Sodium octanoate mediates GPR84-dependent and independent protection against sepsis-induced myocardial dysfunction.

INTRODUCTION: This study aims to evaluate the therapeutic effects of sodium octanoate (SO), a medium-chain fatty acid salt, on SIMD in a murine model and to explore its underlying mechanisms. METHODS: Male mice were subjected to sepsis models through two methods: intraperitoneal injection of lipopolysaccharide (LPS) and cecal ligation and punction (CLP). Mice received interval doses of SO every 2 hours or 4 hours for a total of six times or three times after LPS treatment. The relationship between SO and G protein-coupled receptor 84 (GPR84) was evaluated through GEO data analysis and molecular docking studies. DBA/2 mice were used to study the role of the GPR84 protein in the SO-mediated protection. Energy metabolomics was utilized to comprehensively assess the impact of SO on the levels of cardiac energy metabolic products in septic mice. histone modification identification techniques were used to further identify the specific sites of histone modification in the hearts of SO-treated septic mice. RESULTS: SO treatment significantly improved myocardial contractile function, restored the oxidative stress imbalance and enhanced the myocardium's resistance to oxidative injury. SO significantly promotes the expression of GPR84. The loss of GPR84 function markedly attenuates the protective effects of SO. SO enhanced myocardial energy metabolism by promoting the synthesis of acetyl-CoA and upregulating genes involved in fatty acid ß-oxidation which were abolished by medium-chain acyl-CoA dehydrogenase (MCAD) knockdown. SO induced histone acetylation, particularly at H3K123 and H3K80. CONCLUSION: Our study demonstrates that SO exerts protective effects against SIMD through both GPR84-mediated anti-inflammatory and antioxidant actions and GPR84-independent enhancement of myocardial energy metabolism, possibly mediated by MCAD.

Sodium octanoate alleviates cardiac and cerebral injury after traumatic cardiac arrest in a porcine model.

INTRODUCTION: Traumatic cardiac arrest (TCA) is a severe condition with a high mortality rate, and patients who survive from TCA face a poor prognosis due to post-resuscitation injury, including cardiac and cerebral injury, which remains a serious challenge. Sodium octanoate has shown protective effects against various diseases. The present study aims to investigate sodium octanoate's protective effects against cardiac and cerebral injury after TCA in a porcine model. METHODS: The study included a total of 22 male domestic pigs divided into three groups: Sham group (n = 7), TCA group (n = 7), and sodium octanoate (SO) group (n = 8). Hemorrhage was initiated via the right femoral artery by a blood pump at a rate of 2 ml·kg-1·min-1 to establish TCA model. The Sham group underwent only endotracheal intubation and arteriovenous catheterization, without experiencing the blood loss/cardiac arrest/resuscitation model. At 5 min after resuscitation, the SO group received a continuous sodium octanoate infusion while the TCA group received the same volume of saline. General indicators were monitored, and blood samples were collected at baseline and at different time points after resuscitation. At 24 h after resuscitation, pigs were sacrificed, and heart and brain were obtained for cell apoptosis detection, iron deposition staining, oxidative stress detection, and the expression of ferroptosis-related proteins (ACSL4 and GPX4). RESULTS: Sodium octanoate significantly improved mean arterial pressure, cardiac output and ejection fraction induced by TCA. Serum biomarkers of cardiac and cerebral injury were found to increase at all time points after resuscitation, while sodium octanoate significantly reduced their levels. The apoptosis rates of cardiomyocytes and cerebral cortex cells in the SO group were significantly lower than in the TCA group, along with a reduced area of iron deposition staining. The sodium octanoate also reduced oxidative stress and down-regulated ferroptosis which was indicated by protein level alteration of ACSL4 and GPX4. CONCLUSION: Our study's findings suggest that early infusion of sodium octanoate significantly alleviates post-resuscitation cardiac and cerebral injury in a porcine model of TCA, possibly through inhibition of cell apoptosis and GPX4-mediated ferroptosis. Therefore, sodium octanoate could be a potential therapeutic strategy for patients with TCA.

Research progress on the influence of ligands on the stability of albumin / 中国输血杂志

It is necessary to improve the stability of human serum albumin in response to the complex temperature, light and other conditions during the manufacture and storage. In this paper, the stabilization effect and simple stabilization mechanism of ligands on albumin were described from the perspective of ligand binding to albumin.Through review and comparison, it can be concluded that the common ligand sodium octanoate mainly plays a role in improving thermal stability, and the common ligand N-acetyl-L-tryptophan mainly plays a role in improving antioxidant activity, N-acetyl-L-methionine has better antioxidant and anti-photooxidation than N-acetyl-L-tryptophan.

Effect of sodium octanoate on renal-intestinal ischemia-reperfusion injury after resuscitation from traumatic cardiac arrest in pigs / 中华创伤杂志

Objective:To investigate the effect of sodium octanoate on renal-intestinal ischemia- reperfusion injury (IRI) after resuscitation from traumatic cardiac arrest in pigs.Methods:Twenty-two miniature piglets with a body weight of (37.6±2.5)kg were divided into three groups according to the random-number table method: normal group ( n=7), IRI group ( n=7) and IRI-treated group ( n=8). A renal-intestinal IRI model of the pig was established by allowing femoral artery to bleed through blood pump at a rate of 2 ml·kg -1·min -1 until cardiac arrest, followed by whole blood transfusion through the femoral vein at a rate of 5 ml·kg -1·min -1 after observation for 6 minutes, and 50% of total blood loss was reinfused before resuscitation. Both the IRI group and IRI-treated group were with IRI model, while normal group was just monitored without induction of IRI. Besides, IRI-treated group was injected intravenously with sodium octanoate (30 mg/kg) for 1 hour at 5 minutes after restoration of spontaneous circulation (ROSC). (1) The rate of resuscitation success, survival rate at 4, 24 hours after resuscitation, blood loss when reaching cardiac arrest criteria and resuscitation time when reaching the ROSC criteria were compared in the three groups. (2) Levels of serum creatinine (SCr), urea nitrogen (BUN), intestinal fatty acid binding protein (iFABP) and diamine oxidase (DAO) were measured before resuscitation and at 1, 2, 4, 24 hours after resuscitation. (3) The animals were sacrificed at 24 hours post-resuscitation to harvest renal and intestinal tissues rapidly. TUNEL test was applied for the cellular apoptosis index. Prussian blue was used to detect the rate of iron deposition. Western blot analysis was used to measure levels of glutathione peroxidase 4 (GPX4) and acyl-CoA synthetase long-chain family member4 (ACSL4). Results:In three groups, all pigs survived. There was no significant difference in blood loss or resuscitation time between IRI group and IRI-treated group (all P>0.05). There was no significant difference in levels of SCr, BUN, iFABP or DAO before resuscitation and at 1, 2, 4, 24 hours after resuscitation in normal group (all P>0.05). But their levels were gradually increased at 1, 2, 4, 24 hours after resuscitation from that before resuscitation in IRI group and IRI-treated group (all P<0.01). Among three groups, levels of SCr, BUN, iFABP and DAO had no significant difference before resuscitation (all P>0.05), but showed obvious increase in IRI group and the IRI-treated group at 1, 2, 4, 24 hours after resuscitation compared with normal group, especially in IRI group (all P<0.01). In normal group, IRI group and IRI-treated group after 24 hours for resuscitation, the cellular apoptosis index of renal tissues was (2.3±0.8)%, (44.0±5.4)% and (13.8±4.3)%; the cellular apoptosis index of intestinal tissues was (2.6±0.9)%, (61.3±10.4)% and (20.8±3.7)%; the rate of iron deposition of renal tissues was (0.6±0.1)%, (3.9±1.0)% and (1.7±0.3)%; the rate of iron deposition of intestinal tissues was (0.8±0.1)%, (4.9±0.9)% and (2.1±0.5)% (all P<0.01). The cellular apoptosis index and rate of iron deposition of both renal and intestinal tissues were the highest in IRI group. The renal-intestinal expression of GPX4 in IRI group and IRI-treated group was lower than that in normal group at 24 hours after resuscitation (all P<0.05), with the lowest in IRI group. The renal-intestinal expression of ACSL4 in IRI group and IRI-treated group was higher than that in normal group at 24 hours after resuscitation (all P< 0.01), with the highest in IRI group. Conclusion:Sodium octanoate can reduce renal-intestinal IRI after resuscitation from traumatic cardiac arrest in pigs, the mechanism for which is probably due to that sodium octanoate can inhibit cellular apoptosis and reduce ferroptosis by regulating the expression levels of GPX4 and ACSL4.

Enhancement of microbial pigment production from Monascus ruber by sodium octanoate addition.

BACKGROUND: The addition of fatty acids and other molecules to culture media may intensify the production of biomolecules, such as monascus pigments, however, few studies of this have been developed. Thus, the objective of the present study was to investigate the effects of adding sodium octanoate to the culture medium, with a view to increasing the synthesis and production of the pigments produced by Monascus ruber CCT 3802 on solid and submerged cultivations. METHODS: Monacus ruber CCT 3802 was cultivated on solid and submerged media supplemented with different concentrations of sodium octanoate. The radial growth rate of the colonies was obtained from the declivity of the linear regression of the radius of the colonies as a function of cultivation time and the kinetics of submerged cultivations were performed. The filtrate obtained was submitted to scanning spectrophotometry at a range from 350 to 550 nm and the color parameters were determined by using the CIELAB color system. The data were submitted to a univariate analysis of variance (ANOVA) and the means obtained for each treatment submitted to Tukey's test using Statistica version 5.0 software at a 5% level of significance. RESULTS: Sodium octanoate exerted a strong influence on growth and pigment production in solid and submerged cultivations. The values for L*, a* and b* were positive for pigments produced, with regards to colors close to red and yellow. In the media supplemented with 1.0 mM and 1.5 mM of sodium octanoate, the production of red pigments became expressive from 48 hours-cultivation, increasing considerably from the second to the fourth days. This shows that supplementation with sodium octanoate provides a greater production of pigments in a shorter time interval than the control culture, which required 144 hours of cultivation to present a higher value for AU510nm, which directly influenced pigment productivity. CONCLUSIONS: The addition of sodium octanoate exerted a significant influence on both microbial growth and pigment production in both solid and submerged cultivations. The supplementation of the submerged cultures with sodium octanoate was responsible for an expressive production of pigments in just 48 hours, whereas 144 hours were necessary in the absence of sodium octanoate. These results are promising for increasing the productivity of pigment production, including possibilities for application on an industrial scale.

Crystallographic analysis of the ternary complex of octanoate and N-acetyl-l-methionine with human serum albumin reveals the mode of their stabilizing interactions.

During pasteurization and storage of albumin products, Sodium octanoate (Oct) and N-acethyl-l-tryptophan (N-AcTrp) are used as the thermal stabilizer and the antioxidant for human serum albumin (HSA), respectively. We recently reported that N-acethyl-l-methionine (N-AcMet) is an antioxidant for HSA, which is superior to N-AcTrp when it is especially exposed to light during storage. The objective of the present study is to clarify the molecular mechanism responsible for the HSA protective effect of Oct and N-AcMet based on their ternary complex structure. Crystal structure of the HSA-Oct-N-AcMet complex showed that one N-AcMet molecule is bound to the entrance of drug site 1 of HSA, and its side chain, which is susceptible to the oxidation, is exposed to the solvent. At the same time, two Oct binding sites are observed in drug sites 1 and 2 of HSA, respectively, and each Oct molecule occupies the hydrophobic cavity in them. These results indicate the molecular mechanism responsible for the HSA stabilization by these small molecules as follows. N-AcMet seals the entrance of drug site 1 while it acts as an antioxidant for HSA. Oct is chiefly bound to drug site 2 of HSA and it increases the thermal stability of HSA because of the occupying the largest intra-cavity of sub-domain IIIA in HSA. These findings suggest that N-AcMet acts positively as useful stabilizer for albumin formulated products such as functionalized HSA and HSA fusion proteins.