Modified Serum ALP Values and Timing of Apparition of Knee Epiphyseal Ossification Centers in Preterm Infants with Cholestasis and Risk of Concomitant Metabolic Bone Disease of Prematurity

Role of fibroblast growth factor-23 as an early marker of metabolic bone disease of prematurity

PURPOSE

Metabolic bone disease of prematurity (MBDP) remains a significant cause of morbidity in extremely premature newborns. In high-risk patients, suspected diagnosis and subsequent treatment modifications, with limitations in terms of sensitivity and specificity, rely on low phosphorus levels and/or high levels of alkaline phosphatase (ALP). We investigated the potential of fibroblast growth factor-23 (FGF23) as an early marker for MBDP when measured at 3-4 weeks of life in at-risk patients.

METHODS

A single-center prospective observational non-interventional study including preterm newborns of both sexes, with a gestational age of less than 32 weeks and/or a birth weight of less than 1500 g. In the standard biochemical screening for MBDP performed between 3 and 4 weeks of life within a nutritional profile, the determination of FGF23 was included along with other clinical and metabolic studies. The study was conducted at Marqués de Valdecilla University Hospital in Santander, Spain, from April 2020 to March 2021. Participants provided informed consent. Biochemical analyses were conducted using various platforms, and follow-up evaluations were performed at the discretion of neonatologists. Patients at high risk for MBDP received modifications in treatment accordingly. The sample was descriptively analyzed, presenting measures of central tendency and dispersion for continuous variables, and absolute numbers/percentages for categorical ones. Tests used included t-tests, Mann‒Whitney U tests, chi-square tests, logistic regressions, Pearson correlation, and ROC curve analysis (IBM SPSS Statistics version 19). Significance level: P < 0.05.

RESULTS

In the study involving 25 at-risk premature newborns, it was found that 20% (n = 5) were diagnosed with MBDP. Three of these patients (60%) were identified as high-risk based on standard biochemical evaluation at 3-4 weeks of age, while the other two patients (40%) were diagnosed in subsequent weeks. However, in all 5 patients, measurement of FGF23 levels would allow for early identification and optimization of treatment before other markers become altered. Low levels of FGF23 at 3-4 weeks, even with normal phosphorus and ALP levels, indicate the need for modifications in nutritional supplementation.

CONCLUSIONS

MBDP remains a significant concern in extremely premature newborns. Current diagnostic methods rely on limited biochemical markers. Early detection of low FGF23 levels enables timely interventions, potentially averting demineralization.

O-Linked N-Acetylglucosamine Transferase Regulates Bone Homeostasis Through Alkaline Phosphatase Pathway in Diabetic Periodontitis

Periodontitis is one of the most common complications of diabetes, which seriously affects patients' life quality. It is important to find the key factors and mechanisms to improve the treatment of periodontitis. In our study, high glucose (HG) and lipopolysaccharide (LPS) treated human periodontal ligament cells (hPDLCs) and LPS treated diabetic mice was used to establish the diabetic periodontitis model in vitro and in vivo. O-linked beta-N-acetylglucosamine glycosylation (O-GlcNAcylation) and O-linked N-acetylglucosamine transferase (OGT) protein levels were detected by western blot assay. Cell counting kit-8, alkaline phosphatase (ALP), and alizarin red staining (ARS) assays were used to observe the O-GlcNAcylation and OGT effects on cell viability and osteoblast differentiation. Co-immunoprecipitation (Co-IP) assay was used to detect the relationship between OGT and ALP. The results showed that the levels of OGT and O-GlcNAcylation were significantly increased in both cell and mouse models. ALP and ARS staining results showed that silencing of OGT or inhibition of O-glycosylation notably improved osteogenic differentiation, increased the osteoprotegerin (OPG) protein levels and decreased the receptor activator for nuclear factor-κB Ligand (RANKL) protein levels of the HG and LPS treated hPDLCs. In diabetic periodontitis mice, knockdown of OGT relieved the injury of gingival tissue, increased the ALP and OPG levels and decreased the RANKL levels. Besides, ALP interacted with OGT protein, and OGT protein was found to act on ALP serine 513 glycosylation. In conclusion, our study demonstrated that excessive O-GlcNAcylation could restrain osteoblast differentiation by O-glycosylation in ALP.

Early elevated alkaline phosphatase as a surrogate biomarker of ongoing metabolic bone disease of prematurity

Very low birth weight (VLBW) neonates present a high risk of metabolic bone disease (MBD). Our main objective was to determine the easiest way to make an early diagnosis of this disease by identifying surrogate biomarkers before any radiological signs occurred. We conducted in our NICU a 6-month observational prospective study, with inclusion of all singleton VLBW neonates. We collected clinical and biological data, and nutritional intakes during hospitalization. We defined biological MBD (bMBD) as alkaline phosphatase (ALP) levels superior to 600 UI/L at day of life 30 (DOL30) and performed a case-control analysis. Nine out of 30 patients (30%) exhibited bMBD. All have extremely low birth weight and were significantly younger in gestational age (GA) and smaller at birth. There was no statistically significant difference in nutritional intake between bMBD and control groups. In the bMBD group, phosphatemia was lower since DOL3. ALP was already significantly higher at DOL15, and way beyond normal range.

CONCLUSIONS

Our results showed that even the strict respect of nutritional guidelines cannot completely prevent bMBD in high-risk patients and suggest that an early screening from DOL15, with ALP levels greater than 500 UI/L, could be sufficient for detection of upcoming MBD.

WHAT IS KNOWN

• Metabolic bone disease of prematurity (MBD) definition is not consensual, but biological changes appear earlier than radiological signs of rickets. • MBD management relies on biological evidence. Treatment is based on phosphate and/or calcium and calcitriol supplementation.

WHAT IS NEW

• Studying phosphocalcic biological assessment in very low birth weight neonates, we showed respect of nutritional guidelines could not protect from biological MBD. • Increase in alkaline phosphatase (ALP), about 500 UI/l at day of life 15, could be a biomarker of MBD with no need of X-ray evaluation and sufficient to begin a treatment to prevent osteopenia.

Proteomic Identification of Plasma Components in Tachypleus tridentatus and Their Effects on the Longitudinal Bone Growth Rate in Rats

Tachypleus tridentatus (T. tridentatus) is a marine animal and traditional Chinese medicine. T. tridentatus plasma is a valuable resource for important medical and health-based functions. In this experiment, in order to evaluate the effect and mechanism of T. tridentatus plasma with respect to the promotion of bone tissue growth in rats, the processes of ultrafiltration and mass spectrometry were first used to separate and identify the components of T. tridentatus plasma. Then, a comparison of the effects of the T. tridentatus plasma samples, which each possessed different molecular weights, regarding the growth of the long bones of rats was conducted. Finally, transcriptomics, proteomics, and bioinformatics were all used to analyze the biological functions and related signaling pathways of the T. tridentatus plasma in order to promote rat bone growth. The results showed that the contents of amino acid residues in peptides are related to the growth promotion that was contained in the 10-30 kDa plasma group. Moreover, the T. tridentatus plasma samples were found to be higher in this respect than those in the whole plasma group. In addition, the 10-30 kDa plasma group could significantly promote bone growth activity in rats. The proteomic analysis showed that the proteins that were differentially expressed in the 10-30 kDa plasma group were mainly enriched in the PI3K-AKT signal pathway. Our study suggested that the T. tridentatus plasma possesses promising potential for the purposes of clinical use, whereby it can serve the role of a growth-promoting agent.

Anti-Postmenopausal osteoporosis effects of Isopsoralen: A bioinformatics-integrated experimental study

Isopsoralen (IPRN), which comes from the fruit of Psoralea corylifolia, has been identified as a kind of phytoestrogen and has been proven to be effective for the treatment of osteoporosis (OP). However, the mechanisms underlying IPRN's anti-OP effects, especially the anti-postmenopausal osteoporosis (PMOP) effects, remain indistinct. Thus, this study aimed to investigate the effects and mechanisms of IPRN's anti-PMOP activity. In this study, the bioinformatics results predicted that IPRN could resist PMOP by targeting EGFR, AKT1, SRC, CCND1, ESR1 (ER-α), AR, PGR, BRCA1, PTGS2, and IGF1R. An ovariectomized (OVX) mice model and a H₂ O₂ -induced bone marrow mesenchyml stem cells (BMSCs) model confirmed that IPRN could inhibit the bone loss induced by OVX in mice and promote the osteogenic differentiation in H₂ O₂ -induced BMSCs by inhibiting oxidative stress and apoptosis. Moreover, IPRN could significantly produce the above effects by upregulating ESR1. IPRN might be a therapeutic agent for PMOP by acting as an estrogen replacement agent and a natural antioxidant.

Elevated serum alkaline phosphatase correlates with postoperative cognitive dysfunction: A retrospective cohort study based on STROBE statement

Little is known about the association between serum alkaline phosphatase (ALP) levels and postoperative cognitive dysfunction (POCD) after general anesthesia. Thus, we investigated the association of serum ALP levels with POCD in patients who underwent surgery with general anesthesia in a retrospective cohort study. We retrospectively collected data from patients who underwent surgery with general anesthesia between May 2016 and June 2020. Serum ALP activity was detected using a p-nitrophenyl phosphate assay. Pre-and postoperative cognitive function were evaluated using the Chinese version of the Mini-Mental State Examination. Univariate and multivariate logistic regression were used to explore the effect of ALP on cognitive function. The incidence of POCD was 13.5%. Compared with the control group, the POCD group had higher ALP levels. The neuropsychological test results suggested that the scores of most items were lower in the POCD group than in the non-POCD group. Univariate logistic regression indicated that increased ALP levels were significantly associated with cognitive dysfunction (odds ratio = 1.15, 95% confidence interval: 1.13-1.18, P = .000). Multivariate regression showed that elevated ALP was still associated with POCD after adjusting for confounding factors (odds ratio = 1.16, 95% confidence interval: 1.13-1.18, P = .000). The spline regression model indicated the dose-response associations between ALP level and POCD risk (P for nonlinear trend < .001). Our study indicated that elevated serum ALP was an independent predictive factor of POCD at the 3-month follow-up. The occurrence of POCD could be associated with inflammatory status.

Bone Mineralization and Calcium Phosphorus Metabolism

The accretion of adequate mineral content is essential for normal bone mineralization [...].