The 26S proteasome degrades the majority of cellular proteins and affects all aspects of cellular life. Therefore, the 26S proteasome abundance, proper assembly, and activity in different life contexts need to be precisely controlled. Impaired proteasome activity is considered a causative factor in several serious disorders. Recent advances in proteasome biology have revealed that the proteasome can be activated by different factors or small molecules. Thus, activated ubiquitin-dependent proteasome degradation has effects such as extending the lifespan in different models, preventing the accumulation of protein aggregates, and reducing their negative impact on cells. Increased 26S proteasome-mediated degradation reduces proteotoxic stress and can potentially improve the efficacy of engineered degraders, such as PROTACs, particularly in situations characterized by proteasome malfunction. Here, emerging ideas and recent insights into the pharmacological activation of the proteasome at the transcriptional and posttranslational levels are summarized.

• Publication type
• Journal Article MeSH
• Review MeSH

Heavy metals are naturally occurring components of the Earth's crust and persistent environmental pollutants. Human exposure to heavy metals occurs via various pathways, including inhalation of air/dust particles, ingesting contaminated water or soil, or through the food chain. Their bioaccumulation may lead to diverse toxic effects affecting different body tissues and organ systems. The toxicity of heavy metals depends on the properties of the given metal, dose, route, duration of exposure (acute or chronic), and extent of bioaccumulation. The detrimental impacts of heavy metals on human health are largely linked to their capacity to interfere with antioxidant defense mechanisms, primarily through their interaction with intracellular glutathione (GSH) or sulfhydryl groups (R-SH) of antioxidant enzymes such as superoxide dismutase (SOD), catalase, glutathione peroxidase (GPx), glutathione reductase (GR), and other enzyme systems. Although arsenic (As) is believed to bind directly to critical thiols, alternative hydrogen peroxide production processes have also been postulated. Heavy metals are known to interfere with signaling pathways and affect a variety of cellular processes, including cell growth, proliferation, survival, metabolism, and apoptosis. For example, cadmium can affect the BLC-2 family of proteins involved in mitochondrial death via the overexpression of antiapoptotic Bcl-2 and the suppression of proapoptotic (BAX, BAK) mechanisms, thus increasing the resistance of various cells to undergo malignant transformation. Nuclear factor erythroid 2-related factor 2 (Nrf2) is an important regulator of antioxidant enzymes, the level of oxidative stress, and cellular resistance to oxidants and has been shown to act as a double-edged sword in response to arsenic-induced oxidative stress. Another mechanism of significant health threats and heavy metal (e.g., Pb) toxicity involves the substitution of essential metals (e.g., calcium (Ca), copper (Cu), and iron (Fe)) with structurally similar heavy metals (e.g., cadmium (Cd) and lead (Pb)) in the metal-binding sites of proteins. Displaced essential redox metals (copper, iron, manganese) from their natural metal-binding sites can catalyze the decomposition of hydrogen peroxide via the Fenton reaction and generate damaging ROS such as hydroxyl radicals, causing damage to lipids, proteins, and DNA. Conversely, some heavy metals, such as cadmium, can suppress the synthesis of nitric oxide radical (NO·), manifested by altered vasorelaxation and, consequently, blood pressure regulation. Pb-induced oxidative stress has been shown to be indirectly responsible for the depletion of nitric oxide due to its interaction with superoxide radical (O2·-), resulting in the formation of a potent biological oxidant, peroxynitrite (ONOO-). This review comprehensively discusses the mechanisms of heavy metal toxicity and their health effects. Aluminum (Al), cadmium (Cd), arsenic (As), mercury (Hg), lead (Pb), and chromium (Cr) and their roles in the development of gastrointestinal, pulmonary, kidney, reproductive, neurodegenerative (Alzheimer's and Parkinson's diseases), cardiovascular, and cancer (e.g. renal, lung, skin, stomach) diseases are discussed. A short account is devoted to the detoxification of heavy metals by chelation via the use of ethylenediaminetetraacetic acid (EDTA), dimercaprol (BAL), 2,3-dimercaptosuccinic acid (DMSA), 2,3-dimercapto-1-propane sulfonic acid (DMPS), and penicillamine chelators.

• MeSH
• Antioxidants metabolism   MeSH
• Bioaccumulation MeSH
• Environmental Pollutants toxicity   MeSH
• Humans MeSH
• Oxidative Stress * drug effects   MeSH
• Metals, Heavy * toxicity   MeSH
• Environmental Exposure adverse effects   MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Review MeSH

Atherosclerosis is a chronic inflammatory disease of the blood vessels caused by elevated levels of lipoproteins. The hyperlipoproteinemia triggers a series of cellular changes, particularly the activation of the macrophages, which play a crucial role in the development and progression of atherosclerosis. The presence of free cholesterol (FC) in lipoproteins may contribute to macrophage stimulation. However, the mechanisms linking the accumulation of FC in macrophages to their pro-inflammatory activation remain poorly understood. Our research found a positive correlation between the number of pro-inflammatory macrophages (CD14 + CD16 + CD36high) in visceral adipose tissue and the levels of LDL-C and cholesterol remnant particles in 56 healthy people. In contrast, the proportion of anti-inflammatory, alternatively activated macrophages (CD14 + CD16-CD163+) correlated negatively with HDL-C. Additionally, our in vitro study demonstrated that macrophages accumulating FC promoted a pro-inflammatory response, activating the TNF-α and chemokine CCL3 genes. Furthermore, the accumulation of FC in macrophages alters the surface receptors on macrophages (CD206 and CD16) and increases cellular granularity. Notably, the CD36 surface receptor and the ACAT and CD36 genes did not show a response. These results suggest a link between excessive FC accumulation and systemic inflammation to underlie the development of atherosclerosis.

• MeSH
• Macrophage Activation MeSH
• CD36 Antigens metabolism   MeSH
• Atherosclerosis metabolism   MeSH
• Antigens, CD metabolism   MeSH
• Cholesterol * metabolism   MeSH
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Macrophages * metabolism   immunology   drug effects   MeSH
• Intra-Abdominal Fat metabolism   MeSH
• Tumor Necrosis Factor-alpha metabolism   genetics   MeSH
• Inflammation * metabolism   MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Female MeSH
• Publication type
• Journal Article MeSH

Background: Type 2 diabetes is a common condition that causes the level of sugar (glucose) in the blood to become too high. It can cause symptoms relative insulin deficit, whether due to beta-cell damage, insulin resistance. The study of carnitine and LDH levels in diabetic patients is significant because both play important roles in the metabolism of glucose and fatty acids. Carnitine is a compound that transports fatty acids into the mitochondria for energy production, while LDH (lactate dehydrogenase) is an enzyme involved in the conversion of glucose to lactate. Humans with type 2 diabetes develop lipid accumulation due to carnitine depletion. LDH is an essential physiological molecule in the glycolytic pathway, and its concentration may be indicative of the condition of cellular metabolism.Aim: For measuring and evaluating the levels of serum carnitine and LDH in all study groups.Method: A case-control study was done in the Al-Zahraa Teaching Hospital, Kut, Iraq on 150 Iraqi males and females as patients and control between (April 2022 and January 2023). Their ages ranged between 44 and 77 years. Among them were 120 patients divided into 4 groups 30 type 2 diabetes mellitus; 30 diabetic cardiomyopathies; 30 diabetic nephropathies; 30 diabetic retinopathies and 30 control group where control group's age and gender matched those of the patient groups. All patients gave written informed consent to participate in the clinical study. ELISA was used to measure carnitine and LDH.Result: In present study, it was confirmed that carnitine was significantly lower than the control group and that LDH was significantly higher than the control group. the study demonstrated significant differences in fasting blood sugar and HbA1C levels among the control group, DM2, DCM, DNP, and DRP groups.Conclusion: This case-control study revealed significant differences in carnitine levels, LDH, FBS, and HbA1C levels among patients with Type 2 diabetes mellitus (T2DM) and their complications compared to the control group. These findings suggest alterations in energy metabolism and cellular damage in patients, indicating poorer glycemic control, and supporting the presence of uncontrolled diabetes.

• MeSH
• Diabetes Mellitus, Type 2 * diagnosis   complications   blood   MeSH
• Adult MeSH
• Energy Metabolism physiology   MeSH
• Carnitine * blood   MeSH
• Diabetes Complications diagnosis   classification   blood   MeSH
• Blood Glucose metabolism   MeSH
• Lactate Dehydrogenases * blood   MeSH
• Middle Aged MeSH
• Humans MeSH
• Fatty Acids metabolism   MeSH
• Aged MeSH
• Case-Control Studies MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Aged MeSH
• Female MeSH
• Geographicals
• Iraq MeSH

Protein misfolding diseases, including α1-antitrypsin deficiency (AATD), pose substantial health challenges, with their cellular progression still poorly understood1-3. We use spatial proteomics by mass spectrometry and machine learning to map AATD in human liver tissue. Combining Deep Visual Proteomics (DVP) with single-cell analysis4,5, we probe intact patient biopsies to resolve molecular events during hepatocyte stress in pseudotime across fibrosis stages. We achieve proteome depth of up to 4,300 proteins from one-third of a single cell in formalin-fixed, paraffin-embedded tissue. This dataset reveals a potentially clinically actionable peroxisomal upregulation that precedes the canonical unfolded protein response. Our single-cell proteomics data show α1-antitrypsin accumulation is largely cell-intrinsic, with minimal stress propagation between hepatocytes. We integrated proteomic data with artificial intelligence-guided image-based phenotyping across several disease stages, revealing a late-stage hepatocyte phenotype characterized by globular protein aggregates and distinct proteomic signatures, notably including elevated TNFSF10 (also known as TRAIL) amounts. This phenotype may represent a critical disease progression stage. Our study offers new insights into AATD pathogenesis and introduces a powerful methodology for high-resolution, in situ proteomic analysis of complex tissues. This approach holds potential to unravel molecular mechanisms in various protein misfolding disorders, setting a new standard for understanding disease progression at the single-cell level in human tissue.

• MeSH
• alpha 1-Antitrypsin metabolism   MeSH
• Single-Cell Analysis MeSH
• alpha 1-Antitrypsin Deficiency * pathology   metabolism   genetics   MeSH
• Phenotype MeSH
• Hepatocytes metabolism   pathology   MeSH
• Liver Cirrhosis pathology   metabolism   MeSH
• Liver pathology   metabolism   MeSH
• Humans MeSH
• Disease Progression MeSH
• Proteome * analysis   metabolism   MeSH
• Proteomics * methods   MeSH
• Unfolded Protein Response MeSH
• Machine Learning MeSH
• Check Tag
• Humans MeSH
• Male MeSH
• Female MeSH
• Publication type
• Journal Article MeSH

PI3K signaling pathway is crucial for a plethora of cellular processes and is extensively linked with tumorigenesis and chemo-/radioresistance. Although a number of small molecule inhibitors have been synthesized to control PI3K-mediated signaling, only a limited clinical success has been reached. Thus, the search for novel promising candidates is still ongoing. Herein, we present a novel series of N-(5-(2-morpholino-4-oxo-3,4-dihydroquinazolin-8-yl)pyridin-2-yl)acylamides designed to simultaneously inhibit PI3K and DNA-PK activity. Compared to a commercial DNA-PK/PI3K inhibitor AZD7648, synthesized compounds generally exhibited markedly lower baseline cytotoxicity in all tested cell lines (MC38, B16F10, 4T1, CT26 and HEK-239). Through an array of biological experiments, we selected two most promising compounds, 2 and 6. While in cell-free conditions, 6 acted as a very efficient pan-PI3K and DNA-PK inhibitor, in physiological conditions, 2 performed better and acted as a potent chemosensitizer able to increase the amount of DNA double strand breaks induced by doxorubicin. This was plausibly due to its improved ability to accumulate in nuclei as evidenced by confocal analyses. Importantly, using P-gp overexpressing CT26 cells, we found that 2 is an efficient inhibitor of multidrug resistance (MDR) able to down-regulate expression of mRNA encoding MDR-driving proteins ABCB1A, ABCB1B and ABCC1. We also demonstrate that 2 can be simply loaded into lipid nanoparticles that retain its chemosensitizing properties. Taken together, the presented study provides a solid basis for a subsequent rational structure optimization towards new generation of multitarget inhibitors able to control crucial signaling pathways involved in tumorigenesis and drug resistance.

• MeSH
• Drug Resistance, Neoplasm * drug effects   MeSH
• Phosphatidylinositol 3-Kinases metabolism   MeSH
• Phosphoinositide-3 Kinase Inhibitors * pharmacology   MeSH
• Protein Kinase Inhibitors * pharmacology   chemistry   chemical synthesis   MeSH
• Humans MeSH
• Drug Resistance, Multiple * drug effects   MeSH
• Molecular Structure MeSH
• Mice MeSH
• Cell Line, Tumor MeSH
• ATP Binding Cassette Transporter, Subfamily B, Member 1 * antagonists & inhibitors   metabolism   MeSH
• Cell Proliferation drug effects   MeSH
• DNA-Activated Protein Kinase * antagonists & inhibitors   metabolism   MeSH
• Antineoplastic Agents * pharmacology   chemistry   chemical synthesis   MeSH
• Drug Screening Assays, Antitumor MeSH
• Dose-Response Relationship, Drug MeSH
• Structure-Activity Relationship MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Mice MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH

Changes in cellular physiology and proteomic homeostasis accompanied the initiation and progression of colorectal cancer. Thus, ubiquitination represents a central regulatory mechanism in proteome dynamics. However, the complexity of the ubiquitinating network involved in carcinogenesis remains unclear. This study revealed the tumor-suppressive role of the ubiquitin ligase Cullin4A (CUL4A) in the intestine. We showed that simultaneous loss of CUL4A and hyperactivation of the Wnt pathway promotes tumor development in the distal colon. This tumor development is caused by an accumulation of the inactive SMAD3, a TGF-β pathway mediator. Depletion of CUL4A resulted in stabilization of HUWE1, which attenuated SMAD3 function. We showed a correlation between the intracellular localization of CUL4A and colorectal cancer progression, where nuclear CUL4A localization correlates with advanced colorectal cancer progression. In summary, we identified CUL4A as an important regulator of SMAD3 signal transduction competence in a HUWE1-dependent manner and demonstrated a critical role for the crosstalk between ubiquitination and the Wnt/TGF-β signaling pathways in gastrointestinal homeostasis.

• MeSH
• HCT116 Cells MeSH
• Colorectal Neoplasms * pathology   genetics   metabolism   MeSH
• Cullin Proteins * metabolism   genetics   MeSH
• Humans MeSH
• Mice MeSH
• Cell Line, Tumor MeSH
• Tumor Suppressor Proteins * metabolism   genetics   MeSH
• Smad3 Protein * metabolism   genetics   MeSH
• Gene Expression Regulation, Neoplastic MeSH
• Wnt Signaling Pathway MeSH
• Ubiquitination MeSH
• Ubiquitin-Protein Ligases * metabolism   genetics   MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Mice MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH

DNA damage is a common event in cells, resulting from both internal and external factors. The maintenance of genomic integrity is vital for cellular function and physiological processes. The inadequate repair of DNA damage results in the genomic instability, which has been associated with the development and progression of various human diseases. Accumulation of DNA damage can lead to multiple diseases, such as neurodegenerative disorders, cancers, immune deficiencies, infertility, and ageing. This comprehensive review delves the impact of alterations in DNA damage response genes (DDR) and tries to elucidate how and to what extent the same traits modulate diverse major human diseases, such as cancer, neurodegenerative diseases, and immunological disorders. DDR is apparently the trait connecting important complex disorders in humans. However, the pathogenesis of the above disorders and diseases are different and lead to divergent consequences. It is important to discover the switch(es) that direct further the pathogenic process either to proliferative, or degenerative diseases. Our understanding of the influence of DNA damage on diverse human disorders may enable the development of the strategies to prevent, diagnose, and treat these diseases. In our article, we analysed publicly available GWAS summary statistics from the NHGRI-EBI GWAS Catalog and identified 12 009 single-nucleotide polymorphisms (SNPs) associated with cancer. Among these, 119 SNPs were found in DDR pathways, exhibiting significant P-values. Additionally, we identified 44 SNPs linked to various cancer types and neurodegenerative diseases (NDDs), including four located in DDR-related genes: ATM, CUX2, and WNT3. Furthermore, 402 SNPs were associated with both cancer and immunological disorders, with two found in the DDR gene RAD51B. This highlights the versatility of the DDR pathway in multifactorial diseases. However, the specific mechanisms that regulate DDR to initiate distinct pathogenic processes remain to be elucidated.

• MeSH
• Genome-Wide Association Study MeSH
• Genetic Predisposition to Disease MeSH
• Polymorphism, Single Nucleotide MeSH
• Humans MeSH
• Neoplasms * genetics   MeSH
• Immune System Diseases * genetics   MeSH
• Genomic Instability genetics   MeSH
• Neurodegenerative Diseases * genetics   MeSH
• DNA Repair * genetics   MeSH
• DNA Damage * genetics   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Review MeSH

PSMA-617 is recognized as a benchmark ligand for prostate-specific membrane antigen (PSMA) owing to its broad utilization in prostate cancer (PCa) targeted radionuclide therapy. In this study, the structure-activity relationships (SAR) of PSMA-617 and two novel analogs featuring modified linkers were investigated. In compounds P17 and P18, the 2-naphthyl-l-Ala moiety was replaced with a less lipophilic 3-styryl-l-Ala moiety while the cyclohexyl ring in P18 was replaced with a phenyl group. The first ever crystal structure of the PSMA/PSMA-617 complex reported here revealed a folded conformation of the PSMA-617 linker while for the PSMA/P17 and PSMA/P18 complexes, the extended orientations of the linkers revealed linker flexibility within the PSMA cavity, a change in binding that can be exploited for the structure-guided design of PSMA-targeting agents. Despite structural differences from PSMA-617, the analogs maintained high PSMA inhibition potency, cellular binding, and internalization. In vivo biodistribution studies revealed comparable tumor uptake across all three compounds with P18 displaying higher spleen accumulation, likely due to phenyl ring lipophilicity. These SAR findings provide a strategic framework for the rational design of PSMA ligands, paving the way for the development of next-generation theranostic agents for PCa.

• Publication type
• Journal Article MeSH

The current understanding of lipid droplets (LDs) in cell biology has evolved from being viewed merely as storage compartments. LDs are now recognized as metabolic hubs that act as cytosolic buffers against the detrimental effects of free fatty acids (FAs). Upon activation, FAs traverse various cellular pathways, including oxidation in mitochondria, integration into complex lipids, or storage in triacylglycerols (TGs). Maintaining a balance among these processes is crucial in cellular FA trafficking, and under metabolically challenging circumstances the routes of FA metabolism adapt to meet the current cellular needs. This typically involves an increased demand for anabolic intermediates or energy and the prevention of redox stress. Surprisingly, LDs accumulate under certain conditions such as amino acid starvation. This review explores the biochemical aspects of FA utilization in both physiological contexts and within cancer cells, focusing on the metabolism of TGs, cholesteryl esters (CEs), and mitochondrial FA oxidation. Emphasis is placed on the potential toxicity associated with non-esterified FAs in cytosolic and mitochondrial compartments. Additionally, we discuss mechanisms that lead to increased LD biogenesis due to an inhibited mitochondrial import of FAs.

• MeSH
• Humans MeSH
• Lipid Droplets * metabolism   MeSH
• Fatty Acids * metabolism   MeSH
• Lipid Metabolism MeSH
• Mitochondria * metabolism   MeSH
• Oxidation-Reduction MeSH
• Triglycerides metabolism   MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Review MeSH