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Journal of Thrombosis and Haemostasis :... Jun 2024Tissue factor pathway inhibitor (TFPI) regulates tissue factor (TF)-triggered coagulation. Humans and mice express transcripts encoding for multi-distributed...
BACKGROUND
Tissue factor pathway inhibitor (TFPI) regulates tissue factor (TF)-triggered coagulation. Humans and mice express transcripts encoding for multi-distributed (endothelial, platelet, and plasma) 3-Kunitz domain TFPIα and endothelial membrane-anchored 2-Kunitz TFPIβ. Mice express a third transcript, γ, that encodes plasma lipoprotein-associated 2-Kunitz TFPI. In humans, proteolysis of α and/or β produces plasma lipoprotein-associated 2-Kunitz TFPI at lower levels. In clinical trials, monoclonal antibodies that target all TFPI isoforms extend coagulation and correct bleeding in hemophilia patients but with some thrombosis risks.
OBJECTIVES
Determine the impact of TFPI isoform-specific deletions on promoting clotting in hemophilia mice.
METHODS
Engineered TFPI isoform-specific, hemophilia (FVIII-null) mice were evaluated for clotting.
RESULTS
Mice expressing any single TFPI isoform are healthy. Thrombin generation assays identified TFPIγ as the dominant anticoagulation isoform in mouse plasma. Hemostasis was assessed by serial bleeding times from a tail vein laceration. Repeatedly, after a clot forms, it is manually disrupted; the number of clots/disruptions occurring over a 15-minute period is reported. C57BL/6 and hemophilia mice clot on average 25.6 versus 5.4 times, respectively. On a hemophilia background, TFPIβ or TFPIγ-specific deletion improves clotting to 14.6 and 15.2 times, respectively (p<0.0001). TFPIα-specific deletion is without impact, clotting 5.1 times. Heterozygous deletion of TFPIβ is effective, clotting 11.8 times (p<0.0001). Heterozygous deletion of TFPIα or TFPIγ alone is ineffective clotting 3.0 and 6.1 times, respectively; but heterozygous TFPIαγ deletion improves clotting to 11.2 times (p<0.001).
CONCLUSION
In hemophilia mice, endothelial TFPIβ and plasma γ-derived 2-Kunitz TFPI individually contribute more to bleeding than total TFPIα.
PubMed: 38925489
DOI: 10.1016/j.jtha.2024.06.006 -
Small (Weinheim An Der Bergstrasse,... Jun 2024While peptide-based drug development is extensively explored, this strategy has limitations due to rapid excretion from the body (or shorter half-life in the body) and...
While peptide-based drug development is extensively explored, this strategy has limitations due to rapid excretion from the body (or shorter half-life in the body) and vulnerability to protease-mediated degradation. To overcome these limitations, a novel strategy for the development of a peptide-based anticancer agent is introduced, utilizing the conformation switch property of a chameleon sequence stretch (PEP1) derived from a mycobacterium secretory protein, MPT63. The selected peptide is then loaded into a new porous organic polymer (PG-DFC-POP) synthesized using phloroglucinol and a cresol derivative via a condensation reaction to deliver the peptide selectively to cancer cells. Utilizing ensemble and single-molecule approaches, this peptide undergoes a transition from a disordered to an alpha-helical conformation, triggered by the acidic environment within cancer cells that is demonstrated. This adopted alpha-helical conformation resulted in the formation of proteolysis-resistant oligomers, which showed efficient membrane pore-forming activity selectively for negatively charged phospholipids accumulated in cancer cell membranes. The experimental results demonstrated that the peptide-loaded PG-DFC-POP-PEP1 exhibited significant cytotoxicity in cancer cells, leading to cell death through the Pyroptosis pathway, which is established by monitoring numerous associated events starting from lysosome membrane damage to GSDMD-induced cell membrane demolition. This novel conformational switch-based drug design strategy is believed to have great potential in endogenous environment-responsive cancer therapy and the development of future drug candidates to mitigate cancers.
PubMed: 38923392
DOI: 10.1002/smll.202402953 -
Metabolites Jun 2024Food deprivation can occur for different reasons. Fasting (<24 h duration) occurs to meet religious or well-being goals. Starvation (>1-day duration) occurs when there... (Review)
Review
Food deprivation can occur for different reasons. Fasting (<24 h duration) occurs to meet religious or well-being goals. Starvation (>1-day duration) occurs when there is intentional (hunger strike or treatment of a medical condition) or unintentional (anorexia nervosa, drought, epidemic famine, war, or natural disaster) food deprivation. A scoping review was undertaken using the PubMed database to explore 1805 abstracts and review 88 eligible full-text articles to explore the adaptive relationships that emerge between cortisol, insulin, glucagon, and thyroid hormones on the metabolic pathways of macronutrients in humans during fasting and starvation. The collected data indicate that fasting and starvation prime the human body to increase cortisol levels and decrease the insulin/glucagon ratio and triiodothyronine (T) levels. During fasting, increased levels of cortisol and a decreased insulin/glucagon ratio enhance glycogenolysis and reduce the peripheral uptake of glucose and glycogenesis, whereas decreased T levels potentially reduce glycogenolysis. During starvation, increased levels of cortisol and a decreased insulin/glucagon ratio enhance lipolysis, proteolysis, fatty acid and amino acid oxidation, ketogenesis, and ureagenesis, and decreased T levels reduce thermogenesis. We present a potential crosstalk between T and the above hormones, including between T and leptin, to extend their adaptive roles in the metabolism of endogenous macronutrients during food deprivation.
PubMed: 38921471
DOI: 10.3390/metabo14060336 -
Cells Jun 2024Serine/threonine kinase AKT isoforms play a well-established role in cell metabolism and growth. Most pancreatic adenocarcinomas (PDACs) harbor activation mutations of...
Serine/threonine kinase AKT isoforms play a well-established role in cell metabolism and growth. Most pancreatic adenocarcinomas (PDACs) harbor activation mutations of KRAS, which activates the PI3K/AKT signaling pathway. However, AKT inhibitors are not effective in the treatment of pancreatic cancer. To better understand the role of AKT signaling in mutant-KRAS pancreatic tumors, this study utilized proteolysis-targeting chimeras (PROTACs) and CRISPR-Cas9-genome editing to investigate AKT proteins. The PROTAC down-regulation of AKT proteins markedly slowed the growth of three pancreatic tumor cell lines harboring mutant KRAS. In contrast, the inhibition of AKT kinase activity alone had very little effect on the growth of these cell lines. The concurrent genetic deletion of all AKT isoforms (AKT1, AKT2, and AKT3) in the KPC (; ; ) pancreatic cancer cell line also dramatically slowed its growth in vitro and when orthotopically implanted in syngeneic mice. Surprisingly, insulin-like growth factor-1 (IGF-1), but not epidermal growth factor (EGF), restored KPC cell growth in serum-deprived conditions, and the IGF-1 growth stimulation effect was AKT-dependent. The RNA-seq analysis of AKT1/2/3-deficient KPC cells suggested that reduced cholesterol synthesis may be responsible for the decreased response to IGF-1 stimulation. These results indicate that the presence of all three AKT isoforms supports pancreatic tumor cell growth, and the pharmacological degradation of AKT proteins may be more effective than AKT catalytic inhibitors for treating pancreatic cancer.
Topics: Proto-Oncogene Proteins c-akt; Pancreatic Neoplasms; Animals; Cell Line, Tumor; Mice; Humans; Down-Regulation; Proto-Oncogene Proteins p21(ras); Mutation; Cell Proliferation; Signal Transduction; Gene Expression Regulation, Neoplastic
PubMed: 38920688
DOI: 10.3390/cells13121061 -
Drug Design, Development and Therapy 2024Ferroptosis, a unique form of programmed cell death, is initiated by an excess of iron accumulation and lipid peroxidation-induced damage. There is a growing body of... (Review)
Review
Ferroptosis, a unique form of programmed cell death, is initiated by an excess of iron accumulation and lipid peroxidation-induced damage. There is a growing body of evidence indicating that ferroptosis plays a critical role in the advancement of tumors. The increased metabolic activity and higher iron levels in tumor cells make them particularly vulnerable to ferroptosis. As a result, the targeted induction of ferroptosis is becoming an increasingly promising approach for cancer treatment. This review offers an overview of the regulatory mechanisms of ferroptosis, delves into the mechanism of action of traditional small molecule ferroptosis inducers and their effects on various tumors. In addition, the latest progress in inducing ferroptosis using new means such as proteolysis-targeting chimeras (PROTACs), photodynamic therapy (PDT), sonodynamic therapy (SDT) and nanomaterials is summarized. Finally, this review discusses the challenges and opportunities in the development of ferroptosis-inducing agents, focusing on discovering new targets, improving selectivity, and reducing toxic and side effects.
Topics: Ferroptosis; Humans; Neoplasms; Antineoplastic Agents; Photochemotherapy; Animals; Small Molecule Libraries
PubMed: 38919962
DOI: 10.2147/DDDT.S472178 -
The Iowa Orthopaedic Journal 2024Female athletes are at increased risk for anterior cruciate ligament (ACL) injuries. The influence of hormonal variation on female ACL injury risk remains ill-defined....
BACKGROUND
Female athletes are at increased risk for anterior cruciate ligament (ACL) injuries. The influence of hormonal variation on female ACL injury risk remains ill-defined. Recent data suggests that the collagen-degrading menstrual hormone relaxin may cyclically impact female ACL tissue quality. This review aims to identify any correlation between menstrual relaxin peaks and rates of female ACL injury.
METHODS
A systematic review was performed, utilizing the MEDLINE, EMBASE, and CINAHL databases. Included studies had to directly address relaxin/female ACL interactions. The primary outcome variable was relaxin proteolysis of the ACL, at cellular, tissue, joint, and whole-organism levels. The secondary outcome variable was any discussed method of moderating relaxin levels, and the clinical results if available.
RESULTS
AllThe numerous relaxin receptors on female ACLs upregulate local collagenolysis and suppress local collagen production. Peak serum relaxin concentrations (SRC) occur during menstrual cycle days 21-24; a time phase associated with greater risk of ACL injury. Oral contraceptives (OCPs) reduce SRC, with a potential ACLprotective effect.
CONCLUSION
A reasonable correlative and plausible causative relationship exists between peak relaxin levels and increased risk of ACL injury in females, and further investigation is warranted. .
Topics: Humans; Relaxin; Female; Anterior Cruciate Ligament Injuries; Menstrual Cycle; Athletic Injuries; Athletes
PubMed: 38919370
DOI: No ID Found -
Frontiers in Pharmacology 2024Alzheimer's disease (AD) is one of the most common chronic neurodegenerative diseases. Hyperphosphorylated tau plays an indispensable role in neuronal dysfunction and...
Alzheimer's disease (AD) is one of the most common chronic neurodegenerative diseases. Hyperphosphorylated tau plays an indispensable role in neuronal dysfunction and synaptic damage in AD. Proteolysis-targeting chimeras (PROTACs) are a novel type of chimeric molecule that can degrade target proteins by inducing their polyubiquitination. This approach has shown promise for reducing tau protein levels, which is a potential therapeutic target for AD. Compared with traditional drug therapies, the use of PROTACs to reduce tau levels may offer a more specific and efficient strategy for treating AD, with fewer side effects. In the present study, we designed and synthesized a series of small-molecule PROTACs to knock down tau protein. Of these, compound was able to lower both total and phosphorylated tau levels in HEK293 cells with stable expression of wild-type full-length human tau (termed HEK293-htau) and htau-overexpressed mice. Western blot findings indicated that degraded tau protein through the ubiquitin-proteasome system in a time-dependent manner. In htau-overexpressed mice, the results of both the novel object recognition and Morris water maze tests revealed that markedly improved cognitive function. Together, our findings suggest that the use of the small-molecule PROTAC to degrade phosphorylated tau may be a promising therapeutic strategy for AD.
PubMed: 38919259
DOI: 10.3389/fphar.2024.1351792 -
Molecular Systems Biology Jun 2024The variability of proteins at the sequence level creates an enormous potential for proteome complexity. Exploring the depths and limits of this complexity is an ongoing...
The variability of proteins at the sequence level creates an enormous potential for proteome complexity. Exploring the depths and limits of this complexity is an ongoing goal in biology. Here, we systematically survey human and plant high-throughput bottom-up native proteomics data for protein truncation variants, where substantial regions of the full-length protein are missing from an observed protein product. In humans, Arabidopsis, and the green alga Chlamydomonas, approximately one percent of observed proteins show a short form, which we can assign by comparison to RNA isoforms as either likely deriving from transcript-directed processes or limited proteolysis. While some detected protein fragments align with known splice forms and protein cleavage events, multiple examples are previously undescribed, such as our observation of fibrocystin proteolysis and nuclear translocation in a green alga. We find that truncations occur almost entirely between structured protein domains, even when short forms are derived from transcript variants. Intriguingly, multiple endogenous protein truncations of phase-separating translational proteins resemble cleaved proteoforms produced by enteroviruses during infection. Some truncated proteins are also observed in both humans and plants, suggesting that they date to the last eukaryotic common ancestor. Finally, we describe novel proteoform-specific protein complexes, where the loss of a domain may accompany complex formation.
PubMed: 38918600
DOI: 10.1038/s44320-024-00048-3 -
Cell Regeneration (London, England) Jun 2024F-box proteins play essential roles in various cellular processes of spermatogenesis by means of ubiquitylation and subsequent target protein degradation. They are the... (Review)
Review
F-box proteins play essential roles in various cellular processes of spermatogenesis by means of ubiquitylation and subsequent target protein degradation. They are the substrate-recognition subunits of SKP1-cullin 1-F-box protein (SCF) E3 ligase complexes. Dysregulation of F‑box protein‑mediated proteolysis could lead to male infertility in humans and mice. The emerging studies revealed the physiological function, pathological evidence, and biochemical substrates of F-box proteins in the development of male germ cells, which urging us to review the current understanding of how F‑box proteins contribute to spermatogenesis. More functional and mechanistic study will be helpful to define the roles of F-box protein in spermatogenesis, which will pave the way for the logical design of F-box protein-targeted diagnosis and therapies for male infertility, as the spermatogenic role of many F-box proteins remains elusive.
PubMed: 38918264
DOI: 10.1186/s13619-024-00196-9 -
Medical Mycology Jun 2024The increasing prevalence of Candida parapsilosis as a causative agent of fungal infections underscores the need to comprehensively understand its virulence factors....
The increasing prevalence of Candida parapsilosis as a causative agent of fungal infections underscores the need to comprehensively understand its virulence factors. Secreted aspartic proteases (Saps) play a significant role in adhesion events, promoting biofilm formation, causing tissue damage and evading the host immune response. The present study investigates the production dynamics of Sapp1 and Sapp2 across 10 clinical isolates of C. parapsilosis using various approaches. Each fungal isolate demonstrated the capability to utilize bovine serum albumin (BSA) as the sole nitrogen source, as evidenced by its degradation in cell-free culture medium, forming low molecular mass polypeptides. Interestingly, the degradation of different proteinaceous substrates, such as BSA, human serum albumin (HSA), gelatin and hemoglobin, was typically isolate-dependent. Notably, higher proteolysis of HSA compared to BSA, gelatin and hemoglobin was observed. A quantitative assay revealed that the cleavage of a peptide fluorogenic substrate (cathepsin D) was isolate-specific, ranging from 44.15 to 270.61 FAU, with a mean proteolysis of 150.7 FAU. The presence of both Sapp1 and Sapp2 antigens on the cell surface of these fungal isolates was confirmed through immunological detection employing specific anti-Sapp1 and anti-Sapp2 antibodies. The surface levels of Sapp1 were consistently higher, up to fourfold, compared to Sapp2. Similarly, higher levels of Sapp1 than Sapp2 were detected in fungal secretions. This study provides insights into the dynamic expression and regulation of Sapps in C. parapsilosis, highlighting a known virulence factor that is considered a potential target for drug development against this increasingly prominent pathogen.
PubMed: 38918050
DOI: 10.1093/mmy/myae066