46 research outputs found
The Role of Human Dopamine Transporter in NeuroAIDS
HIV-associated neurocognitive disorder (HAND) remains highly prevalent in HIV infected individuals and represents a special group of neuropathological disorders, which are associated with HIV-1 viral proteins, such as transactivator of transcription (Tat) protein. Cocaine abuse increases the incidence of HAND and exacerbates its severity by enhancing viral replication. Perturbation of dopaminergic transmission has been implicated as a risk factor of HAND. The presynaptic dopamine (DA) transporter (DAT) is essential for DA homeostasis and dopaminergic modulation of the brain function including cognition. Tat and cocaine synergistically elevate synaptic DA levels by acting directly on human DAT (hDAT), ultimately leading to dysregulation of DA transmission. Through integrated computational modeling and experimental validation, key residues have been identified in hDAT that play a critical role in Tat-induced inhibition of DAT and induce transporter conformational transitions. This review presents current information regarding neurological changes in DAT-mediated dopaminergic system associated with HIV infection, DAT-mediated adaptive responses to Tat as well as allosteric modulatory effects of novel compounds on hDAT. Understanding the molecular mechanisms by which Tat induces DAT-mediated dysregulation of DA system is of great clinical interest for identifying new targets for an early therapeutic intervention for HAND
Allosteric Modulatory Effects of SRI-20041 and SRI-30827 on Cocaine and HIV-1 Tat Protein Binding to Human Dopamine Transporter
Dopamine transporter (DAT) is the target of cocaine and HIV-1 transactivator of transcription (Tat) protein. Identifying allosteric modulatory molecules with potential attenuation of cocaine and Tat binding to DAT are of great scientific and clinical interest. We demonstrated that tyrosine 470 and 88 act as functional recognition residues in human DAT (hDAT) for Tat-induced inhibition of DA transport and transporter conformational transitions. Here we investigated the allosteric modulatory effects of two allosteric ligands, SRI-20041 and SRI-30827 on cocaine binding on wild type (WT) hDAT, Y470 H and Y88 F mutants. Effect of SRI-30827 on Tat-induced inhibition of [3H]WIN35,428 binding was also determined. Compared to a competitive DAT inhibitor indatraline, both SRI-compounds displayed a similar decrease (30%) in IC50 for inhibition of [3H]DA uptake by cocaine in WT hDAT. The addition of SRI-20041 or SRI-30827 following cocaine slowed the dissociation rate of [3H]WIN35,428 binding in WT hDAT relative to cocaine alone. Moreover, Y470H and Y88F hDAT potentiate the inhibitory effect of cocaine on DA uptake and attenuate the effects of SRI-compounds on cocaine-mediated dissociation rate. SRI-30827 attenuated Tat-induced inhibition of [3H]WIN35,428 binding. These observations demonstrate that tyrosine 470 and 88 are critical for allosteric modulatory effects of SRI-compounds on the interaction of cocaine with hDAT
A cell based high-throughput screening approach for the discovery of new inhibitors of respiratory syncytial virus
Background:
Human respiratory syncytial virus (hRSV) is a highly contagious pathogen and is the most common cause of bronchiolitis and pneumonia for infants and children under one year of age. Worldwide, greater than 33 million children under five years of age are affected by hRSV resulting in three million hospitalizations and 200,000 deaths. However, severe lower respiratory tract disease may occur at any age, especially among the elderly or those with compromised cardiac, pulmonary, or immune systems. There is no vaccine commercially available. Existing therapies for the acute infection are ribavirin and the prophylactic humanized monoclonal antibody (Synagis® from MedImmune) that is limited to use in high risk pediatric patients. Thus, the discovery of new inhibitors for hRSV would be clinically beneficial.
Results:
We have developed and validated a 384-well cell-based, high-throughput assay that measures the cytopathic effect of hRSV (strain Long) in HEp-2 cells using a luminescent-based detection system for signal endpoint (Cell Titer Glo®). The assay is sensitive and robust, with Z factors greater than 0.8, signal to background greater than 35, and signal to noise greater than 24. Utilizing this assay, 313,816 compounds from the Molecular Libraries Small Molecule Repository were screened at 10 μM. We identified 7,583 compounds that showed greater than 22% CPE inhibition in the primary screen. The top 2,500 compounds were selected for confirmation screening and 409 compounds showed at least 50% inhibition of CPE and were considered active. We selected fifty-one compounds, based on potency, selectivity and chemical tractability, for further evaluation in dose response and secondary assays Several compounds had SI50 values greater than 3, while the most active compound displayed an SI50 value of 58.9.
Conclusions:
A robust automated luminescent-based high throughput screen that measures the inhibition of hRSV-induced cytopathic effect in HEp-2 cells for the rapid identification of potential inhibitors from large compound libraries has been developed, optimized and validated. The active compounds identified in the screen represent different classes of molecules, including aryl sulfonylpyrrolidines which have not been previously identified as having anti-hRSV activity
Recommended from our members
Impact of regular consumption of millets on fasting and post-prandial blood glucose level: a systematic review and meta-analysis
Millets have a low Glycemic Index and are thus expected to help reduce
concentration of Fasting and Post-Prandial Blood Sugar (FBS and PPBS) and
glycated hemoglobin (HbA1c), which can potentially help the management
of type 2 diabetes. This study conducts a systematic review and meta-analysis of the effects of millets consumption on FBS, PPBS, and HbA1c levels
in comparison to major staple diets using the difference-in-differences
(DID) method, where the effect size was computed on the Standardized
Mean Difference scale. Among twelve eligible articles, ten were used in the
meta-analysis to assess the effects on FBS levels, while five were used to
assess the effects on PPBS levels. The results show significant effects on FBS
(p <  0.01) and PPBS (p <  0.05) levels with the effect size of −0.71 and −0.42,
respectively. There were 11.8% (p =  0.001) and 15.1% (p =  0.012) reductions
in FBS and PPBS level respectively observed in the millet consuming group
whereas the comparator group did not have significant reductions in either
indicator. On the other hand, the effects on HbA1c levels were insignificant,
presumably due to the small sample size where only two studies were
undertaken over 90 days, which warrants further research. The findings
corroborate the evidence that millets can contribute to managing FBS and
PPBS levels better than major staple diets, implying that millets consumption
helps reduce the risk of type 2 diabete
(S)-N-(2,5-Dimethylphenyl)-1-(quinoline-8-ylsulfonyl)pyrrolidine-2-carboxamide as a Small Molecule Inhibitor Probe for the Study of Respiratory Syncytial Virus Infection
A high-throughput, cell-based screen was used to identify chemotypes as inhibitors for human respiratory syncytial virus (hRSV). Optimization of a sulfonylpyrrolidine scaffold resulted in compound 5o that inhibited a virus-induced cytopathic effect in the entry stage of infection (EC50 = 2.3 ± 0.8 µM) with marginal cytotoxicity (CC50 = 30.9 ± 1.1 µM) and reduced viral titer by 100-fold. Compared to ribavirin, sulfonylpyrrolidine 5o demonstrated an improved in vitro potency and selectivity index
Recommended from our members
Calcium from finger millet—a systematic review and meta-analysis on calcium retention, bone resorption, and in vitro bioavailability
Calcium deficiency during child growth leads to osteoporosis in later stages of life. Finger
millet is one of the calcium dense foods, with three times the level of calcium than milk, and
the only cereal that contains high calcium content which is consistent across different varieties
(364 � 58 mg/100 g). Thus, finger millet has potential for addressing calcium deficiency naturally.
This study aimed to determine the retention and impact of finger millet calcium on bone turnover
through a systematic review and meta-analysis. Three human studies were eligible for systematic
review. Of these, only two were eligible for meta-analysis to assess the retention of calcium in
children of 9 to 12 years. One study on bone turnover markers was not used in the meta-analysis
as at least two studies are required to conduct meta-analysis. Due to the lack of complete data
only four studies were eligible for meta-analysis to assess the in vitro bioavailability of calcium
from unprocessed and a range of different types of processed finger millet. The result shows that
there was significant retention (p < 0.05) of 23.4 � 2.9% calcium from finger-millet-based diet which
could help bone accretion during child growth if finger-millet-based diet is consumed. The bone
turnover marker study shows that the resorption of calcium reduced by 28% and 47% among peri
and post-menopausal women respectively after feeding the nutria mixed grain ball. However, there
is no significant change in bone formation marker. Depending on the type of processing, calcium
bioavailability either increased or decreased. One in vitro study showed that calcium bioavailability
from finger millet was 28.6% when boiled, whereas three studies on processing show that certain
processing can double the calcium bioavailability to 61.4%. Irrespective of the type of processing,
finger millets contribute to high calcium retention and extremely high bioavailable calcium and could
be useful for healthy growth and in dealing with complications related to calcium deficiency
A systematic review and meta-analysis of the potential of millets for managing and reducing the risk of developing diabetes mellitus
Millets (including sorghum) are known to be highly nutritious besides having a low carbon footprint and the ability to survive in high temperatures with minimal water. Millets are widely recognised as having a low Glycaemic Index (GI) helping to manage diabetes. This systematic review and meta-analyzes across the different types of millets and different forms of processing/cooking collated all evidences. Of the 65 studies that were collected globally, 39 studies with 111 observations were used to analyze GI outcomes and 56 studies were used to analyze fasting, post-prandial glucose level, insulin index and HbA1c outcomes in a meta-analysis. It is evident from the descriptive statistics that the mean GI of millets is 52.7 ± 10.3, which is about 36% lower than in typical staples of milled rice (71.7 ± 14.4) and refined wheat (74.2 ± 14.9). The descriptive, meta and regression analyses revealed that Job's tears, fonio, foxtail, barnyard, and teff were the millets with low mean GI (69). A meta-analysis also showed that all millets had significantly (p < 0.01) lower GI than white rice, refined wheat, standard glucose or white wheat bread except little millet which had inconsistent data. Long term millet consumption lowered fasting and post-prandial blood glucose levels significantly (p < 0.01) by 12 and 15%, respectively, in diabetic subjects. There was a significant reduction in HbA1c level (from 6.65 ± 0.4 to 5.67 ± 0.4%) among pre-diabetic individuals (p < 0.01) who consumed millets for a long period. Minimally processed millets were 30% more effective in lowering GI of a meal compared to milled rice and refined wheat. In conclusion, millets can be beneficial in managing and reducing the risk of developing diabetes and could therefore be used to design appropriate meals for diabetic and pre-diabetic subjects as well as for non-diabetic people for a preventive approach
Millets can have a major impact on improving iron status, hemoglobin level, and in reducing iron deficiency anemia– a systematic review and meta-analysis
The prevalence of iron deficiency anemia is highest among low and middle-income countries. Millets, including sorghum, are a traditional staple in many of these countries and are known to be rich in iron. However, a wide variation in the iron composition of millets has been reported, which needs to be understood in consonance with its bioavailability and roles in reducing anemia. This systematic review and meta-analysis were carried out to analyze the scientific evidence on the bioavailability of iron in different types of millets, processing, and the impact of millet-based food on iron status and anemia. The results indicated that iron levels in the millets used to study iron bioavailability (both in vivo and in vitro) and efficacy varied with the type and variety from 2 mg/100 g to 8 mg/100 g. However, not all the efficacy studies indicated the iron levels in the millets. There were 30 research studies, including 22 human interventions and 8 in vitro studies, included in the meta-analysis which all discussed various outcomes such as hemoglobin level, serum ferritin level, and absorbed iron. The studies included finger millet, pearl millet, teff and sorghum, or a mixture of millets. The results of 19 studies conducted on anaemic individuals showed that there was a significant (p < 0.01) increase in hemoglobin levels by 13.2% following regular consumption (21 days to 4.5 years) of millets either as a meal or drink compared with regular diets where there was only 2.7% increase. Seven studies on adolescents showed increases in hemoglobin levels from 10.8 ± 1.4 (moderate anemia) to 12.2 ± 1.5 g/dl (normal). Two studies conducted on humans demonstrated that consumption of a pearl millet-based meal significantly increased the bioavailable iron (p < 0.01), with the percentage of bioavailability being 7.5 ± 1.6, and provided bioavailable iron of 1 ± 0.4 mg. Four studies conducted on humans showed significant increases in ferritin level (p < 0.05) up to 54.7%. Eight in-vitro studies showed that traditional processing methods such as fermentation and germination can improve bioavailable iron significantly (p < 0.01) by 3.4 and 2.2 times and contributed to 143 and 95% of the physiological requirement of women, respectively. Overall, this study showed that millets can reduce iron deficiency anemia
Can feeding a millet-based diet improve the growth of children?—A systematic review and meta-analysis
Undernutrition, such as stunting and underweight, is a major public health concern, which
requires multi-sectoral attention. Diet plays a key role in growth and should optimally supply all
required nutrients to support the growth. While millets (defined broadly to include sorghum) are
traditional foods, and climate smart nutritious crops, which are grown across Africa and Asia, they
have not been mainstreamed like rice, wheat, and maize. Diversifying staples with millets can
potentially provide more macro and micro nutrients, compared to the mainstream crops. However,
there is little known scientific evidence to prove millets’ efficacy on growth. Therefore, a systematic
review and meta-analysis was conducted to collate evidence of the benefits of millets in improving
the growth of children. Eight eligible randomized feeding trials were included in the meta-analysis.
Results from the randomized effect model showed a significant effect (p < 0.05) of millet-based diets
on mean height (+28.2%) (n = 8), weight (n = 9) (+26%), mid upper arm circumference (n = 5) (+39%)
and chest circumference (n = 5) (+37%) in comparison to regular rice-based diets over for the period of
3 months to 4.5 years, which was based on largely substituting rice with millets. When an enhanced
and diverse diet was served, replacing rice with millet had only minimal growth improvement on
chest circumference (p < 0.05). The quality assessment using GRADE shows that the evidence used
for this systematic review and meta-analysis had moderate quality, based on eight scoring criteria.
These results demonstrate the value of adding millet as the staple for undernourished communities.
Further understanding of the efficacy of millets on growth in a wider range of diets is important
to develop appropriate dietary programs and improve the nutritional status of various age groups
across Africa and Asia
Recommended from our members
Does millet consumption contribute to raising blood hemoglobin levels compared to regular refined staples?: a systematic review and meta-analysis
Millets are recognized for their health and nutritional values, and the United Nations declared 2023 the International Year of Millets. Among the several health and nutritional benefits of millets, their impact on hemoglobin concentration is important since anemia is a major public health issue in many countries. To investigate the effect of millet (including sorghum) consumption on hemoglobin concentration in the blood, a systematic review and meta-analysis were conducted. Thirteen published studies featuring randomized control trials involving 590 individuals in the intervention group and 549 control individuals were eligible for the meta-analysis. The difference-in-differences analysis revealed highly significant (  < 0.01) positive effects of millet consumption on hemoglobin concentration, with an effect size of +0.68 standardized mean difference units. The change in hemoglobin concentration observed in the intervention group was +13.6%, which is statistically significant (  < 0.0005), compared to that in the control group, which was +4.8% and not statistically significant (  = 0.1362). In four studies, the consumption of millets in the intervention group demonstrated a change from mild anemia to normal status among children, whereas there was no change in the control group. The findings provide evidence that the consumption of millets can improve blood hemoglobin concentration, likely resulting from increased iron intake. Further research is needed involving the assessment of iron content and bioavailability to better understand the effect variation among millet types and the mechanisms involved