Protrudin in protrudinG invadopodia : Membrane contact sites and cell invasion

Invadopodia are dynamic protrusions that harbor matrix metalloproteinases for pericellular matrix degradation. However, the mechanisms underlying their maturation are poorly understood. Pedersen et al. (2020. J. Cell Biol. https://doi.org/10.1083/jcb.202003063) demonstrate a dual role of Protrudin in invadopodia elongation and matrix degradation, central to cell invasion and cancer metastasis.Non peer reviewe

Antenatal counselling as a tool to increase acceptability of postpartum intrauterine contraceptive device insertion in a tertiary care hospital

Background: Acceptance of postpartum intrauterine device (IUD) insertions in women in Uttar Pradesh is low. In response to the concept that a good postpartum programme should begin prenatally, this study was designed to determine whether the provision of expert contraceptive counselling during the antenatal period would have an impact on its uptake as compared to women who were counselled in post partum period.Methods: Expert contraceptive counselling was given to 264 and154 women during their antenatal visits and postpartum hospitalization, respectively. Acceptors received IUCDs within 48 h of delivery in the case of vaginal delivery or transcesarean insertion in case of abdominal delivery. The acceptance rate of PPIUCD and the percentage of actual insertions were recorded. The causes of refusal were also recorded.Results: Among the 264 couples counselled in antenatal period 116 (43.9%) had PPIUCD insertion. Among the 154 unbooked women who were counselled postpartum only PPIUCD was inserted in 36 (23.4%) women. PPIUCD insertion was significantly high in women receiving expert counselling during antenatal period as compared to the women who were counselled in postnatal period (p< 0.001). Family refusal, No knowledge of PPIUCD and preference for another contraceptive methods were the most common reasons for refusing the use of PPIUCD.Conclusion: Acceptability of PPIUCD insertion was high in women counselled in antenatal period. Hence, it is suggested that counselling for PPIUCD should start in antenatal period

Influence of thyroid hormones on biochemical parameters of liver function: a case-control study in North Indian population

Normal level of thyroid hormones is important for normal hepatic function and thyroid dysfunction may modulate metabolic function of liver. The purpose of this study is to determine whether liver function is associated with subclinical and overt hypothyroidism. Thyroid and liver function tests were evaluated in 47 patients with overt (TSH ≥10.0 mIU/L) and 77 patients with subclinical hypothyroidism (TSH 6.0-9.9mIU/L) and compared with 120 age-matched euthyroid controls. Subjects with overt hypothyroidism had significantly raised serum ALT, AST, ALP and total protein levels as compared to controls whereas subclinical hypothyroid patients had significantly increased levels of serum ALT, ALP and total protein. Further, TSH showed significant positive correlation with AST and ALP values whereas fT3 and fT4 had a negative correlation with AST in overt hypothyroidism. Thus, overt hypothyroid state is associated with significant derangement in biochemical parameters of liver function. Hence, liver function should be regularly monitored in hypothyroid patients

Comparison of drug information in package inserts with standard medical textbook of pharmacology

Background: Accurate and reliable drug product information is important for the safe and effective use of medicines. But there are variations in the quantity and quality of information mentioned in different drug information sources and a single credible benchmark is lacking. This study was carried out to compare the presentation and completeness of clinical information in package inserts (PIs) marketed by pharmaceutical companies in India with standard medical textbook of pharmacology.Methods: Out of eighty five PIs of different drugs, only 55 were found eligible to be included in this study after applying inclusion and exclusion criteria. These PIs and medical textbook were analysed for quantitative and qualitative drug information and were compared using Chi square test of two proportions. The p value of 0.05 was used as cut off to evaluate statistical significance.Results: Quantitatively medical textbook was significantly better statistically in context of treatment of overdose and references. No statistically significant difference was observed in relation to information related to mechanism of action (MOA) and pharmacokinetics (Pk). After qualitative analysis, medical textbook was significantly better statistically in context of size and readability, references related to adverse drug reactions (ADRs) and indications and pictures. No statistically significant difference was observed in context of dosing interval, frequency of doses and pharmacokinetic parameters.Conclusions: PIs can be used as a reliable source of drug information by health care professionals in addition to other sources like medical textbooks

Coordination of inter-organelle communication and lipid fluxes by OSBP-related proteins

Oxysterol-binding protein (OSBP) and OSBP-related proteins (ORPs) constitute one of the largest families of lipid-binding/transfer proteins (LTPs) in eukaryotes. The current view is that many of them mediate interorganelle lipid transfer over membrane contact sites (MCS). The transfer occurs in several cases in a 'countercurrent' fashion: A lipid such as cholesterol or phosphatidylserine (PS) is transferred against its concentration gradient driven by transport of a phosphoinositide in the opposite direction. In this way ORPs are envisioned to maintain the distinct organelle lipid compositions, with impacts on multiple organelle functions. However, the functions of ORPs extend beyond lipid homeostasis to regulation of processes such as cell survival, proliferation and migration. Important expanding areas of mammalian ORP research include their roles in viral and bacterial infections, cancers, and neuronal function. The yeast OSBP homologue (Osh) proteins execute multifaceted functions in sterol and glycerophospholipid homeostasis, post-Golgi vesicle transport, phosphatidylinositol-4-phosphate, sphingolipid and target of rapamycin (TOR) signalling, and cell cycle control. These observations identify ORPs as lipid transporters and coordinators of signals with an unforeseen variety of cellular processes. Understanding their activities not only enlightens the biology of the living cell but also allows their employment as targets of new therapeutic approaches for disease.Peer reviewe

Association between different degrees of hypothyroidism and serum lipids

The association between overt hypothyroidism (OH) and altered lipid profile is well known, however the significance of dyslipidemia in subclinical hypothyroidism (SCH) remain controversial. Therefore, this study was conducted to determine any association between lipid profile and different degrees of thyroid dysfunction. Thyroid and lipid profile parameters were analysed in 58 patients with overt (TSH &#8805; 10.0 &#956;IU/L and/or abnormally low fT4 and fT3 levels) and 87 patients with subclinical hypothyroidism (TSH 6.0-9.9 &#956;IU/L with normal fT4 and fT3 levels) in this case-control study. These were compared with 100 age- and sex-matched euthyroid controls. It was found that only mean serum level of total cholesterol in patients with SCH was significantly high from that in controls (p=0.045). Other lipid parameters did not show any statistical significance. Whereas patients with OH had statistically significant higher levels of total cholesterol (p&lt;0.001), triglyceride (p&lt;0.05), LDL-C (p&lt;0.001) and VLDL-C (p&lt;0.05). There was also an increase in HDL-C in both SCH and OH group though not significant statistically. In conclusion, lipid profile is not much deranged in SCH whereas OH is a major cause of secondary dyslipidemia which may lead to increased risk of coronary artery disease. Therefore, thyroid hormone replacement would be most beneficial in patients with OH instead of SCH. However, patients with SCH should be monitored for deterioration of thyroid function and dyslipidemia at regular intervals.Keywords: Cholesterol; Dyslipidemia; HDL cholesterol; Hypothyroidism; SubclinicalInternet Journal of Medical Update 2012 July;7(2):3-

OSBP-related protein 2 (ORP2) : Unraveling its functions in cellular lipid/carbohydrate metabolism, signaling and F-actin regulation

Oxysterol-binding protein (OSBP)-related proteins (ORPs) constitute a family of intracellular lipid-binding/transport proteins (LTPs) in eukaryotes. They typically have a modular structure comprising a lipid-binding domain and membrane targeting determinants, being thus suited for function at membrane contact sites. Among the mammalian ORPs, ORP2/OSBPL2 is the only member that only exists as a 'short' variant lacking a membrane-targeting pleckstrin homology domain. ORP2 is expressed ubiquitously and has been assigned a multitude of functions. Its OSBP-related domain binds cholesterol, oxysterols, and phosphoinositides, and its overexpression enhances cellular cholesterol efflux. Consistently, the latest observations suggest a function of ORP2 in cholesterol transport to the plasma membrane (PM) in exchange for phosphatidylinositol 4,5-bisphosphate (PI4,5P(2)), with significant impacts on the concentrations of PM cholesterol and PI4,5P(2). On the other hand, ORP2 localizes at the surface of cytoplasmic lipid droplets (LDs) and at endoplasmic-reticulum-LD contact sites, and its depletion modifies cellular triglyceride (TG) metabolism. Study in an adrenocortical cell line further suggested a function of ORP2 in the synthesis of steroid hormones. Our recent knock-out of ORP2 in human hepatoma cells revealed its function in hepatocellular PI3K/Akt signaling, glucose and triglyceride metabolism, as well as in actin cytoskeletal regulation, cell adhesion, migration and proliferation. ORP2 was shown to interact physically with F-actin regulators such as DIAPH1, ARHGAP12, SEPT9 and MLC12, as well as with IQGAP1 and the Cdc37-Hsp90 chaperone complex controlling the activity of Akt. Interestingly, mutations in OSBPL2 encoding ORP2 are associated with autosomal dominant non-syndromic hearing loss, and the protein was found to localize in cochlear hair cell stereocilia. The functions assigned to ORP2 suggest that this protein, in concert with other LTPs, controls the subcellular distribution of cholesterol in various cell types and steroid hormone synthesis in adrenocortical cells. However, it also impacts cellular TG and carbohydrate metabolism and F-actin-dependent functions, revealing a bewildering spectrum of activities.Peer reviewe

Protrudin regulates FAK activation, endothelial cell migration and angiogenesis

During angiogenesis, endothelial cells form protrusive sprouts and migrate towards the angiogenic stimulus. In this study, we investigate the role of the endoplasmic reticulum (ER)-anchored protein, Protrudin, in endothelial cell protrusion, migration and angiogenesis. Our results demonstrate that Protrudin regulates angiogenic tube formation in primary endothelial cells, Human umbilical vein endothelial cells (HUVECs). Analysis of RNA sequencing data and its experimental validation revealed cell migration as a prominent cellular function affected in HUVECs subjected to Protrudin knockdown. Further, our results demonstrate that knockdown of Protrudin inhibits focal adhesion kinase (FAK) activation in HUVECs and human aortic endothelial cells (HAECs). This is associated with a loss of polarized phospho-FAK distribution upon Protrudin knockdown as compared to Protrudin expressing HUVECs. Reduction of Protrudin also results in a perinuclear accumulation of mTOR and a decrease in VEGF-mediated S6K activation. However, further experiments suggest that the observed inhibition of angiogenesis in Protrudin knockdown cells is not affected by mTOR disturbance. Therefore, our findings suggest that defects in FAK activation and its abnormal subcellular distribution upon Protrudin knockdown are associated with a detrimental effect on endothelial cell migration and angiogenesis. Furthermore, mice with global Protrudin deletion demonstrate reduced retinal vascular progression. To conclude, our results provide evidence for a novel key role of Protrudin in endothelial cell migration and angiogenesis.Peer reviewe

ORP2, a cholesterol transporter, regulates angiogenic signaling in endothelial cells

https://doi.org/10.1096/fj.202000202ROxysterol-binding protein-related protein 2 (ORP2), a cholesterol-PI(4,5)P(2)countercurrent transporter, was recently identified as a novel regulator of plasma membrane (PM) cholesterol and PI(4,5)P(2)content in HeLa cells. Here, we investigate the role of ORP2 in endothelial cell (EC) cholesterol and PI(4,5)P(2)distribution, angiogenic signaling, and angiogenesis. We show that ORP2 knock-down modifies the distribution of cholesterol accessible to a D4H probe, between late endosomes and the PM. Depletion of ORP2 from ECs inhibits their angiogenic tube formation capacity, alters the gene expression of angiogenic signaling pathways such as VEGFR2, Akt, mTOR, eNOS, and Notch, and reduces EC migration, proliferation, and cell viability. We show that ORP2 regulates the integrity of VEGFR2 at the PM in a cholesterol-dependent manner, the depletion of ORP2 resulting in proteolytic cleavage by matrix metalloproteinases, and reduced activity of VEGFR2 and its downstream signaling. We demonstrate that ORP2 depletion increases the PM PI(4,5)P(2)coincident with altered F-actin morphology, and reduces both VEGFR2 and cholesterol in buoyant raft membranes. Moreover, ORP2 knock-down suppresses the expression of the lipid raft-associated proteins VE-cadherin and caveolin-1. Analysis of the retinal microvasculature in ORP2 knock-out mice generated during this study demonstrates the subtle alterations of morphology characterized by reduced vessel length and increased density of tip cells and perpendicular sprouts. Gene expression changes in the retina suggest disturbance of sterol homeostasis, downregulation of VE-cadherin, and a putative disturbance of Notch signaling. Our data identifies ORP2 as a novel regulator of EC cholesterol and PI(4,5)P(2)homeostasis and cholesterol-dependent angiogenic signaling.Peer reviewe

Rice Phospholipase A Superfamily: Organization, Phylogenetic and Expression Analysis during Abiotic Stresses and Development

Background: Phospholipase A (PLA) is an important group of enzymes responsible for phospholipid hydrolysis in lipid signaling. PLAs have been implicated in abiotic stress signaling and developmental events in various plants species. Genome-wide analysis of PLA superfamily has been carried out in dicot plant Arabidopsis. A comprehensive genome-wide analysis of PLAs has not been presented yet in crop plant rice. Methodology/Principal Findings: A comprehensive bioinformatics analysis identified a total of 31 PLA encoding genes in the rice genome, which are divided into three classes; phospholipase A 1 (PLA 1), patatin like phospholipases (pPLA) and low molecular weight secretory phospholipase A2 (sPLA2) based on their sequences and phylogeny. A subset of 10 rice PLAs exhibited chromosomal duplication, emphasizing the role of duplication in the expansion of this gene family in rice. Microarray expression profiling revealed a number of PLA members expressing differentially and significantly under abiotic stresses and reproductive development. Comparative expression analysis with Arabidopsis PLAs revealed a high degree of functional conservation between the orthologs in two plant species, which also indicated the vital role of PLAs in stress signaling and plant development across different plant species. Moreover, sub-cellular localization of a few candidates suggests their differential localization and functional role in the lipid signaling. Conclusion/Significance: The comprehensive analysis and expression profiling would provide a critical platform for th