg/L) fPLI was estimated using the area under the receiver operating characteristic curve (AUROC).

Results

Four hundred and seven of 630 metabolites (64.6%) were quantified in all cats. When controlled for potential confounders only 3 sphingolipids were significantly positively correlated with fPLI: 2 cerebrosides: HexCer(d18:1/24:0); (R_s = .56), and HexCer(d18:1/24:1); (R_s = .58) and 1 sphingomyelin: SM C18:0 (R_s = .55). Their AUROCs in identifying cats with increased fPLI were 82% (95% confidence interval [CI 95%], 70%‐94%), 84% (CI 95%, 72%‐96%), and 78% (CI 95%, 65%‐92%), respectively.

Conclusions and Clinical Importance

Selected sphingolipids are moderately positively correlated with fPLI and appear to have fair to moderate diagnostic accuracy in discriminating between cats with normal and increased fPLI.

Identification and validation of a multivariable prediction model based on blood plasma and serum metabolomics for the distinction of chronic pancreatitis subjects from non-pancreas disease control subjects

OBJECTIVE

Chronic pancreatitis (CP) is a fibroinflammatory syndrome leading to organ dysfunction, chronic pain, an increased risk for pancreatic cancer and considerable morbidity. Due to a lack of specific biomarkers, diagnosis is based on symptoms and specific but insensitive imaging features, preventing an early diagnosis and appropriate management.

DESIGN

We conducted a type 3 study for multivariable prediction for individual prognosis according to the TRIPOD guidelines. A signature to distinguish CP from controls (n=160) was identified using gas chromatography-mass spectrometry and liquid chromatography-tandem mass spectrometry on ethylenediaminetetraacetic acid (EDTA)-plasma and validated in independent cohorts.

RESULTS

A Naive Bayes algorithm identified eight metabolites of six ontology classes. After algorithm training and computation of optimal cut-offs, classification according to the metabolic signature detected CP with an area under the curve (AUC) of 0.85 ((95% CI 0.79 to 0.91). External validation in two independent cohorts (total n=502) resulted in similar accuracy for detection of CP compared with non-pancreatic controls in EDTA-plasma (AUC 0.85 (95% CI 0.81 to 0.89)) and serum (AUC 0.87 (95% CI 0.81 to 0.95)).

CONCLUSIONS

This is the first study that identifies and independently validates a metabolomic signature in plasma and serum for the diagnosis of CP in large, prospective cohorts. The results could provide the basis for the development of the first routine laboratory test for CP.

Metabolomic-based clinical studies and murine models for acute pancreatitis disease: A review

Acute pancreatitis (AP) is one of the most common gastroenterological disorders requiring hospitalization and is associated with substantial morbidity and mortality. Metabolomics nowadays not only help us to understand cellular metabolism to a degree that was not previously obtainable, but also to reveal the importance of the metabolites in physiological control, disease onset and development. An in-depth understanding of metabolic phenotyping would be therefore crucial for accurate diagnosis, prognosis and precise treatment of AP. In this review, we summarized and addressed the metabolomics design and workflow in AP studies, as well as the results and analysis of the in-depth of research. Based on the metabolic profiling work in both clinical populations and experimental AP models, we described the metabolites with potential utility as biomarkers and the correlation between the altered metabolites and AP status. Moreover, the disturbed metabolic pathways correlated with biological function were discussed in the end. A practical understanding of current and emerging metabolomic approaches applicable to AP and use of the metabolite information presented will aid in designing robust metabolomics and biological experiments that result in identification of unique biomarkers and mechanisms, and ultimately enhanced clinical decision-making.

Impact of Acute Pancreatic Injury on Sphingolipid Metabolism in the Salivary Glands

Acute pancreatic injury can be related to both parenchymal (responsible for exocrine functions) and islet (mainly β-cells, responsible for endocrine functions) damage. During embryonic development, both the salivary glands and the pancreas originate from the foregut, which explains many of the observed histological and functional similarities between these two organs. The relationship between several diseases of the pancreas and salivary glands, resulting from morphological and functional similarities, is well established. Sphingolipids constitute a class of biologically active molecules involved in numerous physiological and pathological processes, including acute pancreatitis (AP) and diabetes mellitus. However, the effect of AP on sphingolipid metabolism in the salivary glands remains uncertain. In the presented study, we examined the effect of AP and type 1 diabetes mellitus on sphingolipid metabolism in the salivary glands of rats. We demonstrated that acute pancreatic injury, related to both exocrine and endocrine functions, affects the metabolism of sphingolipids in the parotid, but not submandibular, salivary glands.

Cinnamic acid nanoparticles modulate redox signal and inflammatory response in gamma irradiated rats suffering from acute pancreatitis

Acute Pancreatitis (AP) is a multifactorial disease. It was characterized by severe inflammation and acinar cell destruction. Thus, the present study was initiated to evaluate the role the of Cinnamic acid nanoparticles (CA-NPs) as a modulator for the redox signaling pathway involved in the development of pancreatitis. AP in rats was induced by L-arginine and exposure to gamma radiation. The pancreatic injury was evaluated using biochemical and histological parameters. Upon the oral administration of CA-NPs, both the severity of acute pancreatitis and the serum levels of amylase and lipase were decreased. Furthermore, the malondialdehyde (MDA) levels of the pancreatic tissue were significantly reduced and the depletion of glutathione was considerably restored. The injury and apoptosis of pancreatic tissues were markedly improved by the reduction of the caspase-3 levels. Additionally, the alleviation of pancreatic oxidative damage by CA-NPs was accompanied by a down-regulation of the NLRP3, NF-κB, and ASK1/MAPK signaling pathways. Collectively, the current findings showed that CA-NPs could protect the pancreatic acinar cell from injury not only by its antioxidant, anti-inflammatory effect but also by modulation of the redox-sensitive signal transduction pathways contributed to acute pancreatitis severity. Accordingly, cinnamic acid nanoparticles have therapeutic potential for the management of acute pancreatitis.

Detection of Lipase Activity in Cells by a Fluorescent Probe Based on Formation of Self-Assembled Micelles

Reliable and sensitive detection of lipase activity is essential for the early diagnosis and monitoring of acute pancreatitis or progression of digestive diseases. However, the available fluorescent probes for detection of lipase activity are only implemented in a hexane-water two-phase system due to the nature of heterogeneous catalysis of lipase, thus limiting their applications in direct imaging of lipase activity in living cells and tissues. Here we designed and synthesized a "turn on" fluorescent probe CPP based on self-assembled micelles for hydrolysis of lipase. The CPP probe exhibits high selectivity and excellent sensitivity for the detection of lipase in such a homogeneous system and is successfully applied for monitoring lipase activity in pancreatic AR42J cells, tissues, and serums. Taken together, the fluorescent CPP probe not only provides a tool for diagnostic potential in pancreatic disease but also demonstrates an application potential for micelle self-assembly-based development of biological probes.

The Effect of N-Acetylcysteine on Respiratory Enzymes, ADP/ATP Ratio, Glutathione Metabolism, and Nitrosative Stress in the Salivary Gland Mitochondria of Insulin Resistant Rats

This is the first study to assess the effect of N-acetylcysteine (NAC) on the mitochondrial respiratory system, as well as free radical production, glutathione metabolism, nitrosative stress, and apoptosis in the salivary gland mitochondria of rats with high-fat diet (HFD)-induced insulin resistance (IR). The study was conducted on male Wistar rats divided into four groups of 10 animals each: C (control, rats fed a standard diet containing 10.3% fat), C + NAC (rats fed a standard diet, receiving NAC intragastrically), HFD (rats fed a high-fat diet containing 59.8% fat), and HFD + NAC (rats fed HFD diet, receiving NAC intragastrically). We confirmed that 8 weeks of HFD induces systemic IR as well as disturbances in mitochondrial complexes of the parotid and submandibular glands of rats. NAC supplementation leads to a significant increase in the activity of complex I, II + III and cytochrome c oxidase (COX), and also reduces the ADP/ATP ratio compared to HFD rats. Furthermore, NAC reduces the hydrogen peroxide production/activity of pro-oxidant enzymes, increases the pool of mitochondrial glutathione, and prevents cytokine formation, apoptosis, and nitrosative damage to the mitochondria in both aforementioned salivary glands of HFD rats. To sum up, NAC supplementation enhances energy metabolism in the salivary glands of IR rats, and prevents inflammation, apoptosis, and nitrosative stress.

Antioxidant Defense, Oxidative Modification, and Salivary Gland Function in an Early Phase of Cerulein Pancreatitis

Acute pancreatitis (AP) is a multifactorial disease characterized by necroinflammatory changes of the pancreas. Our study is the first study which evaluated the relationship between the free radical production, enzymatic and nonenzymatic antioxidants, oxidative damage, and secretory function of the salivary glands of AP rats. Male Wistar rats were divided equally into 2 groups: control (n = 9) and AP (n = 9). AP was induced by intraperitoneal injection with cerulein and confirmed by higher serum amylase and lipase. We have demonstrated that the superoxide dismutase and glutathione reductase activities, as well as reduced glutathione concentration, were significantly decreased in both the parotid and submandibular glands of AP rats as compared to the control rats. The production of free radicals evidenced as dichlorodihydrofluorescein assay and the activity of NADPH oxidase and xanthine oxidase and IL-1β concentration were significantly higher in the parotid and submandibular glands of AP rats compared to the controls. In AP rats, we also showed a statistical increase in oxidation modification products (advanced glycation end products and advanced oxidation protein products), salivary amylase activity, and significant decrease in the total protein content. However, we did not show apoptosis and any morphological changes in the histological examination of the salivary glands of AP rats. To sum up, cerulein-induced AP intensifies production of oxygen free radicals, impairs the redox balance of the salivary glands, and is responsible for higher oxidative damage to these glands. Interestingly, oxidative modification of proteins and dysfunction of the antioxidant barrier are more pronounced in the submandibular glands of AP rats.