Tissue Inhibitor of Metalloproteinase 3 (TIMP3) mutations increase glycolytic activity and dysregulate glutamine metabolism in RPE cells.

OBJECTIVES: Mutations in Tissue Inhibitor of Metalloproteinases 3 (TIMP3) cause Sorsby's Fundus Dystrophy (SFD), a dominantly inherited, rare form of macular degeneration that results in vision loss. TIMP3 is synthesized primarily by retinal pigment epithelial (RPE) cells, which constitute the outer blood-retinal barrier. One major function of RPE is the synthesis and transport of vital nutrients, such as glucose, to the retina. Recently, metabolic dysfunction in RPE cells has emerged as an important contributing factor in retinal degenerations. We set out to determine if RPE metabolic dysfunction was contributing to SFD pathogenesis. METHODS: Quantitative proteomics was conducted on RPE of mice expressing the S179C variant of TIMP3, known to be causative of SFD in humans. Proteins found to be differentially expressed (P < 0.05) were analyzed using statistical overrepresentation analysis to determine enriched pathways, processes, and protein classes using g:profiler and PANTHER Gene Ontology. We examined the effects of mutant TIMP3 on RPE metabolism using human ARPE-19 cells expressing mutant S179C TIMP3 and patient-derived induced pluripotent stem cell-derived RPE (iRPE) carrying the S204C TIMP3 mutation. RPE metabolism was directly probed using isotopic tracing coupled with GC/MS analysis. Steady state [U-13C6] glucose isotopic tracing was preliminarily conducted on S179C ARPE-19 followed by [U-13C6] glucose and [U-13C5] glutamine isotopic tracing in SFD iRPE cells. RESULTS: Quantitative proteomics and enrichment analysis conducted on RPE of mice expressing mutant S179C TIMP3 identified differentially expressed proteins that were enriched for metabolism-related pathways and processes. Notably these results highlighted dysregulated glycolysis and glucose metabolism. Stable isotope tracing experiments with [U-13C6] glucose demonstrated enhanced glucose utilization and glycolytic activity in S179C TIMP3 APRE-19 cells. Similarly, [U-13C6] glucose tracing in SFD iRPE revealed increased glucose contribution to glycolysis and the TCA cycle. Additionally, [U-13C5] glutamine tracing found evidence of altered malic enzyme activity. CONCLUSIONS: This study provides important information on the dysregulation of RPE glucose metabolism in SFD and implicates a potential commonality with other retinal degenerative diseases, emphasizing RPE cellular metabolism as a therapeutic target.

ChREBP is activated by reductive stress and mediates GCKR-associated metabolic traits.

Common genetic variants in glucokinase regulator (GCKR), which encodes GKRP, a regulator of hepatic glucokinase (GCK), influence multiple metabolic traits in genome-wide association studies (GWASs), making GCKR one of the most pleiotropic GWAS loci in the genome. It is unclear why. Prior work has demonstrated that GCKR influences the hepatic cytosolic NADH/NAD+ ratio, also referred to as reductive stress. Here, we demonstrate that reductive stress is sufficient to activate the transcription factor ChREBP and necessary for its activation by the GKRP-GCK interaction, glucose, and ethanol. We show that hepatic reductive stress induces GCKR GWAS traits such as increased hepatic fat, circulating FGF21, and circulating acylglycerol species, which are also influenced by ChREBP. We define the transcriptional signature of hepatic reductive stress and show its upregulation in fatty liver disease and downregulation after bariatric surgery in humans. These findings highlight how a GCKR-reductive stress-ChREBP axis influences multiple human metabolic traits.

Systems levels analysis of lipid metabolism in oxygen-induced retinopathy.

Hyperoxia induces glutamine-fueled anaplerosis in the Muller cells, endothelial cells, and retinal explants. Anaplerosis takes away glutamine from the biosynthetic pathway to the energy-producing TCA cycle. This process depletes biosynthetic precursors from newly proliferating endothelial cells. The induction of anaplerosis in the hyperoxic retina is a compensatory response, either to decreased glycolysis or decreased flux from glycolysis to the TCA cycle. We hypothesized that by providing substrates that feed into TCA, we could reverse or prevent glutamine-fueled anaplerosis, thereby abating the glutamine wastage for energy generation. Using an oxygen-induced retinopathy (OIR) mouse model, we first compared the difference in fatty acid metabolism between OIR-resistant BALB/cByJ and OIR susceptible C57BL/6J strains to understand if these strains exhibit metabolic difference that protects BALB/cByJ from the hyperoxic conditions and prevents their vasculature in oxygen-induced retinopathy model. Based on our findings from the metabolic comparison between two mouse strains, we hypothesized that the medium-chain fatty acid, octanoate, can feed into the TCA and serve as an alternative energy source in response to hyperoxia. Our systems levels analysis of OIR model shows that the medium chain fatty acid can serve as an alternative source to feed TCA. We here, for the first time, demonstrate that the retina can use medium-chain fatty acid octanoate to replenish TCA in normoxic and at a higher rate in hyperoxic conditions.

Identification of diphenylurea derivatives as novel endocytosis inhibitors that demonstrate broad-spectrum activity against SARS-CoV-2 and influenza A virus both in vitro and in vivo.

Rapid evolution of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and influenza A virus (IAV) poses enormous challenge in the development of broad-spectrum antivirals that are effective against the existing and emerging viral strains. Virus entry through endocytosis represents an attractive target for drug development, as inhibition of this early infection step should block downstream infection processes, and potentially inhibit viruses sharing the same entry route. In this study, we report the identification of 1,3-diphenylurea (DPU) derivatives (DPUDs) as a new class of endocytosis inhibitors, which broadly restricted entry and replication of several SARS-CoV-2 and IAV strains. Importantly, the DPUDs did not induce any significant cytotoxicity at concentrations effective against the viral infections. Examining the uptake of cargoes specific to different endocytic pathways, we found that DPUDs majorly affected clathrin-mediated endocytosis, which both SARS-CoV-2 and IAV utilize for cellular entry. In the DPUD-treated cells, although virus binding on the cell surface was unaffected, internalization of both the viruses was drastically reduced. Since compounds similar to the DPUDs were previously reported to transport anions including chloride (Cl-) across lipid membrane and since intracellular Cl- concentration plays a critical role in regulating vesicular trafficking, we hypothesized that the observed defect in endocytosis by the DPUDs could be due to altered Cl- gradient across the cell membrane. Using in vitro assays we demonstrated that the DPUDs transported Cl- into the cell and led to intracellular Cl- accumulation, which possibly affected the endocytic machinery by perturbing intracellular Cl- homeostasis. Finally, we tested the DPUDs in mice challenged with IAV and mouse-adapted SARS-CoV-2 (MA 10). Treatment of the infected mice with the DPUDs led to remarkable body weight recovery, improved survival and significantly reduced lung viral load, highlighting their potential for development as broad-spectrum antivirals.

Brevicillin, a novel lanthipeptide from the genus Brevibacillus with antimicrobial, antifungal, and antiviral activity.

AIM: This study was aimed to determine antimicrobial and antiviral activity of a novel lanthipeptide from a Brevibacillus sp. for disinfectant application. METHODS AND RESULTS: The antimicrobial peptide (AMP) was produced by a bacterial strain AF8 identified as a member of the genus Brevibacillus representing a novel species. Whole genome sequence analysis using BAGEL identified a putative complete biosynthetic gene cluster involved in lanthipeptide synthesis. The deduced amino acid sequence of lanthipeptide named as brevicillin, showed >30% similarity with epidermin. Mass determined by MALDI-MS and Q-TOF suggested posttranslational modifications like dehydration of all Ser and Thr amino acids to yield Dha and Dhb, respectively. Amino acid composition determined upon acid hydrolysis is in agreement with core peptide sequence deduced from the putative biosynthetic gene bvrAF8. Biochemical evidence along with stability features ascertained posttranslational modifications during formation of the core peptide. The peptide showed strong activity with 99% killing of pathogens at 12 µg ml-1 within 1 minute. Interestingly, it also showed potent anti-SARS-CoV-2 activity by inhibiting ∼99% virus growth at 10 µg ml-1 in cell culture-based assay. Brevicillin did not show dermal allergic reactions in BALB/c mice. CONCLUSION: This study provides detailed description of a novel lanthipeptide and demonstrates its effective antibacterial, antifungal and anti-SARS-CoV-2 activity.

Continuous Glucose Monitoring System Profile of Women Stratified Using Different Levels of Glycated Hemoglobin (HbA1c) in Early Pregnancy: A Cross-sectional Study.

AIM: To evaluate the differences in the continuous glucose monitoring system (CGMS) profiles of women in early pregnancy stratified based on different HbA1c levels known to be predictive of gestational diabetes mellitus (GDM) at 24-28 weeks of gestation (≥ 5.2%) and adverse pregnancy outcomes (≥ 5.5%) in Indian women. METHODS: We enrolled women at 8+ 0 to 19+ 6 weeks of gestation (early pregnancy), evaluated the glycaemic parameters of clinical interest using CGMS, and reported them per standard methodology proposed by Hernandez et al. WHO 2013 criteria were used for diagnosis of early GDM. RESULTS: Ninety-six women were enrolled at 14.0 ± 3.2 weeks of gestation. Of these, 38 were found to have early GDM (diagnosed before 20 weeks of gestation) on evaluation. Of 96 women, 33 (34.4%) had HbA1c value ≥ 5.5% [11 (19.0%) with normoglycaemia and 22 (57.9%) with GDM]. The women with elevated HbA1c differed significantly from those with HbA1c < 5.5% for all evaluated parameters. The differences for overall women were > 10 mg/dl (0.56 mmol/l) for 1-h postprandial glucose (difference of 0.78 mmol/l), 2-h postprandial glucose (difference of 0.59 mmol/l), peak postprandial glucose (difference of 0.75 mmol/l), and 1-h postprandial glucose excursion (difference of 0.59 mmol/l). Of 58 women with normoglycaemia, 29 (50.0%) had an HbA1c value ≥ 5.2%. In comparison, in the normoglycaemic group of women with and without HbA1c ≥ 5.2% (known to be predictive of future GDM), the results were significant for 1-h (difference of 0.44 mmol/l), 2-h (difference of 0.278 mmol/l), and peak postprandial glucose (difference of 0.35 mmol/l). CONCLUSIONS: The results suggest that women with elevated HbA1c (≥ 5.5%) in early pregnancy significantly differ from those with HbA1c < 5.5% in all glycaemic parameters evaluated in this study, suggesting that HbA1c at this cut-off has a role to play in early pregnancy.

Disruption of MenT2 toxin impairs the growth of Mycobacterium tuberculosis in guinea pigs.

Toxin-antitoxin (TA) systems are abundantly present in the genomes of various bacterial pathogens. TA systems have been implicated in either plasmid maintenance or protection against phage infection, stress adaptation or disease pathogenesis. The genome of Mycobacterium tuberculosis encodes for more than 90 TA systems and 4 of these belong to the type IV subfamily (MenAT family). The toxins and antitoxins belonging to type IV TA systems share sequence homology with the AbiEii family of nucleotidyl transferases and the AbiEi family of putative transcriptional regulators, respectively. Here, we have performed experiments to understand the role of MenT2, a toxin from the type IV TA system, in mycobacterial physiology and disease pathogenesis. The ectopic expression of MenT2 using inducible vectors does not inhibit bacterial growth in liquid cultures. Bioinformatic and molecular modelling analysis suggested that the M. tuberculosis genome has an alternative start site upstream of the annotated menT2 gene. The overexpression of the reannotated MenT2 resulted in moderate growth inhibition of Mycobacterium smegmatis. We show that both menT2 and menA2 transcript levels are increased when M. tuberculosis is exposed to nitrosative stress, in vitro. When compared to the survival of the wild-type and the complemented strain, the ΔmenT2 mutant strain of M. tuberculosis was more resistant to being killed by nitrosative stress. However, the survival of both the ΔmenT2 mutant and the wild-type strain was similar in macrophages and when exposed to other stress conditions. Here, we show that MenT2 is required for the establishment of disease in guinea pigs. Gross pathology and histopathology analysis of lung tissues from guinea pigs infected with the ∆menT2 strain revealed significantly reduced tissue damage and inflammation. In summary, these results provide new insights into the role of MenT2 in mycobacterial pathogenesis.

Continuous Glucose Monitoring System Profile of Women with Gestational Diabetes Mellitus Missed Using Isolated Fasting Plasma Glucose-Based Strategies Alternative to WHO 2013 Criteria: A Cross-Sectional Study.

INTRODUCTION: The aim of the study was to evaluate the differences in the continuous glucose monitoring system (CGMS)-based glycemic parameters between women with normoglycemia and early gestational diabetes mellitus (GDM) identified on the basis of mild fasting plasma glucose elevation (FPG, 5.1-5.5 mmol/L) and/or post-load plasma glucose elevation (PLG, 1-h ≥ 10.0 mmol/L or 2-h ≥ 8.5 mmol/L). METHODS: This cross-sectional study included women with singleton pregnancy (8+0 to 19+6 weeks of gestation) and normoglycemia or GDM per World Health Organization (WHO) 2013 criteria. We evaluated the glycemic parameters of clinical interest using blinded CGMS evaluation and reported them per standard methodology proposed by Hernandez et al. RESULTS: A total of 87 women (GDM, n = 38) were enrolled at 28.6 ± 4.5 years. Among women with GDM, 10 (26.3%) had isolated mild FPG elevation (5.1-5.5 mmol/L), 10 (26.3%) had isolated PLG elevation (1-h ≥ 10.0 mmol/L or 2-h ≥ 8.5 mmol/L), and 7 (18.4%) had a combination of both. The remaining 11 (28.9%) had elevated FPG (≥ 5.6 mmol/L) with or without PLG elevation. Thus, when an isolated FPG cutoff ≥ 5.6 mmol/L is used to diagnose GDM, 27 (71.0%) women would be perceived as normoglycemic. Such women had significantly higher CGMS parameters of clinical interest, such as 24-h mean glucose, fasting glucose, 1-h and 2-h postprandial glucose (PPG), 1-h PPG excursion, and peak PPG. CONCLUSIONS: An isolated FPG threshold, especially the higher cutoff ≥ 5.6 mmol/L, can potentially miss a large proportion of women (nearly three-fourths) diagnosed with GDM per WHO 2013 criteria. Eventually, such women fare significantly differently from normoglycemic women in various CGMS parameters of clinical interest.

Continuous glucose monitoring system profile of women diagnosed as gestational diabetes mellitus by International Association of Diabetes and Pregnancy Study Groups criteria and labeled as normoglycemic by alternate criteria in early pregnancy.

AIMS/INTRODUCTION: We aimed to evaluate and compare continuous glucose monitoring system (CGMS)-based glycemic parameters in women in early pregnancy (<20 weeks of gestation) who were classified as: (i) gestational diabetes mellitus (GDM) by the International Association of Diabetes and Pregnancy Study Groups (IADPSG), but normoglycemia by alternate (UK National Institute for Health and Care Excellence, Canadian Diabetes Association and Diabetes in Pregnancy Study group of India) criteria; and (ii) normoglycemia by both (IADPSG and alternate) criteria. MATERIAL AND METHODS: In this cross-sectional study, eligible women underwent standard 75-g oral glucose tolerance test, followed by the placement of a CGMS. Glycemia-related parameters were calculated using the standard approach for CGMS data in pregnancy. RESULTS: We enrolled 96 women at 14.0 ± 3.2 weeks of gestation. Of the women diagnosed as GDM by IADPSG criteria, 34.2%, 26.3% and 44.7% were classified as normoglycemic by UK National Institute for Health and Care Excellence, Canadian Diabetes Association and Diabetes in Pregnancy Study group of India criteria, respectively. Mean 1-h postprandial glucose and time above range were significantly higher in women who were GDM by IADPSG, but normoglycemia by Canadian Diabetes Association criteria, compared with women with normoglycemia using both criteria. Similarly, mean 1-h postprandial glucose, 2-h postprandial glucose, peak postprandial glucose, 1-h postprandial glucose excursion and time above range were significantly higher in women who were not identified as GDM by the UK National Institute for Health and Care Excellence criteria. Finally, women missed by the Diabetes in Pregnancy Study group of India criteria had significantly higher mean 1-h postprandial glucose, 2-h postprandial glucose, peak postprandial glucose, postprandial glucose excursion, 24-h glucose and time above range parameters. CONCLUSIONS: More than one-quarter of women diagnosed as GDM by IADPSG criteria are not identified by alternate criteria. Such women are significantly different from normoglycemic women in terms of several CGMS-based glycemic parameters of clinical significance.

Metabolism and Vascular Retinopathies: Current Perspectives and Future Directions.

The retina is one of the most metabolically active organs in the body. Although it is an extension of the brain, the metabolic needs of the retina and metabolic exchanges between the different cell types in the retina are not the same as that of the brain. Retinal photoreceptors convert most of the glucose into lactate via aerobic glycolysis which takes place in their cytosol, yet there are immense numbers of mitochondria in photoreceptors. The present article is a focused review of the metabolic dysregulation seen in retinopathies with underlying vascular abnormalities with aberrant mitochondrial metabolism and Hypoxia-inducible factor (HIF) dependent pathogenesis. Special emphasis has been paid to metabolic exchanges between different cell types in retinopathy of prematurity (ROP), age-related macular degeneration (AMD), and diabetic retinopathy (DR). Metabolic similarities between these proliferative retinopathies have been discussed.

A novel plant lectin, NTL-125, interferes with SARS-CoV-2 interaction with hACE2.

COVID-19 caused by SARS-CoV-2 virus has had profound impact on the world in the past two years. Intense research is going on to find effective drugs to combat the disease. Over the past year several vaccines were approved for immunization. But SARS-CoV-2 being an RNA virus is continuously mutating to generate new variants, some of which develop features of immune escape. This raised serious doubts over the long-term efficacy of the vaccines. We have identified a unique mannose binding plant lectin from Narcissus tazetta bulb, NTL-125, which effectively inhibits SARS-CoV-2 replication in Vero-E6 cell line. In silico docking studies revealed that NTL-125 has strong affinity to viral Spike RBD protein, preventing it from attaching to hACE2 receptor, the gateway to cellular entry. Binding analyses revealed that all the mutant variants of Spike protein also have stronger affinity for NTL-125 than hACE2. The unique α-helical tail of NTL-125 plays most important role in binding to RBD of Spike. NTL-125 also interacts effectively with some glycan moieties of S-protein in addition to amino acid residues adding to the binding strength. Thus, NTL-125 is a highly potential antiviral compound of natural origin against SARS-CoV-2 and may serve as an important therapeutic for management of COVID-19.

Continuous glucose monitoring and Rituximab treatment in insulin autoimmune syndrome.

Insulin autoimmune syndrome (IAS) or Hirata's disease is a rare cause of hypoglycemia. It is characterized by hyperinsulinemic hypoglycemia, elevated insulin autoantibody titers, no prior exposure to exogenous insulin and no pathological abnormalities of pancreatic islets. Hypoglycemia usually occurs in the post prandial and post absorptive state. Most cases of IAS are self-limiting, with resolution of symptoms within six months to one year. In intractable cases, treatment modalities include low-carbohydrate meals; acarbose; diazoxide; glucocorticoids; immune-suppressants like Azathioprine, cyclophosphamide, mycophenolate mofetil; plasmapheresis and partial pancreatectomy. Rituximab, an anti CD20 monoclonal antibody, was first used in 2016 in a patient with IAS who did not respond to glucocorticoids. Subsequently, there have been three more case reports of IAS where Rituximab was used along with other modalities of treatment. Here, we report the case of a 64-year old Asian Indian woman who presented with recurrent episodes of severe post prandial hypoglycemia and was diagnosed with insulin autoimmune syndrome. She was managed with continuous glucose monitoring and two doses of Rituximab 10 weeks apart, that resulted in resolution of hypoglycemia. This case report underlies the role of Rituximab as a first line agent for treatment of hypoglycemia in IAS.

Hyperoxia Inhibits Proliferation of Retinal Endothelial Cells in a Myc-Dependent Manner.

Oxygen supplementation is necessary to prevent mortality in severely premature infants. However, the supraphysiological concentration of oxygen utilized in these infants simultaneously creates retinovascular growth attenuation and vasoobliteration that induces the retinopathy of prematurity. Here, we report that hyperoxia regulates the cell cycle and retinal endothelial cell proliferation in a previously unknown Myc-dependent manner, which contributes to oxygen-induced retinopathy.

Chlorhexidine: An effective anticovid mouth rinse.

CONTEXT: Dentists across the globe are witnessing a completely unforeseen and uncertain professional situation during these times of COVID-19 pandemic. There is conflicting evidence regarding the effectiveness of routinely used mouthwashes and especially Chlorhexidine, to reduce the viral load in oral cavity and the aerosols during oral procedures. AIMS: Comparative evaluation of the effectiveness of the current 'gold standard' chlorhexidine and povidone iodine as a control agent, through an in-vitro analysis. SETTINGS AND DESIGN: In-vitro laboratory analysis. METHODS AND MATERIAL: All the experiments for analysis of antiviral efficacy of chlorhexidine digluconate (2%)and povidone iodine(1%), against SARS-CoV-2 virus were performed in the BSL3 facility at the Council of Scientific and Industrial Research-Institute of Microbial Technology, using the VeroE6 cell lines. The analysis of the virus inactivation was based on quantification of viral RNA (Cycle threshold (Ct) profile) present in the culture supernatant using Real-Time Quantitative Reverse Transcription PCR (qRT-PCR). STATISTICAL ANALYSIS USED: Descriptive analysis (Statistical package for social sciences (SPSS Inc., Chicago, IL, version 15.0 for Windows). RESULTS: Chlorhexidine digluconate in 0.2% concentration inactivated more than 99.9% of SARS CoV 2 virus, in minimal contact time of 30 seconds, which was considered better efficacy than povidone-iodine utilized for 30 and 60 seconds. Subtle differences were observed in the activity of both the compounds in terms of percent inactivation of virus, though a greater relative change in Ct values was observed for chlorhexidine. CONCLUSIONS: Within the limitations of the present study, it can be concluded that Chlorhexidine digluconate in 0.2% concentration inactivated SARS CoV 2 in minimal contact time i.e 30 secs, however both compounds tested i.e Chlorhexidine and povidone-iodine were found to have antiviral activity against SARS CoV2 virus.

Reduction of Glut1 in the Neural Retina But Not the RPE Alleviates Polyol Accumulation and Normalizes Early Characteristics of Diabetic Retinopathy.

Hyperglycemia is a key determinant for development of diabetic retinopathy (DR). Inadequate glycemic control exacerbates retinopathy, while normalization of glucose levels delays its progression. In hyperglycemia, hexokinase is saturated and excess glucose is metabolized to sorbitol by aldose reductase via the polyol pathway. Therapies to reduce retinal polyol accumulation for the prevention of DR have been elusive because of low sorbitol dehydrogenase levels in the retina and inadequate inhibition of aldose reductase. Using systemic and conditional genetic inactivation, we targeted the primary facilitative glucose transporter in the retina, Glut1, as a preventative therapeutic in diabetic male and female mice. Unlike WT diabetics, diabetic Glut1+/- mice did not display elevated Glut1 levels in the retina. Furthermore, diabetic Glut1+/- mice exhibited ameliorated ERG defects, inflammation, and oxidative stress, which was correlated with a significant reduction in retinal sorbitol accumulation. Retinal pigment epithelium-specific reduction of Glut1 did not prevent an increase in retinal sorbitol content or early hallmarks of DR. However, like diabetic Glut1+/- mice, reduction of Glut1 specifically in the retina mitigated polyol accumulation and diminished retinal dysfunction and the elevation of markers for oxidative stress and inflammation associated with diabetes. These results suggest that modulation of retinal polyol accumulation via Glut1 in photoreceptors can circumvent the difficulties in regulating systemic glucose metabolism and be exploited to prevent DR.SIGNIFICANCE STATEMENT Diabetic retinopathy affects one-third of diabetic patients and is the primary cause of vision loss in adults 20-74 years of age. While anti-VEGF and photocoagulation treatments for the late-stage vision threatening complications can prevent vision loss, a significant proportion of patients do not respond to anti-VEGF therapies, and mechanisms to stop progression of early-stage symptoms remain elusive. Glut1 is the primary facilitative glucose transporter for the retina. We determined that a moderate reduction in Glut1 levels, specifically in the retina, but not the retinal pigment epithelium, was sufficient to prevent retinal polyol accumulation and the earliest functional defects to be identified in the diabetic retina. Our study defines modulation of Glut1 in retinal neurons as a targetable molecule for prevention of diabetic retinopathy.

X-Linked Hypophosphatemic Rickets Manifesting as Sclerotic Bone Disease and Enthesopathy.

X-linked hypophosphatemic (XLH) rickets is a genetic disease caused due to the inactivation of the PHEX gene (phosphate regulating gene with homology to endopeptidase on the X chromosome). The usual presentation is with rickets and osteomalacia, and dental abscesses leading to premature loss of teeth. However, enthesopathy and sclerotic bone disease in XLH have also been reported in a few case reports. In this report, we describe the case of a 23-year-old female patient who presented to us with severe bone deformities, proximal myopathy, truncal weakness, and recent onset of pain and stiffness around the joints. She was diagnosed with XLH and was found to have severe enthesopathy along with heterotopic ossification.

Insulin Autoimmune Syndrome - A Case Series.

Insulin autoimmune syndrome, or Hirata's disease, is a rare cause of hypoglycaemia. It is characterised by spontaneous episodes of hypoglycaemia, without any exposure to exogenous insulin. The majority of cases are seen in the Japanese population and it is rarely found to affect other ethnicities. The recognition of this disease is important to avoid unnecessary investigations and procedures. Here, we report two cases of insulin autoimmune syndrome, which were diagnosed and managed in our institute.

Glycemic profile of women with normoglycemia and gestational diabetes mellitus during early pregnancy using continuous glucose monitoring system.

AIM: We studied women between 8 and 20 weeks of gestation with the aim of evaluating and comparing those having normoglycemia and GDM according to WHO 2013 criteria. METHODS: In this cross-sectional study (2017-2019), eligible pregnant women underwent a 75-g OGTT, followed by placement of a CGMS. RESULTS: Women (n = 96, 58 with normoglycemia and 38 with GDM) were enrolled at 14.0 ± 3.2 weeks of gestation. Mean preprandial, 1-h and 2-h postprandial and peak glucose values were significantly higher in women with GDM. Peak glucose value was achieved 60.0 ± 12.3 and 64.3 ± 11.6 min after meal in the normoglycemia and GDM group, respectively. 24-h mean glucose (5.8 ± 0.6 vs. 5.3 ± 0.4 mmol/L), mean daytime glucose (6.0 ± 0.6 vs. 5.5 ± 0.4 mmol/L) and mean nocturnal glucose (5.4 ± 0.7 vs. 5.0 0 ± 0.5 mmol/L) were significantly higher in women with GDM. Total time spent in range was significantly lower in the GDM group compared to the normoglycemia group (92.1 vs. 98.2%). CONCLUSIONS: This study highlights differences in glycemic patterns between women with normoglycemia and GDM in the context of a South Asian population where burden of GDM is high but good quality data in early pregnancy are limited.

Hyperoxia induces glutamine-fuelled anaplerosis in retinal Müller cells.

Although supplemental oxygen is required to promote survival of severely premature infants, hyperoxia is simultaneously harmful to premature developing tissues such as in the retina. Here we report the effect of hyperoxia on central carbon metabolism in primary mouse Müller glial cells and a human Müller glia cell line (M10-M1 cells). We found decreased flux from glycolysis entering the tricarboxylic acid cycle in Müller cells accompanied by increased glutamine consumption in response to hyperoxia. In hyperoxia, anaplerotic catabolism of glutamine by Müller cells increased ammonium release two-fold. Hyperoxia induces glutamine-fueled anaplerosis that reverses basal Müller cell metabolism from production to consumption of glutamine.

Serine and 1-carbon metabolism are required for HIF-mediated protection against retinopathy of prematurity.

We determined which metabolic pathways are activated by hypoxia-inducible factor 1-mediated (HIF-1-mediated) protection against oxygen-induced retinopathy (OIR) in newborn mice, the experimental correlate to retinopathy of prematurity, a leading cause of infant blindness. HIF-1 coordinates the change from oxidative to glycolytic metabolism and mediates flux through serine and 1-carbon metabolism (1CM) in hypoxic and cancer cells. We used untargeted metabolite profiling in vivo to demonstrate that hypoxia mimesis activates serine/1CM. Both [13C6] glucose labeling of metabolites in ex vivo retinal explants as well as in vivo [13C3] serine labeling of metabolites followed in liver lysates strongly suggest that retinal serine is primarily derived from hepatic glycolytic carbon and not from retinal glycolytic carbon in newborn pups. In HIF-1α2lox/2lox albumin-Cre-knockout mice, reduced or near-0 levels of serine/glycine further demonstrate the hepatic origin of retinal serine. Furthermore, inhibition of 1CM by methotrexate blocked HIF-mediated protection against OIR. This demonstrated that 1CM participates in protection induced by HIF-1 stabilization. The urea cycle also dominated pathway enrichment analyses of plasma samples. The dependence of retinal serine on hepatic HIF-1 and the upregulation of the urea cycle emphasize the importance of the liver to remote protection of the retina.