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International Journal of Molecular... Jun 2024Leptin regulates lipid metabolism, maximizing insulin sensitivity; however, peripheral leptin resistance is not fully understood, and its contribution to metabolic...
Leptin regulates lipid metabolism, maximizing insulin sensitivity; however, peripheral leptin resistance is not fully understood, and its contribution to metabolic dysfunction-associated steatotic liver disease (MASLD) is unclear. This study evaluated the contribution of the leptin axis to MASLD in humans. Forty-three participants, mostly female (86.04%), who underwent cholecystectomy were biopsied. Of the participants, 24 were healthy controls, 8 had MASLD, and 11 had metabolic dysfunction-associated steatohepatitis (MASH). Clinical and biochemical data and the gene expression of leptin, leptin receptor (), suppressor of cytokine signaling 3 (), sterol regulatory element-binding transcription factor 1 (), stearoyl-CoA desaturase-1 (), and patatin-like phospholipase domain-containing protein 2 (), were determined from liver and adipose tissue. Higher serum leptin and levels in the omental adipose tissue (OAT) and liver with MASH were found. In the liver, was positively correlated with leptin expression in adipose tissue, and was correlated with . In OAT, was correlated with insulin resistance and transaminase enzymes ( < 0.05 for all. In conclusion, we evidenced the correlation between the peripheral leptin resistance axis in OAT-liver crosstalk and the complications of MASLD in humans.
Topics: Humans; Leptin; Female; Male; Liver; Middle Aged; Omentum; Adipose Tissue; Adult; Fatty Liver; Receptors, Leptin; Suppressor of Cytokine Signaling 3 Protein; Insulin Resistance; Sterol Regulatory Element Binding Protein 1; Stearoyl-CoA Desaturase
PubMed: 38928125
DOI: 10.3390/ijms25126420 -
Biomedicines May 2024The sperm-specific phospholipase C zeta (PLCζ) protein is widely considered as the predominant physiological stimulus for initiating the Ca release responsible for...
The sperm-specific phospholipase C zeta (PLCζ) protein is widely considered as the predominant physiological stimulus for initiating the Ca release responsible for oocyte activation during mammalian fertilization. The increasing number of genetic and clinical reports that directly link PLCζ defects and/or deficiencies with oocyte activation failure (OAF) necessitates the use of a powerful therapeutic intervention to overcome such cases of male factor infertility. Currently, in vitro fertilization (IVF) clinics treat OAF cases after intracytoplasmic sperm injection (ICSI) with Ca ionophores. Despite their successful use, such chemical agents are unable to trigger the physiological pattern of Ca oscillations. Moreover, the safety of these ionophores is not yet fully established. We have previously demonstrated that recombinant PLCζ protein can be successfully used to rescue failed oocyte activation, resulting in efficient blastocyst formation. Herein, we produced a maltose binding protein (MBP)-tagged recombinant human PLCζ protein capable of inducing Ca oscillations in mouse oocytes similar to those observed at fertilization. Circular dichroism (CD) experiments revealed a stable, well-folded protein with a high helical content. Moreover, the recombinant protein could retain its enzymatic properties for at least up to 90 days after storage at -80 °C. Finally, a chick embryo model was employed and revealed that exposure of fertilized chicken eggs to MBP-PLCζ did not alter the embryonic viability when compared to the control, giving a first indication of its safety. Our data support the potential use of the MBP-PLCζ recombinant protein as an effective therapeutic tool but further studies are required prior to its use in a clinical setting.
PubMed: 38927390
DOI: 10.3390/biomedicines12061183 -
Biomolecules Jun 2024This work describes a novel route for phospholipid fatty acid remodeling involving the monounsaturated fatty acid palmitoleic acid. When administered to human monocytes,...
This work describes a novel route for phospholipid fatty acid remodeling involving the monounsaturated fatty acid palmitoleic acid. When administered to human monocytes, palmitoleic acid rapidly incorporates into membrane phospholipids, notably into phosphatidylcholine (PC). In resting cells, palmitoleic acid remains within the phospholipid pools where it was initially incorporated, showing no further movement. However, stimulation of the human monocytes with either receptor-directed (opsonized zymosan) or soluble (calcium ionophore A23187) agonists results in the rapid transfer of palmitoleic acid moieties from PC to phosphatidylinositol (PI). This is due to the activation of a coenzyme A-dependent remodeling route involving two different phospholipase A enzymes that act on different substrates to generate free palmitoleic acid and lysoPI acceptors. The stimulated enrichment of specific PI molecular species with palmitoleic acid unveils a hitherto-unrecognized pathway for lipid turnover in human monocytes which may play a role in regulating lipid signaling during innate immune activation.
Topics: Humans; Monocytes; Fatty Acids, Monounsaturated; Phosphatidylcholines; Phosphatidylinositols
PubMed: 38927110
DOI: 10.3390/biom14060707 -
Journal of Diabetes Jul 2024Cardiovascular disease (CVD) is recognized as a primary and severe comorbidity in patients with type 2 diabetes mellitus (T2DM) and is also identified as a leading cause...
BACKGROUND
Cardiovascular disease (CVD) is recognized as a primary and severe comorbidity in patients with type 2 diabetes mellitus (T2DM) and is also identified as a leading cause of mortality within this population. Consequently, the identification of novel biomarkers for the risk stratification and progression of CVD in individuals with T2DM is of critical importance.
METHODS
This retrospective cohort study encompassed 979 patients diagnosed with T2DM, of whom 116 experienced CVD events during the follow-up period. Clinical assessments and comprehensive blood laboratory analyses were conducted. Age- and sex-adjusted Cox proportional hazard regression analysis was utilized to evaluate the association between lipoprotein-associated phospholipase A (Lp-PLA), C1q/tumor necrosis factor-related protein 3 (CTRP-3), and the incidence of CVD in T2DM. The diagnostic performance of these biomarkers was assessed through receiver operating characteristic (ROC) curve analysis and the computation of the area under the curve (AUC).
RESULTS
Over a median follow-up of 84 months (interquartile range: 42 [32-54] months), both novel inflammatory markers, Lp-PLA and CTRP-3, and traditional lipid indices, such as low-density lipoprotein cholesterol and apolipoprotein B, exhibited aberrant expression in the CVD-afflicted subset of the T2DM cohort. Age- and sex-adjusted Cox regression analysis delineated that Lp-PLA (hazard ratio [HR] = 1.007 [95% confidence interval {CI}: 1.005-1.009], p < 0.001) and CTRP-3 (HR = 0.943 [95% CI: 0.935-0.954], p < 0.001) were independently associated with the manifestation of CVD in T2DM. ROC curve analysis indicated a substantial predictive capacity for Lp-PLA (AUC = 0.81 [95% CI: 0.77-0.85], p < 0.001) and CTRP-3 (AUC = 0.91 [95% CI: 0.89-0.93], p < 0.001) in forecasting CVD occurrence in T2DM. The combined biomarker approach yielded an AUC of 0.94 (95% CI: 0.93-0.96), p < 0.001, indicating enhanced diagnostic accuracy.
CONCLUSIONS
The findings suggest that the biomarkers Lp-PLA and CTRP-3 are dysregulated in patients with T2DM who develop CVD and that each biomarker is independently associated with the occurrence of CVD. The combined assessment of Lp-PLA and CTRP-3 may significantly augment the diagnostic precision for CVD in the T2DM demographic.
Topics: Humans; Diabetes Mellitus, Type 2; Male; Female; Biomarkers; Middle Aged; Cardiovascular Diseases; 1-Alkyl-2-acetylglycerophosphocholine Esterase; Retrospective Studies; Aged; Follow-Up Studies; ROC Curve; Risk Factors
PubMed: 38924255
DOI: 10.1111/1753-0407.13574 -
Environmental Microbiology Reports Jun 2024The global landscape of Candida infections has seen a significant shift. Previously, Candida albicans was the predominant species. However, there has been an emergence... (Comparative Study)
Comparative Study
The global landscape of Candida infections has seen a significant shift. Previously, Candida albicans was the predominant species. However, there has been an emergence of non-albicans Candida species, which are often less susceptible to antifungal treatment. Candida kefyr, in particular, has been increasingly associated with infections. This study aimed to investigate the profiles of enzymatic activity and biofilm formation in both clinical and non-clinical isolates of C. kefyr. A total of 66 C. kefyr isolates were analysed. The activities of proteinase and phospholipase were assessed using bovine serum albumin and egg yolk agar, respectively. Haemolysin, caseinolytic and esterase activities were evaluated using specific methods. Biofilm formation was investigated using crystal violet staining. The findings indicated that biofilm and proteinase activity were detected in 81.8% and 93.9% of all the isolates, respectively. Haemolysin activity was observed with the highest occurrence (95.5%) among normal microbiota isolates. Esterase activity was predominantly identified in dairy samples and was absent in hospital samples. Caseinase production was found with the highest occurrence (18.2%) in normal microbiota and hospital samples. Phospholipase activity was limited, found in only 3% of all the isolates. These findings reveal variations in enzyme activity between clinical and non-clinical C. kefyr isolates. This sheds light on their pathogenic potential and has implications for therapeutic strategies.
Topics: Biofilms; Candida; Humans; Candidiasis; Phospholipases; Esterases; Hemolysin Proteins; Peptide Hydrolases; Environmental Microbiology
PubMed: 38923398
DOI: 10.1111/1758-2229.13282 -
Toxins May 2024In the published publication [...].
In the published publication [...].
PubMed: 38922178
DOI: 10.3390/toxins16060250 -
Toxins Jun 2024Cytotoxins (CTs) are three-finger membrane-active toxins present mainly in cobra venom. Our analysis of the available CT amino acid sequences, literature data on their... (Review)
Review
Cytotoxins (CTs) are three-finger membrane-active toxins present mainly in cobra venom. Our analysis of the available CT amino acid sequences, literature data on their membrane activity, and conformational equilibria in aqueous solution and detergent micelles allowed us to identify specific amino acid residues which interfere with CT incorporation into membranes. They include Pro9, Ser28, and Asn/Asp45 within the N-terminal, central, and C-terminal loops, respectively. There is a hierarchy in the effect of these residues on membrane activity: Pro9 > Ser28 > Asn/Asp45. Taking into account all the possible combinations of special residues, we propose to divide CTs into eight groups. Group 1 includes toxins containing all of the above residues. Their representatives demonstrated the lowest membrane activity. Group 8 combines CTs that lack these residues. For the toxins from this group, the greatest membrane activity was observed. We predict that when solely membrane activity determines the cytotoxic effects, the activity of CTs from a group with a higher number should exceed that of CTs from a group with a lower number. This classification is supported by the available data on the cytotoxicity and membranotropic properties of CTs. We hypothesize that the special amino acid residues within the loops of the CT molecule may indicate their involvement in the interaction with non-lipid targets.
Topics: Cell Membrane; Animals; Cytotoxins; Elapid Venoms; Amino Acids; Amino Acid Sequence; Humans
PubMed: 38922156
DOI: 10.3390/toxins16060262 -
JGH Open : An Open Access Journal of... Jun 2024After pancreaticoduodenectomy, 20-40% of patients develop steatotic liver disease (SLD), and steatohepatitis can be a problem. Although patatin-like phospholipase...
AIM
After pancreaticoduodenectomy, 20-40% of patients develop steatotic liver disease (SLD), and steatohepatitis can be a problem. Although patatin-like phospholipase domain-containing 3 protein (PNPLA3) and transmembrane 6 superfamily member 2 (TM6SF2) polymorphisms are involved in SLD and steatohepatitis development, whether this is the case after pancreaticoduodenectomy is unclear.
METHODS AND RESULTS
Forty-three patients with pancreatic cancer who underwent pancreaticoduodenectomy at our hospital between April 1, 2018, and March 31, 2021, were included. We extracted DNA from noncancerous areas of residual specimens after pancreaticoduodenectomy and determined PNPLA3 and TM6SF2 gene polymorphisms using real-time polymerase chain reaction. SLD was defined as a liver with an attenuation value of ≤40 HU or a liver-to-spleen ratio of ≤0.9 on computed tomography. We defined high hepatic fibrosis indexes (HFI) instead of steatohepatitis as a Fibrosis-4 index of ≥2.67 or nonalcoholic fatty liver disease fibrosis score of ≥0.675 in patients with SLD. The cumulative incidence of SLD ( = 0.299) and high HFI ( = 0.987) after pancreaticoduodenectomy were not significantly different between the PNPLA3 homozygous and minor allele groups. The incidences of high HFI at 1 year after pancreaticoduodenectomy were 16.8% and 27.0% in the TM6SF2 major homozygous and minor allele groups, respectively, with a significant difference in the cumulative incidence ( = 0.046).
CONCLUSION
The TM6SF2 minor allele may contribute to steatohepatitis development after pancreaticoduodenectomy.
PubMed: 38919271
DOI: 10.1002/jgh3.13113 -
Biochimica Et Biophysica Acta.... Jun 2024Phospholipase A's (PLA's) constitute a superfamily of enzymes that hydrolyze the sn-2 fatty acyl chain on glycerophospholipids. We have previously reported that each PLA...
Phospholipase A's (PLA's) constitute a superfamily of enzymes that hydrolyze the sn-2 fatty acyl chain on glycerophospholipids. We have previously reported that each PLA Type shows a unique substrate specificity for the molecular species it hydrolyzes, especially the acyl chain that is cleaved from the sn-2 position and to some extent the polar group. However, phosphatidylinositol (PI) and PI phosphates (PIPs) have not been as well studied as substrates as other phospholipids because the PIPs require adaptation of the standard analysis methods, but they are important in vivo. We determined the in vitro activity of the three major types of human PLA's, namely the cytosolic (c), calcium-independent (i), and secreted (s) PLAs toward PI, PI-4-phosphate (PI(4)P), and PI-4,5-bisphosphate (PI(4,5)P). The in vitro assay revealed that Group IVA cPLA (GIVA cPLA) showed relatively high activity toward PI and PI(4)P among the tested PLA's; nevertheless, the highly hydrophilic headgroup disrupted the interaction between the lipid surface and the enzyme. GIVA cPLA and GVIA iPLA showed detectable activity toward PI(4,5)P, but it appeared to be a poorer substrate for all of the PLA's tested. Furthermore, molecular dynamics (MD) simulations demonstrated that Thr416 and Glu418 of GIVA cPLA contribute significantly to accommodating the hydrophilic head groups of PI and PI(4)P, which could explain some selectivity for PI and PI(4)P. These results indicated that GIVA cPLA can accommodate PI and PI(4)P in its active site and hydrolyze them, suggesting that the GIVA cPLA may best account for the PI and PIP hydrolysis in living cells.
PubMed: 38917952
DOI: 10.1016/j.bbalip.2024.159527 -
Bioresources and Bioprocessing Jun 2024Phospholipase A1 (PLA1) is a kind of specific phospholipid hydrolase widely used in food, medical, textile. However, limitations in its expression and enzymatic activity...
Phospholipase A1 (PLA1) is a kind of specific phospholipid hydrolase widely used in food, medical, textile. However, limitations in its expression and enzymatic activity have prompted the investigation of the phospholipase-assisting protein PlaS. In this study, we elucidate the role of PlaS in enhancing the expression and activity of PlaA1 through N-terminal truncation. Our research demonstrates that truncating the N-terminal region of PlaS effectively overcomes its inhibitory effect on host cells, resulting in improved cell growth and increased protein solubility of the protein. The yeast two-hybrid assay confirms the interaction between PlaA1 and N-terminal truncated PlaS (∆N27 PlaS), highlighting their binding capabilities. Furthermore, in vitro studies using Biacore analysis reveal a concentration-dependent and specific binding between PlaA1 and ∆N27 PlaS, exhibiting high affinity. Molecular docking analysis provides insights into the hydrogen bond interactions between ∆N27 PlaS and PlaA1, identifying key amino acid residues crucial for their binding. Finally, the enzyme activity of PLA1 was boost to 8.4 U/mL by orthogonal test. Study significantly contributes to the understanding of the interaction mechanism between PlaS and PlaA1, offering potential strategies for enhancing PlaA1 activity through protein engineering approaches.
PubMed: 38916814
DOI: 10.1186/s40643-024-00777-1