The live biotherapeutic SYNB1353 decreases plasma methionine via directed degradation in animal models and healthy volunteers.

Methionine is an essential proteinogenic amino acid, but its excess can lead to deleterious effects. Inborn errors of methionine metabolism resulting from loss of function in cystathionine ß-synthase (CBS) cause classic homocystinuria (HCU), which is managed by a methionine-restricted diet. Synthetic biotics are gastrointestinal tract-targeted live biotherapeutics that can be engineered to replicate the benefits of dietary restriction. In this study, we assess whether SYNB1353, an E. coli Nissle 1917 derivative, impacts circulating methionine and homocysteine levels in animals and healthy volunteers. In both mice and nonhuman primates (NHPs), SYNB1353 blunts the appearance of plasma methionine and plasma homocysteine in response to an oral methionine load. A phase 1 clinical study conducted in healthy volunteers subjected to an oral methionine challenge demonstrates that SYNB1353 is well tolerated and blunts plasma methionine by 26%. Overall, SYNB1353 represents a promising approach for methionine reduction with potential utility for the treatment of HCU.

Exogenous methionine contributes to reversing the resistance of Streptococcus suis to macrolides.

Streptococcus suis (S. suis) has been increasingly recognized as a porcine zoonotic pathogen that threatens the health of both pigs and humans. Multidrug-resistant Streptococcus suis is becoming increasingly prevalent, and novel strategies to treat bacterial infections caused by these organisms are desperately needed. In the present study, an untargeted metabolomics analysis showed that the significant decrease in methionine content and the methionine biosynthetic pathway were significantly affected by the Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis in drug-resistant S. suis. The addition of L-methionine restored the bactericidal activity of macrolides, doxycycline, and ciprofloxacin on S. suis in vivo and in vitro. Further studies showed that the exogenous addition of methionine affects methionine metabolism by reducing S-adenosylmethionine synthetase activity and the contents of S-adenosylmethionine, S-adenosyl homocysteine, and S-ribose homocysteine. Methionine can decrease the total methylation level and methylesterase activity in multidrug resistant S. suis. The drug transport proteins and efflux pump genes were significantly downregulated in S. suis by exogenous L-methionine. Moreover, the exogenous addition of methionine can reduce the survival of S. suis by affecting oxidative stress and metal starvation in bacteria. Thus, L-methionine may influence the development of resistance in S. suis through methyl metabolism and metal starvation. This study provides a new perspective on the mitigation of drug resistance in S. suis.IMPORTANCEBacterial antibiotic resistance has become a severe threat to human and animal health. Increasing the efficacy of existing antibiotics is a promising strategy against antibiotic resistance. Here, we report that L-methionine enhances the efficacy of macrolides, doxycycline, and ciprofloxacin antibiotics in killing Streptococcus suis, including multidrug-resistant pathogens. We investigated the mechanism of action of exogenous methionine supplementation in restoring macrolides in Streptococcus suis and the role of the methionine cycle pathway on methylation levels, efflux pump genes, oxidative stress, and metal starvation in Streptococcus suis. It provides a theoretical basis for the rational use of macrolides in clinical practice and also identifies a possible target for restoring drug resistance in Streptococcus suis.

Association Between Human Metabolomics and Rheumatoid Arthritis: A Systematic Review and Meta-analysis.

OBJECTIVE: The underdiagnosis and inadequate treatment of rheumatoid arthritis (RA) can be attributed to the various clinical manifestations presented by patients. To address this concern, we conducted an extensive review and meta-analysis, focusing on RA-related metabolites. METHODS: A comprehensive literature search was conducted in PubMed, the Cochrane Library, Web of Science, and Embase to identify relevant studies published up to October 5, 2022. The quality of the included articles was evaluated and, subsequently, a meta-analysis was conducted using Review Manager software to analyze the association between metabolites and RA. RESULTS: Forty nine studies met the inclusion criteria for the systematic review, and six of these studies were meta-analyzed to evaluate the association between 28 reproducible metabolites and RA. The results indicated that, compared to controls, the levels of histidine (RoM = 0.83, 95% CI = 0.79-0.88, I2 = 0%), asparagine (RoM = 0.83, 95% CI = 0.75-0.91, I2 = 0%), methionine (RoM = 0.82, 95% CI = 0.69-0.98, I2 = 85%), and glycine (RoM = 0.81, 95% CI = 0.67-0.97, I2 = 68%) were significantly lower in RA patients, while hypoxanthine levels (RoM = 1.14, 95% CI = 1.09-1.19, I2 = 0%) were significantly higher. CONCLUSION: This study identified histidine, methionine, asparagine, hypoxanthine, and glycine as significantly correlated with RA, thus offering the potential for the advancement of biomarker discovery and the elucidation of disease mechanisms in RA.

Metabolomic profile of neuroendocrine tumors identifies methionine, porphyrin, and tryptophan metabolisms as key dysregulated pathways associated with patient survival.

OBJECTIVE: Metabolic profiling is a valuable tool to characterize tumor biology but remains largely unexplored in neuroendocrine tumors (NETs). Our aim was to comprehensively assess the metabolomic profile of NETs and identify novel prognostic biomarkers and dysregulated molecular pathways. DESIGN AND METHODS: Multiplatform untargeted metabolomic profiling (GC-MS, CE-MS, and LC-MS) was performed in plasma from 77 patients with G1-2 extra-pancreatic NETs enrolled in the AXINET trial (NCT01744249) (study cohort) and from 68 non-cancer individuals (control). The prognostic value of each differential metabolite (n = 155) in NET patients (P < .05) was analyzed by univariate and multivariate analyses adjusted for multiple testing and other confounding factors. Related pathways were explored by Metabolite Set Enrichment Analysis (MSEA) and Metabolite Pathway Analysis (MPA). RESULTS: Thirty-four metabolites were significantly associated with progression-free survival (PFS) (n = 16) and/or overall survival (OS) (n = 27). Thirteen metabolites remained significant independent prognostic factors in multivariate analysis, 3 of them with a significant impact on both PFS and OS. Unsupervised clustering of these 3 metabolites stratified patients in 3 distinct prognostic groups (1-year PFS of 71.1%, 47.7%, and 15.4% (P = .012); 5-year OS of 69.7%, 32.5%, and 27.7% (P = .003), respectively). The MSEA and MPA of the 13-metablolite signature identified methionine, porphyrin, and tryptophan metabolisms as the 3 most relevant dysregulated pathways associated with the prognosis of NETs. CONCLUSIONS: We identified a metabolomic signature that improves prognostic stratification of NET patients beyond classical prognostic factors for clinical decisions. The enriched metabolic pathways identified reveal novel tumor vulnerabilities that may foster the development of new therapeutic strategies for these patients.

Protocol of a Phase II Randomized, Multi-Center, Double-Blind, Placebo-Controlled Trial of S-Adenosyl Methionine in Participants with Mild Cognitive Impairment or Dementia Due to Alzheimer's Disease.

BACKGROUND: S-adenosyl methionine (SAMe) is a pivotal metabolite in multiple pathways required for neuronal homeostasis, several of which are compromised in Alzheimer's disease (AD). Correction of the SAMe deficiency that is characteristic of the AD brain may attenuate or prevent pathological processes driving AD-associated neurodegeneration including aberrant tau hyperphosphorylation and DNA hypomethylation. OBJECTIVES: The primary aim is to test the hypothesis that daily treatment with 400 mg oral SAMe for 180 days will lead to a greater reduction from baseline in plasma levels of p-tau181 compared to placebo in patients with mild cognitive impairment or dementia due to AD. DESIGN, SETTING, PARTICIPANTS: This is a phase II, randomized, multi-center, double-blind, placebo-controlled trial among 60 participants with mild cognitive impairment or dementia due to AD. Participants will be randomized in a 1:1 ratio to receive either SAMe or matching placebo, to be taken as an adjunct to their AD standard of care. MEASUREMENTS AND RESULTS: The primary outcome is change in plasma p-tau181 concentration between baseline and following 180 days of treatment, which will be compared between the active and placebo group. Secondary outcomes are the safety of SAMe administration (incidence of serious adverse events), change from baseline in cognitive performance (as measured by the Repeatable Battery for the Assessment of Neuropsychological Status), and epigenetic changes in DNA methylation. CONCLUSION: Demonstration of effective and safe lowering of plasma p-tau181 with SAMe in this phase II trial would pave the way for an exciting field of translational research and a larger phase III trial.

Targeted deprivation of methionine with engineered Salmonella leads to oncolysis and suppression of metastasis in broad types of animal tumor models.

The strong dependency of almost all malignant tumors on methionine potentially offers a pathway for cancer treatment. We engineer an attenuated strain of Salmonella typhimurium to overexpress an L-methioninase with the aim of specifically depriving tumor tissues of methionine. The engineered microbes target solid tumors and induce a sharp regression in several very divergent animal models of human carcinomas, cause a significant decrease in tumor cell invasion, and essentially eliminate the growth and metastasis of these tumors. RNA sequencing analyses reveal that the engineered Salmonella reduce the expression of a series of genes promoting cell growth, cell migration, and invasion. These findings point to a potential treatment modality for many metastatic solid tumors, which warrants further tests in clinical trials.

d,l-Methionine in combination with amoxicillin-clavulanic acid successfully dissolves spontaneously occurring infection-induced struvite urocystoliths in dogs: a pilot study.

OBJECTIVE: To determine the efficacy and safety of a urinary acidifier (d,l-methionine [Methio-Form]) and an antimicrobial agent (amoxicillin-clavulanic acid [Clavamox]) without changing diet for dissolving infection-induced struvite urocystoliths in dogs. ANIMALS: 14 dogs were recruited for this prospective study; 11 completed it and 3 dogs withdrew due to inability of the owners to administer the treatment (n = 2) or refusal of treatment by the dog (1). PROCEDURES: All dogs were administered d,l-methionine (approx initial dose of 75 mg/kg, PO, q 12 h) and amoxicillin-clavulanic acid (22 mg/kg, PO, q 12 h) based on urine culture and sensitivity. Urine pH, urinalysis, urine culture, venous blood gas and serum biochemical analysis, and lateral survey abdominal radiographic images were evaluated initially and every 4 weeks until urolith dissolution (success) or lack of change in size and/or shape of urocystoliths on 2 consecutive reevaluation points (failure) occurred. RESULTS: Uroliths dissolved in 8 of 11 dogs in a median of 2 months (range, 1 to 4 months) with a final effective dosage of d,l-methionine of approximately 100 mg/kg, PO, every 12 hours. In 3 dogs, uroliths failed to dissolve and were removed surgically; they contained variable amounts of calcium oxalate. No adverse events occurred. CLINICAL RELEVANCE: Infection-induced struvite urolithiasis is 1 of the 2 most common minerals occurring in canine uroliths. Results of this study supported the use of d,l-methionine and amoxicillin-clavulanic acid without changing diet for dissolution of infection-induced struvite urocystoliths in dogs.

Selective Methionine Pool Exhaustion Mediated by a Sequential Positioned MOF Nanotransformer for Intense Cancer Immunotherapy.

Cancer cells are addictive to exogenous methionine to gear toward tumor proliferation. Meanwhile, they can replenish methionine pool from polyamine metabolism through a methionine salvage pathway. However, the current developed therapeutic tactics for methionine depletion are still facing great challenges in terms of the selectivity, safety, and efficiency. Herein, a sequential positioned metal-organic framework (MOF) nanotransformer is designed to selectively exhaust the methionine pool via inhibiting the uptake of methionine and throttling its salvage pathway for enhanced cancer immunotherapy. The MOF nanotransformer can restrain the open source and reduce the reflux of methionine to exhaust the methionine pool of cancer cells. Moreover, the intracellular traffic routes of the sequential positioned MOF nanotransformer match well with the distribution of polyamines, which is conducive to the oxidation of polyamines via its responsive deformability and nanozyme-augmented Fenton-like reaction for the final exhaustion of intracellular methionine. These results verify that the well-designed platform cannot only kill cancer cells efficiently but also promote the infiltration of CD8 and CD4 T cells for intensive cancer immunotherapy. Overall, it is believed that this work will inspire the construction of novel MOF-based antineoplastic platforms and provide new insights into the development of metabolic-related immunotherapy.

Pharmacokinetic/pharmacodynamic model of a methionine starvation based anti-cancer drug.

A new therapeutic approach against cancer is developed by the firm Erytech. This approach is based on starved cancer cells of an amino acid essential to their growth (the L-methionine). The depletion of plasma methionine level can be induced by an enzyme, the methionine-γ-lyase. The new therapeutic formulation is a suspension of erythrocytes encapsulating the activated enzyme. Our work reproduces a preclinical trial of a new anti-cancer drug with a mathematical model and numerical simulations in order to replace animal experiments and to have a deeper insight on the underlying processes. With a combination of a pharmacokinetic/pharmacodynamic model for the enzyme, substrate, and co-factor with a hybrid model for tumor, we develop a "global model" that can be calibrated to simulate different human cancer cell lines. The hybrid model includes a system of ordinary differential equations for the intracellular concentrations, partial differential equations for the concentrations of nutrients and drugs in the extracellular matrix, and individual based model for cancer cells. This model describes cell motion, division, differentiation, and death determined by the intracellular concentrations. The models are developed on the basis of experiments in mice carried out by Erytech. Parameters of the pharmacokinetics model were determined by fitting a part of experimental data on the concentration of methionine in blood. Remaining experimental protocols effectuated by Erytech were used to validate the model. The validated PK model allowed the investigation of pharmacodynamics of cell populations. Numerical simulations with the global model show cell synchronization and proliferation arrest due to treatment similar to the available experiments. Thus, computer modeling confirms a possible effect of treatment based on the decrease of methionine concentration. The main goal of the study is the development of an integrated pharmacokinetic/pharmacodynamic model for encapsulated methioninase and of a mathematical model of tumor growth/regression in order to determine the kinetics of L-methionine depletion after co-administration of Erymet product and Pyridoxine.

Exacerbation-prone pediatric asthma is associated with arginine, lysine, and methionine pathway alterations.

BACKGROUND: The asthma of some children remains poorly controlled, with recurrent exacerbations despite treatment with inhaled corticosteroids. Aside from prior exacerbations, there are currently no reliable predictors of exacerbation-prone asthma in these children and only a limited understanding of the potential underlying mechanisms. OBJECTIVE: We sought to quantify small molecules in the plasma of children with exacerbation-prone asthma through mass spectrometry-based metabolomics. We hypothesized that the plasma metabolome of these children would differ from that of children with non-exacerbation-prone asthma. METHODS: Plasma metabolites were extracted from 4 pediatric asthma cohorts (215 total subjects, with 41 having exacerbation-prone asthma) and detected with a mass spectrometer. High-confidence annotations were retained for univariate analysis and were confirmed by a sensitivity analysis in subjects receiving high-dose inhaled corticosteroids. Metabolites that varied by cohort were excluded. MetaboAnalyst software was used to identify pathways of interest. Concentrations were calculated by reference standardization. RESULTS: We identified 32 unique, cohort-independent metabolites that differed in children with exacerbation-prone asthma compared to children with non-exacerbation-prone asthma. Comparison of metabolite concentrations to literature-reported values for healthy children revealed that most metabolites were decreased in both asthma groups, but more so in exacerbation-prone asthma. Pathway analysis identified arginine, lysine, and methionine pathways as most impacted. CONCLUSIONS: Several plasma metabolites are perturbed in children with exacerbation-prone asthma and are largely related to arginine, lysine, and methionine pathways. While validation is needed, plasma metabolites may be potential biomarkers for exacerbation-prone asthma in children.

S-adenosyl methionine improves motor co-ordination with reduced oxidative stress, dopaminergic neuronal loss, and DNA methylation in the brain striatum of 6-hydroxydopamine-induced neurodegeneration in rats.

PURPOSE: Parkinson's disease (PD) is the most common age-related neurodegenerative disease worldwide. S-adenosyl methionine (SAMe), a methyl donor that plays an important role in DNA methylation, could replenish the cellular antioxidant glutathione (GSH). Herein, we investigated the neuroprotective effects of SAMe in 6-hydroxydopamine (6-OHDA) rat models of PD and elucidated the underlying mechanism. METHODS: PD model rats were developed by injecting 6-OHDA stereotaxically into the striatum. In Phase 1 of the study, we performed the neurobehavioral tests, GSH assay, and histopathology to evaluate the neuroprotective effects of SAMe. The animals were treated with SAMe (150 or 300 mg/kg body weight) orally for 28 days. The positive control group received selegiline (5 mg/kg), whereas the disease control group received normal saline. In Phase 2, we evaluated the striatal dopamine levels and performed DNA methylation assay to uncover the mechanism of action of SAMe. In this phase, a higher dose of SAMe (300 mg/kg) was used. RESULTS: SAMe (300 mg/kg) treatment for 4 weeks significantly attenuated the abnormal circling behavior in PD rats (p < 0.05). Moreover, SAMe at both doses (150 and 300 mg/kg) enhanced the performance of PD rats in the open field test and stepping test (p < 0.05). SAMe treatment significantly increased the GSH levels, and at high dose, SAMe restricted neuronal loss in the striatum of PD-model rats (p < 0.05). Moreover, SAMe treatment led to a significant recovery in the dopamine levels and improved the DNA methylation status in the dopaminergic neurons (p < 0.05) of PD model rats. CONCLUSION: SAMe exhibits antioxidant activity and DNA methylation modulating effects in 6-OHDA model PD rats. Moreover, SAMe prevents neuronal loss in PD rats suggesting that SAMe has therapeutic potential in preventing PD development. The neuroprotective potential of SAMe is greater at high doses.

Pirfenidone alleviates vascular intima injury caused by hyperhomocysteinemia.

OBJECTIVES: Hyperhomocysteinemia (HHcy) can induce vascular inflammatory and oxidative damage and accelerate intimal hyperplasia. This study investigated the protective effect of pirfenidone (PFD) on the recovery process of injured endothelial arteries during HHcy. MATERIALS AND METHODS: Thirty rabbits were randomly separated into three groups: A control group (n=10, standard rabbit chow), a model group (n=10, control diet plus 30 g methionine/kg food), and a PFD group (n=10, model diet plus oral administration of 90 mg/day of PFD). After 14 weeks of arterial injury, histopathological changes were determined. Plasma homocysteine (Hcy) concentrations, lipid profiles and oxidant and antioxidant status were evaluated. Macrophage infiltration was assessed using immunohistochemical staining. RESULTS: PFD supplementation decreased macrophage infiltration of iliac artery significantly without changes in blood lipids and Hcy concentrations. Compared with the model group, PFD restored superoxide dismutase and glutathione peroxidase activities and reduced malondialdehyde and reactive oxygen species levels. A high-methionine diet significantly increased neointimal area and the ratio between neointimal and media area. Systemic administration of PFD inhibited neointimal formation. CONCLUSIONS: PFD can partly alleviate intimal hyperplasia by inhibiting inflammatory and oxidative stress response induced by HHcy during endothelial injury. It may be a potential therapeutic agent for the prevention and treatment of endothelial injury-associated diseases such as atherosclerosis.

Inhibition of human peptide deformylase by actinonin sensitizes glioblastoma cells to temozolomide chemotherapy.

Glioblastoma multiforme (GBM) is a common intracranial primary tumor of the central nervous system with high malignancy, poor prognosis, and short survival. Studies have shown that mitochondrial energy metabolism plays an important role in GBM chemotherapy resistance, suggesting that interrupting mitochondrial oxidative phosphorylation (OXPHOS) may improve GBM treatment. Human peptide deformylase (HsPDF) is a mitochondrial deformylase that removes the formylated methionine from the N-terminus of proteins encoded by mitochondrial DNA (mtDNA), thereby contributing to correct protein folding and participating in the assembly of the electron respiratory chain complex. In this study, we found that the expression of mtDNA-encoded proteins was significantly downregulated after treatment of GBM cells U87MG and LN229 with the HsPDF inhibitor, actinonin. In combination with temozolomide, a preferred chemotherapeutic medicine for GBM, the OXPHOS level decreased, mitochondrial protein homeostasis was unbalanced, mitochondrial fission increased, and the integrated stress response was activated to promote mitochondrial apoptosis. These findings suggest that HsPDF inhibition is an important strategy for overcoming chemoresistance of GBM cells.

5-Methoxyflavone-induced AMPKα activation inhibits NF-κB and P38 MAPK signaling to attenuate influenza A virus-mediated inflammation and lung injury in vitro and in vivo.

Influenza-related acute lung injury (ALI) is a life-threatening condition that results mostly from uncontrolled replication of influenza virus (IV) and severe proinflammatory responses. The methoxy flavonoid compound 5-methoxyflavone (5-MF) is believed to have superior biological activity in the treatment of cancer. However, the effects and underlying mechanism of 5-MF on IV-mediated ALI are still unclear. Here, we showed that 5-MF significantly improved the survival of mice with lethal IV infection and ameliorated IV-mediated lung edema, lung histological changes, and inflammatory cell lung recruitment. We found that 5-MF has antiviral activity against influenza A virus (IAV), which was probably associated with increased expression of radical S-adenosyl methionine domain containing 2 (RSAD2) and suppression of endosomal acidification. Moreover, IV-infected A549 cells with 5-MF treatment markedly reduced proinflammatory mediator expression (IL-6, CXCL8, TNF-α, CXCL10, CCL2, CCL3, CCL4, GM-CSF, COX-2, and PGE2) and prevented P-IKBα, P-P65, and P-P38 activation. Interestingly, we demonstrated that 5-MF treatment could trigger activation of AMP-activated protein kinase (AMPK)α in IV-infected A549 cells, as evidenced by activation of the AMPKα downstream molecule P53. Importantly, the addition of AMPKα blocker compound C dramatically abolished 5-MF-mediated increased levels of RSAD2, the inhibitory effects on H1N1 virus-elicited endosomal acidification, and the suppression expression of proinflammatory mediators (IL-6, TNF-α, CXCL10, COX-2 and PGE2), as well as the inactivation of P-IKBα, P-P65, and P-P38 MAPK signaling pathways. Furthermore, inhibition of AMPKα abrogated the protective effects of 5-MF on H1N1 virus-mediated lung injury and excessive inflammation in vivo. Taken together, these results indicate that 5-MF alleviated IV-mediated ALI and suppressed excessive inflammatory responses through activation of AMPKα signaling.

A patent review of MAT2a inhibitors (2018-2021).

INTRODUCTION: In methylthioadenosine phosphorylase (MTAP)-deficient tumor cells, reduced S-adenosylmethionine (SAM) levels in the context of elevated methylthioadenosine (MTA) has been hypothesized to lead to inhibition of protein arginine methyltransferase 5 (PRMT5) and tumor growth inhibition. Inhibitors of methionine adenosyltransferase 2A (MAT2a) prevent the synthesis of SAM from methionine and have therefore attracted increasing attention as potential chemotherapeutic agents in cancers characterized by MTAP-loss. AREAS COVERED: This review covers patent applications between January 2018 and December 2021. 18 patent applications from 5 different applicants are evaluated. EXPERT OPINION: Recent advances in the field show a significant interest in the MAT2a therapeutic hypothesis. Agios and Ideaya in particular have capitalized on an allosteric binding mode first published by Pfizer in at least two of the filings during this time period, leading to potent, selective inhibitors. They have advanced MAT2a inhibitors to phase I clinical studies to explore their benefit to patients suffering with MTAP-deficient solid tumors or lymphoma. Whilst the other patent disclosures during this time frame have not led to disclosed candidates, the trials initiated by Agios and Ideaya studies will clearly inform on the potential for such inhibitors as viable therapeutic agents either as single agent or in combination.

Homocystinuria and ocular complications - A review.

Homocystinuria is a rare metabolic inborn disorder caused due to dysfunctional cystathionine ß-synthase (CBS) enzyme activity, thus resulting in elevated levels of methionine and homocysteine in the blood and urine. The timely recognition of this rare metabolic disorder and prompt methionine-restricted diet are crucial in lessening the systemic consequences. The recalcitrant cases have a higher risk for cardiovascular diseases, neurodegenerative diseases, neural tube defects, and other severe clinical complications. This review aims to present the ophthalmic spectrum of homocystinuria and its molecular basis, the disease management, as well as the current and potential treatment approaches with a greater emphasis on preventive strategies.

[Clinical characteristics and CBS gene analysis of 13 cases with classic homocystinuria].

Objective: To analyze the clinical features and CBS gene variants of 13 patients with classic homocystinuria, and the strategies of individual treatment and prevention were explored. Methods: The general information, clinical manifestations, laboratory tests, cranial images, CBS gene variants, diagnosis and therapeutic strategies of 13 patients with classic homocystinuria admitted to the Department of Pediatrics of Children's Hospital Affiliated to Zhengzhou University and Peking University First Hospital from November 2013 to June 2021 were analyzed retrospectively. Results: There were 13 patients diagnosed at the age of 10 days to 14 years, 6 were male and 7 were female. There were 3 patients detected by newborn screening and received treatment at the asymptomatic stage. There were 10 patients clinically diagnosed at the age of 5 to 14 years. Their symptoms appeared at age of 1 to 6 years. The major clinical manifestations were marfanoid features, lens dislocation and (or) myopia, developmental delay, osteoporosis, and cardiovascular diseases. Brain magnetic resonance imaging showed asymmetric infarcts in 4 patients and hypomyelination in 1 case. Increased blood methionine, plasma total homocysteine and urinary total homocysteine with normal urinary methylmalonic acid were found in 13 patients. The biochemical features were consistent with classic homocystinuria. Totally 18 variants were identified in CBS gene of 13 patients, 10 variants were novel and 8 were reported. only 1 patient was partially responsive to vitamin B6 treatment, while 12 cases were non-responsive. They were mainly treated with low methionine diet and betaine supplement. Three vitamin B6 non-responsive cases received liver transplantation at age of 3, 8 and 8 years, respectively. Their blood methionine and total homocysteine returned to normal within a week after liver transplantation. One patient died. Prenatal diagnosis was performed for a fetus when the mother was pregnant again. Two pathogenic CBS gene variants were identified from the amniocytes as same as the proband. Conclusions: The clinical manifestations of classic homocystinuria are complex and variable. Blood amino acid analysis, serum or urine total homocysteine assay and gene analysis are critical for its diagnosis. There were 10 novel CBS gene varients were identified expanding the CBS gene varient spectrum. Liver transplantation is an effective treatment. Prenatal diagnosis is important to prevent classic homocysteinuria.

The improvement of nonalcoholic steatohepatitis by Poria cocos polysaccharides associated with gut microbiota and NF-κB/CCL3/CCR1 axis.

BACKGROUND: Nonalcoholic steatohepatitis (NASH) has been linked to inflammation induced by intestinal microbiota. Poria cocos polysaccharides (PCP) possesses anti-inflammation and immunomodulation functions; however, its preventive effects against NASH and potential mechanisms need to be explored. METHODS: The composition of PCP was determined using ion chromatography. C57BL/6 mice were administered the methionine and choline deficient (MCD) diet for 4 weeks to establish the NASH model or methionine-choline-sufficient (MCS) diet to serve as the control. Mice were assigned to the MCS group, MCD group, low-dose PCP (LP) group, and high-dose PCP (HP) group, and were administered the corresponding medications via gavage. Serum biochemical index analysis and liver histopathology examination were performed to verify the successful establishment of NASH model and to evaluate the efficacy of PCP. The composition of intestinal bacteria was profiled through 16S rRNA gene sequencing. Hepatic RNA sequencing (RNA-Seq) was performed to explore the potential mechanisms, which were further confirmed using qPCR, western blot, and immunohistochemistry. RESULTS: PCP consists of glucose, galactose, mannose, D-glucosamine hydrochloride, xylose, arabinose, and fucose. PCP could significantly alleviate symptoms of NASH, including histological liver damage, impaired hepatic function, and increased oxidative stress. Meanwhile, HP could reshape the composition of intestinal bacteria by significantly increasing the relative abundance of Faecalibaculum and decreasing the level of endotoxin load derived from gut bacteria. PCP could also downregulate the expression of pathways associated with immunity and inflammation, including the chemokine signaling pathway, Toll-like receptor signaling pathway, and NF-kappa B signaling pathway. The expression levels of CCL3 and CCR1 (involved in the chemokine signaling pathway), Tlr4, Cd11b, and NF-κb (involved in the NF-kappa B signaling pathway), and Tnf-α (involved in the TNF signaling pathway) were significantly reduced in the HP group compared to the MCD group. CONCLUSIONS: PCP could prevent the development of NASH, which may be associated with the modulation of intestinal microbiota and the downregulation of the NF-κB/CCL3/CCR1 axis.

Deuterium-Reinforced Polyunsaturated Fatty Acids Prevent Diet-Induced Nonalcoholic Steatohepatitis by Reducing Oxidative Stress.

Background and Objectives: Oxidative stress is implicated in the progression of nonalcoholic steatohepatitis (NASH) through the triggering of inflammation. Deuterium-reinforced polyunsaturated fatty acids (D-PUFAs) are more resistant to the reactive oxygen species (ROS)-initiated chain reaction of lipid peroxidation than regular hydrogenated (H-) PUFAs. Here, we aimed to investigate the impacts of D-PUFAs on oxidative stress and its protective effect on NASH. Materials and Methods: C57BL/6 mice were randomly divided into three groups and were fed a normal chow diet, a methionine-choline-deficient (MCD) diet, and an MCD with 0.6% D-PUFAs for 5 weeks. The phenotypes of NASH in mice were determined. The levels of oxidative stress were examined both in vivo and in vitro. Results: The treatment with D-PUFAs attenuated the ROS production and enhanced the cell viability in tert-butyl hydroperoxide (TBHP)-loaded hepatocytes. Concurrently, D-PUFAs decreased the TBHP-induced oxidative stress in Raw 264.7 macrophages. Accordingly, D-PUFAs increased the cell viability and attenuated the lipopolysaccharide-stimulated proinflammatory cytokine expression of macrophages. In vivo, the administration of D-PUFAs reduced the phenotypes of NASH in MCD-fed mice. Specifically, D-PUFAs decreased the liver transaminase activity and attenuated the steatosis, inflammation, and fibrosis in the livers of NASH mice. Conclusion: D-PUFAs may be potential therapeutic agents to prevent NASH by broadly reducing oxidative stress.

11C-methionine PET aids localization of microprolactinomas in patients with intolerance or resistance to dopamine agonist therapy.

PURPOSE: To assess the potential for 11C-methionine PET (Met-PET) coregistered with volumetric magnetic resonance imaging (Met-PET/MRCR) to inform clinical decision making in patients with poorly visualized or occult microprolactinomas and dopamine agonist intolerance or resistance. PATIENTS AND METHODS: Thirteen patients with pituitary microprolactinomas, and who were intolerant (n = 11) or resistant (n = 2) to dopamine agonist therapy, were referred to our specialist pituitary centre for Met-PET/MRCR between 2016 and 2020. All patients had persistent hyperprolactinemia and were being considered for surgical intervention, but standard clinical MRI had shown either no visible adenoma or equivocal appearances. RESULTS: In all 13 patients Met-PET/MRCR demonstrated a single focus of avid tracer uptake. This was localized either to the right or left side of the sella in 12 subjects. In one patient, who had previously undergone surgery for a left-sided adenoma, recurrent tumor was unexpectedly identified in the left cavernous sinus. Five patients underwent endoscopic transsphenoidal selective adenomectomy, with subsequent complete remission of hyperprolactinaemia and normalization of other pituitary function; three patients are awaiting surgery. In the patient with inoperable cavernous sinus disease PET-guided stereotactic radiosurgery (SRS) was performed with subsequent near-normalization of serum prolactin. Two patients elected for a further trial of medical therapy, while two declined surgery or radiotherapy and chose to remain off medical treatment. CONCLUSIONS: In patients with dopamine agonist intolerance or resistance, and indeterminate pituitary MRI, molecular (functional) imaging with Met-PET/MRCR can allow precise localization of a microprolactinoma to facilitate selective surgical adenomectomy or SRS.