Salivary transforming growth factor beta in oral submucous fibrosis: A diagnostic and predictive marker.

CONTEXT: Growth factors and cytokines like transforming growth factor beta (TGF-ß) play a key role in the pathogenesis of oral submucous fibrosis. AIMS: To elucidate the role of Salivary TGF-ß isoforms as a predictive and diagnostic marker for oral submucous fibrosis. SETTINGS AND DESIGN: A total of 30 OSMF and 10 control patients were included in this study, and their clinic-epidemiological data was recorded. METHODOLOGY: The expression of TGF-ß genes-TGF-ß1, TGF-ß2, TGF-ß3-was studied by a real-time polymerase chain reaction in tissue and saliva. Patients were given medicinal intervention for 12 weeks along with jaw-opening exercises. Expression of salivary TGF-ß genes was studied at 12 weeks. STATISTICAL ANALYSIS USED: SPSS software version 20. RESULT: Expression of salivary TGF beta isoforms in OSMF was more than in the control group. There was an increase in salivary TGF-ß1, ß2, ß3 expressions with increasing clinical grades of OSMF and advancing the stage of the disease. Expression of all the TGF beta isoforms was decreased after treatment with statistically significant results. Statistically significant correlations were found between the mean difference of TGF-ß1 and the mean difference between mouth opening and tongue protrusion. CONCLUSION: Salivary TGF-ß isoforms may be used in diagnosis, risk assessment, and screening of the entire population at risk of OSMF after its clinical validation. However, adequate sample size and segmental assessment of the expression of TGF-ß isoforms are needed for further evaluation.

Exposure assessment of children to dietary mycotoxins: A pilot study conducted in Ribeirão Preto, São Paulo, Brazil.

Exposure to mycotoxins through food is a major health concern, especially for youngsters. This study performed a preliminary investigation on children's exposure to dietary mycotoxins in Ribeirão Preto, Brazil. Sampling procedures were conducted between August and December 2022, to collect foods (N = 213) available for consumption in the households of children (N = 67), including preschoolers (aged 3-6 years, n = 21), schoolers (aged 7-10 years, n = 15), and adolescents (aged 11-17 years, n = 31) cared in the Vila Lobato Community Social Medical Center of Ribeirão Preto. Ultra-performance liquid chromatography coupled to tandem mass spectrometry (UPLC-MS/MS) was used to determine concentrations of the mycotoxins in foods. Mycotoxins measured in all foods comprised aflatoxins (AFs), fumonisins (FBs), zearalenone (ZEN), T-2 toxin, deoxynivalenol (DON) and ochratoxin A (OTA). Higher incidence and levels were found for FBs, ZEN, and DON in several commonly consumed foods. Furthermore, 32.86 % foods had two to four quantifiable mycotoxins in various combinations. The mean estimated daily intake (EDI) values were lower than the tolerable daily intake (TDI) for AFs, FBs, and ZEN, but higher than the TDI (1.0 µg/kg bw/day) for DON, hence indicating a health risk for all children age groups. Preschoolers and adolescents were exposed to DON through wheat products (EDIs: 2.696 ± 7.372 and 1.484 ± 2.395 µg/kg body weight (bw)/day, respectively), while schoolers were exposed through wheat products (EDI: 1.595 ± 1.748 µg/kg bw/day) and rice (EDI: 1.391 ± 1.876 µg/kg bw/day). The results indicate that wheat-based foods and rice may be risky to children, implying the need for stringent measures to avoid DON contamination in these products.

Understanding nitrogen dynamics in the Brazilian beef industry: A comprehensive decadal analysis.

Brazil stands as a prominent beef producer and exporter, witnessing major transformations and expansions in its production chain over the past 20 years. These changes have prompted concerns regarding waste generation and environmental pressure. This study employs material flow analysis (MFA) to quantify nitrogen flows throughout the cattle slaughter process and subsequent beef consumption in Brazil, spanning from 2011 to 2021. The analysis encompasses co-production streams like leather, tallow, viscera, and blood. Nitrogen use efficiency (NUE) and the nitrogen cascade indicator (NCI) were used to evaluate efficiency and nitrogen accumulation in the production chain. Nitrogen inputs in the system increased by 8.47 %, while beef production rose by 7.29 %. In contrast, per capita beef consumption decreased by 1.29 kg, despite an overall consumption increase of 2.84 %, attributed to population growth in Brazil. Beef exports witnessed a notable surge of 86.03 %. Conversely, human excreta and food waste losses experienced increments of 10.88 % and 2.84 %, respectively. Examining NUE reveals the highest values during the slaughter phase (90 %), followed by processing, transportation, and storage stages (79-88 %). The consumption phase exhibited the lowest NUE values (29-34 %). Regarding the cumulative nitrogen effect, the NCI varied between 77 % and 82 % throughout the study period. This highlights opportunities for enhancing nitrogen use efficiency, particularly by addressing food waste at the consumer level. Notably, the study observes nitrogen accumulation across the Brazilian beef production chain, potentially contributing to the nitrogen cascade effect and heightening environmental pressure. Recognizing these dynamics provides avenues for targeted improvements, emphasizing the need to address nitrogen-related challenges and enhance sustainability in the beef production and consumption landscape.

Reactivity and Stability of (Hetero)Benzylic Alkenes via the Wittig Olefination Reaction.

Wittig olefination at hetero-benzylic positions for electron-deficient and electron-rich heterocycles has been studied. The electronic effects of some commonly used protective groups associated with the N-heterocycles were also investigated for alkenes obtained in the context of the widely employed Wittig olefination reaction. It was observed that hetero-benzylic positions of the pyridine, thiophene and furan derivatives were stable after Wittig olefination. Similarly, electron-withdrawing groups (EWGs) attached to N-heterocycles (indole and pyrrole derivatives) directly enhanced the stability of the benzylic position during and after Wittig olefination, resulting in the formation of stable alkenes. Conversely, electron-donating group (EDG)-associated N-heterocycles boosted the reactivity of benzylic alkene, leading to lower yields or decomposition of the olefination products.

Investigating the impact of sous vide cooking on the eating quality of spent buffalo (BUBALUS BUBALIS) meat.

This study describes the impact of sous vide cooking at different temperatures and time intervals on the eating quality, specifically tenderness of two muscles, bicep femoris (BF) and semitendinosus (ST) from spent buffalo (Bubalus bubalis). Spent buffalo refers to water buffalo that are no longer considered productive following a sixth lactation cycle. Steaks from each muscle were obtained and cooked at three combinations of time and temperature, namely 55 °C-8H, 65 °C-5H, and 95 °C-45 M, respectively. Warner-Bratzler Shear Force (WBSF), cooking loss, cooking yield, color, water activity (aw), total water content (TWC), total collagen content (TCC), heat soluble collagen (HSC), myofibrillar fragmentation index (MFI), and sensory evaluation were measured. The collagen solubilization results showed that temperature and time interacted (P ≤ 0.05), reducing the toughness of the muscles. The tenderization achieved through sous vide cooking was mainly attributed to the thermal denaturation of proteins at the typically lower temperatures and extended time used, weakening of connective tissue through collagen solubilization, and water retention. More cooking loss (P ≤ 0.05) was observed at high temperature treatment of 95 °C-45 M. Meat color, TWC, MFI, and overall acceptability exhibited differences among treatments (P ≤ 0.05). An extended heat interval at lower temperatures caused initial denaturation of myofibrillar proteins, then solubilization of connective tissue proteins. Cooking treatment 55 °C-8H (P ≤ 0.05) reduced the WBSF in both muscles; however, the ST appeared more tender than BF.

Impaired intracellular Ca2+ signaling contributes to age-related cerebral small vessel disease in Col4a1 mutant mice.

Humans and mice with mutations in COL4A1 and COL4A2 manifest hallmarks of cerebral small vessel disease (cSVD). Mice with a missense mutation in Col4a1 at amino acid 1344 (Col4a1+/G1344D) exhibit age-dependent intracerebral hemorrhages (ICHs) and brain lesions. Here, we report that this pathology was associated with the loss of myogenic vasoconstriction, an intrinsic vascular response essential for the autoregulation of cerebral blood flow. Electrophysiological analyses showed that the loss of myogenic constriction resulted from blunted pressure-induced smooth muscle cell (SMC) membrane depolarization. Furthermore, we found that dysregulation of membrane potential was associated with impaired Ca2+-dependent activation of large-conductance Ca2+-activated K+ (BK) and transient receptor potential melastatin 4 (TRPM4) cation channels linked to disruptions in sarcoplasmic reticulum (SR) Ca2+ signaling. Col4a1 mutations impair protein folding, which can cause SR stress. Treating Col4a1+/G1344D mice with 4-phenylbutyrate, a compound that promotes the trafficking of misfolded proteins and alleviates SR stress, restored SR Ca2+ signaling, maintained BK and TRPM4 channel activity, prevented loss of myogenic tone, and reduced ICHs. We conclude that alterations in SR Ca2+ handling that impair ion channel activity result in dysregulation of SMC membrane potential and loss of myogenic tone and contribute to age-related cSVD in Col4a1+/G1344D mice.

Bioaccessibility data of potentially toxic elements in complementary foods for infants: A review.

The introduction of complementary foods (CFs) is a critical step in an infant's transition to solid foods, providing essential nutrients beyond breast milk. However, CFs may contain potentially toxic elements (PTEs), such as arsenic and cadmium that pose health risks to infants. In this context, understanding the bioaccessibility of PTEs is vital as it determines the fraction of a contaminant released from the food matrix and available for absorption in the gastrointestinal tract. Efforts have been made to standardize the assessment methodology for bioaccessibility, ensuring consistent and reliable data. Moreover, regulatory agencies have established guidelines for PTEs levels in food. However, important gaps still exist, which motivates many research opportunities on this topic.

Efficacy of Two Commercially Available Adsorbents to Reduce the Combined Toxic Effects of Dietary Aflatoxins, Fumonisins, and Zearalenone and Their Residues in the Tissues of Weaned Pigs.

Mycotoxins present a significant health concern within the animal-feed industry, with profound implications for the pig-farming sector. The objective of this study was to evaluate the efficacy of two commercial adsorbents, an organically modified clinoptilolite (OMC) and a multicomponent mycotoxin detoxifying agent (MMDA), to ameliorate the combined adverse effects of dietary aflatoxins (AFs: sum of AFB1, AFB2, AFG1, and AFG2), fumonisins (FBs), and zearalenone (ZEN) at levels of nearly 0.5, 1.0, and 1.0 mg/kg, on a cohort of cross-bred female pigs (N = 24). Pigs were randomly allocated into six experimental groups (control, mycotoxins (MTX) alone, MTX + OMC 1.5 kg/ton, MTX + OMC 3.0 kg/ton, MTX + MMDA 1.5 kg/ton, and MTX + MMDA 3.0 kg/ton), each consisting of four individuals, and subjected to a dietary regimen spanning 42 days. The administration of combined AFs, FBs, and ZEN reduced the body-weight gain and increased the relative weight of the liver, while there was no negative influence observed on the serum biochemistry of animals. The supplementation of OMC and MMDA ameliorated the toxic effects, as observed in organ histology, and provided a notable reduction in residual AFs, FBs, and ZEN levels in the liver and kidneys. Moreover, the OMC supplementation was able to reduce the initiation of liver carcinogenesis without any hepatotoxic side effects. These findings demonstrate that the use of OMC and MMDA effectively mitigated the adverse effects of dietary AFs, FBs, and ZEN in piglets. Further studies should explore the long-term protective effects of the studied adsorbent supplementation to optimize mycotoxin management strategies in pig-farming operations.

Clay-Polymer Nanocomposites Mediated Inhibition of Protein Aggregation: Possible Role in the Prevention of Proteinopathies.

BACKGROUND: The transformation of proteins from their native conformation into highly ordered fibrillar structures due to their misfolding and aggregation under particular conditions are described as beta-sheet enriched amyloid fibrils. The accumulation of these fibrils in different body parts is the major cause of several neurological and non-neurological conditions (proteinopathies). OBJECTIVES: To prevent these proteinopathies, inhibition of protein aggregation is considered a promising strategy. Therefore, in this study, we synthesized montmorillonite (MMT) based poly- orthophenylenediamine (PoPD) nanocomposites (NCs) and characterized their size and morphology due to their remarkable biological properties. Further, the effect of these nanocomposites on inhibition of fibril formation was assessed. METHODS: These nanocomposites were evaluated for their anti-amyloidogenic potential on two model proteins of amyloidopathies, i.e., human lysozyme and human serum albumin (HL & HSA), by using several biophysical methods, such as Thioflavin T (ThT) and 1-anilino-8-naphthalene sulfonate (ANS) fluorescence, congo red dye binding assay (CR). Secondary structural content was evaluated by Circular dichroism (CD) spectroscopy. RESULTS: Results demonstrated that synthesized nanocomposites significantly inhibited fibril formation in dose-dependent manner that corresponds to their ability to arrest fibrillation. It is suggested that they may adsorb proteins to protect them against aggregation when they are subjected to aggregating conditions. CONCLUSION: This study offers an opportunity to understand the mechanism of inhibition of fibril formation by nanocomposites, showing that they inhibit amyloid formation and amyloid diseases. Thus, the study concludes that these nanocomposites are promising candidates as therapeutic molecules for proteinopathies and are envisaged to enrich the area of personalized medicine, augmenting the human healthcare system.

Palladium-Catalyzed Direct Selanylation of Chalcogenophenes and Arenes Assisted by 2-(Methylthio)amide.

The direct and selective conversion of a C-H bond into a C-Se bond remains a significant challenge, which is even more intricate with substrates having an innate regioselectivity under several reaction conditions, such as chalcogenophenes. We overrode their selectivity toward selanylation using palladium, copper, and the 2-(methylthio)amide directing group. This chelation-assisted direct selanylation was also suitable for mono and double ortho functionalization of arenes. The mechanistic studies indicate high-valent Pd(IV) species in the catalytic cycle, a reversible C-H activation step, and Cu(II) as a sequestering agent for organoselenide byproducts.

PI3K block restores age-dependent neurovascular coupling defects associated with cerebral small vessel disease.

Neurovascular coupling (NVC), a vital physiological process that rapidly and precisely directs localized blood flow to the most active regions of the brain, is accomplished in part by the vast network of cerebral capillaries acting as a sensory web capable of detecting increases in neuronal activity and orchestrating the dilation of upstream parenchymal arterioles. Here, we report a Col4a1 mutant mouse model of cerebral small vessel disease (cSVD) with age-dependent defects in capillary-to-arteriole dilation, functional hyperemia in the brain, and memory. The fundamental defect in aged mutant animals was the depletion of the minor membrane phospholipid phosphatidylinositol 4,5 bisphosphate (PIP2) in brain capillary endothelial cells, leading to the loss of inwardly rectifying K+ (Kir2.1) channel activity. Blocking phosphatidylinositol-3-kinase (PI3K), an enzyme that diminishes the bioavailability of PIP2 by converting it to phosphatidylinositol (3, 4, 5)-trisphosphate (PIP3), restored Kir2.1 channel activity, capillary-to-arteriole dilation, and functional hyperemia. In longitudinal studies, chronic PI3K inhibition also improved the memory function of aged Col4a1 mutant mice. Our data suggest that PI3K inhibition is a viable therapeutic strategy for treating defective NVC and cognitive impairment associated with cSVD.

Snodgrass Hypospadias Repair At Ayub Teaching Hospital: An Audit Of Complications And Outcomes.

BACKGROUND: There are many reported techniques for the repair of hypospadias, and new ones are being reported, which suggests that none is perfect. This study reports the anatomical success rate when using Snodgrass Technique. METHODS: In this descriptive case series, 296 patients who fulfilled the inclusion criteria, by being treated by Snodgrass urethroplasty, were enrolled. The study was conducted at the Department of Surgery, Unit-C, MTI, Ayub Teaching Hospital Abbottabad between May 2008 and June 2021. RESULTS: Mean age of the patients was 2.4±.8 years, 79.7% (n=236) had anterior (glanular, coronal, sub coronal) meatal location and 20.3 % (n=60) had middle urethral meatus (distal & mid-shaft). The mean operative time was 52 min. 5.1% of patients developed neo-meatal stenosis (n=15), 7.1% (n=21) patients develop a urethral cutaneous fistula (compared to 5% in larger centers, 16% from smaller centers), 11.8% (n=35) developed wound infection, 2% (n=6) had complete disruption. The cosmetic appearance of the penis was "excellent"/good (shape of meatus was slit-like and vertically oriented) in 60.1% (n=178) patients, "acceptable" in 30.1% (n=89), and "not acceptable" in 9.8% (n=29). CONCLUSIONS: Snodgrass technique has a low complication rate, offers an acceptable cosmetic outcome and can be successfully applied to a wide range of defects from distal to mid-shaft hypospadias. Common complications include urethral-cutaneous fistula and meatal stenosis; both occur in a low and acceptable number of patients.

Variation in the anti-oxidant, anti-obesity, and anti-cancer potential of different polarity extracts of saffron petals.

The aim of the present study is to explore the anti-cancer, anti-oxidant, and anti-obesity potential of saffron petal extract (SPE) prepared through the hydro-alcoholic extraction method. Further partitioning was done with a series of polar and non-polar solvents to find out the most potent fraction of SPE against HCC. Organoleptic characterization depicted the color, odor, taste, and texture of the sub-fractions of SPE. Phytochemical, and pharmacognostic screening of these fractions revealed the presence of alkaloids, flavonoids, carbohydrates, glycosides, and phenols. The quantitative assessment demonstrated that the n-butanol fraction showed maximum phenolic (60.8 mg GAE eq./mg EW), and flavonoid (23.3 mg kaempferol eq./mg EW) content. The anti-oxidant study revealed that the n-butanol fraction exhibited the highest radical scavenging activity, as assessed through DPPH and FRAP assay. The results of the comparative cytotoxic potential also showed n-butanol as the best against liver cancer cells (Huh-7), as it has the least IC50 value (462.8 µg/ml). While other extracts viz., chloroform, n-hexane, ethyl acetate, and aqueous fractions have IC50 values as 1088, 733.9, 1043, and 1245 µg/ml, respectively. Additionally, the n-butanol fraction exerted the highest inhibitory potential against α-amylase (92.5%) and pancreatic lipase enzymes (78%), indicating its anti-adipogenesis property. Based on the current finding, we can deduce that the n-butanol fraction of SPE has better cytotoxic, anti-oxidant, and anti-obesity potential than the other fractions. Supplementary Information: The online version contains supplementary material available at 10.1007/s13205-023-03669-x.

Shedding light on ORAI1 channel with genetic code expansion.

Genetic code expansion technology has been widely applied to control protein activity and biological systems by taking advantage of an amber stop codon suppressor tRNA and orthogonal aminoacyl-tRNA synthetase pair. With this chemical biology approach, Maltan et al. incorporated photocrosslinking unnatural amino acids (UAAs) into the transmembrane domains of ORAI1 to enable UV light-inducible calcium influx across the plasma membrane, mechanistic interrogation of the calcium release-activated calcium (CRAC) channel at the single amino acid level, and remote control of downstream calcium-modulated signaling in mammalian cells.

PI3K block restores age-dependent neurovascular coupling defects associated with cerebral small vessel disease.

Neurovascular coupling (NVC), a vital physiological process that rapidly and precisely directs localized blood flow to the most active regions of the brain, is accomplished in part by the vast network of cerebral capillaries acting as a sensory web capable of detecting increases in neuronal activity and orchestrating the dilation of upstream parenchymal arterioles. Here, we report a Col4a1 mutant mouse model of cerebral small vessel disease (cSVD) with age-dependent defects in capillary-to-arteriole dilation, functional hyperemia in the brain, and memory. The fundamental defect in aged mutant animals was the depletion of the minor membrane phospholipid phosphatidylinositol 4,5 bisphosphate (PIP 2 ) in brain capillary endothelial cells, leading to the loss of inwardly rectifier K + (Kir2.1) channel activity. Blocking phosphatidylinositol-3-kinase (PI3K), an enzyme that diminishes the bioavailability of PIP 2 by converting it to phosphatidylinositol (3,4,5)-trisphosphate (PIP 3 ), restored Kir2.1 channel activity, capillary-to-arteriole dilation, and functional hyperemia. In longitudinal studies, chronic PI3K inhibition also improved the memory function of aged Col4a1 mutant mice. Our data suggest that PI3K inhibition is a viable therapeutic strategy for treating defective NVC and cognitive impairment associated with cSVD. One-sentence summary: PI3K inhibition rescues neurovascular coupling defects in cerebral small vessel disease.

The potential role of the KFG and KITLG proteins in preventing granulosa cell apoptosis in Bubalus bubalis.

BACKGROUND: The dynamics of mammalian follicular development and atresia is an intricate process involving the cell-cell communication mediated by secreted ovarian factors. These interactions are critical for oocyte development and regulation of follicular atresia which in part are mediated by keratinocyte growth factor (KGF) and kit ligand (KITLG), but their roles in the regulation of apoptosis in buffalo granulosa cells have not yet been defined. During mammalian follicular development, granulosa cell apoptosis triggers the atresia so ~ 1% follicles reach the ovulation stage. In the present study, we used buffalo granulosa cells to examine the effects of KGF and KITLG in apoptosis regulation and investigated potential mechanism on Fas-FasL and Bcl-2 signaling pathways. RESULT: Isolated buffalo granulosa cells were cultured with KGF and KITLG proteins using different doses (0, 10, 20, and 50 ng/ml) independently or in combination. Expression analysis for both anti-apoptotic (Bcl-2, Bcl-xL, and cFLIP) and pro-apoptotic (Bax, Fas, and FasL) genes at transcriptional levels were carried out by real-time PCR. Upon treatments, expression levels of anti-apoptotic genes were significantly upregulated in a dose-dependent manner, showing an upregulation at 50 ng/ml (independently), and at 10 ng/ml in combination. Additionally, upregulation of growth-promoting factors, bFGF, and α-Inhibin was also observed. CONCLUSIONS: Our findings suggest the potential roles of KGF and KITLG in determining granulosa cell growth and regulating apoptosis.

Incidence and Levels of Aflatoxin M1 in Artisanal and Manufactured Cheese in Pernambuco State, Brazil.

Cheese is one of the most susceptible dairy foods to accumulating aflatoxins due to their high affinity to caseins. The consumption of cheese contaminated with high levels of aflatoxin M1 (AFM1) can be highly harmful to humans. The present work, based on high-performance liquid chromatography (HPLC), highlights the frequency and levels of AFM1 in coalho and mozzarella cheese samples (n = 28) from the main cheese-processing plants in Araripe Sertão and Agreste in the state of Pernambuco, Brazil. Of the evaluated cheeses, 14 samples were artisanal cheeses and the remaining 14 were industrial (manufactured) cheeses. All samples (100%) had detectable levels of AFM1, with concentrations ranging from 0.026 to 0.132 µg/kg. Higher levels (p < 0.05) of AFM1 were observed in artisanal mozzarella cheeses, but none of the cheese samples exceed the maximum permissible limits (MPLs) of 2.5 µg/kg established for AFM1 in cheese in Brazil and 0.25 µg/kg in the European countries by the European Union (EU). The high incidence of low levels of AFM1 found in the evaluated cheeses underscores the need for stringent control measures to prevent this mycotoxin in milk used for cheese production in the study area, with the aim of protecting public health and reducing significant economic losses for producers.

Brazilian soybeans as feed for livestock in Europe: an insight into the nitrogen flows.

Given the agricultural demand to supply animals with food, the scope of today's soybean production and international trade can influence the nitrogen cycle. Rather than using soybeans from within the region of animal production, animal producers import nutritional supplements from distant growers. This widely opens the biogeochemical cycle of nitrogen, which reduces local recycling and increases carriage of reactive nitrogen via the supply chain. Ultimately, this potentiates the effects of a "nitrogen cascade" process. This study estimates nitrogen flows for Brazilian soybean transported to feed European livestock and attempts to quantify the understanding of how this flow can impact the nitrogen cascade effect. The hypothesis is that the growing trade of Brazilian soybean products is sufficient to spike reactive nitrogen production that can potentially cause distant environmental impacts of the nitrogen cascade. In this respect, the estimation of the nitrogen flows was evaluated using material flow analysis, and the cascade effect was quantified by means of a nitrogen cascade indicator (NCI). Notably, NCI can calculate the released amount of nitrogen in the environment along the entire supply chain of livestock products. NCI-based evaluation of Brazilian soybean products consumed by European livestock indicated the accumulation of nitrogen levels. There was also an increase in nitrogen flows in the Brazilian phase (0.058 Gg in 2007 to 139.86 Gg in 2019 for soybean meal; 584.28 Gg in 2007 to 309.78 Gg in 2019 for soybeans) accompanying a stability in European livestock production. This highlights the necessity for adjustments in nitrogen circularity between all levels of food production and improved strategies of more localised feed autonomy for sustainable global development. Supplementary Information: The online version contains supplementary material available at 10.1007/s10113-023-02034-1.

Silver-catalyzed direct selanylation of indoles: synthesis and mechanistic insights.

Herein we describe the Ag(i)-catalyzed direct selanylation of indoles with diorganoyl diselenides. The reaction gave 3-selanylindoles with high regioselectivity and also allowed direct access to 2-selanylindoles when the C3 position of the indole ring was blocked via a process similar to Plancher rearrangement. Experimental analyses and density functional theory calculations were carried out in order to picture the reaction mechanism. Among the pathways considered (via concerted metalation-deprotonation, Ag(iii), radical, and electrophilic aromatic substitution), our findings support a classic electrophilic aromatic substitution via Lewis adducts between Ag(i) and diorganoyl diselenides. The results also afforded new insights into the interactions between Ag(i) and diorganoyl diselenides.

Faulty TRPM4 channels underlie age-dependent cerebral vascular dysfunction in Gould syndrome.

Gould syndrome is a rare multisystem disorder resulting from autosomal dominant mutations in the collagen-encoding genes COL4A1 and COL4A2. Human patients and Col4a1 mutant mice display brain pathology that typifies cerebral small vessel diseases (cSVDs), including white matter hyperintensities, dilated perivascular spaces, lacunar infarcts, microbleeds, and spontaneous intracerebral hemorrhage. The underlying pathogenic mechanisms are unknown. Using the Col4a1+/G394V mouse model, we found that vasoconstriction in response to internal pressure-the vascular myogenic response-is blunted in cerebral arteries from middle-aged (12 mo old) but not young adult (3 mo old) animals, revealing age-dependent cerebral vascular dysfunction. The defect in the myogenic response was associated with a significant decrease in depolarizing cation currents conducted by TRPM4 (transient receptor potential melastatin 4) channels in native cerebral artery smooth muscle cells (SMCs) isolated from mutant mice. The minor membrane phospholipid phosphatidylinositol 4,5 bisphosphate (PIP2) is necessary for TRPM4 activity. Dialyzing SMCs with PIP2 and selective blockade of phosphoinositide 3-kinase (PI3K), an enzyme that converts PIP2 to phosphatidylinositol (3, 4, 5)-trisphosphate (PIP3), restored TRPM4 currents. Acute inhibition of PI3K activity and blockade of transforming growth factor-beta (TGF-ß) receptors also rescued the myogenic response, suggesting that hyperactivity of TGF-ß signaling pathways stimulates PI3K to deplete PIP2 and impair TRPM4 channels. We conclude that age-related cerebral vascular dysfunction in Col4a1+/G394V mice is caused by the loss of depolarizing TRPM4 currents due to PIP2 depletion, revealing an age-dependent mechanism of cSVD.