The Impact of Phospholipid-Based Liquid Crystals' Microstructure on Stability and Release Profile of Ascorbyl Palmitate and Skin Performance.

The drug delivery potential of liquid crystals (LCs) for ascorbyl palmitate (AP) was assessed, with the emphasis on the AP stability and release profile linked to microstructural rearrangement taking place along the dilution line being investigated by a set of complementary techniques. With high AP degradation observed after 56 days, two stabilization approaches, i.e., the addition of vitamin C or increasing AP concentration, were proposed. As a rule, LC samples with the lowest water content resulted in better AP stability (up to 52% of nondegraded AP in LC1 after 28 days) and faster API release (~18% in 8 h) as compared to the most diluted sample (29% of nondegraded AP in LC8 after 28 days, and up to 12% of AP released in 8 h). In addition, LCs exhibited a skin barrier-strengthening effect with up to 1.2-fold lower transepidermal water loss (TEWL) and 1.9-fold higher skin hydration observed in vitro on the porcine skin model. Although the latter cannot be linked to LCs' composition or specific microstructure, the obtained insight into LCs' microstructure contributed greatly to our understanding of AP positioning inside the system and its release profile, also influencing the overall LCs' performance after dermal application.

Human cardiac metabolism.

The heart is the most metabolically active organ in the human body, and cardiac metabolism has been studied for decades. However, the bulk of studies have focused on animal models. The objective of this review is to summarize specifically what is known about cardiac metabolism in humans. Techniques available to study human cardiac metabolism are first discussed, followed by a review of human cardiac metabolism in health and in heart failure. Mechanistic insights, where available, are reviewed, and the evidence for the contribution of metabolic insufficiency to heart failure, as well as past and current attempts at metabolism-based therapies, is also discussed.

Effects of ethyl palmitate on the release of aroma compounds in propanediol-ethanol solution and its mechanisms.

Long-chain esters (LCEs) are known to affect aroma perception, but the mechanism of their effects remains unclear. In this study, ethyl palmitate (EP), an important LCE in Osmanthus fragrans flower absolute (OFFA), was selected as a target to identify its role and mechanism. The release characteristics of 10 aroma compounds from OFFA with and without EP were obtained by headspace gas chromatography mass spectrometry (HS-GC/MS) and olfactometry evaluation, respectively. The results show that EP changes the release behaviors of volatile compounds in solution, increases their olfactory detection thresholds (ODTs), and reduces the equilibrium headspace concentrations. According to Whitman's two-film model, EP was found to change the partition coefficients and mass transfer coefficients of the compounds between the liquid and gas phases. This indicates that EP plays an important role in the scent formation of a flavor product and that it is very valuable for the style design of the flavor product.

Palmitate and group B Streptococcus synergistically and differentially induce IL-1ß from human gestational membranes.

Introduction: Rupture of the gestational membranes often precedes major pregnancy complications, including preterm labor and preterm birth. One major cause of inflammation in the gestational membranes, chorioamnionitis (CAM) is often a result of bacterial infection. The commensal bacterium Streptococcus agalactiae, or Group B Streptococcus (GBS) is a leading infectious cause of CAM. Obesity is on the rise worldwide and roughly 1 in 4 pregnancy complications is related to obesity, and individuals with obesity are also more likely to be colonized by GBS. The gestational membranes are comprised of several distinct cell layers which are, from outermost to innermost: maternally-derived decidual stromal cells (DSCs), fetal cytotrophoblasts (CTBs), fetal mesenchymal cells, and fetal amnion epithelial cells (AECs). In addition, the gestational membranes have several immune cell populations; macrophages are the most common phagocyte. Here we characterize the effects of palmitate, the most common long-chain saturated fatty acid, on the inflammatory response of each layer of the gestational membranes when infected with GBS, using human cell lines and primary human tissue. Results: Palmitate itself slightly but significantly augments GBS proliferation. Palmitate and GBS co-stimulation synergized to induce many inflammatory proteins and cytokines, particularly IL-1ß and matrix metalloproteinase 9 from DSCs, CTBs, and macrophages, but not from AECs. Many of these findings are recapitulated when treating cells with palmitate and a TLR2 or TLR4 agonist, suggesting broad applicability of palmitate-pathogen synergy. Co-culture of macrophages with DSCs or CTBs, upon co-stimulation with GBS and palmitate, resulted in increased inflammatory responses, contrary to previous work in the absence of palmitate. In whole gestational membrane biopsies, the amnion layer appeared to dampen immune responses from the DSC and CTB layers (the choriodecidua) to GBS and palmitate co-stimulation. Addition of the monounsaturated fatty acid oleate, the most abundant monounsaturated fatty acid in circulation, dampened the proinflammatory effect of palmitate. Discussion: These studies reveal a complex interplay between the immunological response of the distinct layers of the gestational membrane to GBS infection and that such responses can be altered by exposure to long-chain saturated fatty acids. These data provide insight into how metabolic syndromes such as obesity might contribute to an increased risk for GBS disease during pregnancy.

Evaluation of Novel Nasal Mucoadhesive Nanoformulations Containing Lipid-Soluble EGCG for Long COVID Treatment.

Following recovery from the acute infection stage of the SARS-CoV-2 virus (COVID-19), survivors can experience a wide range of persistent Post-Acute Sequelae of COVID-19 (PASC), also referred to as long COVID. According to the US National Research Action Plan on Long COVID 2022, up to 23.7 million Americans suffer from long COVID, and approximately one million workers may be out of the workforce each day due to these symptoms, leading to a USD 50 billion annual loss of salary. Neurological symptoms associated with long COVID result from persistent infection with SARS-CoV-2 in the nasal neuroepithelial cells, leading to inflammation in the central nervous system (CNS). As of today, there is no evidence that vaccines or medications can clear the persistent viral infection in olfactory mucosa. Recently published clinical data demonstrate that only 5% of long COVID anosmia patients have fully recovered during the past 2 years, and 10.4% of COVID patients are still symptomatic 18 months post-infection. Our group demonstrated that epigallocatechin-3-gallate-monopalmitate (EC16m) nanoformulations possess strong antiviral activity against human coronavirus, suggesting that this green-tea-derived compound in nanoparticle formulations could be developed as an intranasally delivered new drug targeting the persistent SARS-CoV-2 infection, as well as inflammation and oxidative stress in the CNS, leading to restoration of neurologic functions. The objective of the current study was to evaluate the mucociliary safety of the EC16m nasal nanoformulations and their efficacy against human coronavirus. METHODS: Nanoparticle size and Zeta potential were measured using the ZetaView Nanoparticle Tracking Analysis system; mucociliary safety was determined using the MucilAir human nasal model; contact antiviral activity and post-infection inhibition against the OC43 viral strain were assessed by the TCID50 assay for cytopathic effect on MRC-5 cells. RESULTS: The saline-based EC16 mucoadhesive nanoformulations containing 0.005 to 0.02% w/v EC16m have no significant difference compared to saline (0.9% NaCl) with respect to tissue integrity, cytotoxicity, and cilia beat frequency. A 5 min contact resulted in 99.9% inactivation of ß-coronavirus OC43. OC43 viral replication was inhibited by >90% after infected MRC-5 cells were treated with the formulations. CONCLUSION: The saline-based novel EC16m mucoadhesive nasal nanoformulations rapidly inactivated human coronavirus with mucociliary safety properties comparable to saline, a solution widely used for nasal applications.

Phytochemical analysis, physicochemical, pharmacokinetic properties and molecular docking studies of bioactive compounds in Ottelia alismoides (L.) pers. Against breast cancer proteins.

Plants provide compounds that can be used to treat diseases, and in silico methods help to expedite drug discovery while reducing costs. This study explored the phytochemical profile of methanol extract of O. alismoides using GC-MS to identify potential bioactive compounds. Autodock 4.2.6. was employed for molecular docking evaluation of the efficacy of these identified compounds against Estrogen Receptor Alpha (ERα), Human Epidermal Growth Factor Receptor 2 (HER2), and Epidermal Growth Factor Receptor (EGFR), proteins. Additionally, the ADMET (Absorption, Distribution, Metabolism, Excretion, and Toxicity) properties of the compounds were predicted using the SwissADME online tool. The preliminary phytochemical analysis revealed the presence of alkaloids, carbohydrates, glycosides, and steroids. During the GC-MS analysis, seven compounds were identified, and drug-likeness prediction of these compounds showed good pharmacokinetic properties having high gastrointestinal absorption, and orally bioavailable. The molecular docking studies exhibited promising binding affinities of bioactive compounds against all target proteins. Specifically, the compounds Tricyclo[5.2.1.0(2,6)]decan-10-ol and 2,2,6-Trichloro-7-oxabicyclo[4.1.0]heptane-1-carboxamide demonstrated the highest binding affinities with the ERα (-6.3 and - 6.0 k/cal), HER2 (-5.6 and - 6.1 k/cal), and EGFR (-5.4 and - 5.4 k/cal), respectively. These findings suggest the potential of O. alismoides as a source for developing new cancer therapeutics. The study highlights the effectiveness of in silico approaches for accelerating drug discovery from natural sources and paves the way for further exploration of these promising compounds. Supplementary Information: The online version contains supplementary material available at 10.1007/s40203-024-00227-y.

Saturated fatty acids negatively affect musculoskeletal tissues in vitro and in vivo.

Fish oils rank among the world's most popular nutritional supplements and are purported to have numerous health benefits. Previous work suggested that fish oils increase collagen production; however, the effect of fish oils on musculoskeletal health is poorly understood. Further, the divergent effects of omega-3 (Ω3FA) and saturated fatty acids (SFA) remains poorly understood. We tested the effects of Ω3FA and SFAs on in vitro-engineered human ligament (EHL) function. EHLs were treated with bovine serum albumin (BSA)-conjugated eicosapentaenoic acid (EPA, 20:5(n-3)), palmitic acid (PA, 16:0), or a BSA control for 6 days. EPA did not significantly alter, whereas PA significantly decreased EHL function and collagen content. To determine whether this was an in vitro artifact, mice were fed a control or high-lard diet for 14 weeks and musculoskeletal mass, insulin sensitivity, and the collagen content, and mechanics of tendon and bone were determined. Body weight was 40 % higher on a HFD, but muscle, tendon, and bone mass did not keep up with body weight resulting in relative losses in muscle mass, tendon, and bone collagen, as well as mechanical properties. Importantly, we show that PA acutely decreases collagen synthesis in vitro to a similar extent as the decrease in collagen content with chronic treatment. These data suggest that Ω3FAs have a limited effect on EHLs, whereas SFA exert a negative effect on collagen synthesis resulting in smaller and weaker musculoskeletal tissues both in vitro and in vivo.

Lack of Nr2e1 expression in hepatocytes impaired cell survival and aggravated palmitate-induced oxidative stress.

PURPOSE: Nuclear receptor subfamily 2 group E member 1 (Nr2e1) has been regarded as an essential regulator in neural stem cells. However, its function is still not clear in hepatocytes. This study aimed to clarify the effects of Nr2e1-deficiency in hepatocytes in lipotoxic conditions. MATERIALS/METHODS: Nr2e1-knockdown AML12 cells were generated by lentiviral vector transfection. The influences of Nr2e1-deficiency on hepatocyte survival were determined by cell cycle progression and cell apoptosis rate using flow cytometry. Real-time quantitative PCR and Western blot were used to examine the genes and protein expression related to apoptosis, lipid metabolism, and oxidative stress. Meanwhile, RNA sequencing was adopted in liver samples from Nr2e1-knockout (Nr2e1-KO) mice. RESULTS: Nr2e1 expression was observed with a significant decrease in AML12 cells after palmitic acid-stimulation. Knockdown of Nr2e1 in AML12 cells resulted in increased sensitivity to lipotoxicity, evidenced by a partial G0/G1 cell-cycle arrest and higher rates of cell apoptosis. Moreover, Nr2e1-knockdown AML12 cells presented increased gene expressions relative to lipid synthesis but decreased levels of ß-oxidation related genes. Lack of Nr2e1 augmented palmitate-induced oxidative stress in hepatocytes. In vivo, differential genes in Nr2e1-KO mice liver were enriched in pathways associated with liver regeneration and cell proliferation. CONCLUSIONS: This study indicated that hepatocytes lacking Nr2e1 were more susceptible to lipotoxic-mediated damage. Nr2e1 may serve as a potential target for the development of novel therapies for lipotoxicity-induced liver injury.

Infant Formula with 50% or More of Palmitic Acid Bound to the sn-2 Position of Triacylglycerols Eliminate the Association between Formula-Feeding and the Increase of Fecal Palmitic Acid Levels in Newborns: An Exploratory Study.

The binding ratio of palmitic acid (PA) at the sn-2 position of triacylglycerols in infant formulas is lower than that in breast milk, resulting in higher levels of fecal PA. Even if the ratio is increased to 40-50%, fecal PA levels in formula-fed infants remain higher than those in breast-fed infants. In Japan, infant formulas with 50% or more of PA bound to sn-2 (high sn-2 PA milk) are commercially available; however, their effects on PA excretion have not been investigated. Therefore, this observational study aimed to preliminarily evaluate whether the feeding volume of high sn-2 PA milk is significantly associated with fecal total/soaped PA levels in newborns. Infant formulas were classified as high (≥50% of PA bound to sn-2) or low sn-2 (<50%) PA milk. Associations between feeding volume of high or low sn-2 PA milk and fecal PA levels were evaluated using multiple regression analysis models. The results showed that the feeding volume of low sn-2 PA milk was positively associated with fecal total/soaped PA levels, while there was no significant association between those of high sn-2 PA milk and fecal total/soaped PA levels. Our preliminary study suggests that high sn-2 PA milk may reduce increased fecal PA levels in formula-fed newborns.

Health economics study of paliperidone palmitate in the treatment of schizophrenia: a 12-month cohort study.

BACKGROUND: To analyze the economic benefits of paliperidone palmitate in the treatment of schizophrenia. METHODS: We collected 546 patients who met the diagnostic criteria for schizophrenia according to the 《International Statistical Classification of Diseases and Related Health Problems,10th》(ICD-10). We gathered general population data such as gender, age, marital status, and education level, then initiated treatment with paliperidone palmitate. Then Follow-up evaluations were conducted at 1, 3, 6, 9, and 12 months after the start of treatment to assess clinical efficacy, adverse reactions, and injection doses. We also collected information on the economic burden before and after 12 months of treatment, as well as the number of outpatient visits and hospitalizations in the past year to analyze economic benefits. RESULTS: The baseline patients totaled 546, with 239 still receiving treatment with paliperidone palmitate 12 months later. After 12 months of treatment, the number of outpatient visits per year increased compared to before (4 (2,10) vs. 12 (4,12), Z=-5.949, P < 0.001), while the number of hospitalizations decreased (1 (1,3) vs. 1 (1,2), Z = 5.625, P < 0.001). The inpatient costs in the direct medical expenses of patients after 12 months of treatment decreased compared to before (5000(2000,12000) vs. 3000 (1000,8050), P < 0.05), while there was no significant change in outpatient expenses and direct non-medical expenses (transportation, accommodation, meal, and family accompanying expenses, etc.) (P > 0.05); the indirect costs of patients after 12 months of treatment (lost productivity costs for patients and families, economic costs due to destructive behavior, costs of seeking non-medical assistance) decreased compared to before (300(150,600) vs. 150(100,200), P < 0.05). CONCLUSION: Palmatine palmitate reduces the number of hospitalizations for patients, as well as their direct and indirect economic burdens, and has good economic benefits.

Controlled release of vitamin A palmitate from crosslinked cyclodextrin organic framework for dry eye disease therapy.

Controlled release drug delivery systems of eye drops are a promising ophthalmic therapy with advantages of good patient compliance and low irritation. However, the lack of a suitable drug carrier for ophthalmic use limits the development of the aforementioned system. Herein, the crosslinked cyclodextrin organic framework (COF) with a cubic porous structure and a uniform particle size was synthesized and applied to solidify vitamin A palmitate (VAP) by using the solvent-free method. The VAP@COF suspension eye drops were formulated by screening co-solvents, suspending agents, and stabilizing agents to achieve a homogeneous state and improve stability. According to the in vitro release study, the VAP@COF suspension exhibited a controlled release of VAP within 12 h. Both the ex vivo corneal contact angle and in vivo fluorescence tracking indicated that the VAP@COF suspension prolonged the VAP residence time on the ocular surface. This suspension accelerated the recovery of the dry eye disease (DED) model in New Zealand rabbits. Furthermore, the suspension was non-cytotoxic to human corneal epithelial cells and non-irritation to rabbit eyes. In summary, the particulate COF is an eye-acceptable novel carrier that sustains release and prolongs the VAP residence time on the ocular surface for DED treatment.

Ultrasound-assisted intensification of Pickering interfacial biocatalysis preparation of vitamin A aliphatic esters.

A novel approach to ultrasound-assisted Pickering interfacial biocatalysis (PIB) has been proposed and implemented for the efficient enzymatic transesterification production of vitamin A fatty acid esters. This is the first instance of exploiting the synergistic effect of ultrasound and the bifunctional modification of enzyme supports to accelerate biocatalytic performance in PIB systems. The optimal conditions were determined to be ultrasound power of 70 W, on/off time of 5 s/5 s, substrate molar ratio of 1:1, enzyme addition of 2 %, and a volume ratio of n-hexane to PBS of 3:1, a temperature of 40 °C, and a time of 30 min. The application of ultrasound technology not only improved lipase activity but also allowed for a reduction in emulsion droplet size to enhance interfacial mass transfer.Bifunctional modification of silica-based supports enhanced stability of immobilized enzymes by increasing hydrogen bonding while maintaining the active interface microenvironment. Compared with a non-ultrasound-assisted PIB system stabilized by mono-modified immobilized enzyme particles, the catalytic efficacy (CE) of the novel system reached 8.18 mmol g-1 min-1, which was enhanced by 3.33-fold, while the interfacial area was found to have increased by 17.5-fold. The results facilitated the conversion of vitamin A palmitate (VAP), vitamin A oleate (VAO), vitamin A linoleate (VAL), and vitamin A linolenate (VALn), with conversion rates of approximately 98.2 %, 97.4 %, 96.1 %, and 94.7 %, respectively. This represents the most efficient example that has been reported to our knowledge. Furthermore, the system demonstrated improved reusability, with a conversion rate of 62.1 % maintained even after 10 cycles. The findings presented in this paper provide valuable insights into an efficient and conveniently promising protocol for the development of PIB systems.

Non-esterified fatty acid palmitate facilitates oxidative endoplasmic reticulum stress and apoptosis of ß-cells by upregulating ERO-1α expression.

Adipose tissue-derived non-esterified saturated long-chain fatty acid palmitate (PA) decisively contributes to ß-cell demise in type 2 diabetes mellitus in part through the excessive generation of hydrogen peroxide (H2O2). The endoplasmic reticulum (ER) as the primary site of oxidative protein folding could represent a significant source of H2O2. Both ER-oxidoreductin-1 (ERO-1) isoenzymes, ERO-1α and ERO-1ß, catalyse oxidative protein folding within the ER, generating equimolar amounts of H2O2 for every disulphide bond formed. However, whether ERO-1-derived H2O2 constitutes a potential source of cytotoxic luminal H2O2 under lipotoxic conditions is still unknown. Here, we demonstrate that both ERO-1 isoforms are expressed in pancreatic ß-cells, but interestingly, PA only significantly induces ERO-1α. Its specific deletion significantly attenuates PA-mediated oxidative ER stress and subsequent ß-cell death by decreasing PA-mediated ER-luminal and mitochondrial H2O2 accumulation, by counteracting the dysregulation of ER Ca2+ homeostasis, and by mitigating the reduction of mitochondrial membrane potential and lowered ATP content. Moreover, ablation of ERO-1α alleviated PA-induced hyperoxidation of the ER redox milieu. Importantly, ablation of ERO-1α did not affect the insulin secretory capacity, the unfolded protein response, or ER redox homeostasis under steady-state conditions. The involvement of ERO-1α-derived H2O2 in PA-mediated ß-cell lipotoxicity was corroborated by the overexpression of a redox-active ERO-1α underscoring the proapoptotic activity of ERO-1α in pancreatic ß-cells. Overall, our findings highlight the critical role of ERO-1α-derived H2O2 in lipotoxic ER stress and ß-cell failure.

Nigella sativa, active principle thymoquinone, alleviates palmitate-induced cytotoxicity, inflammation and bioenergetic disruptions in macrophages: An invitro study model.

Thymoquinone (TQ) is one of the main phytochemical bioactive ingredients in Nigella sativa, with reported immunity-boosting properties. The current study evaluated the anti-inflammatory effect of TQ against inflammation brought on by free fatty acid Palmitate (PA) using macrophages raw 264.7 cell line. Data revealed that TQ significantly improved the viability of basal and PA stimulated Macrophages at concentrations of 50 and 100 µg/mL. Also, TQ significantly reduced nitric oxide and triglyceride levels in PA-stimulated macrophages at concentrations of 50 and 100 µg/mL. The pro-inflammatory cytokines studies revealed that PA significantly increased the release of the cytokines TNF-α, MHGB-1, IL-1ß, and IL-6. TQ at concentrations 25, 50, and 100 µg/ml significantly decreases the release of the studied cytokines in PA-stimulated macrophages to variable extents with parallel inhibition to their corresponding gene expression. Bioenergetic assays showed that PA significantly decreased cellular ATP, mitochondrial complexes I and III activities and mitochondrial membrane potential with a subsequent significant increase in lactate production. At the same time, TQ can alleviate the effect of PA on macrophages' bioenergetics parameters to variable extent based on TQ concentration. To conclude, TQ could mitigate palmitate-induced inflammation and cytotoxicity in macrophages by improving macrophage viability and controlling cytokine release with improved PA-induced bioenergetics disruption.

Immortalization and Characterization of GFAP-expressing Glial Cells from the Adult Mouse Hypothalamus, Cortex, and Brain Stem.

The generation of astrocyte cell lines from the hypothalamus is key to study glial involvement in hypothalamic physiology, including energy homeostasis. As such, we immortalized astrocytes from the hypothalamus of an adult male CD-1 mouse using SV40 T-antigen to generate the mHypoA-Ast1 cell line. A comparative approach was taken with two other murine GFAP-expressing cell lines that were also generated in this study: a mixed glial cell line from the cortex (mCortA-G1) and an oligodendrocyte cell line from the brainstem (mBstA-Olig1), as well as an established microglial cell line (IMG). mHypoA-Ast1 cells express GFAP, alongside other astrocytic markers such as Aldh1l1, Aqp4, Glt1 and S100b, and express low levels of microglial, ependymal and oligodendrocyte markers. 100 ng/mL lipopolysaccharide (LPS) elevated mRNA levels of Il6, Il1b, Tnfα and Cxcl5 in mHypoA-Ast1 cells after 4 h, while 50 µM palmitate increased Il6 and Chop mRNA, demonstrating the ability of these cells to respond to inflammatory and nutrient signals. Interestingly, co-culture of mHypoA-Ast1 cells with mHypoE-N46 hypothalamic neuronal cells prevented the palmitate-mediated increase in orexigenic neuropeptide Agrp mRNA in mHypoE-N46 cells, suggesting that this cell line can alter neuronal responses to nutrients. In conclusion, we report mHypoA-Ast1 cells representing a functional astrocyte cell line from the adult mouse brain that can be used to study the complex interactions of hypothalamic cells, as well as dysregulation that may occur in disease states, providing a key tool for neuroendocrine research.

The protective effect of vitamin A palmitate eye gel on the ocular surface during general anaesthesia surgery: a randomized controlled trial.

PURPOSE: To investigate the change in tear production associated with general anesthesia and the protective effect of vitamin A palmitate eye gel on the ocular surface during general anesthesia. METHODS: This double-blind, randomized clinical trial included patients undergoing non-ophthalmic surgery under general anesthesia who randomly received vitamin A palmitate eye gel and taping for one eye (Group A, n = 60) or taping alone for the other eye (Group B, n = 60). Symptom assessment in dry eye (SANDE) score, tear film break-up time (TBUT), corneal fluorescein staining (CFS) score, and Schirmer tear test I (STT-1) were analyzed under a hand-held slit lamp before anesthesia (T0), 0.5 h postoperatively (T1), and 24 h postoperatively (T2). RESULTS: At 0.5 h postoperatively, an increase in CFS score was observed in both groups (P < 0.05 in Group A and P < 0.01 in Group B), and the participants in Group A had less corneal abrasions than those in Group B. STT-1 significantly increased in Group A (P < 0.05), while it significantly decreased in Group B (P < 0.001). The changes between the two groups were statistically significant (P < 0.001). At 24 h postoperatively, both CFS score and STT-1 almost returned to baseline levels in the two groups. In both groups, the SANDE score and TBUT showed little change at 0.5 h and 24 h postoperatively (all P > 0.05). CONCLUSION: Vitamin A palmitate eye gel effectively protected the ocular surface and aqueous supplementation during general anesthesia. TRIAL REGISTRATION: This study was registered in the Chinese Clinical Trial Registry (ChiCTR2100052140) on 20/10/2021.

L-AP Alleviates Liver Injury in Septic Mice by Inhibiting Macrophage Activation via Suppressing NF-κB and NLRP3 Inflammasome/Caspase-1 Signal Pathways.

Liver injury and progressive liver failure are severe life-threatening complications in sepsis, further worsening the disease and leading to death. Macrophages and their mediated inflammatory cytokine storm are critical regulators in the occurrence and progression of liver injury in sepsis, for which effective treatments are still lacking. l-Ascorbic acid 6-palmitate (L-AP), a food additive, can inhibit neuroinflammation by modulating the phenotype of the microglia, but its pharmacological action in septic liver damage has not been fully explored. We aimed to investigate L-AP's antisepticemia action and the possible pharmacological mechanisms in attenuating septic liver damage by modulating macrophage function. We observed that L-AP treatment significantly increased survival in cecal ligation and puncture-induced WT mice and attenuated hepatic inflammatory injury, including the histopathology of the liver tissues, hepatocyte apoptosis, and the liver enzyme levels in plasma, which were comparable to NLRP3-deficiency in septic mice. L-AP supplementation significantly attenuated the excessive inflammatory response in hepatic tissues of septic mice in vivo and in cultured macrophages challenged by both LPS and ATP in vitro, by reducing the levels of NLRP3, pro-IL-1ß, and pro-IL-18 mRNA expression, as well as the levels of proteins for p-I-κB-α, p-NF-κB-p65, NLRP3, cleaved-caspase-1, IL-1ß, and IL-18. Additionally, it impaired the inflammasome ASC spot activation and reduced the inflammatory factor contents, including IL-1ß and IL-18 in plasma/cultured superannuants. It also prevented the infiltration/migration of macrophages and their M1-like inflammatory polarization while improving their M2-like polarization. Overall, our findings revealed that L-AP protected against sepsis by reducing macrophage activation and inflammatory cytokine production by suppressing their activation in NF-κB and NLRP3 inflammasome signal pathways in septic liver.

A Residual N-Terminal Peptide Enhances Signaling of Depalmitoylated Hedgehog to the Patched Receptor.

During their biosynthesis, Sonic hedgehog (Shh) morphogens are covalently modified by cholesterol at the C-terminus and palmitate at the N-terminus. Although both lipids initially anchor Shh to the plasma membrane of producing cells, it later translocates to the extracellular compartment to direct developmental fates in cells expressing the Patched (Ptch) receptor. Possible release mechanisms for dually lipidated Hh/Shh into the extracellular compartment are currently under intense debate. In this paper, we describe the serum-dependent conversion of the dually lipidated cellular precursor into a soluble cholesteroylated variant (ShhC) during its release. Although ShhC is formed in a Dispatched- and Scube2-dependent manner, suggesting the physiological relevance of the protein, the depalmitoylation of ShhC during release is inconsistent with the previously postulated function of N-palmitate in Ptch receptor binding and signaling. Therefore, we analyzed the potency of ShhC to induce Ptch-controlled target cell transcription and differentiation in Hh-sensitive reporter cells and in the Drosophila eye. In both experimental systems, we found that ShhC was highly bioactive despite the absence of the N-palmitate. We also found that the artificial removal of N-terminal peptides longer than eight amino acids inactivated the depalmitoylated soluble proteins in vitro and in the developing Drosophila eye. These results demonstrate that N-depalmitoylated ShhC requires an N-peptide of a defined minimum length for its signaling function to Ptch.