ß-caryophyllene blocks reactive oxygen species-mediated hyperlipidemia in isoproterenol-induced myocardial infarcted rats.

Myocardial infarction (MI) is a leading cause of death. Lipid-lowering interventions have been shown to decrease coronary events and mortality of MI and heart failure. In this investigation, we assessed the anti-hyperlipidemic effects of ß-caryophyllene in isoproterenol-induced myocardial infarcted rats. ß-Caryophyllene (20 mg/kg body weight) pre-and co-treatment was given to rats orally, daily, for 3 weeks. Isoproterenol (100 mg/kg body weight) was administered to rats to induce MI. The levels of serum cardiac troponins T and I, serum and heart total cholesterol, triglycerides, free fatty acids, and the levels of serum low-density and very low-density lipoprotein-cholesterols were augmented, and the level of serum high-density lipoprotein-cholesterol was lessened in myocardial infarcted rats. Further, the activity/levels of liver 3-hydroxy-3-methylglutaryl-coenzyme A reductase and plasma thiobarbituric acid reactive substances were amplified and the activity/levels of heart glutathione -S- transferase, vitamin C, and vitamin E were lessened by isoproterenol. A down-regulated expression of liver sterol regulatory element-binding protein-2 and liver low-density lipoprotein-receptor genes was observed by a reverse transcription-polymerase chain reaction study. Moreover, histopathology of Sudan III staining revealed an accumulation of fats in the heart of isoproterenol-induced rats. Nevertheless, ß-caryophyllene pre-and co-treatment blocked alterations in all the parameters examined in isoproterenol-induced rats and inhibited the risk of MI. Moreover, the in vitro study revealed the potent free radical scavenging and antioxidant effects of ß-caryophyllene. ß-Caryophyllene's antioxidant and anti-hyperlipidemic properties are the possible mechanisms for the observed protective effects in this investigation.

Circular RNA circARPC1B functions as a stabilisation enhancer of Vimentin to prevent high cholesterol-induced articular cartilage degeneration.

BACKGROUND: Osteoarthritis (OA) is a prevalent and debilitating condition, that is, directly associated with cholesterol metabolism. Nevertheless, the molecular mechanisms of OA remain largely unknown, and the role of cholesterol in this process has not been thoroughly investigated. This study aimed to investigate the role of a novel circular RNA, circARPC1B in the relationship between cholesterol and OA progression. METHODS: We measured total cholesterol (TC) levels in the synovial fluid of patients with or without OA to determine the diagnostic role of cholesterol in OA. The effects of cholesterol were explored in human and mouse chondrocytes in vitro. An in vivo OA model was also established in mice fed a high-cholesterol diet (HCD) to explore the role of cholesterol in OA. RNAseq analysis was used to study the influence of cholesterol on circRNAs in chondrocytes. The role of circARPC1B in the OA development was verified through circARPC1B overexpression and knockdown. Additionally, RNA pulldown assays and RNA binding protein immunoprecipitation were used to determine the interaction between circARPC1B and Vimentin. CircARPC1B adeno-associated virus (AAV) was used to determine the role of circARPC1B in cholesterol-induced OA. RESULTS: TC levels in synovial fluid of OA patients were found to be elevated and exhibited high sensitivity and specificity as predictors of OA diagnosis. Moreover, elevated cholesterol accelerated OA progression. CircARPC1B was downregulated in chondrocytes treated with cholesterol and played a crucial role in preserving the extracellular matrix (ECM). Mechanistically, circARPC1B is competitively bound to the E3 ligase synoviolin 1 (SYVN1) binding site on Vimentin, inhibiting the proteasomal degradation of Vimentin. Furthermore, circARPC1B AAV infection alleviates Vimentin degradation and OA progression caused by high cholesterol. CONCLUSIONS: These findings indicate that the cholesterol-circARPC1B-Vimentin axis plays a crucial role in OA progression, and circARPC1B gene therapy has the opportunity to provide a potential therapeutic approach for OA.

24-hydroxycholesterol replacement rate measured in blood is a non-invasive biomarker of brain demyelination and remyelination in cuprizone-treated mice.

In mice, dietary cuprizone causes brain demyelination with subsequent spontaneous remyelination upon return to normal chow. Heavy water (2H2O) labeling with mass spectrometric analysis can be used to measure brain de novo synthesis of several myelin components including cholesterol, phospholipids, galactocereboside (GalC) and myelin-associated proteins. 24-hydroxycholesterol (24-OHC), the major metabolite of brain cholesterol, is detected in blood and is believed to be specifically derived from CNS cholesterol metabolism. We assessed changes in syntheses of myelin components in brain and of blood sterols during cuprizone-induced experimental demyelination and remyelination, with and without thyroid hormone (T3) treatment. Mice were fed cuprizone for 4 weeks, then returned to control diet and treated with either placebo or T3 (0.005 mg/day). 2H2O was administered for the last 14 days of cuprizone diet, and for either 6, 12 or 19 days of treatment during recovery from cuprizone, after which blood and corpus callosum (CC) samples were collected (n = 5/time point/treatment). 2H incorporation into cholesterol and 24-OHC in blood and CC, and incorporation into phospholipid (PL)-palmitate, GalC, myelin basic protein (MBP) and 2',3'-cyclic-nucleotide 3'-phosphodiesterase (CNPase) in CC were measured. Cuprizone significantly (p < 0.05) decreased syntheses of cholesterol, 24-OHC, GalC, MBP, CNPase and PL-palmitate in the CC and these effects were all reversed during recovery. T3 treatment significantly (p < 0.05) increased syntheses of cholesterol, 24-OHC and palmitate compared to placebo. 24-OHC and cholesterol turnover rates in brain and blood were nearly identical and 24-OHC rates in blood paralleled rates in CC, indicating that blood 24-OHC derives primarily from the brain and reflects oligodendrocyte function. In summary, changes in synthesis of several lipid and protein components in brain during cuprizone-induced demyelination and remyelination are measurable through stable isotope labeling. Blood 24-OHC turnover rates closely reflect flux rates of brain cholesterol in response to cuprizone and T3, which alter oligodendrocyte function. Labeling of blood 24-OHC has potential as a non-invasive marker of brain de novo cholesterol synthesis and breakdown rates in demyelinating conditions.

AIBP regulates TRPV1 activation in chemotherapy-induced peripheral neuropathy by controlling lipid raft dynamics and proximity to TLR4 in dorsal root ganglion neurons.

ABSTRACT: Nociceptive afferent signaling evoked by inflammation and nerve injury is mediated by the opening of ligand-gated and voltage-gated receptors or channels localized to cholesterol-rich lipid raft membrane domains. Dorsal root ganglion (DRG) nociceptors express high levels of toll-like receptor 4 (TLR4), which also localize to lipid rafts. Genetic deletion or pharmacologic blocking of TLR4 diminishes pain associated with chemotherapy-induced peripheral neuropathy (CIPN). In DRGs of mice with paclitaxel-induced CIPN, we analyzed DRG neuronal lipid rafts, expression of TLR4, activation of transient receptor potential cation channel subfamily V member 1 (TRPV1), and TLR4-TRPV1 interaction. Using proximity ligation assay, flow cytometry, and whole-mount DRG microscopy, we found that CIPN increased DRG neuronal lipid rafts and TLR4 expression. These effects were reversed by intrathecal injection of apolipoprotein A-I binding protein (AIBP), a protein that binds to TLR4 and specifically targets cholesterol depletion from TLR4-expressing cells. Chemotherapy-induced peripheral neuropathy increased TRPV1 phosphorylation, localization to neuronal lipid rafts, and proximity to TLR4. These effects were also reversed by AIBP treatment. Regulation of TRPV1-TLR4 interactions and their associated lipid rafts by AIBP covaried with the enduring reversal of mechanical allodynia otherwise observed in CIPN. In addition, AIBP reduced intracellular calcium in response to the TRPV1 agonist capsaicin, which was increased in DRG neurons from paclitaxel-treated mice and in the naïve mouse DRG neurons incubated in vitro with paclitaxel. Together, these results suggest that the assembly of nociceptive and inflammatory receptors in the environment of lipid rafts regulates nociceptive signaling in DRG neurons and that AIBP can control lipid raft-associated nociceptive processing.

The Association Between Lipid Serum and Semen Parameters: a Systematic Review.

Increased lipid levels sometimes not only affect sexual function but also are considered to harm semen quality. It is often a suspicion that elevated lipids are a factor in infertility. We conduct a systematic review. Articles that met the criteria were identified according to The Preferred Reporting Items for Systematic Review and Meta-analysis of recommendations in the PubMed, ProQuest, EBSCO, Web of Science Wiley Online, Springer Link, Scopus, and Science Direct databases with no time restriction for publication. Seven studies are eligible for qualitative analysis from nine studies that have the potential to be assessed. These studies measure the correlation of serum lipids (VLDL, HDL, LDL, triglycerides, total cholesterol, free cholesterol, phospholipids, free fatty acids) with semen parameters (concentration, motility, morphology, DNA fragmentation index). Although not all studies consistently report that lipids impact semen quality, this review suspects that lipids have a significant impact on sperm quality. This study implies that it is necessary to maintain lipid levels to maintain sperm quality and quality of life. However, further investigation with an observational cohort study design needs to be carried out to assess the effect of lipids on semen quality more precisely for the promotion of reproductive health care.

New insights into cholesterol-mediated ERRα activation in breast cancer progression and pro-tumoral microenvironment orchestration.

Breast cancer remains the greatest cause of cancer-related death in women worldwide. Its aggressiveness and progression derive from intricate processes that occur simultaneously both within the tumour itself and in the neighbouring cells that make up its microenvironment. The aim of the present work was firstly to study how elevated cholesterol levels increase tumour aggressiveness. Herein, we demonstrate that cholesterol, by activating ERRα pathway, promotes epithelium-mesenchymal transition (EMT) in breast cancer cells (MCF-7 and MDA-MB-231) as well as the release of pro-inflammatory factors able to orchestrate the tumour microenvironment. A further objective of this work was to study the close symbiosis between tumour cells and the microenvironment. Our results allow us to highlight, for the first time, that breast cancer cells exposed to high cholesterol levels promote (a) greater macrophages infiltration with induction of an M2 phenotype, (b) angiogenesis and endothelial branching, as well as (c) a cancer-associated fibroblasts (CAFs) phenotype. The effects observed could be due to direct activation of the ERRα pathway by high cholesterol levels, since the simultaneous inhibition of this pathway subverts such effects. Overall, these findings enable us to identify the cholesterol-ERRα synergy as an interesting target for breast cancer treatment.

Lesiones perirradiculares persistentes: revisión narrativa / Persistent periradicular lesions: a narrative review

La persistencia de lesiones perirradiculares luego del tra- tamiento endodóntico es un problema que requiere del clínico un conocimiento cabal de la histofisiología y de la histopato- logía del sistema de conductos radiculares del tejido pulpar y de los tejidos perirradiculares (periodonto y hueso); además de considerar siempre la posible existencia de enfermedades sistémicas que también pueden actuar como factores de in- fluencia. La presencia de bacterias remanentes a posteriori del tratamiento es considerada como una de las causas principales y más frecuentes para la perpetuación de las lesiones perirra- diculares. Sin embargo, existen otros factores causales, como la existencia de conductos laterales o accesorios infectados y no tratados, la reabsorción dentinaria interna, intercomunica- ciones, cul-de-sacs o istmos; que representan áreas de difícil acceso durante la instrumentación e irrigación. Cuando la cau- sa original se localiza en la zona perirradicular, como en los casos de actinomicosis, reacciones a cuerpo extraño, cristales de colesterol (CRCo) y granulomas o quistes con alto conte- nido de CRCo, la indicación más adecuada es el retratamiento y la cirugía periapical como complemento (AU)

The persistence of periradicular lesions after endodontic treatment is a problem that requires the doctor to have a thor- ough knowledge of the histophysiology and histopathology of the root canal system, the pulp tissue and periradicular tis- sues (periodontium and bone); as well as always considering the possible existence of systemic alterations that can also be influencing factors. Persisting bacteria within the root canal system after treatment is one of the major and most frequent causes for the perpetuation of periradicular lesions. Howev- er, there are other possible causal factors such as the exist- ence of untreated lateral or accessory canals, internal dentin resorption, intercommunications, cul-de-sacs or isthmuses; areas that represent a difficulty in access during instrumen- tation and irrigation. If the original cause is located in the periradicular area, in cases like actinomycosis, foreign-body reactions, cholesterol crystals (CRCo) and granulomas or cysts with high content of CRCo, retreatment coupled with periapical surgery is the best approach to treatment (AU)

JMJD4-demethylated RIG-I prevents hepatic steatosis and carcinogenesis.

BACKGROUND: Hepatocarcinogenesis is driven by necroinflammation or metabolic disorders, and the underlying mechanisms remain largely elusive. We previously found that retinoic acid-inducible gene-I (RIG-I), a sensor for recognizing RNA virus in innate immune cells, is mainly expressed by parenchymal hepatocytes in the liver. However, its roles in hepatocarcinogenesis are unknown, which is intensively investigated in this study. METHODS: DEN-induced necroinflammation-driven hepatocarcinogenesis and STAM NASH-hepatocarcinogenesis were carried out in hepatocyte-specific RIG-I knockout mice. The post-translational modification of RIG-I was determined by mass spectrometry, and specific antibodies against methylated lysine sites and the RIG-I lysine mutant mice were constructed to identify the functions of RIG-I methylation. RESULTS: We interestingly found that DEN-induced hepatocarcinogenesis was enhanced, while NASH-induced hepatocarcinogenesis was suppressed by hepatocyte-specific RIG-I deficiency. Further, IL-6 decreased RIG-I expression in HCC progenitor cells (HcPCs), which then viciously promoted IL-6 effector signaling and drove HcPCs to fully established HCC. RIG-I expression was increased by HFD, which then enhanced cholesterol synthesis and steatosis, and the in-turn NASH and NASH-induced hepatocarcinogenesis. Mechanistically, RIG-I was constitutively mono-methylated at K18 and K146, and demethylase JMJD4-mediated RIG-I demethylation suppressed IL-6-STAT3 signaling. The constitutive methylated RIG-I associated with AMPKα to inhibit HMGCR phosphorylation, thus promoting HMGCR enzymatic activity and cholesterol synthesis. Clinically, RIG-I was decreased in human hepatic precancerous dysplastic nodules while increased in NAFLD livers, which were in accordance with the data in mouse models. CONCLUSIONS: Decreased RIG-I in HcPCs promotes necroinflammation-induced hepatocarcinogenesis, while increased constitutive methylated RIG-I enhances steatosis and NASH-induced hepatocarcinogenesis. JMJD4-demethylated RIG-I prevents both necroinflammation and NASH-induced hepatocarcinogenesis, which provides mechanistic insight and potential target for preventing HCC.

Maternal high-cholesterol diet negatively programs offspring bone development and downregulates hedgehog signaling in osteoblasts.

Cholesterol is one of the essential intrauterine factors required for fetal growth and development. Maternal high cholesterol levels are known to be detrimental for offspring health. However, its long-term effect on offspring skeletal development remains to be elucidated. We performed our studies in two strains of mice (C57BL6/J and Swiss Albino) and human subjects (65 mother-female newborn dyads) to understand the regulation of offspring skeletal growth by maternal high cholesterol. We found that mice offspring from high-cholesterol-fed dams had low birth weight, smaller body length, and delayed skeletal ossification at the E18.5 embryonic stage. Moreover, we observed that the offspring did not recover from the reduced skeletal mass and exhibited a low bone mass phenotype throughout their life. We attributed this effect to reduced osteoblast cell activity with a concomitant increase in the osteoclast cell population. Our investigation of the molecular mechanism revealed that offspring from high-cholesterol-fed dams had a decrease in the expression of ligands and proteins involved in hedgehog signaling. Further, our cross-sectional study of human subjects showed a significant inverse correlation between maternal blood cholesterol levels and cord blood bone formation markers. Moreover, the bone formation markers were significantly lower in the female newborns of hypercholesterolemic mothers compared with mothers with normal cholesterolemic levels. Together, our results suggest that maternal high cholesterol levels deleteriously program offspring bone mass and bone quality and downregulate the hedgehog signaling pathway in their osteoblasts.

Regulatory roles of external cholesterol in human airway epithelial mitochondrial function through STARD3 signalling.

BACKGROUND: Hypercholesterolemia is found in patients with chronic lung inflammation, during which airway epithelial cells play important roles in maintenance of inflammatory responses to pathogens. The present study aims at molecular mechanisms by which cholesterol changes airway epithelial sensitivity in response to smoking. METHODS: Human bronchial epithelial cells (HBEs) were stimulated with cigarette smoke extract (CSE) and mice were exposed to CS/lipopolysaccharide (LPS) as models in vitro and in vivo. Severe COPD patients and healthy volunteers were also enrolled and the level of cholesterol in plasma was detected by metabolomics. Filipin III and elisa kits were used to stain free cholesterol. Mitochondrial function was detected by mitotracker green, mitotracker green, and Seahorse. Mitochondrial morphology was detected by high content screening and electron microscopy. The mRNA and protein levels of mitochondrial dynamics-related proteins were detected by RT-qPCR and Western blot,respectively. BODIPY 493/503 was used to stain lipid droplets. Lipidomics was used to detect intracellular lipid components. The mRNA level of interleukin (IL)-6 and IL-8 were detected by RT-qPCR. RESULTS: We found that the cholesterol overload was associated with chronic obstructive pulmonary disease (COPD) and airway epithelia-driven inflammation, evidenced by hypercholesterolemia in patients with COPD and preclinical models, alteration of lipid metabolism-associated genes in CSE-induced airway epithelia and production of ILs. External cholesterol altered airway epithelial sensitivity of inflammation in response to CSE, through the regulation of STARD3-MFN2 pathway, cholesterol re-distribution, altered transport and accumulation of cholesterol, activities of lipid transport regulators and disorder of mitochondrial function and dynamics. MFN2 down-regulation increased airway epithelial sensitivity and production of ILs after smoking, at least partially by injuring fatty acid oxidation and activating mTOR phosphorylation. CONCLUSIONS: Our data provide new insights for understanding molecular mechanisms of cholesterol-altered airway epithelial inflammation and for developing diagnostic biomarkers and therapeutic targets to improve patient outcomes.

A high-fat/high-cholesterol diet, but not high-cholesterol alone, increases free cholesterol and apoE-rich HDL serum levels in rats and upregulates hepatic ABCA1 expression.

A high-fat/high-cholesterol (HFC) diet, but not a high-cholesterol (HC) diet, is known to induce elevated serum apolipoprotein E (apoE)-rich high-density lipoprotein (HDL) levels in animal models. However, the exact mechanisms by which the combination of dietary fat and cholesterol induces apoE-rich HDL production is not well understood. Here, we investigated the effects of dietary fat and cholesterol on serum lipoprotein profiles and hepatic mRNA expression that are associated with HDL production, cholesterol transport, and bile acid metabolism. Male Sprague-Dawley rats were fed HFC, HC, high-fat, or control diets and then evaluated. The HFC diet induced significant increases in hepatic free-cholesterol accumulation (1.4-fold, p < 0.01) and serum apoE-rich HDL cholesterol (8.7-fold, p < 0.001) levels compared with the HC diet. The apoE-rich HDL induced by the HFC diet was remarkably rich in free cholesterol. Liver gene-expression was mostly similar between the HC and HFC diet groups. However, there was a significant increase of ATP-binding cassette transporter A1 (ABCA1) levels in the HFC group compared to the HC group for both mRNA (1.9-fold, p < 0.001) and protein (6.6-fold, p < 0.01). These results suggest that an increase in apoE-rich HDL induced by dietary fat and cholesterol may be involved in cholesterol efflux from the liver through increased ABCA1-mediated free-cholesterol efflux.

Serological and Histological Evaluation of the Effect of Honeybee Venom on Pancreas and Liver in Diabetic Mice.

Natural toxins have been traditionally used to trigger several diseases among which bee venom (HBV) is of great importance. The present study aimed to investigate the therapeutic effects of honeybee venom (HBV) on alloxan and glucose fluid-induced Type 2 diabetes mellitus (T2DM). Therefore, a total of 20 adult laboratory male mice (Mus musculus) were selected, acclimated, and divided into four equal groups (n=5). Initially, 15 mice were fasted for 12 hrs and injected with alloxan at a single dose of 150 mg/kg of body weight. The animals were exposed to drinking glucose fluid in the morning for 4 days. Then, the blood glucose was measured. The studied animals having blood glucose of ≤200 mg/dl were considered non-diabetic and re-subjected to injecting alloxan (150 mg/kg body weight) and drinking glucose fluid for another 4 days. Four groups of mice population included, Group 1: non-diabetic and untreated with HBV, Group 2: diabetic and received no HBV as the potential therapeutic agent, Group 3: diabetic and received a low level of HBV at a dose of 0.5 mg/kg, Group 4: diabetic and received a high level of HBV at a dose of 1 mg/kg. At the end of the 35-day testing period, blood samples were tested to determine the levels of insulin, glucose, and lipid profiles [cholesterol, triglyceride (TG), high-density lipoprotein (HDL), and low-density lipoprotein (LDL)] using Sandwich ELISA kits. The results indicated a significant increase in blood glucose in the diabetic group compared to that of the control one, while both concentrations of HBV significantly reduced the level of blood glucose compared to that of the diabetic group. Furthermore, the level of insulin was significantly decreased in the diabetic group compared to that of the controls, while HBV significantly increased the level of insulin compared to that of the diabetic group. Moreover, the diabetic mice demonstrated a significant increase in the concentration of cholesterol and TG compared to that of control mice which were significantly reversed in response to HBV treatment. The level of HDL was significantly decreased in the diabetic group compared to that of the control group which was modulated by treatment, while no significant differences were seen between all the studied groups regarding the level of LDL. Histological examination of diabetic mice revealed a significant alteration in acinar cells and destruction of ß-cells of pancreatic sections with marked lacerations in the liver extended to all structures of the organ. The present study concluded that HBV could be a potential therapeutic agent to prevent and manage diabetes and its complication.

Effect of Codonopsis Radix and Polygonati Rhizoma on the regulation of the IRS1/PI3K/AKT signaling pathway in type 2 diabetic mice.

Objective: Codonopsis Radix and Polygonati Rhizoma (CRPR) has a good hypoglycemic effect. The aims of the present study were to investigate the effect of CRPR on high-fat/high-sugar diet (HFHSD)- and streptozotocin (STZ)-induced type 2 diabetes mellitus (T2DM) mice as well as to investigate the involved mechanism. Methods: A T2DM mouse model was generated by combining HFHSD and STZ. After the model was established, normal and model groups received the same volume of normal saline intragastrically, and the negative control group was treated with metformin (200 mg/kg·BW). The low, medium, and high CRPR groups received four consecutive weeks of oral gavage with CRPR doses of 2.5, 5, and 10 g/kg·BW, respectively, during the course of the study. Body weight and fasting blood glucose (FBG) were measured on a weekly basis. Enzyme-linked immunosorbent assay (ELISAs) were used to evaluate the serum and liver samples. Hematoxylin and eosin (H&E) staining was utilized to observe the pathological status of the liver and pancreas. Western blot (WB) analysis was performed to evaluate the protein expression levels of PI3K, p-PI3K, AKT, and p-AKT. Results: Compared to model mice, each treatment group had significantly elevated levels of FBG, total cholesterol (TC), and triacylglycerol (TG) (P<0.01 and P<0.05, respectively). The levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were significantly reduced in the treatment groups compared to the model group (P<0.01). Compared to the model group, fasting insulin (FINS) levels were elevated in all groups of CRPR (P<0.05), and there were significantly higher levels of high-density lipoprotein cholesterol (HDL-C) in both the low-dose and high-dose CRPR groups (P<0.05). H&E staining indicated that CRPR treatment reduced organ enlargement, improved liver lipid accumulation, and repaired islet injury in T2DM mice. Moreover, WB analysis demonstrated that all CRPR groups significantly upregulated the protein expression of IRS1, p-GSK3ß, PI3K, p-Akt and p-FOXO1(P<0.05) as well as significantly downregulated p-IRS1 and FOXO1 protein expression (P<0.05). Conclusion: The present study demonstrated that CRPR effectively improves the metabolic disturbance of lipids, repairs damaged liver tissues, repairs damaged pancreatic tissues, and reduces insulin resistance (IR) in T2DM mice. The mechanism of action may be associated with upregulation of the IRS1/PI3K/AKT signaling pathway and inhibition of IRS1 phosphorylation.

Total Cholesterol and APOE-Related Risk for Alzheimer's Disease in the Alzheimer's Disease Neuroimaging Initiative.

BACKGROUND: APOEɛ4 allele confers greatest genetic risk for Alzheimer's disease (AD), yet mechanisms underlying this risk remain elusive. APOE is involved in lipid metabolism, and literature suggest relationships between high total cholesterol, APOE, and AD. Further investigation is needed to elucidate the potential role of total cholesterol in AD risk. OBJECTIVE: To investigate the relationship between total cholesterol and APOE-related AD risk in the Alzheimer's Disease Neuroimaging Initiative. METHODS: Participants (N = 1,534) were classified as controls (cognitively normal; N = 404), early mild cognitive impairment (MCI; N = 294), late MCI (N = 539), or AD (N = 297). Total cholesterol levels were compared across APOE genotype and diagnosis. Mendelian randomization was performed to examine causality between total cholesterol and AD risk using APOE as a genetic instrument. RESULTS: Total cholesterol was higher in APOE4+ compared to APOE3 and APOE2+ (ps < 0.04) carriers. Those with AD and late MCI (ps < 0.001) had higher total cholesterol than the control group. Comparing APOE4+ to APOE3 carriers, the predicted odds ratios per mg/dL greater total cholesterol were 1.11 for MCI (95% confidence interval, 1.04-7.32), 1.05 for early MCI (1.01-3.22), 1.13 for late MCI (1.05-11.70), 1.21 for AD (1.09-54.05), and 1.13 for composite dementia (MCI or AD; 1.06-11.59) (ps < 0.05, F-statistics > 10). CONCLUSION: Higher total cholesterol may be a significant contributor to AD risk, particularly in APOE4 carriers who, based on existing literature, tend to have impaired cholesterol metabolism. Our findings highlight a possible mechanism by which APOE confers AD risk and indicate potential for AD risk modification through maintenance of healthy total cholesterol levels.

Dano fotoinduzido no sistema endolisossomal: modulação da autofagia e metabolismo de lipídios em células de câncer colorretal / Endo-lysosomal system photodamage: modulation of autophagy and lipid metabolism in colorectal cancer cells

O câncer colorretal (CCR) é o terceiro câncer mais diagnosticado em humanos. O CCR causou mais de 900.000 mortes em 2020 e foi estimado, para o período entre 2020 - 2025, um incremento de 13.5 % no número de casos novos de acordo com a plataforma Web Global Cancer Observatory. A Terapia Fotodinâmica (PDT) é uma alternativa terapêutica promissora. Conhecer as vias de sinalização de morte celular, assim como, as respostas associadas com a resistência ao dano foto-oxidativo, são relevantes para incrementar a eficiência da PDT. Neste trabalho, investigamos como as células de adenocarcinoma colorretal HT 29 respondem ao dano fotoinduzido gerado pelo fotossensibilizador (FS) meso-tetrafenilporfirina dissulfônado (TPPS2a), uma molécula que é ativada pela irradiação com luz em 522 nm. Como esperado, após irradiação (2.1 J cm-2) foi verificado que com o incremento do TPPS2a houve diminuição da viabilidade celular. A concentração do FS escolhida para darmos seguimento ao estudo foi a necessária para reduzir em 30 % a sobrevida celular (DL30; 148 nM). Abordagens moleculares nos permitiram identificar que nas células fotossensibilizadas a redução na maturação da catepsina D (CTSD, 55 %) e da catepsina B (CTSB, 52 %) contribuem com a disfunção endolisossomal. Além disso, comprovamos que as células fotossensibilizadas tiveram, pela menor quantidade de CTSD ativa, o processamento da prosaposina (PSAP) significativamente afetado. Células coletadas após 24 horas de irradiação expressaram 7 vezes mais PSAP do que as amostras dos grupos controle, sugerindo que as reações de oxidação causadas pelo TPPS2a podem ocasionar o acúmulo de glicoesfingolipídios nos endossomos e nos lisossomos, mimetizando o fenótipo observado em doenças de armazenamento lisossomal. Imagens de células HT 29 com expressão estável da proteína LGALS3 fusionada ao marcador EFGP mostraram que, após 24 horas de irradiação, as células não ativaram a lisofagia para remover os endossomos e os lisossomos danificados. A ausência do recrutamento da LGALS3 também apontou que as membranas dos endossomos e dos lisossomos não apresentam rupturas permanentes que permitam a passagem de uma molécula de 26 kDa. Experimentos complementares de análise da expressão proteica dos marcadores autofágicos LC3-II e p62/SQSTM1 (referida como p62) confirmaram o bloqueio do fluxo autofágico nas células fotosenssibilizadas. Pelo envolvimento do sistema endolisossomal no tráfego de membranas e no fluxo de lipídios, o aumento da transcrição da Hidroximetilglutaril-CoA reductase (HMGCR) (≈ 1.6 vezes) uma enzima envolvida na síntese de novo do colesterol - sugeriu que a disfunção dos endossomos e dos lisossomos altera a distribuição de colesterol. Não obstante, para manter a homeostase lipídica nas células fotossensibilizadas este não foi o único mecanismocompensatório acionado, uma vez que houve um incremento sutil; porém, significativo (1.2 vezes) na transcrição da ceramidase ácida (ASAH1). Em conjunto, nossos dados apontam que a fotossensibilização com TPPS2a constitui uma ferramenta promissora para causar dano no sistema endolisossomal, inibindo a autofagia e permitindo o estudo das respostas metabólicas em células expostas a estresse oxidativo

Colorectal cancer (CRC) is the third most commonly diagnosed cancer in humans. CRC caused more than 900,000 deaths in 2020 and it was estimated for the period 2020 - 2025, an increase of 13.5 % in the number of new cases according to the Global Cancer Observatory Web platform. Photodynamic Therapy (PDT) is a promising therapeutic alternative. Understandings of cell death signaling pathways as well as the adaptive responses associated with resistance to photo-oxidative damage are relevant to optimize the effectiveness of PDT. For this purpose, in this research, we investigated how HT-29 colorectal adenocarcinoma cells respond to photosensitization reactions generated by TPPS2a, a molecule activated by irradiation with light at 522 nm. PS concentrations displayed increased inhibitory effect on cell viability after irradiation (2.1 J cm-2). The lethal dose selected to photosensibilize cells was the TPPS2a concentration able to reduce 30 % of cell survival (LD30; 148 nM). By molecular methods, we observed a reduction in cathepsin D (CTSD, 55 %) and cathepsin B (CTSB, 52 %) maturation, depletion that may contribute to endo-lysosomal dysfunction in photosensitized cells. It is widely known that endo-lysosomal cathepsins are crucial in protein turnover and degradation. Thus, we focused on the consequence of CTSD reduction. Literature data indicate that CTSD plays a key role in prosaposin (PSAP) processing to the four saposins (SAPs) that are required in glycosphingolipids breakdown. In fact, our results in photosensitized cells showed that, due to the lower amount of active CTSD, PSAP processing was significantly affected. Cells collected after irradiation expressed 7 times more PSAP than cells from the control groups. This data suggest that oxidative photodamage induced by TPPS2a may result in glycosphingolipid-accumulating endosomes and lysosomes, phenotype which mimics lysosomal storage diseases. Furthermore, we monitored by fluorescence microscopy a form of selective autophagy which detects and removes damaged endosomes and lysosomes known as lysophagy. Images of HT-29 cells expressing Galectin 3/LGALS3 fused to EFGP showed that photosensitized cells did not activate lysophagy. The absence of LGALS3 recruitment also indicated that the membranes of endosomes and lysosomes do not present ruptures which allow the passage of proteins with a molecular weight up to at least 26 kDa. Protein expression analysis of the autophagic markers LC3-II and p62/SQSTM1 (referred as p62) confirmed autophagic flux blockade in cells challenged with photoactivated TPPS2a. The endo-lysosomal system plays a key role in membrane trafficking and lipid flux. At the transcriptional level, 1.6-fold increase in gene expression of Hydroxymethylglutaryl-CoA reductase (HMGCR) - an enzyme involved in the synthesis de novo of cholesterol - indicated that endosomes and lysosomes dysfunction alters the distribution of cholesterol in cellschallenged with photoactivated TPPS2a. However, to maintain lipid homeostasis in photosensitized cells, this was not the only compensatory mechanism triggered, since there was a slightly increase (1.2-fold) in the transcription of acid ceramidase (ASAH1). Taken together, our data showed that photosensitization with TPPS2a constitutes a promising tool to damage the endolysosomal system, to inhibit autophagy and to study metabolic responses in cells exposed to oxidative stress

Acetate wheat starch improving blood glucose response and bilan lipid on obesity dyslipidemia mice

Abstract Resistant starch is particularly concerned with beneficial effects in regulating blood glucose concentration and lipid metabolism, reducing the risk of diabetes and cardiovascular diseases. This study aimed to validate the effects of wheat starch acetate containing 32.1% resistant starch on postprandial blood glucose response and lipid profile on obesity, dyslipidemia Swiss mice induced by a high-fat diet. The result showed that there was a restriction on postprandial hyperglycemia and remained stable for 2 hours after meal efficiently comparing with the control group fed natural wheat starch. Simultaneously, when maintaining the dose of 5g/kg once or twice a day for 8 weeks, wheat starch acetate to be able to reduce body weight and blood glucose, triglyceride, cholesterol levels compared to the control group (p<0.05)

Dietary plant sterols prevented cholesterol gallstone formation in mice.

Cholesterol gallstone disease is a common global condition. This study investigated the role of plant sterols (PS) in the prevention of gallstone formation and the underlying mechanisms. Adult male mice were fed a lithogenic diet (LD) alone or supplemented with PS (LD-ps), phospholipids (LD-pl) or both PS and phospholipids (LD-ps/pl) for 8 weeks. Incidences of gallstone formation were compared among the groups. Lipids in the bile, liver and serum were analyzed. The expression of genes involved in cholesterol absorption, transport and metabolism in the liver and small intestine was determined. The incidences of gallstone formation were 100% (10/10), 20% (2/10), 100% (10/10) and 40% (4/10) in the LD, LD-ps, LD-pl and LD-ps/pl groups, respectively. Serum cholesterol and intestinal cholesterol absorption were decreased in PS-supplemented mice. The expression of genes related to cholesterol transport and metabolism in the liver was down-regulated by dietary PS. PS supplementation decreased Niemann-Pick C1-like 1 expression in the small intestine and reduced intestinal cholesterol absorption. Our results demonstrated that PS could inhibit intestinal cholesterol absorption and thus prevent cholesterol gallstone formation.

Association of remnant cholesterol with nonalcoholic fatty liver disease: a general population-based study.

BACKGROUND: Remnant cholesterol (RC) mediates the progression of coronary artery disease, diabetic complications, hypertension, and chronic kidney disease. Limited information is available on the association of RC with nonalcoholic fatty liver disease (NAFLD). This study aimed to explore whether RC can be used to independently evaluate the risk of NAFLD in the general population and to analyze the predictive value of RC for NAFLD. METHODS: The study included 14,251 subjects enrolled in a health screening program. NAFLD was diagnosed by ultrasound, and the association of RC with NAFLD was assessed using the receiver operating characteristic (ROC) curve and logistic regression equation. RESULTS: Subjects with elevated RC had a significantly higher risk of developing NAFLD after fully adjusting for potential confounding factors (OR 1.77 per SD increase, 95% CI 1.64-1.91, P trend< 0.001). There were significant differences in this association among sex, BMI and age stratification. Compared with men, women were facing a higher risk of RC-related NAFLD. Compared with people with normal BMI, overweight and obesity, the risk of RC-related NAFLD was higher in thin people. In different age stratifications, when RC increased, young people had a higher risk of developing NAFLD than other age groups. Additionally, ROC analysis results showed that among all lipid parameters, the AUC of RC was the largest (women: 0.81; men: 0.74), and the best threshold for predicting NAFLD was 0.54 in women and 0.63 in men. CONCLUSIONS: The results obtained from this study indicate that (1) in the general population, RC is independently associated with NAFLD but not with other risk factors. (2) Compared with traditional lipid parameters, RC has a better predictive ability for NAFLD in men.

Safety assessment of two strains and anti-obese effects on mice fed a high-cholesterol diet.

Previous study documented that Lactobacillus paracasei S0940 and Streptococcus thermophilus ldbm1 have obvious cholesterol-lowering abilities in vitro. In this study, the safety of two strains were evaluated by nitroreductase test, hemolysis test and antibiotic sensitivity test and to evaluate the cholesterol-reducing abilities in vivo. The results indicated that two strains did not exhibit nitroreductase activities and were ɤ-hemolytic on blood agar plates. Further, both strains did not represent a health risk by antibiotic sensitivity test, and significantly reduced serum and liver cholesterol and triglyceride levels of high fat-fed mice. Compared with the high-fat model group, administration of the strains to mice fed a high-cholesterol diet increased fecal water content and fecal cholesterol and significantly improved the intestinal microbiota, which indicating that Lactobacillus paracasei S0940 and Streptococcus thermophilus ldbm1 have a positive effect on reducing cholesterol levels and may be used in functional food.

miR-344-5p Modulates Cholesterol-Induced ß-Cell Apoptosis and Dysfunction Through Regulating Caveolin-1 Expression.

Diabetes is a metabolic disorder induced by the modulation of insulin on glucose metabolism, and the dysfunction and decreased number of islets ß-cells are the main causes of T2DM (type 2 diabetes mellitus). Among multiple factors that might participate in T2DM pathogenesis, the critical roles of miRNAs in T2DM and ß-cell dysfunction have been reported. Through bioinformatics analyses and literature review, we found that miR-344 might play a role in the occurrence and progression of diabetes in rats. The expression levels of miR-344-5p were dramatically decreased within cholesterol-stimulated and palmitic acid (PA)-induced rats' islet ß-cells. In cholesterol-stimulated and PA-induced diabetic ß-cell model, cholesterol-caused and PA-caused suppression on cell viability, increase in intracellular cholesterol level, decrease in GSIS, and increase in lip droplet deposition were dramatically attenuated via the overexpression of miR-344-5p, whereas aggravated via the inhibition of miR-344-5p. miR-344-5p also inhibited cholesterol-induced ß-cell death via affecting the apoptotic caspase 3/Bax signaling. Insulin receptor downstream MPAK/ERK signaling was involved in the protection of miR-344-5p against cholesterol-induced pancreatic ß-cell dysfunction. Moreover, miR-344-5p directly targeted Cav1; Cav1 silencing could partially reverse the functions of miR-344-5p inhibition upon cholesterol-induced ß-cell dysfunction, ß-cell apoptosis, the apoptotic caspase 3/Bax signaling, and insulin receptor downstream MPAK/ERK signaling. In conclusion, the miR-344-5p/Cav1 axis modulates cholesterol-induced ß-cell apoptosis and dysfunction. The apoptotic caspase 3/Bax signaling and MAPK/ERK signaling might be involved.