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Frontiers in Veterinary Science 2023Arthrodesis, performed as a salvage surgical procedure to treat intractable joint conditions in dogs and cats, is associated with a high incidence of complications intra...
INTRODUCTION
Arthrodesis, performed as a salvage surgical procedure to treat intractable joint conditions in dogs and cats, is associated with a high incidence of complications intra and postoperative, proving the need for improved and new techniques in arthrodesis surgery. Adding a new resorbable bone glue to the arthrodesis could potentially add fixation strength and lower complications. The objectives of this experimental biomechanical study were therefore to develop a biomechanical test model of partial tarsal arthrodesis and to determine whether the new resorbable bone glue (phosphoserine modified cement) produced measurable fixation strength in canine calcaneoquartal arthrodesis, without orthopedic implants.
METHODS
Four biomechanical test models with a total of 35 canine tarsal joints were used. Soft tissues were dissected to 4 different test models with variable contributions from soft tissues. The calcaneoquartal joint was prepared as arthrodesis and the glue was applied to joint surfaces as a liquid/putty (0.4 cc). After curing for 24 h, a shear force was applied to the joint (1 mm per minute) and the failure strength was recorded.
RESULTS
Calcaneoquartal joints, where all soft tissues had been completely resected and fixated with glue (1-1.5 cm joint surface), withstood 2-5 mm of displacement and an average of 100 ± 58 N/cm of shear force (Model 1). Similar adhesive fixation strengths were obtained in Model 2 and 3 with increasing contributions from soft tissues (80 ± 44 and 63 ± 23 N/cm, = 0.39, ANOVA).
CONCLUSION
The developed biomechanical model was sensitive enough to measure differences in fixation strengths between different glue formulations. The average fixation strength (60-100 N/cm) should be strong enough to support short-term load bearing in medium sized canines (20 kg). The developed cadaver biomechanical test model is of potential use for other arthrodesis studies. The new resorbable glue can potentially contribute to stability at arthrodesis surgery, acting as a complement to today's standard fixation, metal implants.
PubMed: 37799403
DOI: 10.3389/fvets.2023.1250147 -
Frontiers in Bioscience (Landmark... Oct 2023Current evidence suggests that phosphoserine aminotransferase 1 () is overexpressed in various tumors. Herein, we investigate the significance of in non-small cell lung...
PURPOSE
Current evidence suggests that phosphoserine aminotransferase 1 () is overexpressed in various tumors. Herein, we investigate the significance of in non-small cell lung cancer (NSCLC) and its correlation with immune infiltration.
METHODS
The expression profile of in NSCLC patients and related clinical information was obtained from the Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA-NSCLC) databases. and experimental validation were conducted to assess the role of in NSCLC. Gene set enrichment analysis (GSEA) was performed to investigate the disparities in biological functions between groups with high and low expression. Additionally, the biological characteristics and immune cell infiltration were compared between these two groups. We also assessed whether expression could predict the sensitivity of NSCLC patients to immunotherapy using the immunophenotype score (IPS) and an anti-PD-L1 immunotherapy cohort (IMvig-or210). Furthermore, the difference in drug sensitivity between -high and -low expression cell lines was investigated.
RESULTS
Analysis of transcriptional expression profiles using TCGA data revealed overexpression of in NSCLC tissues correlated with poor overall survival (OS). GSEA results showed enrichment of DNA recombination and repair, nucleotide biosynthesis, and the P53 signaling pathway in the -high group. Experimental validation demonstrated that the knockdown of suppressed cell proliferation, migration, and invasion of NSCLC. Immune cell infiltration analysis revealed an immune-activated tumor microenvironment in the -low group. It was also observed that -low cell lines were more likely to benefit from immunotherapy and several chemotherapy drugs.
CONCLUSIONS
has enormous potential for applications in the prediction of NSCLC patient outcomes and provides the foothold for more precise individualized treatment of this patient population.
Topics: Humans; Carcinoma, Non-Small-Cell Lung; Cell Line; Cell Proliferation; Immunotherapy; Lung Neoplasms; Tumor Microenvironment
PubMed: 37919070
DOI: 10.31083/j.fbl2810243 -
Acta Biomaterialia Jan 2024Phosphoserine is a ubiquitous molecule found in numerous proteins and, when combined with alpha-tricalcium phosphate (α-TCP) powder, demonstrates the ability to...
Multi-objective property optimisation of a phosphoserine-modified calcium phosphate cement for orthopaedic and dental applications using design of experiments methodology.
Phosphoserine is a ubiquitous molecule found in numerous proteins and, when combined with alpha-tricalcium phosphate (α-TCP) powder, demonstrates the ability to generate an adhesive biomaterial capable of stabilising and repairing bone fractures. Design of Experiments (DoE) approach was able to optimise the composition of phosphoserine-modified calcium phosphate cement (PM-CPC) demonstrating that the liquid:powder ratio (LPR) and quantity of phosphoserine (wt%) significantly influenced the handling, mechanical, and adhesion properties. Subsequently, the DoE optimisation process identified the optimal PM-CPC formulation, exhibiting a compressive strength of 29.2 ± 4.9 MPa and bond/shear strength of 3.6 ± 0.9 MPa after a 24 h setting reaction. Moreover, the optimal PM-CPC composition necessitated a mixing time of 20 s and displayed an initial setting time between 3 and 4 min, thus enabling homogenous mixing and precise delivery within a surgical environment. Notably, the PM-CPC demonstrated a bone-to-bone bond strength of 1.05 ± 0.3 MPa under wet conditions, coupled with a slow degradation rate during the first five days. These findings highlight the ability of PM-CPC to effectively support and stabilise bone fragments during the initial stages of natural bone healing. The developed PM-CPC formulations fulfil the clinical requirements for working and setting times, static mechanical, degradation properties, and injectability, enabling surgeons to stabilise complex bone fractures. This innovative bioinspired adhesive represents a significant advancement in the treatment of challenging bone injuries, offering precise delivery within a surgical environment and the potential to enhance patient outcomes. STATEMENT OF SIGNIFICANCE: This manuscript presents a noteworthy contribution to the field of bone fracture healing and fixation by introducing a novel phosphoserine-modified calcium phosphate cement (PM-CPC) adhesive by incorporating phosphoserine and alpha-TCP. This study demonstrates the fabrication and extensive characterisation of this adhesive biomaterial that holds great promise for stabilising and repairing complex bone fractures. Design of Experiment (DoE) software was used to investigate the correlations between process, property, and structure of the adhesive, resulting in a cost-effective formulation with desirable physical and handling properties. The PM-CPC adhesive exhibited excellent adhesion and cohesion properties in wet-field conditions. This research offers significant potential for clinical translation and contributes to the ongoing advancements in bone tissue engineering.
Topics: Humans; Phosphoserine; Orthopedics; Powders; Biocompatible Materials; Calcium Phosphates; Fractures, Bone; Bone Cements; Materials Testing
PubMed: 38000527
DOI: 10.1016/j.actbio.2023.11.024 -
Molecular Genetics & Genomic Medicine Apr 2024Phosphoserine aminotransferase deficiency (PSATD) is an autosomal recessive disorder associated with hypertonia, psychomotor retardation, and acquired microcephaly.... (Review)
Review
BACKGROUND
Phosphoserine aminotransferase deficiency (PSATD) is an autosomal recessive disorder associated with hypertonia, psychomotor retardation, and acquired microcephaly. Patients with PSATD have low concentrations of serine in plasma and cerebrospinal fluid.
METHODS
We reported a 2-year-old female child with developmental delay, dyskinesia, and microcephaly. LC-MS/MS was used to detect amino acid concentration in the blood and whole-exome sequencing (WES) was used to identify the variants. PolyPhen-2 web server and PyMol were used to predict the pathogenicity and changes in the 3D model molecular structure of protein caused by variants.
RESULTS
WES demonstrated compound heterozygous variants in PSAT1, which is associated with PSATD, with a paternal likely pathogenic variant (c.235G>A, Gly79Arg) and a maternal likely pathogenic variant (c.43G>C, Ala15Pro). Reduced serine concentration in LC-MS/MS further confirmed the diagnosis of PSATD in this patient.
CONCLUSIONS
Our findings demonstrate the importance of WES combined with LC-MS/MS reanalysis in the diagnosis of genetic diseases and expand the PSAT1 variant spectrum in PSATD. Moreover, we summarize all the cases caused by PSAT1 variants in the literature. This case provides a vital reference for the diagnosis of future cases.
Topics: Child, Preschool; Female; Humans; Chromatography, Liquid; Exome Sequencing; Liquid Chromatography-Mass Spectrometry; Microcephaly; Psychomotor Disorders; Seizures; Serine; Tandem Mass Spectrometry; Transaminases
PubMed: 38546032
DOI: 10.1002/mgg3.2400 -
Biomolecules Dec 2023N-methyl-D-aspartate (NMDA) receptors, a subtype of ionotropic glutamate receptors, are important in regulating sympathetic tone and cardiovascular function in the...
N-methyl-D-aspartate (NMDA) receptors, a subtype of ionotropic glutamate receptors, are important in regulating sympathetic tone and cardiovascular function in the rostral ventrolateral medulla (RVLM). Amyloid-beta peptide (Aβ) is linked to the pathogenesis of Alzheimer's disease (AD). Cerebro- and cardiovascular diseases might be the risk factors for developing AD. The present study examines the acute effects of soluble Aβ on the function of NMDA receptors in rats RVLM. We used the magnitude of increases in the blood pressure (pressor responses) induced by microinjection of NMDA into the RVLM as an index of NMDA receptor function in the RVLM. Soluble Aβ was applied by intracerebroventricular (ICV) injection. Aβ1-40 at a lower dose (0.2 nmol) caused a slight reduction, and a higher dose (2 nmol) showed a significant decrease in NMDA-induced pressor responses 10 min after administration. ICV injection of Aβ1-42 (2 nmol) did not affect NMDA-induced pressor responses in the RVLM. Co-administration of Aβ1-40 with ifenprodil or memantine blocked the inhibitory effects of Aβ1-40. Immunohistochemistry analysis showed a significant increase in the immunoreactivity of phosphoserine 1480 of GluN2B subunits (pGluN2B-serine1480) in the neuron of the RVLM without significant changes in phosphoserine 896 of GluN1 subunits (pGluN1-serine896), GluN1 and GluN2B, 10 min following Aβ1-40 administration compared with saline. Interestingly, we found a much higher level of Aβ1-40 compared to that of Aβ1-42 in the cerebrospinal fluid (CSF) measured using enzyme-linked immunosorbent assay 10 min following ICV administration of the same dose (2 nmol) of the peptides. In conclusion, the results suggest that ICV Aβ1-40, but not Aβ1-42, produced an inhibitory effect on NMDA receptor function in the RVLM, which might result from changes in pGluN2B-serine1480 (regulated by casein kinase II). The different elimination of the peptides in the CSF might contribute to the differential effects of Aβ1-40 and Aβ1-42 on NMDA receptor function.
Topics: Rats; Animals; Receptors, N-Methyl-D-Aspartate; N-Methylaspartate; Amyloid beta-Peptides; Phosphoserine; Blood Pressure
PubMed: 38136607
DOI: 10.3390/biom13121736 -
Pathogens (Basel, Switzerland) Dec 2023Strains of , an enteric parasite of poultry, vary in virulence. Here, we performed microscopy and RNA sequencing on oocysts of strains APU-1 (which exhibits more...
Strains of , an enteric parasite of poultry, vary in virulence. Here, we performed microscopy and RNA sequencing on oocysts of strains APU-1 (which exhibits more virulence) and APU-2. Although each underwent parallel development, APU-1 initially approached maturation more slowly. Each strain sporulated by hour 36; their gene expression diverged somewhat thereafter. Candidate biomarkers of viability included 58 genes contributing at least 1000 Transcripts Per Million throughout sporulation, such as cation-transporting ATPases and zinc finger domain-containing proteins. Many genes resemble constitutively expressed genes also important to Throughout sporulation, the expression of only a few genes differed between strains; these included cyclophilin A, EF-1α, and surface antigens (SAGs). Mature and immature oocysts uniquely differentially express certain genes, such as an X-Pro dipeptidyl-peptidase domain-containing protein in immature oocysts and a profilin in mature oocysts. The immature oocysts of each strain expressed more phosphoserine aminotransferase and the mature oocysts expressed more SAGs and microneme proteins. These data illuminate processes influencing sporulation in and related genera, such as , and identify biological processes which may differentiate them. Drivers of development and senescence may provide tools to assess the viability of oocysts, which would greatly benefit the poultry industry and food safety applications.
PubMed: 38276148
DOI: 10.3390/pathogens13010002 -
Biochimica Et Biophysica Acta.... Mar 2024L-Ser supply in the central nervous system of mammals mostly relies on its endogenous biosynthesis by the phosphorylated pathway (PP). Defects in any of the three...
L-Ser supply in the central nervous system of mammals mostly relies on its endogenous biosynthesis by the phosphorylated pathway (PP). Defects in any of the three enzymes operating in the pathway result in a group of neurometabolic diseases collectively known as serine deficiency disorders (SDDs). Phosphoserine phosphatase (PSP) catalyzes the last, irreversible step of the PP. Here we investigated in detail the role of physiological modulators of human PSP activity and the properties of three natural PSP variants (A35T, D32N and M52T) associated with SDDs. Our results, partially contradicting previous reports, indicate that: i. PSP is almost fully saturated with Mg under physiological conditions and fluctuations in Mg and Ca concentrations are unlikely to play a modulatory role on PSP activity; ii. Inhibition by L-Ser, albeit at play on the isolated PSP, does not exert any effect on the flux through the PP unless the enzyme activity is severely impaired by inactivating substitutions; iii. The so-far poorly investigated A35T substitution was the most detrimental, with a 50-fold reduction in catalytic efficiency, and a reduction in thermal stability (as well as an increase in the IC for L-Ser). The M52T substitution had similar, but milder effects, while the D32N variant behaved like the wild-type enzyme. iv. Predictions of the structural effects of the A35T and M52T substitutions with ColabFold suggest that they might affect the structure of the flexible helix-loop region.
Topics: Animals; Humans; Serine; Magnesium; Ions; Mammals; Dapsone; Phosphoric Monoester Hydrolases
PubMed: 38278334
DOI: 10.1016/j.bbadis.2024.167034 -
Frontiers in Oncology 2024Acute myeloid leukemia (AML) is a heterogeneous hematological malignancy characterized by disrupted blood cell production and function. Recent investigations have...
Acute myeloid leukemia (AML) is a heterogeneous hematological malignancy characterized by disrupted blood cell production and function. Recent investigations have highlighted the potential of targeting glutamine metabolism as a promising therapeutic approach for AML. Asparaginases, enzymes that deplete circulating glutamine and asparagine, are approved for the treatment of acute lymphoblastic leukemia, but are also under investigation in AML, with promising results. We previously reported an elevation in plasma serine levels following treatment with -derived asparaginase (also called crisantaspase). This led us to hypothesize that AML cells initiate the serine biosynthesis pathway in response to crisantaspase treatment and that inhibiting this pathway in combination with crisantaspase would enhance AML cell death. Here we report that in AML cell lines, treatment with the clinically available crisantaspase, Rylaze, upregulates the serine biosynthesis enzymes phosphoglycerate dehydrogenase (PHGDH) and phosphoserine aminotransferase (PSAT1) through activation of the Amino Acid Response (AAR) pathway, a cellular stress response mechanism that regulates amino acid metabolism and protein synthesis under conditions of nutrient limitation. Inhibition of serine biosynthesis through CRISPR--mediated knockout of PHGDH resulted in a ~250-fold reduction in the half-maximal inhibitory concentration (IC) for Rylaze, indicating heightened sensitivity to crisantaspase therapy. Treatment of AML cells with a combination of Rylaze and a small molecule inhibitor of PHGDH (BI4916) revealed synergistic anti-proliferative effects in both cell lines and primary AML patient samples. Rylaze-BI4916 treatment in AML cell lines led to the inhibition of cap-dependent mRNA translation and protein synthesis, as well as a marked decrease in intracellular glutathione levels, a critical cellular antioxidant. Collectively, our results highlight the clinical potential of targeting serine biosynthesis in combination with crisantaspase as a novel therapeutic strategy for AML.
PubMed: 38690164
DOI: 10.3389/fonc.2024.1326754 -
American Journal of Translational... 2024Breast cancer is the most common cancer and the leading cause of cancer-related death among women. An Estrogen Receptor (ER) antagonist called tamoxifen is used as an...
OBJECTIVES
Breast cancer is the most common cancer and the leading cause of cancer-related death among women. An Estrogen Receptor (ER) antagonist called tamoxifen is used as an adjuvant therapy for ER-positive breast cancers. Approximately 40% of patients develop tamoxifen resistance (TAMR) while receiving treatment. Cancer cells can rewire their metabolism to develop resistant phenotypes, and their metabolic state determines how receptive they are to chemotherapy.
METHODS
Metabolite extraction from human MCF-7 and MCF-7/TAMR cells was done using the methanol-methanol-water extraction method. After treating the dried samples with methoxamine hydrochloride in pyridine, the samples were derivatized with 2,2,2-Trifluoro-N-methyl-N-(trimethylsilyl)-acetamide, and Chlorotrimethylsilane (MSTFA + 1% TMCS). The Gas chromatography/mass spectrometry (GC-MS) raw data were processed using MSdial and Metaboanalyst for analysis.
RESULTS
Univariate analysis revealed that 35 metabolites were elevated in TAMR cells whereas 25 metabolites were downregulated. N-acetyl-D-glucosamine, lysine, uracil, tyrosine, alanine, and o-phosphoserine were upregulated in TAMR cells, while hydroxyproline, glutamine, N-acetyl-L-aspartic acid, threonic acid, pyroglutamic acid, glutamine, o-phosphoethanolamine, oxoglutaric acid, and myoinositol were found to be downregulated. Multivariate analysis revealed a distinct separation between the two cell lines, as evidenced by their metabolite levels. The enriched pathways of deregulated metabolites included valine, leucine, and isoleucine degradation, Citric Acid Cycle, Warburg effect, Malate-Aspartate shuttle, glucose-alanine cycle, propanoate metabolism, and Phospholipid biosynthesis.
CONCLUSION
This study revealed dysregulation of various metabolic processes in TAMR cells, which may be crucial in elucidating the molecular basis of the mechanisms underlying acquired tamoxifen resistance.
PubMed: 38715825
DOI: 10.62347/MJLN5908 -
Plants (Basel, Switzerland) Feb 2024Cadmium (Cd) hampers plant growth and harms photosynthesis. Glutamate (Glu) responds to Cd stress and activates the Ca signaling pathway in duckweed, emphasizing Glu's...
Cadmium (Cd) hampers plant growth and harms photosynthesis. Glutamate (Glu) responds to Cd stress and activates the Ca signaling pathway in duckweed, emphasizing Glu's significant role in Cd stress. In this study, we overexpressed phosphoserine aminotransferase (), a crucial enzyme in Glu metabolism, in duckweed. We investigated the response of -transgenic duckweed to Cd stress, including growth, Glu metabolism, photosynthesis, antioxidant enzyme activity, Cd flux, and gene expression. Remarkably, under Cd stress, -transgenic duckweed prevented root abscission, upregulated the expression of photosynthesis ability, and increased Chl a, Chl b, and Chl a + b levels by 13.9%, 7%, and 12.6%, respectively. Antioxidant enzyme activity (CAT and SOD) also improved under Cd stress, reducing cell membrane damage in -transgenic duckweeds. Transcriptomic analysis revealed an upregulation of Glu metabolism-related enzymes in -transgenic duckweed under Cd stress. Moreover, metabolomic analysis showed a 68.4% increase in Glu content in duckweed exposed to Cd. This study sheds novel insights into the role of in enhancing plant resistance to Cd stress, establishing a theoretical basis for the impact of Glu metabolism on heavy metal tolerance in plants.
PubMed: 38475473
DOI: 10.3390/plants13050627