The male neonate in this case study was admitted to the hospital at 15 hours of age due to respiratory distress for 15 hours and poor response for 3 hours after resuscitation from asphyxia. The neonate was highly unresponsive, with central respiratory failure and seizures. Serum ammonia was elevated (>1 000 μmol/L). Blood tandem mass spectrometry revealed a significant decrease in citrulline. Rapid familial whole genome sequencing revealed OTC gene mutations inherited from the mother. Continuous hemodialysis filtration and other treatments were given. Neurological assessment was performed by cranial magnetic resonance imaging and electroencephalogram. The neonate was diagnosed with ornithine transcarbamylase deficiency combined with brain injury. He died at 6 days of age after withdrawing care. This article focuses on the differential diagnosis of neonatal hyperammonemia and introduces the multidisciplinary management of inborn error of metabolism.
Humans ; Infant, Newborn ; Male ; Citrulline ; Electroencephalography ; Hyperammonemia ; Ornithine Carbamoyltransferase Deficiency Disease/therapy* ; Seizures

OBJECTIVE: To investigate whether dynamic monitoring of citrulline (Cit) has guiding value for early enteral nutrition (EN) in patients with severe gastrointestinal injury. METHODS: A observational study was conducted. A total of 76 patients with severe gastrointestinal injury admitted to different intensive care units of Suzhou Hospital Affiliated to Nanjing Medical University from February 2021 to June 2022 were enrolled. Early EN was performed in 24-48 hours after admission as recommended by the guidelines. Those who did not terminate EN after 7 days were enrolled in the early EN success group, and those who terminated EN within 7 days due to persistent feeding intolerance or deterioration of general condition were enrolled in the early EN failure group. There was no intervention during the treatment. Serum Cit levels were measured by mass spectrometry at admission, before EN starting and EN 24 hours, respectively, and the changes in Cit within EN 24 hours (ΔCit) were calculated (ΔCit = EN 24-hour Cit-Cit before EN starting). Receiver operator characteristic curve (ROC curve) was plotted to investigate the predictive value of ΔCit for early EN failure, and the optimal predictive value was calculated. Multivariate unconditional Logistic regression was used to analyze the independent risk factors for early EN failure and death at 28 days. RESULTS: Seventy-six patients were enrolled in the final analysis, of which 40 succeeded in early EN and 36 failed. There were significant differences in age, main diagnosis, acute physiology and chronic health evaluation II (APACHE II) score at admission, blood lactic acid (Lac) before EN initiation and ΔCit between the two groups. Multivariate Logistic regression analysis showed that age [odds ratio (OR) = 0.929, 95% confidence interval (95%CI) was 0.874-0.988, P = 0.018], ΔCit (OR = 2.026, 95%CI was 1.322-3.114, P = 0.001) and increased feeding rate within 48 hours (OR = 13.719, 95%CI was 1.795-104.851, P = 0.012) were independent risk factors for early EN failure in patients with severe gastrointestinal injury. ROC curve analysis showed that ΔCit had a good predictive value for early EN failure in patients with severe gastrointestinal injury [area under the ROC curve (AUC) = 0.787, 95%CI was 0.686-0.887, P < 0.001], and the optimal predictive value of ΔCit was 0.74 μmol/L (sensitivity was 65.0%, specificity was 75.0%). Combined with the optimal predictive value of ΔCit, "overfeeding" was defined as ΔCit < 0.74 μmol/L and increased feeding within 48 hours. Multivariate Logistic regression analysis showed that age (OR = 0.825, 95%CI was 0.732-0.930, P = 0.002), APACHE II score (OR = 0.696, 95%CI was 0.518-0.936, P = 0.017) and early EN failure (OR = 181.803, 95%CI was 3.916-8 439.606, P = 0.008) were independent risk factors for 28-day death in patients with severe gastrointestinal injury. The new variable "overfeeding" was also associated with an increased risk of death at 28 days (OR = 27.816, 95%CI was 1.023-755.996, P = 0.048). CONCLUSIONS Dynamic monitoring of Cit has guiding value for early EN in patients with severe gastrointestinal injury.
Humans ; Infant, Newborn ; Enteral Nutrition ; Citrulline ; APACHE ; Abdominal Injuries ; Cognition ; Thoracic Injuries

OBJECTIVES: To investigate genotype-phenotype characteristics and long-term prognosis of neonatal carbamoyl phosphate synthetase 1 (CPS1) deficiency among children through newborn screening in Zhejiang province. METHODS: The clinical and follow-up data of children with CPS1 deficiency detected through neonatal screening and confirmed by tandem mass spectrometry and genetic testing in Zhejiang Province Newborn Disease Screening Center from September 2013 to August 2023 were retrospectively analyzed. RESULTS: A total of 4 056 755 newborns were screened and 6 cases of CPS1 deficiency were diagnosed through phenotypic and genetic testing. Ten different variations of CPS1 genewere identified in genetic testing, including 2 known pathogenic variations (c.2359C>T and c.1549+1G>T) and 8 unreported variations (c.3405-1G>T, c.2372C>T, c.1436C>T, c.2228T>C, c.2441G>A, c.3031G>A, c.3075T>C and c.390-403del). All patients had decreased citrulline levels (2.72-6.21 μmol/L), and varying degrees of elevated blood ammonia. The patients received restricted natural protein intake (special formula), arginine and supportive therapy after diagnosis, and were followed-up for a period ranging from 9 months to 10 years. Three patients experienced hyperammonemia, and one patient each had attention deficit hyperactivity disorder, transient facial twitching and increased muscle tone. One patient died, while the other five surviving patients had normal scores of the Ages & Stages Questionnaires (ASQ) and Griffiths Development Scales up to the present time; 4 cases had combined height or weight lag and one case was normal in height and weight. CONCLUSIONS Low citrulline levels and hyperammonemia are common in CPS1 deficiency patients in Zhejiang. Most gene variants identified were specific to individual families, and no hotspot mutations were found. Early diagnosis through newborn screening and following standardized treatment can significantly improve the prognosis of the patients.
Child ; Humans ; Infant, Newborn ; Carbamoyl-Phosphate Synthase I Deficiency Disease/therapy* ; Neonatal Screening ; Follow-Up Studies ; Hyperammonemia ; Citrulline/genetics* ; Retrospective Studies ; Mutation

OBJECTIVE: To investigate the expression of citrullinated epitopes in articular cartilage protein and whether its expression is sufficient to induce anti-citrullinated protein antibody (ACPA) response in mice. METHODS: The experimental group was treated with different concentrations of lipopolysaccharide (LPS), heat-inactivated bacteria ( and ) or specific monoclonal antibody against type Ⅱ collagen to induce citrullination of articular cartilage protein, with PBS as the control. Immunohistochemistry with the monoclonal antibody ACC4 (IgG1) that specifically binds to the citrullinated epitope of cartilage protein was performed for detecting the expression of citrullinated protein, with ACC1 (IgG2a) as a positive control antibody and L243 (IgG2a) and Hy2.15 (IgG1) as the negative isotype control. In the in vivo experiment, SD rats were subjected to injection of different doses of LPS in the right knee (with PBS as the controls in the left knee), and 3 days later frozen sections were prepared for immunohistochemical detection of the expression of citrullinated protein. Models of collagen-induced arthritis (CIA) established in different mouse strains were observed for incidence and severity of CIA. Serum samples collected from these models and the sera from rheumatoid arthritis patients were examined for anti-citrullinated protein antibody, and immunohistochemistry was performed to detect the expression of citrullinated protein in the cartilage of the mouse. RESULTS: The citrullinated CII epitope-specific antibody ACC4 did not bind to articular cartilage tissues with different treatments as compared with the positive control antibody ACC1. The ACC4 antibody and the antibodies from patients with rheumatoid arthritis with high titers of anti-citrullinated protein antibody were capable of binding to the synovial tissue around the articular cartilage of the CIA. Luminex analysis showed that the anti-citrullinated protein antibody was lowly expressed in mouse serum, but the anti-type Ⅱ collagen triple helix structure peptide antibody exhibited strong reactivity. CONCLUSIONS Mild acute inflammatory response is not enough to cause citrullination of articular cartilage protein, and the expression of specific epitope requires a high-intensity inflammatory response. Inflammatory articular cartilage protein can express citrullinated epitopes in type Ⅱ collagen-induced arthritis in mice, but the expression of citrullinated epitopes is not sufficient to induce an immune response to anti-citrullinated antibodies. Stronger stimulation signals are required to induce an immune response for producing anti-citrullinated protein antibodies.
Animals ; Arthritis, Experimental ; Autoantibodies ; Cartilage, Articular ; Citrulline ; Humans ; Inflammation ; Mice ; Rats ; Rats, Sprague-Dawley

Lysinuric protein intolerance (LPI) is an autosomal recessive disorder caused by SLC7A7 gene mutation and often involves severe lesions in multiple systems. Lung involvement is frequently seen in children with LPI and such children tend to have a poor prognosis. This article summarizes the clinical manifestations and gene mutation characteristics of three children diagnosed with LPI by SLC7A7 gene analysis. All three children had the manifestations of aversion to protein-rich food after weaning, delayed development, anemia, hepatosplenomegaly, and osteoporosis, as well as an increase in orotic acid in urine. In addition, interstitial pneumonia and diffuse pulmonary interstitial lesions were observed in two children. SLC7A7 gene detection showed three pathogenic mutations in these children, namely c.1387delG(p.V463CfsX56), c.1215G>A(p.W405X) and homozygous c.625+1G>A. After a definite diagnosis was made, all three children were given a low-protein diet and oral administration of citrulline [100 mg/(kg.d)], iron protein succinylate [4 mg/(kg.d)], calcium and zinc gluconates oral solution (10 mL/day) and vitamin D (400 IU/day). In addition, patient 3 was given prednisone acetate (5 mg/day). The children had varying degrees of improvement in symptoms and signs. It is hard to distinguish LPI from urea cycle disorder due to the features of amino acid and organic acid metabolism in LPI, and SLC7A7 gene analysis is the basis for a definite diagnosis of LPI.
Amino Acid Metabolism, Inborn Errors ; genetics ; Child ; Citrulline ; Fusion Regulatory Protein 1, Light Chains ; genetics ; Humans ; Lysine ; Mutation

Intestinal failure (IF) is the critical reduction of the gut mass or its function below the minimum needed to absorb nutrients and fluids required for adequate growth in children. Severe IF requires parenteral nutrition (PN). Pediatric IF is most commonly due to congenital or neonatal intestinal diseases or malformations divided into 3 groups: 1) reduced intestinal length and consequently reduced absorptive surface, such as in short bowel syndrome (SBS) or extensive aganglionosis; 2) abnormal development of the intestinal mucosa such as congenital diseases of enterocyte development; 3) extensive motility dysfunction such as chronic intestinal pseudo-obstruction syndromes. The leading cause of IF in childhood is the SBS. In clinical practice the degree of IF may be indirectly measured by the level of PN required for normal or catch up growth. Other indicators such as serum citrulline have not proven to be highly reliable prognostic factors in children. The last decades have allowed the development of highly sophisticated nutrient solutions consisting of optimal combinations of macronutrients and micronutrients as well as guidelines, promoting PN as a safe and efficient feeding technique. However, IF that requires long-term PN may be associated with various complications including infections, growth failure, metabolic disorders, and bone disease. IF Associated Liver Disease may be a limiting factor. However, changes in the global management of IF pediatric patients, especially since the setup of intestinal rehabilitation centres did change the prognosis thus limiting “nutritional failure” which is considered as a major indication for intestinal transplantation (ITx) or combined liver-ITx.
Bone Diseases ; Child ; Citrulline ; Enterocytes ; Humans ; Intestinal Diseases ; Intestinal Mucosa ; Intestinal Pseudo-Obstruction ; Liver Diseases ; Micronutrients ; Parenteral Nutrition ; Parenteral Nutrition, Home ; Prognosis ; Rehabilitation ; Short Bowel Syndrome

No abstract available.
Arthritis, Rheumatoid* ; Citrulline*

OBJECTIVEThe conversion of arginine into citrulline, termed citrullination, has important consequences for the structure and function of proteins. The present study aimed to identify novel citrullinated proteins in 10 tumor cell lines by 2-D Western blotting (2-D WB).

METHODSTwo identical two-dimensional electrophoresis (2-DE) gels were prepared using extracts from ten cultured human tumor cell lines: ECA(esophageal cancer cells), HEPG2 (hepatocellular carcinoma cells), SKOV3 (ovarian cancer cells), MCF-7 (breast cancer cells), H292 (lung mucoepidermoid carcinoma cells), HeLa (cervical cancer cells), Lovo (colon cancer cells), OS-RC (renal cell carcinoma cells), PANC-1 (pancreatic cancer cells), and SGC (gastric cancer cells). The expression profiles on one 2-DE gels were trans-blotted to PVDF membranes, and the blots were then probed with an anti-citrulline antibody. By comparing the 2-DE profile with the parallel 2-D WB profile at a global level, protein spots with immuno-signals were collected from the second 2-DE gel and identified using mass spectrometry. Immunoprecipitation was used to verify the expression and citrullination of the targeted proteins in the tumor cell lines.

RESULTS2-D WB and mass spectrometry identified citrullinated ENO1 (α-enolase), HSP60 (heat shock protein 60), KRT8 (keratin 8), TUBB (tubulin beta), TCRβ (T cell receptor β chain), VIME (vimentin) and PDI in these cell lines. Immunoprecipitation analyses verified the expression and citrullination of ENO1, HSP60, KRT8, and TUBB in the total protein lysates of the tumor cell lines.

CONCLUSIONThe citrullination of proteins ENO1, HSP60, KRT8, and TUBB suggests a new mechanism in the tumorigenic process.

Blotting, Western ; Cell Line, Tumor ; Citrulline ; metabolism ; Female ; Humans ; Immunoprecipitation ; Mass Spectrometry ; Phosphopyruvate Hydratase ; Vimentin

The multiple post-translational modifications of proteins display specific gain- or loss-of-function under normal and abnormal conditions. These modifications are precisely regulated by post-translational modification enzymes. The altered molecular status perturbs the pattern of gene expression and decides on a direction to signal transduction cascades as well as intrinsic properties of the proteins. Ultimately, it strictly maintains intracellular environment or results in disease manifestations. Recently, it has become that enzyme-dependent modification of arginine residue to citrulline exerts an important role in the induction of autoimmunity including rheumatoid arthritis, multiple sclerosis, and cancer. The modification of arginine residue to citrulline on proteins is called 'citrullination' or 'deimination' and is regulated by the calcium-dependent enzyme peptidylarginine deiminase (PAD). Now many effective PAD inhibitors (for example, Cl-amidine) have developed that ameliorates disease phenotypes. In this review, we discuss crucial roles of PAD enzyme and citrullination, the effectiveness of PAD inhibitors, and the implication in pathology.
Arginine ; Arthritis, Rheumatoid ; Autoimmunity ; Citrulline ; Gene Expression ; Hydrolases ; Multiple Sclerosis ; Ornithine ; Phenotype ; Protein Processing, Post-Translational ; Proteins ; Signal Transduction

This study aimed to investigate the clinical effect of transplantation of CD133⁺ peripheral blood stem cells or umbilical cord mesenchymal stem cells via the hepatic artery in children with type II hyperammonemia and its possible action mechanism. Umbilical cord mesenchymal stem cells were obtained by collecting cord blood (100-150 mL) from healthy fetuses and separating stem cell suspension (5 mL) from the cord blood by hydroxyethyl starch sedimentation. CD133⁺ peripheral blood stem cells were obtained by mobilizing peripheral blood from the fathers of sick children using recombinant human granulocyte colony-stimulating factor for 5 days, collecting mononuclear cells (120 mL), and separating out CD133⁺ cells by sorting. With catheterization and percutaneous puncture, the obtained stem cells were slowly injected into the liver of sick children via the hepatic artery. The changes in clinical symptoms and laboratory indices such as blood ammonia, liver function, and arginine and citrulline concentrations were observed. After stem cell transplantation via the hepatic artery, the 6 children showed significantly decreased blood ammonia levels, and their blood ammonia levels slowly increased 1 to 2 weeks later, but remained below 100 μmol/L, and changes in glutamic-pyruvic transaminase levels were similar to blood ammonia. Plasma citrulline and arginine concentrations increased significantly after transplantation and the increase in citrulline level exceeded the increase in arginine level. An 8 months follow-up visit for one typical patient showed that the weight and height increased after transplantation and sleep was improved without night crying. The child could actively gaze at interesting objects instead of responding indifferently and started to say simple words. With regard to fine motor skills, the child could pinch things with the thumb and middle finger instead of displaying a lack of hand-eye coordination and progress was also made in gross motor skills. Gesell test showed that the child made progress for an average of 3.82 months in all areas. It was concluded that after stem cell transplantation, children with type II hyperammonemia have decreased blood ammonia levels, stable and improved liver function and steadily increased plasma citrulline and arginine concentrations. They display a progressive trend in such aspects as movement, language and environmental adaptability. It is hypothesized that stem cell transplantation via the hepatic artery partially or totally activates, or provides supplementary ornithine carbamoyl transferase, so that plasma citrulline and arginine concentrations increase and urea cycle disorder can be corrected to some extent.
AC133 Antigen ; Ammonia ; blood ; Antigens, CD ; analysis ; Arginine ; blood ; Citrulline ; blood ; Female ; Glycoproteins ; analysis ; Hepatic Artery ; Humans ; Hyperammonemia ; blood ; surgery ; Infant ; Male ; Peptides ; analysis ; Stem Cell Transplantation