Navigating the B vitamins: Dietary diversity, microbial synthesis, and human health

B vitamins are intricately involved in various physiological processes vital for health. Their significance is complicated by the heterogeneous landscape of B vitamin distribution in diets and the contributions of the gut microbiota. Here, we delve into the impact of these factors on B vitamins and introduce strategies, with a focus on microbiota-based therapeutic options, to enhance their availability for improved well-being. Additionally, we provide an ecological and evolutionary perspective on the importance of B vitamins to human-microbiota interactions. In the dynamic realms of nutrition and microbiome science, these essential micronutrients continue to play a fundamental role in our understanding of disease development.

Genetic susceptibility of postmenopausal osteoporosis on sulfide quinone reductase-like gene

Postmenopausal osteoporosis is a major health problem with important genetic factors in postmenopausal women. We explored the relationship between SQRDL and osteoporosis in a cohort of 1006 patients and 2027 controls from Han Chinese postmenopausal women. Our evidence supported the significant role of SQRDL in the etiology of postmenopausal osteoporosis.

INTRODUCTION

Postmenopausal osteoporosis (PMOP) is a metabolic bone disease leading to progressive bone loss and the deterioration of the bone microarchitecture. The sulfide-quinone reductase-like protein is an important enzyme regulating the cellular hydrogen sulfide levels, and it can regulate bone metabolism balance in postmenopausal women. In this study, we aimed to investigate whether SQRDL is associated with susceptibility to PMOP in the Han Chinese population.

METHODS

A total of 3033 postmenopausal women, comprised of 1006 cases and 2027 controls, were recruited in the study. Twenty-two SNPs were selected for genotyping to evaluate the association of SQRDL gene with BMD and PMOP. Association analyses in both single marker and haplotype levels were performed for PMOP. Bone mineral density (BMD) was also utilized as a quantitative phenotype in further analyses. Bioinformatics tools were applied to predict the functional consequences of targeted polymorphisms in SQRDL.

RESULTS

The SNP rs1044032 (P = 6.42 × 10^-5, OR = 0.80) was identified as significantly associated with PMOP. Three SNPs (rs1044032, rs2028589, and rs12913151) were found to be significantly associated with BMD. Although limited functional significance can be obtained for these polymorphisms, significant hits for association with PMOP were found. Moreover, further association analyses with BMD identified three SNPs with significantly independent effects.

CONCLUSIONS

Our evidence supported the significant role of SQRDL in the etiology of PMOP and suggest that it may be a genetic risk factor for BMD and osteoporosis in Han Chinese postmenopausal women.

Expression profiles and associations of muscle regulatory factor (MRF) genes with growth traits in Tibetan chickens

1. Muscle regulatory factors (MRFs), including Myf5, Myf6 (MRF4/herculin), MyoD and MyoG (myogenin), play pivotal roles in muscle growth and development. Therefore, they are considered as candidate genes for meat production traits in livestock and poultry. 2. The objective of this study was to investigate the expression profiles of these genes in skeletal muscles (breast muscle and thigh muscle) at 5 developmental stages (0, 81, 119, 154 and 210 d old) of Tibetan chickens. Relationships between expressions of these genes and growth and carcass traits in these chickens were also estimated. 3. The expression profiles showed that in the breast muscle of both genders the mRNA levels of MRF genes were highest on the day of hatching, then declined significantly from d 0 to d 81, and fluctuated in a certain range from d 81 to d 210. However, the expression of Myf5, Myf6 and MyoG reached peaks in the thigh muscle in 118-d-old females and for MyoD in 154-d-old females, whereas the mRNA amounts of MRF genes in the male thigh muscle were in a narrow range from d 0 to d 210. 4. Correlation analysis suggested that gender had an influence on the relationships of MRF gene expression with growth traits. The RNA levels of MyoD, Myf5 genes in male breast muscle were positively related with several growth traits of Tibetan chickens (P < 0.05). No correlation was found between expressions of MRF genes and carcass traits of the chickens. 5. These results will provide a base for functional studies of MRF genes on growth and development of Tibetan chickens, as well as selective breeding and resource exploration.

Curcumin acts via transient receptor potential vanilloid-1 receptors to inhibit gut nociception and reverses visceral hyperalgesia

BACKGROUND

An antinociceptive effect has been reported for curcumin in animal models and in humans, but the molecular mechanisms of curcumin's effect remain undefined. In this study, we explored the possibility that curcumin inhibit visceral nociception via antagonizing the transient receptor potential vanilloid-1 (TRPV1) receptor.

METHODS

The effects of curcumin were explored using two experimental models: viscero-motor response (VMR) to colorectal distension (CRD) in rats and jejunal afferent firing in the ex vivo mouse jejunum preparations [TRPV1 knockout (KO) and wild-type mice, naive and trinitrobenzene sulfonic acid (TNBS)-treated Kunming mice]. In addition, capsaicin-induced calcium transients and whole-cell currents were examined in acutely dissociated dorsal root ganglia (DRG) neurons.

KEY RESULTS

In the anesthetized rat, curcumin (4 mg kg(-1)  min(-1) for 3 min) caused a marked and rapidly reversible inhibition of CRD-induced VMRs. In the mouse jejunum, the mesenteric afferent nerve response to ramp distension was attenuated by curcumin (3, 10 μmol L(-1) ), an effect that was significantly reduced in TRPV1 KO mice compared with wild-type (WT) controls. Moreover, in WT mice, curcumin (1-30 μmol L(-1) ) was found to inhibit the afferent responses to capsaicin in a concentration-dependent manner. Trinitrobenzene sulfonic acid-induced hypersensitivity of jejunal afferents was also attenuated by curcumin. Curcumin potently inhibited capsaicin-induced rise in intracellular calcium and inward currents in mouse or rat DRG neurons.

CONCLUSIONS & INFERENCES

Our results provide strong evidence that curcumin inhibit visceral nociception via antagonizing TRPV1 and may be a promising lead for the treatment of functional gastrointestinal diseases.

Prioritised research agenda for prevention and control of chronic respiratory diseases

The 2008-2013 World Health Organization (WHO) action plan on noncommunicable diseases (NCDs) includes chronic respiratory diseases as one of its four priorities. Major chronic respiratory diseases (CRDs) include asthma and rhinitis, chronic obstructive pulmonary disease, occupational lung diseases, sleep-disordered breathing, pulmonary hypertension, bronchiectiasis and pulmonary interstitial diseases. A billion people suffer from chronic respiratory diseases, the majority being in developing countries. CRDs have major adverse effects on the life and disability of patients. Effective intervention plans can prevent and control CRDs, thus reducing morbidity and mortality. A prioritised research agenda should encapsulate all of these considerations in the frame of the global fight against NCDs. This requires both CRD-targeted interventions and transverse NCD programmes which include CRDs, with emphasis on health promotion and disease prevention.

IEX-1 targets mitochondrial F1Fo-ATPase inhibitor for degradation

IEX-1 (Immediate Early response gene X-1) is a stress-inducible gene. It suppresses production of reactive oxygen species (ROS) and protects cells from apoptosis induced by a wide range of stimuli, but the underlying mechanism is not known. This study reveals that IEX-1 targets the mitochondrial F1Fo-ATPase Inhibitor (IF1) for degradation, resulting in acceleration of ATP hydrolysis, concomitant with reduction in ROS production. A prominent role for IF1 degradation in the function of IEX-1 was corroborated by siRNA-mediated gene silencing of IF1 that recapitulated the effects of IEX-1 on ATP hydrolysis and ROS production. Moreover, progressive C-terminal truncation studies demonstrated that IEX-1 interacted with the C terminus of IF1 and the interaction might render IF1 prone to degradation by an as yet unidentified mitochondrial protease. In support of a physiological importance of IEX-1 in the modulation of IF1 expression, gene-targeted deletion of IEX-1 stabilized IF1 and reduced mitochondrial F1Fo-ATPase activity in vivo. The altered activity of the F1Fo enzyme may account for a metabolic switch from oxidative phosphorylation toward glycolysis in IEX-1 deficient cells. Thus, IEX-1 deficient cells were more susceptible to glucose deprivation than wild type counterparts and displayed increased glucose uptake and lactate production in hypoxic conditions. The cells were also relatively refractory to oligomycin-mediated inhibition of ATP production. The studies offer novel insights into the primary role of IEX-1 in regulating a balance between energy provision and ROS production.

Sorption and desorption of radiocesium on red earth and its solid components: relative contribution and hysteresis

The relative contributions of organic matter and iron oxides to the Cs+ sorption on red earth were investigated by using the batch technique and selective extraction methods. The sorption and desorption isotherms and the distribution coefficients of Cs+ on the untreated red earth and the three treated soils to remove organic matter, iron oxides and organic matter plus iron oxides were determined at 20 degrees C, pH 6.3+/-0.2, in the presence of 0.01 mol/l CaCl2. It was found that all the isotherms are linear in the Cs+ concentration range used here, that the sorption desorption hysteresis on the red earth actually occurs, and besides the clay minerals, the organic matter present in the red earth is a significant trap of Cs+ and is responsible for the hysteresis instead of the iron oxides.

Nonsteroidal progesterone receptor antagonists based on 6-thiophenehydroquinolines

Synthesis and biological evaluation of 6-thiophene 1,2-dihydro or 1,2,3,4-tetrahydroquinoline derivatives resulted in a number of potent nonsteroidal antiprogestins.

5-Aryl-1,2,3,4-tetrahydrochromeno[3,4-f]quinolin-3-ones as a novel class of nonsteroidal progesterone receptor agonists: effect of A-ring modification

Optimization of the 1,2-dihydroquinoline A-ring of a nonsteroidal human progesterone receptor (hPR) agonist pharmacophore (1) was performed by using the cotransfection and receptor binding assays as guides. The 3-keto group was discovered to regain the potent agonist activity which was lost upon removal of the 3,4-olefin, and it led to a novel hPR agonist series, 5-aryl-1,2,3,4-tetrahydrochromeno[3, 4-f]quinolin-3-ones. The new progestins demonstrated potent hPR agonist activity in the cotransfection assay and high binding affinity similar to progesterone. T47D human breast cancer cell line was employed for further characterization of the new progestins and a number of reference analogues. It was found that the new 3-keto analogues showed full agonist activity in the T47D assay, while the reference compounds from other related nonsteroidal hPR agonist series exhibited only partial agonist activity.

Switching androgen receptor antagonists to agonists by modifying C-ring substituents on piperidino[3,2-g]quinolinone

New nonsteroidal human androgen receptor (hAR) agonists were developed from an hAR antagonist pharmacophore, 2(1H)-piperidino[3,2-g]quinolinone. (+/-)-trans-7,8-Diethyl-4-trifluoromethyl-2(H)-piperidino-[3,2-g]quinoli none was synthesized and demonstrated potent hAR agonist activity (EC50=3 nM) in the cell-based cotransfection assay and high binding affinity (Ki=16 nM) in the competitive receptor binding assay.

Nonsteroidal androgen receptor agonists based on 4-(trifluoromethyl)-2H-pyrano[3,2-g]quinolin-2-one

A series of 2H-pyrano[3,2-g]quinolin-2-ones was prepared and tested for the ability to modulate the transcriptional activity of the human androgen receptor (hAR). The parent compound, 4-(trifluoromethyl)-2H-pyrano[3,2-g]quinolin-2-one, displayed moderate interaction with hAR, but substituted analogues were potent hAR modulators in vitro as measured by an hAR cotransfection assay in CV-1 cells and bound to hAR with high affinity in a whole cell assay. Several analogues were able to activate hAR-mediated gene transcription more potently and efficaciously than dihydrotestosterone.

5-Alkyl 1,2-dihydrochromeno[3,4-f]quinolines: a novel class of nonsteroidal progesterone receptor modulators

A series of nonsteroidal human progesterone receptor (hPR) agonists, 5-alkyl 1,2-dihydrochromeno[3,4-f]quinolines, was synthesized and evaluated in cotransfection and competitive receptor binding assays. The 5-alkyl substitution was shown to be responsible for the agonist activity and substitution at C9 dramatically enhanced the potency. A number of analogues in this series showed activities similar to or better than progesterone in the cotransfection and binding assays and analogue 15 exhibited similar in vivo activity as medroxyprogesterone acetate (MPA) in murine uterine wet weight/mammary gland morphology assays.

5-Benzylidene 1,2-dihydrochromeno[3,4-f]quinolines, a novel class of nonsteroidal human progesterone receptor agonists

A novel series of nonsteroidal progestins, 5-benzylidene-1, 2-dihydrochromeno[3,4-f]quinolines (2), was discovered, and a preliminary structure-activity relationship study around the 5-benzylidene ring generated several potent human progesterone receptor agonists (compounds 8, 16). These new progestins showed biological activities (EC50 = 5.7 and 7.6 nM) similar to progesterone (EC50 = 2.9 nM) in the cotransfection assay with high efficacy (132% and 166%) and binding affinity (Ki = 0.66 and 0.83 nM) similar to medroxyprogesterone acetate (MPA) (Ki = 0.34 nM). A representative analogue, 8, demonstrated similar oral potency to MPA in the uterine wet weight/mammary gland morphology assay in ovariectomized rats.

Nonsteroidal progesterone receptor antagonists based on a conformationally-restricted subseries of 6-aryl-1,2-dihydro-2,2,4-trimethylquinolines

A series of nonsteroidal human progesterone receptor (hPR) antagonists based on conformationally-restricted analogues of a 6-aryl-1,2-dihydro-2,2,4-trimethylquinoline pharmacophore were synthesized and evaluated for their ability to bind to the human progesterone receptor and inhibit progesterone-stimulated reporter gene expression in mammalian cells.

Preparation, resolution, and biological evaluation of 5-aryl-1, 2-dihydro-5H-chromeno[3,4-f]quinolines: potent, orally active, nonsteroidal progesterone receptor agonists

Two potent nonsteroidal progestins from the 5-aryl-1, 2-dihydro-5H-chromeno[3,4-f]quinoline class (LG120746 and LG120747) were selected for scale-up, resolution, and biological evaluation of the purified enantiomers. For each quinoline, the levorotatory enantiomer was determined to be the more potent agonist of the human progesterone receptor isoform B (hPR-B) (EC50 < 3 nM), but the dextrorotatory enantiomers retained significant PR modulatory activity (EC50 < 200 nM). In two in vivo rodent models of progestational activity, a pregnancy maintenance assay and a uterine wet weight assay, the two eutomers displayed potent progesterone-like effects. In a third model for progestational activity, the mammary end bud assay, these compounds were significantly less active. These studies demonstrate that certain members of this class of selective progesterone receptor modulators display encouraging and potentially useful tissue-selective progestational effects.

Synthesis and biological activity of a novel series of nonsteroidal, peripherally selective androgen receptor antagonists derived from 1,2-dihydropyridono[5,6-g]quinolines

A new nonsteroidal antiandrogenic pharmacophore has been discovered using cell-based cotransfection assays with human androgen receptor (hAR). This series of AR antagonists is structurally characterized by a linear tricyclic 1,2-dihydropyridono[5,6-g]quinoline core. Analogues inhibit AR-mediated reporter gene expression and bind to AR as potently as or better than any known AR antagonists. Several analogues also showed excellent in vivo activity in classic rodent models of AR antagonism, inhibiting growth of rat ventral prostate and seminal vesicles, without accompanying increases in serum gonadotropin and testosterone levels, as is seen with other AR antagonists. Investigations of structure-activity relationships surrounding this pharmacophore resulted in molecules with complete specificity for AR, antagonist activity on an AR mutant commonly observed in prostate cancer patients, and improved in vivo efficacy. Molecules based on this series of compounds have the potential to provide unique and effective clinical opportunities for treatment of prostate cancer and other androgen-dependent diseases.

5-Aryl-1,2-dihydrochromeno[3,4-f]quinolines: a novel class of nonsteroidal human progesterone receptor agonists

The development of a novel class of nonsteroidal human progesterone receptor (hPR) agonists, 5-aryl-1,2-dihydro-5H-chromeno[3,4-f]quinolines 2, is described. The introduction of a 5-aryl group into the 1,2-dihydrocoumarino[3,4-f]quinoline core 1 is the key for progestational activities. The structure-activity relationship (SAR) studies of the 5-aryl substituents generated a series of potent hPR agonists, which exhibited similar biological activity (EC50 = 8-30 nM) to the natural hormone progesterone (EC50 = 2.9 nM) in cell-based assays with efficacies ranging from 28% to 96%. Most of the analogues displayed similar or greater binding affinity (Ki = 0.41-3.6 nM) than progesterone (Ki = 3.5 nM). Three representative analogues (13, 15, and 24) demonstrated in vivo activities in mammary gland morphology/uterine wet weight assay in ovariectomized rats.

Genomic differentiation among natural populations of orang-utan (Pongo pygmaeus)

BACKGROUND

Orang-utans exist today in small isolated populations on the islands of Borneo (subspecies Pongo pygmaeus pygmaeus) and Sumatra (subspecies P. p. abelii). Although, on the basis of their morphological, behavioral and cytogenetical characteristics, the Bornean and Sumatran orang-utan populations are generally considered as two separate subspecies, there is no universal agreement as to whether their genetic differentiation is sufficient to consider and manage them as species, subspecies or population level taxonomic units. A more precise phylogenetic description would affect many conservation management decisions about captive and free-ranging orang-utans.

RESULTS

We analyzed the amount and patterns of molecular genetic variation in orang-utan populations using cellular DNA from orang-utans from two locations in Sumatra and nine locations-representing four isolated populations-in Borneo. Genetic and phylogenetic analyses of mitochondrial DNA restriction fragment length polymorphisms, nuclear minisatellite (or variable number tandem repeat) loci and mitochondrial 16S ribosomal RNA sequences led to three major findings. First, the genetic distance and phylogenetic differentiation between Sumatran and Bornean orang-utans is large, greater than that between the common chimpanzee, Pan troglodytes, and the pygmy chimpanzee or bonobo, Pan paniscus. The genetic distance suggests that the two island subspecies diverged approximately 1.5-1.7 million years ago, well before the two islands separated and long enough for species-level differentiation. Second, there is considerable endemic genetic diversity within the Bornean and Sumatran orang-utan populations, suggesting that they have not experienced recent bottlenecks or founder effects. And third, there is little genetic differentiation among four geographically isolated populations of Bornean orang-utans, consistent with gene flow having occurred between them until recently.

CONCLUSIONS

Our results are consistent with the view that the genetic differentiation between Sumatran and Bornean orang-utans has reached the level of distinct species. Furthermore, our findings indicate that there is not a genetic imperative for the separate management of geographically isolated Bornean populations.

Design and synthesis of potent retinoid X receptor selective ligands that induce apoptosis in leukemia cells

Structural modifications of the retinoid X receptor (RXR) selective compound 4-[1-(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydro-2- naphthyl)ethenyl]benzoic acid (LGD1069), which is currently in phase I/IIA clinical trials for cancer and dermatological indications, have resulted in the identification of increasingly potent retinoids with > 1000-fold selectivity for the RXRs. This paper describes the design and preparation of a series of RXR selective retinoids as well as the biological data obtained from cotransfection and competitive binding assays which were used to evaluate their potency and selectivity. The most potent and selective of the analogs is 6-[1-(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalen-2- yl)cyclopropyl]nicotinic acid (12d; LG100268). This compound has proven useful for investigating RXR dependent biological pathways including the induction of programmed cell death (PCD) and transglutaminase (TGase) activity. Our studies indicate that the induction of PCD and TGase in human leukemic myeloid cells is dependent upon activation of RXR-mediated pathways.