Discovery of a potent SCAP degrader that ameliorates HFD-induced obesity, hyperlipidemia and insulin resistance via an autophagy-independent lysosomal pathway

NPD7426 suppresses sterol regulatory element-binding proteins by promoting the degradation of mature SREBP forms

Sterol regulatory element-binding proteins (SREBPs) are transcription factors that regulate various genes involved in cholesterol and fatty acid synthesis, playing a central role in lipid metabolism regulation in vivo. SREBP-1c activity is significantly elevated in the liver under conditions of obesity, fatty liver disease, and type II diabetes, while suppression of SREBP-1c activity has been shown to alleviate these symptoms. Consequently, targeting SREBP-1c activity is considered a potential therapeutic approach for these conditions. In this study, we identified NPD7426 as a compound with inhibitory effects on SREBP activity. Furthermore, we demonstrated that NPD7426 promotes the proteasome-mediated degradation of mature SREBP protein forms. These findings provide new insights into the mechanism of SREBP activity suppression by small-molecule compounds containing NPD7426, suggesting that NPD7426 may be a promising candidate for the development of therapeutic drugs targeting SREBPs.

Genome-wide CRISPR screen reveals host factors for gama- and delta-coronavirus infection in Huh7 cells

Genome-wide CRISPR screening has emerged as a powerful tool for identifying novel host factors involved in viral infections. In recent years, host factors for several Alpha- and Beta-coronaviruses have been systematically screened and characterized. However, knowledge regarding Gamma- and Delta-coronavirus infections remains limited. In this study, we conducted genome-scale CRISPR knockout (KO) screening in Huh7 cells infected with infectious bronchitis virus (IBV), a Gamma-coronavirus, and porcine deltacoronavirus (PDCoV), a Delta-coronavirus. We identified known host factors for PDCoV, including APN and TMEM41B. We confirmed that human APN does not serve as a critical host factor for IBV. Notably, SPPL3 was identified as a key factor involved in viral particle entry and S protein-induced syncytium formation through the modulation of cellular N-glycosylation. Furthermore, we performed a meta-analysis integrating all Huh7 cell-based genome-wide CRISPR screens across the four genera of coronaviruses (Alpha-, Beta-, Gamma-, and Delta-coronaviruses). Our analysis highlighted conserved host pathways, particularly those related to proteoglycans, glycoproteins, and vesicle trafficking. TMEM41B, SCAP, and FAM98A emerged as the most frequently targeted host genes. These findings provide valuable insights into the life cycles of IBV and PDCoV infections and facilitate the development of host-directed therapeutic strategies.

Triphenyl phosphate induces lipid metabolism disorder and promotes obesity through PI3K/AKT signaling pathway

Triphenyl phosphate (TPHP) is a widely used organic phosphate flame retardant that has been reported as a potential environmental obesogen. However, the potential impact and mechanism of action of TPHP on adipose tissue are still unclear. This study investigates the potential impact of TPHP on lipid metabolism disorders through in vivo and in vitro experiments. Male and female BALB/c mice were exposed to TPHP (0, 1, 10, and 150 mg/kg/day) for 60 days, and 3T3-L1 preadipocytes were treated with concentrations of TPHP (0, 0.1, 1, 10 μM) during differentiation. The results showed that exposure to TPHP could cause gender specific dyslipidemia, with male mice exhibiting dose-dependent increases in inguinal adipose tissue coefficient, adipocyte hypertrophy, and upregulation of adipose differentiation and adipogenesis-related genes. In contrast, female mice did not show significant changes in tissue morphology. This suggested that TPHP might promote the potential occurrence of adiposity by disrupting the lipid metabolism homeostasis of male adipose tissue. During the differentiation and maturation process of 3T3-L1 preadipocytes, exposure to TPHP led to increased lipid accumulation and disrupted lipid homeostasis by simultaneous activation adipogenesis and lipolysis. Multiple omics data showed that the activation of the peroxisome proliferator-activated receptor γ (PPARγ) signaling pathway and fatty acid metabolism was the core mechanism of TPHP induced metabolic dysfunction. Further research showed that TPHP activated the PI3K/AKT pathway, and PI3K inhibitor (LY294002) could rescue TPHP induced lipid droplet formation and normalize the expression of adipogenic markers. These findings confirm that TPHP is a potential environmental obesogen that can disrupt the metabolic homeostasis of white adipose tissue through the PPARγ and PI3K/AKT signaling pathways, with higher susceptibility in males. This study provides compelling evidence for the obesogenic effects of TPHP and information for risk assessment of organophosphorus flame retardants.

Cholesterol metabolism: physiological versus pathological aspects in intracerebral hemorrhage

Cholesterol is an important component of plasma membranes and participates in many basic life functions, such as the maintenance of cell membrane stability, the synthesis of steroid hormones, and myelination. Cholesterol plays a key role in the establishment and maintenance of the central nervous system. The brain contains 20% of the whole body's cholesterol, 80% of which is located within myelin. A huge number of processes (e.g., the sterol regulatory element-binding protein pathway and liver X receptor pathway) participate in the regulation of cholesterol metabolism in the brain via mechanisms that include cholesterol biosynthesis, intracellular transport, and efflux. Certain brain injuries or diseases involving crosstalk among the processes above can affect normal cholesterol metabolism to induce detrimental consequences. Therefore, we hypothesized that cholesterol-related molecules and pathways can serve as therapeutic targets for central nervous system diseases. Intracerebral hemorrhage is the most severe hemorrhagic stroke subtype, with high mortality and morbidity. Historical cholesterol levels are associated with the risk of intracerebral hemorrhage. Moreover, secondary pathological changes after intracerebral hemorrhage are associated with cholesterol metabolism dysregulation, such as neuroinflammation, demyelination, and multiple types of programmed cell death. Intracellular cholesterol accumulation in the brain has been found after intracerebral hemorrhage. In this paper, we review normal cholesterol metabolism in the central nervous system, the mechanisms known to participate in the disturbance of cholesterol metabolism after intracerebral hemorrhage, and the links between cholesterol metabolism and cell death. We also review several possible and constructive therapeutic targets identified based on cholesterol metabolism to provide cholesterol-based perspectives and a reference for those interested in the treatment of intracerebral hemorrhage.

Protective effects of berberine on MASLD: regulation of glucose and lipid metabolism through PI3K/Akt and STING pathways

This study is aimed at exploring the therapeutic potential of berberine (BBR) in mitigating metabolic dysfunction-associated steatotic liver disease (MASLD) and at elucidating its mechanisms of action, with a focus on the modulation of glucose and lipid metabolism via the PI3K/Akt and STING signaling pathways. Male C57BL/6 J mice were fed a high-fat diet (HFD) to induce MASLD and subsequently treated with BBR or metformin. HepG2 cells were cultured in vitro, and palmitic acid (PA) was used to construct the cell model. Comprehensive analyses, including network pharmacology, transcriptome sequencing, and Western blotting, were conducted to identify critical pathways and molecular targets. Biochemical, histological, and molecular assays were performed to evaluate metabolic and inflammatory responses. BBR significantly attenuated HFD-induced hepatic steatosis, inflammation, and glucose intolerance. It effectively reduced lipid accumulation, enhanced insulin sensitivity, and modulated the expression of genes involved in lipid metabolism. Network pharmacology and transcriptome analysis highlighted the involvement of the PI3K/Akt and STING pathways. BBR activated PI3K/Akt signaling while suppressing the STING pathway, thereby reducing lipid accumulation in both in vivo and in vitro models. The inhibition of AKT negated the beneficial effects of BBR, underscoring the pivotal role of PI3K/Akt in regulating STING signaling. BBR ameliorates MASLD by activating the PI3K/Akt pathway and inhibiting the STING pathway, leading to improved glucose and lipid metabolism. These findings position BBR as a promising therapeutic candidate for the treatment of MASLD.

Lipid metabolism: the potential therapeutic targets in glioblastoma

Glioblastoma is a highly malignant tumor of the central nervous system with a high mortality rate. The mechanisms driving glioblastoma onset and progression are complex, posing substantial challenges for developing precise therapeutic interventions to improve patient survival. Over a century ago, the discovery of the Warburg effect underscored the importance of abnormal glycolysis in tumors, marking a pivotal moment in cancer research. Subsequent studies have identified mitochondrial energy conversion as a fundamental driver of tumor growth. Recently, lipid metabolism has emerged as a critical factor in cancer cell survival, providing an alternative energy source. Research has shown that lipid metabolism is reprogrammed in glioblastoma, playing a vital role in shaping the biological behavior of tumor cells. In this review, we aim to elucidate the impact of lipid metabolism on glioblastoma tumorigenesis and explore potential therapeutic targets. Additionally, we provide insights into the regulatory mechanisms that govern lipid metabolism, emphasizing the critical roles of key genes and regulators involved in this essential metabolic process.

The modulatory effect of oat on brain-derived neurotrophic factor, orexigenic neuropeptides, and dopaminergic signaling in obesity-induced rat model: a comparative study to orlistat

BACKGROUND

Obesity is a non-communicable complex disease that is the fifth leading cause of death worldwide. According to a novel viewpoint, the brain plays a significant role in the central regulation of satiety and energy homeostasis. Because of its rich nutritional profile and versatile uses, oat (Avena sativa) is one of the most popular functional foods recommended by many nutritionists. The anti-obesity effect of oat was hypothesized, focusing on the brain as the target organ. In the current study, the interplay between brain biomarkers, obesity, and its related complications was evaluated in diet-induced obese rats for 25 weeks, in which 60 adult male white albino Wistar rats were divided into three control and seven treatment groups given oat extracts in a dose-dependent manner.

RESULTS

Oat significantly improved obesity-related metabolic complications. In terms of brain function, oat significantly increased dopaminergic signaling, brain-derived neurotrophic factor levels, vaspin, irisin, and uncoupling protein-1 brain levels, while decreasing the expression of agouti-related peptide and neuropeptide Y (P-value < 0.05).

CONCLUSION

The current study proposes oat supplementation as a new conceptual framework with numerous implications for hedonic and homeostatic mechanisms that control satiety. © 2024 Society of Chemical Industry.

Ergosterol alleviates hepatic steatosis and insulin resistance via promoting fatty acid β-oxidation by activating mitochondrial ACSL1

Sterols target sterol-sensing domain (SSD) proteins to lower cholesterol and circulating and hepatic triglyceride levels, but the mechanism remains unclear. In this study, we identify acyl-coenzyme A (CoA) synthetase long-chain family member 1 (ACSL1) as a direct target of ergosterol (ES). The C-terminal domain of ACSL1 undergoes conformational changes from closed to open, and ES may target the drug-binding pocket in the acetyl-CoA synthetase-like domain 1 (ASLD1) of ACSL1 to stabilize the closed conformation and maintain its activity. Moreover, ES is mainly enriched in the mitochondria and promotes fatty acid β-oxidation through ACSL1 allosteric activation. Structure-activity relationship analysis reveals how different structural sterols interact with the sterol-sensing domain-containing protein (SCAP) and ACSL1, explaining their regulatory effects on lipid metabolism. Moreover, our findings reveal that the combination of SCAP inhibitor 25-hydroxycholesterol (25-HC) and ES has a stronger lipid-lowering effect than alone.

Theoretical framework and emerging challenges of lipid metabolism in cancer

Elevated lipid metabolism is one of hallmarks of malignant tumors. Lipids not only serve as essential structural components of biological membranes but also provide energy and substrates for the proliferation of cancer cells and tumor growth. Cancer cells meet their lipid needs by coordinating the processes of lipid absorption, synthesis, transport, storage, and catabolism. As research in this area continues to deepen, numerous new discoveries have emerged, making it crucial for scientists to stay informed about the developments of cancer lipid metabolism. In this review, we first discuss relevant concepts and theories or assumptions that help us understand the lipid metabolism and -based cancer therapies. We then systematically summarize the latest advancements in lipid metabolism including new mechanisms, novel targets, and up-to-date pre-clinical and clinical investigations of anti-cancer treatment with lipid metabolism targeted drugs. Finally, we emphasize emerging research directions and therapeutic strategies, and discuss future prospective and emerging challenges. This review aims to provide the latest insights and guidance for research in the field of cancer lipid metabolism.

Integrated network pharmacology, metabolomics and molecular docking analysis to reveal the mechanisms of quercetin in the treatment of hyperlipidemia

Hyperlipidemia (HLP) is a significant contributor to cardiovascular diseases. Quercetin (QUE), a naturally occurring flavonoid with diverse bioactivities, has garnered attention due to its potential therapeutic effects. However, the precise mechanisms underlying the effects of QUE on HLP remain unclear. In this study, an ultra-high-performance liquid chromatography-quadrupole/electrostatic field Orbitrap high-resolution mass spectrometry (UPLC-Q-Exactive-MS) metabolomics strategy was employed to obtain metabolite profiles, and potential biomarkers were identified following data analysis. Network pharmacology and Drug Affinity Responsive Target Stability (DARTS) assays were utilized to explore the potential targets of QUE for HLP treatment. The results of metabolomics and network pharmacology were then integrated to identify the key targets and metabolic pathways involved in the therapeutic action of the QUE against HLP. Molecular docking and experimental validation were performed to confirm these key targets. A comprehensive database search identified 138 QUE-HLP-related targets. A protein-protein interaction (PPI) network was constructed using STRING, and the shared targets were filtered with Cytoscape. Among these, AKT1, TNF, VEGFA, mTOR, SREBP1, and SCD emerged as potential therapeutic targets. These findings were validated using in vitro cell experiments. Additionally, the mechanism of action of QUE against HLP was evaluated by integrating network pharmacology with metabolomics, identifying two metabolomic pathways crucial to HLP treatment. DARTS experiments confirmed the stable binding of QUE to FASN, p-mTOR, SREBP1, and p-AKT. In HepG2 cells treated with palmitic acid (PA), QUE significantly reduced the mRNA expression of ACLY, ACACA, FASN, and SCD (p < 0.05). Western blot analysis revealed that PA significantly increased protein expression of p-mTOR, SREBP1, FASN, and p-AKT (p < 0.05). In summary, our study provides novel insights into the protective mechanisms of QUE against HLP and offers valuable information regarding its potential benefits in clinical treatment.

The role of GOT1 in cancer metabolism

GOT1, a cytoplasmic glutamic oxaloacetic transaminase, plays a critical role in various metabolic pathways essential for cellular homeostasis and dysregulated metabolism. Recent studies have highlighted the significant plasticity and roles of GOT1 in metabolic reprogramming through participating in both classical and non-classical glutamine metabolism, glycolytic metabolism, and other metabolic pathways. This review summarizes emerging insights on the metabolic roles of GOT1 in cancer cells and emphasizes the response of cancer cells to altered metabolism when the expression of GOT1 is altered. We review how cancer cells repurpose cell intrinsic metabolism and their flexibility when GOT1 is inhibited and delineate the molecular mechanisms of GOT1's interaction with specific oncogenes and regulators at multiple levels, including transcriptional and epigenetic regulation, which govern cellular growth and metabolism. These insights may provide new directions for cancer metabolism research and novel targets for cancer treatment.

Lycorine ameliorates liver steatosis, oxidative stress, ferroptosis and intestinal homeostasis imbalance in MASLD mice

BACKGROUND

Metabolic dysfunction-associated steatotic liver disease (MASLD) is the most common liver disease worldwide and few drugs are available for its treatment. Lycorine has effective anti-inflammatory and lipid-lowering effects, but the impact on MASLD is not fully understood. In this study, we intend to test the intervention effect of lycorine on MASLD.

METHODS

A MASLD mouse model was constructed on a high-fat diet for 16 weeks, and low, medium, and high doses of lycorine were given by gavage for the last 4 weeks. Detecting indicators related to liver steatosis, oxidative stress, and ferroptosis. In vivo and in vitro experiments co-validate potential targets identified by network pharmacology, molecular docking and western blot for lycorine intervention in MASLD liver. A combination of pathology, western blot, qRT-PCR, and 16 S rRNA sequencing verified adipose tissue and intestinal alterations.

RESULTS

Lycorine ameliorated hepatic steatosis, oxidative stress and ferroptosis in MASLD mice by inhibiting the expression of phosphorylated EGFR, inhibiting the PI3K/AKT signaling pathway. We also observed a dose-dependent effect of lycorine to improve some of the indicators of MASLD. In vitro, knockdown of EGFR significantly attenuated palmitic acid-induced hepatocyte steatosis. In addition, lycorine promoted WAT browning for thermogenesis and energy consumption, affected the composition of intestinal flora, improved the intestinal barrier, and reduced intestinal inflammation.

CONCLUSIONS

EGFR was the target of lycorine intervention in MASLD. Lycorine ameliorated hepatic steatosis, oxidative stress and ferroptosis by affecting the EGFR/PI3K/AKT signaling pathway in MASLD mice. Furthermore, lycorine promoted WAT browning and ameliorated intestinal homeostatic imbalance. The above effects may also have dose-dependent effects.

Combined metformin and simvastatin therapy inhibits SREBP2 maturation and alters energy metabolism in glioma

This study aims to explore the inhibitory effects of combined metformin and simvastatin therapy on the malignant progression of glioma. The research specifically examines how the maturation of SREBP2 as a transcription factor affects the expression of GLUT1 and GLUT6 in glioma cells. Additionally, it investigates the impact of this combination therapy on the biological functions and energy metabolism of glioma cells. To assess the functions of GLUT1/6, sh-GLUT1/6 plasmids were employed. The study determined the half-maximal inhibitory concentrations (IC50) of metformin and simvastatin using the CCK-8 assay. Subsequently, the effects of these drugs on glioma metabolism, proliferation, and apoptosis were explored in vitro and in vivo, using drug concentrations significantly lower than their respective IC50 values. The impact of drug treatment on GLUT1/6 and SREBP2 expression levels was also evaluated. The study elucidated the significant impact of GLUT1/6 on glioma cell functions, resulting in decreased glucose uptake. Moreover, it unveiled the regulatory role of SREBP2 in GLUT1 and GLUT6 transcription, alongside revealing differential expression of SREBP2 precursor and mature forms within gliomas. Following combined drug therapy, GLUT1/6 expression decreased, while the precursor form of SREBP2 increased, and mature SREBP2 reduced. This dual-drug treatment effectively modulated glioma cell energy metabolism. Subsequent in vivo experiments affirmed the augmented anti-tumor efficacy of combined drug therapy. Specifically, the synergistic action of metformin and simvastatin reshaped glioma metabolism, curbed malignant proliferation, promoted apoptosis, and demonstrated superior anti-tumor effects both in vitro and in vivo compared to individual administration of metformin or simvastatin. Importantly, the combination therapy achieved these effects at lower doses, rendering it a safer treatment option.

Targeted protein degradation: advances in drug discovery and clinical practice

Targeted protein degradation (TPD) represents a revolutionary therapeutic strategy in disease management, providing a stark contrast to traditional therapeutic approaches like small molecule inhibitors that primarily focus on inhibiting protein function. This advanced technology capitalizes on the cell's intrinsic proteolytic systems, including the proteasome and lysosomal pathways, to selectively eliminate disease-causing proteins. TPD not only enhances the efficacy of treatments but also expands the scope of protein degradation applications. Despite its considerable potential, TPD faces challenges related to the properties of the drugs and their rational design. This review thoroughly explores the mechanisms and clinical advancements of TPD, from its initial conceptualization to practical implementation, with a particular focus on proteolysis-targeting chimeras and molecular glues. In addition, the review delves into emerging technologies and methodologies aimed at addressing these challenges and enhancing therapeutic efficacy. We also discuss the significant clinical trials and highlight the promising therapeutic outcomes associated with TPD drugs, illustrating their potential to transform the treatment landscape. Furthermore, the review considers the benefits of combining TPD with other therapies to enhance overall treatment effectiveness and overcome drug resistance. The future directions of TPD applications are also explored, presenting an optimistic perspective on further innovations. By offering a comprehensive overview of the current innovations and the challenges faced, this review assesses the transformative potential of TPD in revolutionizing drug development and disease management, setting the stage for a new era in medical therapy.

Recent breakthroughs in innovative elements, multidimensional enhancements, derived technologies, and novel applications of PROTACs

Proteolysis Targeting Chimera (PROTAC) is an emerging and evolving technology based on targeted protein degradation (TPD). Small molecule PROTACs have shown great efficacy in degrading disease-specific proteins in preclinical and clinical studies, but also showed various limitations. In recent years, new technologies and advances in TPD have provided additional optimized strategies based on conventional PROTACs that can overcome the shortcomings of conventional PROTACs in terms of undruggable targets, bioavailability, tissue-specificity, spatiotemporal control, and degradation scope. In addition, some designs of special targeting chimeras and applications based on multidisciplinary science have shed light on novel therapeutic modalities and drug design. However, each improvement has its own advantages, disadvantages and application conditions. In this review, we summarize the exploration of PROTAC elements, depict a landscape of improvements and derived concepts of PROTACs, and expect to provide perspectives for technological innovations, combinations and applications in future targeting chimera design.

Ginsenoside Rg3 Restores Mitochondrial Cardiolipin Homeostasis via GRB2 to Prevent Parkinson's Disease

Regulating cardiolipin to maintain mitochondrial homeostasis is a promising strategy for addressing Parkinson's disease (PD). Through a comprehensive screening and validation process involving multiple models, ginsenoside Rg3 (Rg3) as a compound capable of enhancing cardiolipin levels is identified. This augmentation in cardiolipin levels fosters mitochondrial homeostasis by bolstering mitochondrial unfolded protein response, promoting mitophagy, and enhancing mitochondrial oxidative phosphorylation. Consequently, this cascade enhances the survival of tyrosine hydroxylase positive (TH+) dopaminergic neurons, leading to an amelioration in motor performance within PD mouse models. Using limited proteolysis-small-molecule mapping combined with molecular docking analysis, it has confirmed Growth Factor Receptor-Bound Protein 2 (GRB2) as a molecular target for Rg3. Furthermore, these investigations reveal that Rg3 facilitates the interaction between GRB2 and TRKA (Neurotrophic Tyrosine Kinase, Receptor, Type 1), thus promotes EVI1 (Ecotropic Virus Integration Site 1 Protein Homolog) phosphorylation by ERK, subsequently increases CRLS1 (Cardiolipin Synthase 1) gene expression and boosts cardiolipin synthesis. The absence of GRB2 or CRLS1 significantly attenuates the beneficial effects of Rg3 on PD symptoms. Finally, Tenofovir Disoproxil Fumarate (TDF) that also promotes the binding between GRB2 and TRKA is further identified. The identified compounds, Rg3 and TDF, exhibit promising potential for the prevention of PD by bolstering cardiolipin expression and reinstating mitochondrial homeostasis.

Association between a body shape index and cognitive impairment among US older adults aged 40 years and above from a cross-sectional survey of the NHANES 2011-2014

Purpose

This research aimed to assess the correlation between the Adjusted Body Shape Index (ABSI) and the presence of abdominal aortic calcification (AAC) among middle-aged and older American adults.

Methods

Employing a cross-sectional design, this study analyzed data from the 2013-2014 National Health and Nutrition Examination Survey (NHANES), focusing on 3077 participants aged 40 and above. AAC detection was conducted using dual-energy X-ray absorptiometry (DXA). ABSI was determined based on waist circumference (WC), weight, and height data. The association between ABSI and AAC was examined through multiple linear regression, smoothed curve analysis, threshold effect evaluation, subgroup analysis, and interaction testing.

Results

The study encompassed 3077 individuals aged 40 and above. Findings indicated a noteworthy positive relationship between ABSI and AAC when adjusting various covariates. Analysis of threshold effects identified a K-point at 0.0908, showing no significant effect to its left but a significant effect to its right. Further, subgroup and interaction analyses highlighted the ABSI-AAC connection specifically within different age groups and among individuals with diabetes.

Conclusion

Higher ABSI was correlated with higher AAC score.

New horizons in the mechanisms and therapeutic strategies for PD-L1 protein degradation in cancer

Programmed death-ligand 1 (PD-L1) has become a crucial focus in cancer immunotherapy considering it is found in many different cells. Cancer cells enhance the suppressive impact of programmed death receptor 1 (PD-1) through elevating PD-L1 expression, which allows them to escape immune detection. Although there have been significant improvements, the effectiveness of anti-PD-1/PD-L1 treatment is still limited to a specific group of patients. An important advancement in cancer immunotherapy involves improving the PD-L1 protein degradation. This review thoroughly examined the processes by which PD-L1 breaks down, including the intracellular pathways of ubiquitination-proteasome and autophagy-lysosome. In addition, the analysis revealed changes that affect PD-L1 stability, such as phosphorylation and glycosylation. The significant consequences of these procedures on cancer immunotherapy and their potential role in innovative therapeutic approaches are emphasised. Our future efforts will focus on understanding new ways in which PD-L1 degradation is controlled and developing innovative treatments, such as proteolysis-targeting chimeras designed specifically to degrade PD-L1. It is crucial to have a thorough comprehension of these pathways in order to improve cancer immunotherapy strategies and hopefully improve therapeutic effectiveness.

The Art of Finding the Right Drug Target: Emerging Methods and Strategies

Drug targets are specific molecules in biological tissues and body fluids that interact with drugs. Drug target discovery is a key component of drug discovery and is essential for the development of new drugs in areas such as cancer therapy and precision medicine. Traditional in vitro or in vivo target discovery methods are time-consuming and labor-intensive, limiting the pace of drug discovery. With the development of modern discovery methods, the discovery and application of various emerging technologies have greatly improved the efficiency of drug discovery, shortened the cycle time, and reduced the cost. This review provides a comprehensive overview of various emerging drug target discovery strategies, including computer-assisted approaches, drug affinity response target stability, multiomics analysis, gene editing, and nonsense-mediated mRNA degradation, and discusses the effectiveness and limitations of the various approaches, as well as their application in real cases. Through the review of the aforementioned contents, a general overview of the development of novel drug targets and disease treatment strategies will be provided, and a theoretical basis will be provided for those who are engaged in pharmaceutical science research. SIGNIFICANCE STATEMENT: Target-based drug discovery has been the main approach to drug discovery in the pharmaceutical industry for the past three decades. Traditional drug target discovery methods based on in vivo or in vitro validation are time-consuming and costly, greatly limiting the development of new drugs. Therefore, the development and selection of new methods in the drug target discovery process is crucial.

The cellular and molecular targets of natural products against metabolic disorders: a translational approach to reach the bedside

Metabolic disorders, including obesity, dyslipidemia, diabetes, nonalcoholic fatty liver disease, and metabolic syndrome, are characterized by insulin resistance, abnormalities in circulating cholesterol and lipid profiles, and hypertension. The most common pathophysiologies of metabolic disorders are glucose/lipid metabolism dysregulation, insulin resistance, inflammatory response, and oxidative stress. Although several agents have been approved for the treatment of metabolic disorders, there is still a strong demand for more efficacious drugs with less side effects. Natural products have been critical sources of drug research and discovery for decades. However, the usefulness of bioactive natural products is often limited by incomplete understanding of their direct cellular targets. In this review, we highlight the current understanding of the established and emerging molecular mechanisms of metabolic disorders. We further summarize the therapeutic effects and underlying mechanisms of natural products on metabolic disorders, with highlights on their direct cellular targets, which are mainly implicated in the regulation of glucose/lipid metabolism, insulin resistance, metabolic inflammation, and oxidative stress. Finally, this review also covers the clinical studies of natural products in metabolic disorders. These progresses are expected to facilitate the application of these natural products and their derivatives in the development of novel drugs against metabolic disorders.

Identification of activating transcription factor 6 (ATF6) as a novel prognostic biomarker and potential target in oral squamous cell carcinoma

BACKGROUND

Oral squamous cell carcinoma (OSCC) is originating from oral mucosal epithelial cells. Autophagy plays a crucial role in cancer treatment by promoting cellular self-degradation and eliminating damaged components, thereby enhancing therapeutic efficacy. In this study, we aim to identify a novel autophagy-related biomarker to improve OSCC therapy.

METHODS

We firstly utilized Cox and Lasso analyses to identify that ATF6 is associated with OSCC prognosis, and validated the results by Kaplan-Meier survival analysis. We further identified the downstream pathways and related genes by enrichment analysis and WGCNA analysis. Subsequently, we used short interfering RNA to investigate the effects of ATF6 knockdown on proliferation, migration, apoptosis, and autophagy in SCC-9 and SCC-15 cells through cell viability assay, transwell assay, EdU incorporation assay, flow cytometry analysis, western blot analysis and immunofluorescence analysis, etc. RESULTS: Bioinformatics analyses showed that ATF6 overexpression was associated with prognosis and detrimental to survival. In vitro studies verified that ATF6 knockdown reduced OSCC cell proliferation and migration. Mechanistically, ATF6 knockdown could promote cellular autophagy and apoptosis.

CONCLUSION

We propose that ATF6 holds potential as a prognostic biomarker linked to autophagy in OSCC. This study provides valuable clues for further exploration of targeted therapy against OSCC.

Association of METS-IR index with prevalence of erectile dysfunction in US adults: a cross-sectional study

BACKGROUND

Insulin resistance (IR) is involved in the development of erectile dysfunction (ED). The purpose of this study was to assess the correlation between the metabolic score for IR (METS-IR) index and risk of erectile dysfunction in US adults.

METHODS

This study selected individuals from the National Health and Nutrition Examination Survey (NHANES). Logistic regression analysis, subgroup analysis, and dose-response curve analysis were carried out to assess the relationship between the METS-IR index and ED prevalence.

RESULTS

This study ultimately included 1759 participants aged ≥ 20 years, of whom 512 self-reported a history of ED. After adjusting for all confounders, each unit increase in METS-IR index was associated with a 3% increase in erectile dysfunction prevalence (OR = 1.03, 95% CI: 1.01-1.04). In almost all subgroups, an increased METS-IR index was associated with a higher prevalence of ED. The dose-response curve displayed a positive non-linear connection between METS-IR value and the prevalence of ED.

CONCLUSION

The study found a positive association between the METS-IR index and ED. METS-IR is useful as a simplified IR evaluation index for early identification of people with high risk of ED.

A novel marine-derived anti-acute kidney injury agent targeting peroxiredoxin 1 and its nanodelivery strategy based on ADME optimization

Insufficient therapeutic strategies for acute kidney injury (AKI) necessitate precision therapy targeting its pathogenesis. This study reveals the new mechanism of the marine-derived anti-AKI agent, piericidin glycoside S14, targeting peroxiredoxin 1 (PRDX1). By binding to Cys83 of PRDX1 and augmenting its peroxidase activity, S14 alleviates kidney injury efficiently in Prdx1-overexpression (Prdx1-OE) mice. Besides, S14 also increases PRDX1 nuclear translocation and directly activates the Nrf2/HO-1/NQO1 pathway to inhibit ROS production. Due to the limited druggability of S14 with low bioavailability (2.6%) and poor renal distribution, a pH-sensitive kidney-targeting dodecanamine-chitosan nanoparticle system is constructed to load S14 for precise treatment of AKI. l-Serine conjugation to chitosan imparts specificity to kidney injury molecule-1 (Kim-1)-overexpressed cells. The developed S14-nanodrug exhibits higher therapeutic efficiency by improving the in vivo behavior of S14 significantly. By encapsulation with micelles, the AUC0‒t , half-life time, and renal distribution of S14 increase 2.5-, 1.8-, and 3.1-fold, respectively. The main factors contributing to the improved druggability of S14 nanodrugs include the lower metabolic elimination rate and UDP-glycosyltransferase (UGT)-mediated biotransformation. In summary, this study identifies a new therapeutic target for the marine-derived anti-AKI agent while enhancing its ADME properties and druggability through nanotechnology, thereby driving advancements in marine drug development for AKI.

Correlation between changes in serum YKL-40, LXRs, PPM1A, and TGF-β1 levels and airway remodeling and lung function in patients with bronchial asthma

OBJECTIVE

This study investigates the correlation between serum levels of YKL-40, LXRs, PPM1A, and TGF-β1 and airway remodeling and lung function in bronchial asthma patients.

METHODS

The study involved 80 bronchial asthma patients and 92 healthy individuals. Serum cytokines, airway remodeling, and lung function markers were compared across mild, moderate, and severe asthma cases using high-resolution CT, t-tests, ANOVA, and Pearson correlation analysis.

RESULTS

Asthmatic patients exhibited higher levels of serum YKL-40, LXRα, LXRβ, TGF-β1, airway wall thickness (T)/outer diameter (D), and WA% of total cross-sectional area compared to controls. Conversely, their serum PPM1A, Peak Expiratory Flow (PEF), and Forced Expiratory Volume in 1 s (FEV1) were lower. Serum YKL-40 and TGF-β1 levels were positively correlated with T/D and WA%, and negatively correlated with PEF and FEV1. PPM1A levels were strongly associated with T/D, WA%, PEF, and FEV1.

CONCLUSION

The severity of bronchial asthma is associated with increased serum levels of YKL-40, LXRα, LXRβ, and TGF-β1 and decreased PPM1A. The levels of YKL-40, PPM1A, and TGF-β1 have a significant correlation with airway remodeling and lung function.

Regulation and targeting of SREBP-1 in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is an increasing burden on global public health and is associated with enhanced lipogenesis, fatty acid uptake, and lipid metabolic reprogramming. De novo lipogenesis is under the control of the transcription factor sterol regulatory element-binding protein 1 (SREBP-1) and essentially contributes to HCC progression. Here, we summarize the current knowledge on the regulation of SREBP-1 isoforms in HCC based on cellular, animal, and clinical data. Specifically, we (i) address the overarching mechanisms for regulating SREBP-1 transcription, proteolytic processing, nuclear stability, and transactivation and (ii) critically discuss their impact on HCC, taking into account (iii) insights from pharmacological approaches. Emphasis is placed on cross-talk with the phosphatidylinositol-3-kinase (PI3K)-protein kinase B (Akt)-mechanistic target of rapamycin (mTOR) axis, AMP-activated protein kinase (AMPK), protein kinase A (PKA), and other kinases that directly phosphorylate SREBP-1; transcription factors, such as liver X receptor (LXR), peroxisome proliferator-activated receptors (PPARs), proliferator-activated receptor γ co-activator 1 (PGC-1), signal transducers and activators of transcription (STATs), and Myc; epigenetic mechanisms; post-translational modifications of SREBP-1; and SREBP-1-regulatory metabolites such as oxysterols and polyunsaturated fatty acids. By carefully scrutinizing the role of SREBP-1 in HCC development, progression, metastasis, and therapy resistance, we shed light on the potential of SREBP-1-targeting strategies in HCC prevention and treatment.

Neuroprotective effects of chaperone-mediated autophagy in neurodegenerative diseases

ABSTRACT

Chaperone-mediated autophagy is one of three types of autophagy and is characterized by the selective degradation of proteins. Chaperone-mediated autophagy contributes to energy balance and helps maintain cellular homeostasis, while providing nutrients and support for cell survival. Chaperone-mediated autophagy activity can be detected in almost all cells, including neurons. Owing to the extreme sensitivity of neurons to their environmental changes, maintaining neuronal homeostasis is critical for neuronal growth and survival. Chaperone-mediated autophagy dysfunction is closely related to central nervous system diseases. It has been shown that neuronal damage and cell death are accompanied by chaperone-mediated autophagy dysfunction. Under certain conditions, regulation of chaperone-mediated autophagy activity attenuates neurotoxicity. In this paper, we review the changes in chaperone-mediated autophagy in neurodegenerative diseases, brain injury, glioma, and autoimmune diseases. We also summarize the most recent research progress on chaperone-mediated autophagy regulation and discuss the potential of chaperone-mediated autophagy as a therapeutic target for central nervous system diseases.

Alisol B regulates AMPK/mTOR/SREBPs via directly targeting VDAC1 to alleviate hyperlipidemia

BACKGROUND

The occurrence of hyperlipidemia is significantly influenced by lipid synthesis, which is regulated by sterol regulatory element binding proteins (SREBPs), thus the development of drugs that inhibit lipid synthesis has become a popular treatment strategy for hyperlipidemia. Alisol B (ALB), a triterpenoid compound extracted from Alisma, has been reported to ameliorate no-nalcoholic steatohepatitis (NASH) and slow obesity. However, the effect of ALB on hyperlipidemia and mechanism are unclear.

PURPOSE

To examine the therapeutic impact of ALB on hyperlipidemia whether it inhibits SREBPs to reduce lipid synthesis.

STUDY DESIGN

HepG2, HL7702 cells, and C57BL/6J mice were used to explore the effect of ALB on hyperlipidemia and the molecular mechanism in vivo and in vitro.

METHODS

Hyperlipidemia models were established using western diet (WD)-fed mice in vivo and oleic acid (OA)-induced hepatocytes in vitro. Western blot, real-time PCR and other biological methods verified that ALB regulated AMPK/mTOR/SREBPs to inhibit lipid synthesis. Cellular thermal shift assay (CETSA), molecular dynamics (MD), and ultrafiltration-LC/MS analysis were used to evaluate the binding of ALB to voltage-dependent anion channel protein-1 (VDAC1).

RESULTS

ALB decreased TC, TG, LDL-c, and increased HDL-c in blood, thereby ameliorating liver damage. Gene set enrichment analysis (GSEA) indicated that ALB inhibited the biosynthesis of cholesterol and fatty acids. Consistently, ALB inhibited the protein expression of n-SREBPs and downstream genes. Mechanistically, the impact of ALB on SREBPs was dependent on the regulation of AMPK/mTOR, thereby impeding the transportation of SREBPs from endoplasmic reticulum (ER) to golgi apparatus (GA). Further investigations indicated that the activation of AMPK by ALB was independent on classical upstream CAMKK2 and LKB1. Instead, ALB resulted in a decrease in ATP levels and an increase in the ratios of ADP/ATP and AMP/ATP. CETSA, MD, and ultrafiltration-LC/MS analysis indicated that ALB interacted with VDAC1. Molecular docking revealed that ALB directly bound to VDAC1 by forming hydrogen bonds at the amino acid sites S196 and H184 in the ATP-binding region. Importantly, the thermal stabilization of ALB on VDAC1 was compromised when VDAC1 was mutated at S196 and H184, suggesting that these amino acids played a crucial role in the interaction.

CONCLUSION

Our findings reveal that VDAC1 serves as the target of ALB, leading to the inhibition of lipid synthesis, presents potential target and candidate drugs for hyperlipidemia.

Discovery of Novel Binders to Sterol Regulatory Element-Binding Protein-1 by High-Throughput Screening

Sterol regulatory element-binding protein-1 (SREBP-1) is a transcription factor that regulates the expression of genes related to fatty acid biosynthesis. Its high expression and activation in obesity and associated metabolic diseases make it a potential therapeutic target. However, the role of SREBP-1 in the development and exacerbation of these diseases remains unclear, partly because of the impossibility of inhibiting its function because of the lack of specific inhibitors. Here, we aimed to identify small-molecule compounds that directly bind to SREBP-1 using the recombinant N-terminal region of SREBP-1a, which is required for its transcriptional activity. A high-throughput screening campaign was conducted using a thermal shift assay and surface plasmon resonance assay to evaluate the compound affinity and specificity, which resulted in the identification of two compounds. Future analysis of their structure-activity relationships may lead to the development of specific SREBP-1 inhibitors, thereby potentially validating SREBP-1 as a therapeutic target for obesity and resultant atherosclerotic diseases.

Activation of hepatic adenosine A1 receptor ameliorates MASH via inhibiting SREBPs maturation

Metabolic (dysfunction)-associated steatohepatitis (MASH) is the advanced stage of metabolic (dysfunction)-associated fatty liver disease (MAFLD) lacking approved clinical drugs. Adenosine A1 receptor (A1R), belonging to the G-protein-coupled receptors (GPCRs) superfamily, is mainly distributed in the central nervous system and major peripheral organs with wide-ranging physiological functions; however, the exact role of hepatic A1R in MAFLD remains unclear. Here, we report that liver-specific depletion of A1R aggravates while overexpression attenuates diet-induced metabolic-associated fatty liver (MAFL)/MASH in mice. Mechanistically, activation of hepatic A1R promotes the competitive binding of sterol-regulatory element binding protein (SREBP) cleavage-activating protein (SCAP) to sequestosome 1 (SQSTM1), rather than protein kinase A (PKA) leading to SCAP degradation in lysosomes. Reduced SCAP hinders SREBP1c/2 maturation and thus suppresses de novo lipogenesis and inflammation. Higher hepatic A1R expression is observed in patients with MAFL/MASH and high-fat diet (HFD)-fed mice, which is supposed to be a physiologically adaptive response because A1R agonists attenuate MAFL/MASH in an A1R-dependent manner. These results highlight that hepatic A1R is a potential target for MAFL/MASH therapy.

DHCR7 promotes lymph node metastasis in cervical cancer through cholesterol reprogramming-mediated activation of the KANK4/PI3K/AKT axis and VEGF-C secretion

Cervical cancer (CC) patients with lymph node metastasis (LNM) have a poor prognosis. However, the molecular mechanism of LNM in CC is unclear, and there is no effective clinical treatment. Here, we found that 7-dehydrocholesterol reductase (DHCR7), an enzyme that catalyzes the last step of cholesterol synthesis, was upregulated in CC and closely related to LNM. Gain-of-function and loss-of-function experiments proved that DHCR7 promoted the invasion ability of CC cells and lymphangiogenesis in vitro and induced LNM in vivo. The LNM-promoting effect of DHCR7 was partly mediated by upregulating KN motif and ankyrin repeat domains 4 (KANK4) expression and subsequently activating the PI3K/AKT signaling pathway. Alternatively, DHCR7 promoted the secretion of vascular endothelial growth factor-C (VEGF-C), and thereby lymphangiogenesis. Interestingly, cholesterol reprogramming was needed for the DHCR7-mediated promotion of activation of the KANK4/PI3K/AKT axis, VEGF-C secretion, and subsequent LNM. Importantly, treatment with the DHCR7 inhibitors AY9944 and tamoxifen (TAM) significantly inhibited LNM of CC, suggesting the clinical application potential of DHCR7 inhibitors in CC. Collectively, our results uncover a novel molecular mechanism of LNM in CC and identify DHCR7 as a new potential therapeutic target.

Activation of the PERK-CHOP signaling pathway during endoplasmic reticulum stress contributes to olanzapine-induced dyslipidemia

Olanzapine (OLZ) is a widely prescribed antipsychotic drug with a relatively ideal effect in the treatment of schizophrenia (SCZ). However, its severe metabolic side effects often deteriorate clinical therapeutic compliance and mental rehabilitation. The peripheral mechanism of OLZ-induced metabolic disorders remains abstruse for its muti-target activities. Endoplasmic reticulum (ER) stress is implicated in cellular energy metabolism and the progression of psychiatric disorders. In this study, we investigated the role of ER stress in the development of OLZ-induced dyslipidemia. A cohort of 146 SCZ patients receiving OLZ monotherapy was recruited, and blood samples and clinical data were collected at baseline, and in the 4th week, 12th week, and 24th week of the treatment. This case-control study revealed that OLZ treatment significantly elevated serum levels of endoplasmic reticulum (ER) stress markers GRP78, ATF4, and CHOP in SCZ patients with dyslipidemia. In HepG2 cells, treatment with OLZ (25, 50 μM) dose-dependently enhanced hepatic de novo lipogenesis accompanied by SREBPs activation, and simultaneously triggered ER stress. Inhibition of ER stress by tauroursodeoxycholate (TUDCA) and 4-phenyl butyric acid (4-PBA) attenuated OLZ-induced lipid dysregulation in vitro and in vivo. Moreover, we demonstrated that activation of PERK-CHOP signaling during ER stress was a major contributor to OLZ-triggered abnormal lipid metabolism in the liver, suggesting that PERK could be a potential target for ameliorating the development of OLZ-mediated lipid dysfunction. Taken together, ER stress inhibitors could be a potentially effective intervention against OLZ-induced dyslipidemia in SCZ.

Temporal relationship between inflammation and metabolic disorders and their impact on cancer risk

Background

Inflammation and metabolic disorders are closely associated with cancer. Whether inflammation leads to metabolic disorders or vice versa during cancer initiation remains unclear. In this study, we explored this temporal relationship and the co-exposure effect on cancer risk.

Methods

This prospective study had two phases. Initially, we examined the temporal relationship between inflammation (high-sensitivity C-reactive protein (CRP)) and metabolic disorders (metabolic syndrome severity Z-score (MetS-Z)) using a 3.98-year survey and cross-lagged analysis. Subsequently, we assessed the connection of co-exposure to inflammation and metabolic disorders, and the risks of overall cancer, as well as specific obesity-related, non-obesity-related, digestive system, lung, and other cancers using an 11.04-year survey and Cox proportional hazard models.

Results

The cross-lagged analysis revealed that the path coefficient from baseline CRP to follow-up MetS-Z (β2 = 0.032; 95% confidence interval (CI) = 0.026, 0.046) was more significant than the path coefficient from baseline MetS-Z to follow-up CRP (β1 = 0.009; 95% CI = -0.001, 0.019). During the follow-up, 2304 cases of cancer occurred. Compared with the risk of cancer of patients with low average cumulative CRP and MetS-Z, patients with high value had a significantly increased risk (hazard ratio = 1.54, 95% CI = 1.30, 1.83). The mediation analysis showed that MetS-Z mediated the association between CRP levels and overall cancer (12.67%), digestive system cancer (10.16%), and obesity-related cancer risk (13.87%).

Conclusions

Inflammation had a greater impact on metabolic disorders than vice versa. Co-exposure to inflammation and metabolic disorders significantly increased the risk of cancer, particularly digestive system and obesity-related cancers.

Registration

Chinese Clinical Trial Registry: ChiCTR-TNRC-11001489.

A cholesterol-binding bacterial toxin provides a strategy for identifying a specific Scap inhibitor that blocks lipid synthesis in animal cells

Lipid synthesis is regulated by the actions of Scap, a polytopic membrane protein that binds cholesterol in membranes of the endoplasmic reticulum (ER). When ER cholesterol levels are low, Scap activates SREBPs, transcription factors that upregulate genes for synthesis of cholesterol, fatty acids, and triglycerides. When ER cholesterol levels rise, the sterol binds to Scap, triggering conformational changes that prevent activation of SREBPs and halting synthesis of lipids. To achieve a molecular understanding of how cholesterol regulates the Scap/SREBP machine and to identify therapeutics for dysregulated lipid metabolism, cholesterol-mimetic compounds that specifically bind and inhibit Scap are needed. To accomplish this goal, we focused on Anthrolysin O (ALO), a pore-forming bacterial toxin that binds cholesterol with a specificity and sensitivity that is uncannily similar to Scap. We reasoned that a small molecule that would bind and inhibit ALO might also inhibit Scap. High-throughput screening of a ~300,000-compound library for ALO-binding unearthed one molecule, termed UT-59, which binds to Scap's cholesterol-binding site. Upon binding, UT-59 triggers the same conformation changes in Scap as those induced by cholesterol and blocks activation of SREBPs and lipogenesis in cultured cells. UT-59 also inhibits SREBP activation in the mouse liver. Unlike five previously reported inhibitors of SREBP activation, UT-59 is the only one that acts specifically by binding to Scap's cholesterol-binding site. Our approach to identify specific Scap inhibitors such as UT-59 holds great promise in developing therapeutic leads for human diseases stemming from elevated SREBP activation, such as fatty liver and certain cancers.

Direct degradation and stabilization of proteins: New horizons in treatment of nonalcoholic steatohepatitis

Nonalcoholic fatty liver disease (NAFLD) is featured with excessive hepatic lipid accumulation and its global prevalence is soaring. Nonalcoholic steatohepatitis (NASH), the severe systemic inflammatory subtype of NAFLD, is tightly associated with metabolic comorbidities, and the hepatocytes manifest severe inflammation and ballooning. Currently the therapeutic options for treating NASH are limited. Potent small molecules specifically intervene with the signaling pathways that promote pathogenesis of NASH. Nevertheless they have obvious adverse effects and show long-term ineffectiveness in clinical trials. It poses the fundamental question to efficiently and safely inhibit the pathogenic processes. Targeted protein degradation (TPD) belongs to the direct degradation strategies and is a burgeoning strategy. It utilizes the small molecules to bind to the target proteins and recruit the endogenous proteasome, lysosome and autophagosome-mediated degradation machineries. They effectively and specifically degrade the target proteins. It has exhibited promising therapeutic effects in treatment of cancer, neurodegenerative diseases and other diseases in a catalytic manner at low doses. We critically discuss the principles of multiple direct degradation strategies, especially PROTAC and ATTEC. We extensively analyze their emerging application in degradation of excessive pathogenic proteins and lipid droplets, which promote the progression of NASH. Moreover, we discuss the opposite strategy that utilizes the small molecules to recruit deubiquinases to stabilize the NASH/MASH-suppressing proteins. Their advantages, limitations, as well as the solutions to address the limitations have been analyzed. In summary, the innovative direct degradation strategies provide new insights into design of next-generation therapeutics to combat NASH with optimal safety paradigm and efficiency.

Natural compounds as obesity pharmacotherapies

Obesity has become a serious global public health problem, affecting over 988 million people worldwide. Nevertheless, current pharmacotherapies have proven inadequate. Natural compounds have garnered significant attention due to their potential antiobesity effects. Over the past three decades, ca. 50 natural compounds have been evaluated for the preventive and/or therapeutic effects on obesity in animals and humans. However, variations in the antiobesity efficacies among these natural compounds have been substantial, owing to differences in experimental designs, including variations in animal models, dosages, treatment durations, and administration methods. The feasibility of employing these natural compounds as pharmacotherapies for obesity remained uncertain. In this review, we systematically summarized the antiobesity efficacy and mechanisms of action of each natural compound in animal models. This comprehensive review furnishes valuable insights for the development of antiobesity medications based on natural compounds.

The Role of SCAP/SREBP as Central Regulators of Lipid Metabolism in Hepatic Steatosis

The prevalence of metabolic dysfunction-associated steatotic liver disease (MASLD) is rapidly increasing worldwide at an alarming pace, due to an increase in obesity, sedentary and unhealthy lifestyles, and unbalanced dietary habits. MASLD is a unique, multi-factorial condition with several phases of progression including steatosis, steatohepatitis, fibrosis, cirrhosis, and hepatocellular carcinoma. Sterol element binding protein 1c (SREBP1c) is the main transcription factor involved in regulating hepatic de novo lipogenesis. This transcription factor is synthesized as an inactive precursor, and its proteolytic maturation is initiated in the membrane of the endoplasmic reticulum upon stimulation by insulin. SREBP cleavage activating protein (SCAP) is required as a chaperon protein to escort SREBP from the endoplasmic reticulum and to facilitate the proteolytic release of the N-terminal domain of SREBP into the Golgi. SCAP inhibition prevents activation of SREBP and inhibits the expression of genes involved in triglyceride and fatty acid synthesis, resulting in the inhibition of de novo lipogenesis. In line, previous studies have shown that SCAP inhibition can resolve hepatic steatosis in animal models and intensive research is going on to understand the effects of SCAP in the pathogenesis of human disease. This review focuses on the versatile roles of SCAP/SREBP regulation in de novo lipogenesis and the structure and molecular features of SCAP/SREBP in the progression of hepatic steatosis. In addition, recent studies that attempt to target the SCAP/SREBP axis as a therapeutic option to interfere with MASLD are discussed.

SREBPs as the potential target for solving the polypharmacy dilemma

The phenomenon of polypharmacy is a common occurrence among older people with multiple health conditions due to the rapid increase in population aging and the popularization of clinical guidelines. The prevalence of metabolic syndrome is growing quickly, representing a serious threat to both the public and the worldwide healthcare systems. In addition, it enhances the risk of cardiovascular disease as well as mortality and morbidity. Sterol regulatory element binding proteins (SREBPs) are basic helix-loop-helix leucine zipper transcription factors that transcriptionally modulate genes that regulate lipid biosynthesis and uptake, thereby serving an essential role in biological systems regulation. In this article, we have described the structure of SREBPs and explored their activation and regulation of signals. We also reveal that SREBPs are intricately involved in the modulation of metabolic diseases and thus have tremendous potential as the novel target for single-drug therapy for multiple diseases.

Combination of hyperlipidemia and 17β-Estradiol induces TMJOA-like pathological changes in rats

OBJECTIVE

We explored whether hyperlipidemia or combination of hyperlipidemia and E2 could induce TMJOA.

MATERIALS AND METHODS

Four groups of female rats were treated with normal diet, normal diet with E2, high-fat diet, and high-fat diet with E2 (HFD/E2), respectively, to induce TMJOA till 8 weeks. Another three groups were then used for COX2 inhibitor celecoxib to block the induction of TMJOA. Primary condylar chondrocytes were treated with combination of E2, ox-LDL, and corresponding inhibitors for evaluating expressions of related molecules.

RESULTS

Condylar cartilage proliferation with plenty of chondrocyte apoptosis and increased staining for LOX1, nuclear NF-κB, IL-1β, and COX2 at 4 weeks and decreased condylar cartilage and increased subchondral bone density at 8 weeks were observed only in the HFD/E2 group. Celecoxib significantly alleviated the cartilage proliferation and apoptosis in the HFD/E2 group. Serum ox-LDL increased in both high-fat diet groups, while serum IL-1β increased only in the HFD/E2 group. Combination of E2 and ox-LDL synergistically induced expressions of LOX1, phosphorylated NF-κB, IL-1β, and COX2, while LOX1 inhibitor blocked the induction of phosphorylated NF-κB, and NF-κB inhibitor the induction of IL-1β, and IL-1β inhibitor the induction of COX2.

CONCLUSION

Combination of hyperlipidemia and E2-induced TMJOA-like pathological changes through LOX1/NF-κB/IL-1β/COX2-signaling pathway.

Alpha-lipoic acid, apocynin or probiotics influence glutathione status and selected inflammatory parameters in C57/BL6 mice when combined with a low-fat diet

BACKGROUND

The aim of the study was to determine the potential of a low-fat diet (LFD) to protect against oxidative and inflammatory damage in the course of asthma and obesity when combined with antioxidants (alpha-lipoic acid-ALA, apocynin-APO) or a probiotic (P) (Lactobacillus casei).

METHODS

The experiments were carried out on ten groups of male C57/BL6 mice that were fed standard fat (SFD), low-fat (LFD), or high-fat (HFD) diets. Ovalbumin (OVA, administered subcutaneously and by inhalation) was used to sensitize the animals. IL-1α, IL-10, eotaxin-1, leptin, and TNF-α concentrations were examined in blood, while total glutathione (GSHt), reduced glutathione (GSH), oxidized glutathione (GSSG) and -SH groups were measured in lung homogenates.

RESULTS

LFD in combination with the analyzed compounds (APO, P, ALA) significantly decreased the concentration of IL-1α compared to the OVA + HFD group (p < 0.01; p = 0.025; p = 0.002, respectively). Similarly, the treated mice demonstrated lower eotaxin-1 concentrations compared to the HFD group (p < 0.001). Moreover, supplementation of LFD with probiotics significantly increased the concentration of IL-10 vs. controls (p < 0.001) and vs. untreated OVA-sensitized and challenged/obese mice (p < 0.001). Animals administered APO/ALA with LFD displayed a significant decrease in TNF-α concentration compared to OVA + HFD mice (p = 0.013; p = 0.002 respectively). Those treated with ALA displayed significantly improved GSH levels (p = 0.035) compared to OVA + HFD mice.

CONCLUSIONS

Supplementation of the tested compounds with LFD appears to have a positive influence on the glutathione redox status of pulmonary tissues and selected inflammatory parameters in mouse blood.

Caveolin-1 depletion attenuates hepatic fibrosis via promoting SQSTM1-mediated PFKL degradation in HSCs

The key glycolytic enzyme phosphofructokinase (PFK) is responsible for maintaining glycolytic stability and an important energy source for activating hepatic stellate cells (HSCs). However, its regulation in activated HSCs remains unclear. Caveolin-1 (Cav1), a major constituent of caveolae, has emerged as a key target for triggering glycolysis. However, the relationship between Cav1 and glycolysis during HSC activation is not well established. In this study, Cav1 was upregulated in mouse and human fibrotic liver tissues. We concluded that HSC-specific Cav1 knockdown markedly alleviates liver injury and fibrosis. Mechanistically, Cav1 was elevated during primary mouse HSC activation, competing with SQSTM1 for the regulatory subunit of PFK liver type and inhibiting the SQSTM1-mediated autophagy-independent lysosomal degradation pathway to sustain HSC activation. We also identified the heptapeptide alamandine as a promising therapeutic agent that downregulates Cav1 protein levels via proteasomal degradation and may impair glycolysis. Our study provides evidence of the crucial role and mechanism of Cav1 in the glucose metabolic network in HSCs and highlights Cav1 as a critical therapeutic target for the treatment of liver fibrosis.

The Scap-SREBP1-S1P/S2P lipogenesis signal orchestrates the homeostasis and spatiotemporal activation of NF-κB

The nuclear factor κB (NF-κB) pathway plays essential roles in innate and adaptive immunity, but little is known how NF-κB signaling is compartmentalized and spatiotemporally activated in the cytoplasm. Here, we show that the lipogenesis signal cascade Scap-SREBP1-S1P/S2P orchestrates the homeostasis and spatiotemporal activation of NF-κB. SREBP cleavage-activating protein (Scap) and sterol regulatory element-binding protein 1 (SREBP1) form a super complex with inhibitors of NF-κB α (IκBα) to associate NF-κB close to the endoplasmic reticulum (ER). Upon lipopolysaccharide (LPS) stimulation, Scap transports the complex to the Golgi apparatus, where SREBP1 is cleaved by site-1 protease (S1P)/S2P, liberating IκBα for IκB kinase (Ikk)-mediated phosphorylation and subsequent activation of NF-κB. Loss of Scap or inhibition of S1P or S2P diminishes, while SREBP1 deficiency augments, LPS-induced NF-κB activation and subsequent inflammatory responses. Our results reveal the Scap-SREBP1 complex as an additional cytoplasmic checkpoint for NF-κB homeostasis and unveil the Golgi apparatus as the optimal cellular platform for NF-κB activation, providing insights into the crosstalk between lipogenesis signaling and immunity.

Targeting protein modifications in metabolic diseases: molecular mechanisms and targeted therapies

The ever-increasing prevalence of noncommunicable diseases (NCDs) represents a major public health burden worldwide. The most common form of NCD is metabolic diseases, which affect people of all ages and usually manifest their pathobiology through life-threatening cardiovascular complications. A comprehensive understanding of the pathobiology of metabolic diseases will generate novel targets for improved therapies across the common metabolic spectrum. Protein posttranslational modification (PTM) is an important term that refers to biochemical modification of specific amino acid residues in target proteins, which immensely increases the functional diversity of the proteome. The range of PTMs includes phosphorylation, acetylation, methylation, ubiquitination, SUMOylation, neddylation, glycosylation, palmitoylation, myristoylation, prenylation, cholesterylation, glutathionylation, S-nitrosylation, sulfhydration, citrullination, ADP ribosylation, and several novel PTMs. Here, we offer a comprehensive review of PTMs and their roles in common metabolic diseases and pathological consequences, including diabetes, obesity, fatty liver diseases, hyperlipidemia, and atherosclerosis. Building upon this framework, we afford a through description of proteins and pathways involved in metabolic diseases by focusing on PTM-based protein modifications, showcase the pharmaceutical intervention of PTMs in preclinical studies and clinical trials, and offer future perspectives. Fundamental research defining the mechanisms whereby PTMs of proteins regulate metabolic diseases will open new avenues for therapeutic intervention.

The emerging mechanisms and functions of microautophagy

'Autophagy' refers to an evolutionarily conserved process through which cellular contents, such as damaged organelles and protein aggregates, are delivered to lysosomes for degradation. Different forms of autophagy have been described on the basis of the nature of the cargoes and the means used to deliver them to lysosomes. At present, the prevailing categories of autophagy in mammalian cells are macroautophagy, microautophagy and chaperone-mediated autophagy. The molecular mechanisms and biological functions of macroautophagy and chaperone-mediated autophagy have been extensively studied, but microautophagy has received much less attention. In recent years, there has been a growth in research on microautophagy, first in yeast and then in mammalian cells. Here we review this form of autophagy, focusing on selective forms of microautophagy. We also discuss the upstream regulatory mechanisms, the crosstalk between macroautophagy and microautophagy, and the functional implications of microautophagy in diseases such as cancer and neurodegenerative disorders in humans. Future research into microautophagy will provide opportunities to develop novel interventional strategies for autophagy- and lysosome-related diseases.

Lycorine protects against septic myocardial injury by activating AMPK-related pathways

Cardiac dysfunction is a common complication in patients with sepsis triggering high morbidity and mortality. Lycorine (LYC), the main effective monomer component extracted from Lycoris bulbs, possesses antiviral, anti-inflammatory, analgesic, liver protection properties. In this study, the effect of LYC pre- and post-treatment as well as the underlying mechanism were evaluated in the cecal ligation and puncture (CLP) model of Balb/c mice. The survival rate, anal temperature, sepsis score, blood biochemical/routine indicators, cardiac function, sepsis-related pathophysiological processes, and AMPK signaling in septic mice were observed by echocardiography, histological staining, western blot, qPCR, and etc. LYC pretreatment attenuated myocardial injury in septic mice by improving survival rate, sepsis score, blood biochemical/routine indicators, cardiac function and structure, inhibiting inflammation and oxidative stress, improving mitochondrial function, modulating endoplasmic reticulum stress, and activating AMPK pathway. In particular, AMPK deficiency and AMPK inhibitor (Compound C) partially reversed the protective effects of LYC in septic mice. In addition, LYC posttreatment also has slight protective phenotypes on septic myocardial injury, but the effect is not as ideal as pretreatment. Taken together, these findings suggest that LYC may be a potential drug for the treatment of sepsis.

Advancing targeted protein degradation for metabolic diseases therapy

The development and application of traditional drugs represented by small molecule chemical drugs and biological agents, especially inhibitors, have become the mainstream drug development. In recent years, targeted protein degradation (TPD) technology has become one of the most promising methods to remove specific disease-related proteins using cell self-destruction mechanisms. Many different TPD strategies are emerging based on the ubiquitin-proteasome system (UPS) and the autophagy-lysosomal pathway (ALP), including but not limited to proteolysis-targeting chimeras (PROTAC), molecular glues (MG), lysosome targeting chimeras (LYTAC), chaperone-mediated autophagy (CMA)-targeting chimeras, autophagy-targeting chimera (AUTAC), autophagosome-tethering compound (ATTEC), and autophagy-targeting chimera (AUTOTAC). The advent of targeted degradation technology can change most protein targets in human cells from undruggable to druggable, greatly expanding the therapeutic prospect of refractory diseases such as metabolic syndrome. Here, we summarize the latest progress of major TPD technologies, especially in metabolic syndrome and look forward to providing new insights for drug discovery.

Discovery of a potent allosteric activator of DGKQ that ameliorates obesity-induced insulin resistance via the sn-1,2-DAG-PKCε signaling axis

sn-1,2-diacylglycerol (sn-1,2-DAG)-mediated activation of protein kinase Cε (PKCε) is a key pathway that is responsible for obesity-related lipid metabolism disorders, which induces hepatic insulin resistance and type 2 diabetes. No small molecules have been previously reported to ameliorate these diseases through this pathway. Here, we screened and identified the phytochemical atractylenolide II (AT II) that reduces the hepatic sn-1,2-DAG levels, deactivates PKCε activity, and improves obesity-induced hyperlipidemia, hepatosteatosis, and insulin resistance. Furthermore, using the ABPP strategy, the diacylglycerol kinase family member DGKQ was identified as a direct target of AT II. AT II may act on a novel drug-binding pocket in the CRD and PH domains of DGKQ to thereby allosterically regulate its kinase activity. Moreover, AT II also increases weight loss by activating DGKQ-AMPK-PGC1α-UCP-1 signaling in adipose tissue. These findings suggest that AT II is a promising lead compound to improve obesity-induced insulin resistance.

The bHLH-zip transcription factor SREBP regulates triterpenoid and lipid metabolisms in the medicinal fungus Ganoderma lingzhi

Ganoderic acids (GAs) are well recognized as important pharmacological components of the medicinal species belonging to the basidiomycete genus Ganoderma. However, transcription factors directly regulating the expression of GA biosynthesis genes remain poorly understood. Here, the genome of Ganoderma lingzhi is de novo sequenced. Using DNA affinity purification sequencing, we identify putative targets of the transcription factor sterol regulatory element-binding protein (SREBP), including the genes of triterpenoid synthesis and lipid metabolism. Interactions between SREBP and the targets are verified by electrophoretic mobility gel shift assay. RNA-seq shows that SREBP targets, mevalonate kinase and 3-hydroxy-3-methylglutaryl coenzyme A synthetase in mevalonate pathway, sterol isomerase and lanosterol 14-demethylase in ergosterol biosynthesis, are significantly upregulated in the SREBP overexpression (OE::SREBP) strain. In addition, 3 targets involved in glycerophospholipid/glycerolipid metabolism are upregulated. Then, the contents of mevalonic acid, lanosterol, ergosterol and 13 different GAs as well as a variety of lipids are significantly increased in this strain. Furthermore, the effects of SREBP overexpression on triterpenoid and lipid metabolisms are recovered when OE::SREBP strain are treated with exogenous fatostatin, a specific inhibitor of SREBP. Taken together, our genome-wide study clarify the role of SREBP in triterpenoid and lipid metabolisms of G. lingzhi.

Hydrogen Sulfide Attenuates High-Fat Diet-Induced Obesity: Involvement of mTOR/IKK/NF-κB Signaling Pathway

Obesity has become a public health epidemic worldwide and is associated with many diseases with high mortality including hypertension, diabetes, and heart disease. High-fat diet (HFD)-induced energy imbalance is one of the primary causes of obesity, but the underlying mechanisms are not fully elucidated. Our study showed that HFD reduced the level of hydrogen sulfide (H₂S) and its catalytic enzyme cystathionine β-synthase (CBS) in mouse hypothalamus and plasma. We found that HFD activated mTOR, IKK/NF-κB, the main pathway regulating inflammation. Activation of inflammatory pathway promoted the production of pro-inflammatory cytokines including IL-6, IL-1β, and TNF-α, which caused cell damage and loss in the hypothalamus. The disturbance of the hypothalamic neuron circuits resulted in body weight gain in HFD-induced mice. Importantly, we also showed that restoration of H₂S level with NaHS or activation of CBS with SAMe attenuated HFD-induced activation of mTOR, IKK/NF-κB signaling, which reduced the inflammation and the neuronal cell loss in the hypothalamus, and also inhibited body weight gain in mice. The same effects were obtained by inhibiting mTOR or NF-κB, which suggested that mTOR and NF-κB were the critical molecular factors involved in hypothalamic inflammation. Taken together, this study identified that HFD-induced hypothalamus inflammation plays a critical role in the development of obesity. Moreover, the inhibition of hypothalamic inflammation by regaining H₂S level could be a potential therapeutic to prevent the development of obesity.

Study of the Significance of Thromboelastography Changes in Patients with Dyslipidemia

Purpose

To investigate the changes in thromboelastography (TEG) in patients with dyslipidemia to study its effect on the blood coagulation status.

Methods

131 patients hospitalized in Fujian Provincial Jinshan Hospital from January 2018 to December 2020 were selected, and 64 cases in the hyperlipidemia (HL) group and 67 cases in the non-HL group were set according to whether their blood lipids were abnormal. By measuring the changes of each parameter of TEG in patients, the relevant parameters R value, K value, α angle, and MA value were calculated. And routine blood coagulation (PT, APTT, INR, FIB, and TT) and routine blood (platelet count) tests were performed on all study subjects to analyze the changes of each index of the coagulation function and each parameter of TED in both groups and explore the clinical value of TEG on HL diseases.

Results

Compared with the non-HL group, R and K values decreased, and angle and MA values increased in the HL group (P < 0.05). PT, APTT, and INR values decreased, and FIB values increased in the HL group compared with the nonhyperlipidemic group (P < 0.05). The TT levels were similar in the non-HL group and the HL group (P > 0.05). Compared with the non-HL group, PLT values decreased, and PDW and MPV values increased in the HL group (P < 0.05). R value was positively correlated with APTT, r= 0.373, P=0.002. K value was negatively correlated with PLT, r= -0.399, P=0.002. α angle and MA values were positively correlated with PLT, r= 0.319/0.475, P=0.010/P < 0.001. The rest of the indexes did not correlate with each parameter of TEG significant correlation.

Conclusion

TEG can predict the hypercoagulability and hypocoagulability of blood by the changes of R value, K value, α angle, and MA to evaluate the effect of hyperlipidemia on the coagulation status, which is important for guiding the adjustment of lipid-lowering, antithrombotic, and anticoagulation programs in patients with atherosclerosis combined with hyperlipidemia or postsurgery combined with hyperlipidemia.

Lycorine Inhibits Hypertrophic Scar Formation by Inducing ROS-Mediated Apoptosis

Background: Hypertrophic scar (HS) is a fibrotic cutaneous disease with few effective therapies. Lycorine is a drug with pro-apoptotic ability and anti-fibrosis potential. This study aimed to test whether lycorine could trigger the apoptosis of hypertrophic scar fibroblasts (HSFs) to inhibit HS formation.

Methods: The proapoptotic and anti-fibrosis effects of lycorine on the viability and apoptosis of human primary HSFs and their reactive oxygen species (ROS) production as well as a rabbit ear model of HS were determined by CCK-8, flow cytometry, Western blot, immunofluorescence, transwell migration, collagen gel contraction assays.

Results: Lycorine treatment selectively decreased the viability of HSFs, and induced their apoptosis, but not normal fibroblasts (NFs). Lycorine treatment increased the relative levels of Bax and cleaved PARP expression, cytochrome C cytoplasm translocation, but decreased Bcl-2, caspase-3 and caspase-9 expression, the mitochondrial membrane potential (MMP) in HSFs. Lycorine inhibited the migration and contraction of HSFs, and reduced the expression of collagen I, collagen III and α-SMA. Mechanistically, lycorine treatment stimulated high levels of ROS production, leading to apoptosis of HSFs while treatment with NAC, a ROS inhibitor, significantly mitigated or abrogated the pro-apoptotic and antifibrotic activity of lycorine in HSFs. Moreover, lycorine treatment mitigated the severity of HS in rabbit ears by inducing fibroblast apoptosis.

Conclusion: These results indicate that lycorine has a potent anti-fibrotic activity and is a potential drug for intervention of HS.