Electron-Withdrawing meso-Substituents Turn On Magneto-Optical Activity in Porphyrins.

A series of square planar metalloporphyrins (M(TPP), TPP is 5,10,15,20-tetraphenylporphyrin and M(TPFPP), TPFPP is 5,10,15,20-tetrapentafluorophenylporphyrin; M is Zn2+, Ni2+, Pd2+, or Pt2+) with distinct meso-substituents were prepared, and their magneto-optical activity (MOA) was characterized by magnetic circular dichroism (MCD) and magneto-optical rotary dispersion spectroscopy (MORD; also known as Faraday rotation spectroscopy). MOA is crucial in the development of next-generation magneto-optical devices and quantum computing. The data show that the presence of meso-pentafluorophenyl substituents results in significant increase in MOA in comparison to the homologous phenyl group. Differences in the MOA of these metalloporphyrins are rationalized using the Gouterman four-orbital model and pave the way for rational design of improved and tailorable magneto-optical materials.

CNN-Based Facial Expression Recognition with Simultaneous Consideration of Inter-Class and Intra-Class Variations.

Facial expression recognition is crucial for understanding human emotions and nonverbal communication. With the growing prevalence of facial recognition technology and its various applications, accurate and efficient facial expression recognition has become a significant research area. However, most previous methods have focused on designing unique deep-learning architectures while overlooking the loss function. This study presents a new loss function that allows simultaneous consideration of inter- and intra-class variations to be applied to CNN architecture for facial expression recognition. More concretely, this loss function reduces the intra-class variations by minimizing the distances between the deep features and their corresponding class centers. It also increases the inter-class variations by maximizing the distances between deep features and their non-corresponding class centers, and the distances between different class centers. Numerical results from several benchmark facial expression databases, such as Cohn-Kanade Plus, Oulu-Casia, MMI, and FER2013, are provided to prove the capability of the proposed loss function compared with existing ones.

Mapping the influence of ligand electronics on the spectroscopic and 1O2 sensitization characteristics of Pd(II) biladiene complexes bearing phenyl-alkynyl groups at the 2- and 18-positions.

Photodynamic therapy (PDT) is a promising treatment for certain cancers that proceeds via sensitization of ground state 3O2 to generate reactive 1O2. Classic macrocyclic tetrapyrrole ligand scaffolds, such as porphyrins and phthalocyanines, have been studied in detail for their 1O2 photosensitization capabilities. Despite their compelling photophysics, these systems have been limited in PDT applications because of adverse biological side effects. Conversely, the development of non-traditional oligotetrapyrrole ligands metalated with palladium (Pd[DMBil1]) have established new candidates for PDT that display excellent biocompatibility. Herein, the synthesis, electrochemical, and photophysical characterization of a new family of 2,18-bis(phenylalkynyl)-substituted PdII 10,10-dimethyl-5,15-bis(pentafluorophenyl)-biladiene (Pd[DMBil2-R]) complexes is presented. These second generation biladienes feature extended conjugation relative to previously characterized PdII biladiene scaffolds (Pd[DMBil1]). We show that these new derivatives can be prepared in good yield and, that the electronic nature of the phenylalkynyl appendages dramatically influence the PdII biladiene photophysics. Extending the conjugation of the Pd[DMBil1] core through installation of phenylacetylene resulted in a ∼75 nm red-shift of the biladiene absorption spectrum into the phototherapeutic window (600-900 nm), while maintaining the PdII biladiene's steady-state spectroscopic 1O2 sensitization characteristics. Varying the electronics of the phenylalkyne groups via installation of electron donating or withdrawing groups dramatically influences the steady-state spectroscopic and photophysical properties of the resulting Pd[DMBil2-R] family of complexes. The most electron rich variants (Pd[DMBil2-N(CH3)2]) can absorb light as far red as ∼700 nm but suffer from significantly reduced ability to sensitize formation of 1O2. By contrast, Pd[DMBil2-R] derivatives bearing electron withdrawing functionalities (Pd[DMBil2-CN] and Pd[DMBil2-CF3]) display 1O2 quantum yields above 90%. The collection of results we report suggest that excited state charge transfer from more electron-rich phenyl-alkyne appendages to the electron deficient biladiene core circumvents triplet sensitization. The spectral and redox properties, as well as the triplet sensitization efficiency of each Pd[DMBil2-R] derivative is considered in relation to the Hammett value (σp) for each biladiene's R-group. More broadly, the results reported in this study clearly demonstrate that biladiene redox properties, spectral properties, and photophysics can be perturbed greatly by relatively minor alterations to biladiene structure.

Evogliptin, a DPP-4 inhibitor, prevents diabetic cardiomyopathy by alleviating cardiac lipotoxicity in db/db mice.

Dipeptidyl peptidase-4 (DPP-4) inhibitors are glucose-lowering drugs for type 2 diabetes mellitus (T2DM). We investigated whether evogliptin® (EVO), a DPP-4 inhibitor, could protect against diabetic cardiomyopathy (DCM) and the underlying mechanisms. Eight-week-old diabetic and obese db/db mice were administered EVO (100 mg/kg/day) daily by oral gavage for 12 weeks. db/db control mice and C57BLKS/J as wild-type (WT) mice received equal amounts of the vehicle. In addition to the hypoglycemic effect, we examined the improvement in cardiac contraction/relaxation ability, cardiac fibrosis, and myocardial hypertrophy by EVO treatment. To identify the mechanisms underlying the improvement in diabetic cardiomyopathy by EVO treatment, its effect on lipotoxicity and the mitochondrial damage caused by lipid droplet accumulation in the myocardium were analyzed. EVO lowered the blood glucose and HbA1c levels and improved insulin sensitivity but did not affect the body weight or blood lipid profile. Cardiac systolic/diastolic function, hypertrophy, and fibrosis were improved in the EVO-treated group. EVO prevented cardiac lipotoxicity by reducing the accumulation of lipid droplets in the myocardium through suppression of CD36, ACSL1, FABP3, PPARgamma, and DGAT1 and enhancement of the phosphorylation of FOXO1, indicating its inhibition. The EVO-mediated improvement in mitochondrial function and reduction in damage were achieved through activation of PGC1a/NRF1/TFAM, which activates mitochondrial biogenesis. RNA-seq results for the whole heart confirmed that EVO treatment mainly affected the differentially expressed genes (DEGs) related to lipid metabolism. Collectively, these findings demonstrate that EVO improves cardiac function by reducing lipotoxicity and mitochondrial injury and provides a potential therapeutic option for DCM.

A potential histone-chaperone activity for the MIER1 histone deacetylase complex.

Histone deacetylases 1 and 2 (HDAC1/2) serve as the catalytic subunit of six distinct families of nuclear complexes. These complexes repress gene transcription through removing acetyl groups from lysine residues in histone tails. In addition to the deacetylase subunit, these complexes typically contain transcription factor and/or chromatin binding activities. The MIER:HDAC complex has hitherto been poorly characterized. Here, we show that MIER1 unexpectedly co-purifies with an H2A:H2B histone dimer. We show that MIER1 is also able to bind a complete histone octamer. Intriguingly, we found that a larger MIER1:HDAC1:BAHD1:C1QBP complex additionally co-purifies with an intact nucleosome on which H3K27 is either di- or tri-methylated. Together this suggests that the MIER1 complex acts downstream of PRC2 to expand regions of repressed chromatin and could potentially deposit histone octamer onto nucleosome-depleted regions of DNA.

Echinochrome A Prevents Diabetic Nephropathy by Inhibiting the PKC-Iota Pathway and Enhancing Renal Mitochondrial Function in db/db Mice.

Echinochrome A (EchA) is a natural bioproduct extracted from sea urchins, and is an active component of the clinical drug, Histochrome®. EchA has antioxidant, anti-inflammatory, and antimicrobial effects. However, its effects on diabetic nephropathy (DN) remain poorly understood. In the present study, seven-week-old diabetic and obese db/db mice were injected with Histochrome (0.3 mL/kg/day; EchA equivalent of 3 mg/kg/day) intraperitoneally for 12 weeks, while db/db control mice and wild-type (WT) mice received an equal amount of sterile 0.9% saline. EchA improved glucose tolerance and reduced blood urea nitrogen (BUN) and serum creatinine levels but did not affect body weight. In addition, EchA decreased renal malondialdehyde (MDA) and lipid hydroperoxide levels, and increased ATP production. Histologically, EchA treatment ameliorated renal fibrosis. Mechanistically, EchA suppressed oxidative stress and fibrosis by inhibiting protein kinase C-iota (PKCι)/p38 mitogen-activated protein kinase (MAPK), downregulating p53 and c-Jun phosphorylation, attenuating NADPH oxidase 4 (NOX4), and transforming growth factor-beta 1 (TGFß1) signaling. Moreover, EchA enhanced AMPK phosphorylation and nuclear factor erythroid-2-related factor 2 (NRF2)/heme oxygenase 1 (HO-1) signaling, improving mitochondrial function and antioxidant activity. Collectively, these findings demonstrate that EchA prevents DN by inhibiting PKCι/p38 MAPK and upregulating the AMPKα/NRF2/HO-1 signaling pathways in db/db mice, and may provide a therapeutic option for DN.

Elucidation of complex triplet excited state dynamics in Pd(II) biladiene tetrapyrroles.

Pd(II) biladienes have been developed over the last five years as non-aromatic oligotetrapyrrole complexes that support a rich triplet photochemistry. In this work, we have undertaken the first detailed photophysical interrogation of three homologous Pd(II) biladienes bearing different combinations of methyl- and phenyl-substituents on the frameworks' sp3-hybridized meso-carbon (i.e., the 10-position of the biladiene framework). These experiments have revealed unexpected excited-state dynamics that are dependent on the wavelength of light used to excite the biladiene. More specifically, transient absorption spectroscopy revealed that higher-energy excitation (λexc ∼ 350-500 nm) led to an additional lifetime (i.e., an extra photophysical process) compared to experiments carried out following excitation into the lowest-energy excited states (λexc = 550 nm). Each Pd(II) biladiene complex displayed an intersystem crossing lifetime on the order of tens of ps and a triplet lifetime of ∼20 µs, regardless of the excitation wavelength. However, when higher-energy light is used to excite the complexes, a new lifetime on the order of hundreds of ps is observed. The origin of the 'extra' lifetime observed upon higher energy excitation was revealed using density functional theory (DFT) and time-dependent DFT (TDDFT). These efforts demonstrated that excitation into higher-energy metal-mixed-charge-transfer excited states with high spin-orbit coupling to higher energy metal-mixed-charge-transfer triplet states leads to the additional excitation deactivation pathway. The results of this work demonstrate that Pd(II) biladienes support a unique triplet photochemistry that may be exploited for development of new photochemical schemes and applications.

Isocorrole-Loaded Polymer Nanoparticles for Photothermal Therapy under 980 nm Light Excitation.

Photothermal therapy (PTT) is a promising treatment option for diseases, including cancer, arthritis, and periodontitis. Typical photothermal agents (PTAs) absorb light in the near-infrared (NIR)-I region of 650-900 nm with a predominant focus around 800 nm, as these wavelengths are minimally absorbed by water and blood in the tissue. Recently, interest has grown in developing nanomaterials that offer more efficient photothermal conversion and that can be excited by light close to or within the NIR-II window of 1000-1700 nm, which offers less absorption by melanin. Herein, we report on the development of 5,5-diphenyl isocorrole (5-DPIC) complexes containing either Zn(II) or Pd(II) (Zn[5-DPIC] and Pd[5-DPIC], respectively) that absorb strongly across the 850-1000 nm window. We also show that poly(lactic-co-glycolic acid) (PLGA) nanoparticles loaded with these designer isocorroles exhibit low toxicity toward triple-negative breast cancer (TNBC) cells in the dark but enable efficient heat production and photothermal cell ablation upon excitation with 980 nm light. These materials represent an exciting new platform for 980 nm activated PTT and demonstrate the potential for designer isocorroles to serve as effective PTAs.

An Easily Prepared Monomeric Cobalt(II) Tetrapyrrole Complex That Efficiently Promotes the 4e-/4H+ Peractivation of O2 to Water.

The selective 4e-/4H+ reduction of dioxygen to water is an important reaction that takes place at the cathode of fuel cells. Monomeric aromatic tetrapyrroles (such as porphyrins, phthalocyanines, and corroles) coordinated to Co(II) or Co(III) have been considered as oxygen reduction catalysts due to their low cost and relative ease of synthesis. However, these systems have been repeatedly shown to be selective for O2 reduction by the less desired 2e-/2H+ pathway to yield hydrogen peroxide. Herein, we report the initial synthesis and study of a Co(II) tetrapyrrole complex based on a nonaromatic isocorrole scaffold that is competent for 4e-/4H+ oxygen reduction reaction (ORR). This Co(II) 10,10-dimethyl isocorrole (Co[10-DMIC]) is obtained in just four simple steps and has excellent yield from a known dipyrromethane synthon. Evaluation of the steady state spectroscopic and redox properties of Co[10-DMIC] against those of Co porphyrin (cobalt 5,10,15,20-tetrakis(pentafluorophenyl)porphyrin, [Co(TPFPP)]) and corrole (cobalt 5,10,15-tris(pentafluorophenyl)corrole triphenylphosphine, Co[TPFPC](PPh3)) homologues demonstrated that the spectroscopic and electrochemical properties of the isocorrole are distinct from those displayed by more traditional aromatic tetrapyrroles. Further, the investigation of the ORR activity of Co[10-DMIC] using a combination of electrochemical and chemical reduction studies revealed that this simple, unadorned monomeric Co(II) tetrapyrrole is ∼85% selective for the 4e-/4H+ reduction of O2 to H2O over the more kinetically facile 2e-/2H+ process that delivers H2O2. In contrast, the same ORR evaluations conducted for the Co porphyrin and corrole homologues demonstrated that these traditional aromatic systems catalyze the 2e-/2H+ conversion of O2 to H2O2 with near complete selectivity. Despite being a simple, easily prepared, monomeric tetrapyrrole platform, Co[10-DMIC] supports an ORR catalysis that has historically only been achieved using elaborate porphyrinoid-based architectures that incorporate pendant proton-transfer groups or ditopic molecular clefts or that impose cofacially oriented O2 binding sites. Accordingly, Co[10-DMIC] represents the first simple, unadorned, monomeric metalloisocorrole complex that can be easily prepared and shows a privileged performance for the 4e-/4H+ peractivation of O2 to water as compared to other simple cobalt containing tetrapyrroles.

Cereblon contributes to cardiac dysfunction by degrading Cav1.2α.

AIMS: Cereblon (CRBN) is a substrate receptor of the E3 ubiquitin ligase complex that was reported to target ion channel proteins. L-type voltage-dependent Ca2+ channel (LTCC) density and dysfunction is a critical player in heart failure with reduced ejection fraction (HFrEF). However, the underlying cellular mechanisms by which CRBN regulates LTCC subtype Cav1.2α during cardiac dysfunction remain unclear. Here, we explored the role of CRBN in HFrEF by investigating the direct regulatory role of CRBN in Cav1.2α activity and examining how it can serve as a target to address myocardial dysfunction. METHODS AND RESULTS: Cardiac tissues from HFrEF patients exhibited increased levels of CRBN compared with controls. In vivo and ex vivo studies demonstrated that whole-body CRBN knockout (CRBN-/-) and cardiac-specific knockout mice (Crbnfl/fl/Myh6Cre+) exhibited enhanced cardiac contractility with increased LTCC current (ICaL) compared with their respective controls, which was modulated by the direct interaction of CRBN with Cav1.2α. Mechanistically, the Lon domain of CRBN directly interacted with the N-terminal of Cav1.2α. Increasing CRBN levels enhanced the ubiquitination and proteasomal degradation of Cav1.2α and decreased ICaL. In contrast, genetic or pharmacological depletion of CRBN via TD-165, a novel PROTAC-based CRBN degrader, increased surface expression of Cav1.2α and enhanced ICaL. Low CRBN levels protected the heart against cardiomyopathy in vivo. CONCLUSION: Cereblon selectively degrades Cav1.2α, which in turn facilitates cardiac dysfunction. A targeted approach or an efficient method of reducing CRBN levels could serve as a promising strategy for HFrEF therapeutics.

Novel GSK-3ß Inhibitor Neopetroside A Protects Against Murine Myocardial Ischemia/Reperfusion Injury.

Recent trends suggest novel natural compounds as promising treatments for cardiovascular disease. The authors examined how neopetroside A, a natural pyridine nucleoside containing an α-glycoside bond, regulates mitochondrial metabolism and heart function and investigated its cardioprotective role against ischemia/reperfusion injury. Neopetroside A treatment maintained cardiac hemodynamic status and mitochondrial respiration capacity and significantly prevented cardiac fibrosis in murine models. These effects can be attributed to preserved cellular and mitochondrial function caused by the inhibition of glycogen synthase kinase-3 beta, which regulates the ratio of nicotinamide adenine dinucleotide to nicotinamide adenine dinucleotide, reduced, through activation of the nuclear factor erythroid 2-related factor 2/NAD(P)H quinone oxidoreductase 1 axis in a phosphorylation-independent manner.

Non-achievement of the Low-Density Lipoprotein Cholesterol Goal in Older Patients with Type 2 Diabetes Mellitus and a Very High Cardiovascular Disease Risk: A Multicenter Study in Vietnam.

BACKGROUND: Lowering the low-density lipoprotein cholesterol (LDL-c) level is important for reducing cardiovascular (CV) events. However, little is known about the management of LDL-c in older patients with type 2 diabetes mellitus (T2DM). This study investigated the prevalence and factors associated with the non-achievement of LDL-c goals in older T2DM patients with a very high risk of CV diseases. METHODS: This multicenter cross-sectional study measured the LDL-c levels of 733 T2DM outpatients from December 2019 to July 2020. The patients were aged ≥60 years, had very high risks of CV disease, and had been on LDL-c-lowering therapy for 6 months or more. The goal of lipid concentrations were assessed based on the recent guidelines of the European Society of Cardiology. We applied logistic regression analysis to identify the factors associated with the non-achievement of the LDL-c goal. RESULTS: The mean age of the patients was 68.6±7.2 years. In total, 654 patients (89.2%) did not achieve the aggressive LDL-c goal of <1.4 mmol/L. In the adjusted model, the factors associated with the non-achievement of the LDL-c goal were obesity defined by body mass index (odds ratio [OR]=2.33; 95% confidence interval [CI], 1.13-4.81; p=0.022) and high-intensity statin therapy (OR=0.03; 95% CI, 0.01-0.05; p<0.001), while age, sex, education level, smoking habit, and comorbidities were not associated. CONCLUSION: Older patients with T2DM who are at a very high CV disease risk are often unable to achieve their LDL-c goal. Obesity can increase the probability of not achieving the LDL-c goal, whereas high-intensity statin therapy can decrease this probability.

Tectonic Deep Anterior Lamellar Keratoplasty to Treat Corneal Perforation and Descemetocele from Microbial Keratitis.

PURPOSE: To evaluate the result of tectonic deep anterior lamellar keratoplasty (DALK) for keratitis with perforation and descemetocele. PATIENTS AND METHODS: A prospective clinical study of 36 patients (36 eyes) treated with tectonic DALK for corneal perforation or descemetocele from microbial keratitis managed at the Vietnam National Eye Hospital over a two-year period. The surgical technique was manual lamellar dissection. The grafts were harvested from the anterior corneal cap of pre-cut donor tissues used for DSAEK or donor corneas with a low endothelial cell count. RESULTS: A mean age was 55.36 ± 13.98 years (ranged from 25 to 75 years). Female gender represented 52%. causative agents were herpes simplex virus (58.3%), bacteria (22.2%), fungi (13.9%) and microsporidia (5.6%). There were 24 eyes with descemetocele (66.7%) and 12 with perforation (33.3%). There were 33 successful cases (91.7%) and 3 failed cases (8.3%). Best corrected visual acuity (BCVA) improved in 28 eyes (84.8%). The range of post-operative BCVA was from hand motions to 20/70. Eleven eyes (33.3%) attained vision 20/200 and higher. Clear graft was obtained in 15 eyes (45.5%), while mild or severe graft opacity was observed in 14 eyes (42.4%), and 4 eyes (12.1%), respectively. Surgical complications included descemet rupture (20.8%), pseudo anterior chamber (41.6%), persistent corneal epithelial defects (8.3%), reinfection (11.1%), glaucoma or ocular hypertension (5.6%) and cataract (8.3%). CONCLUSION: The study demonstrates that DALK is an effective procedure to treat corneal descemetocele, especially when an urgent penetrating keratoplasty (PKP) cannot be performed.

Proteomic Approaches to Study Cysteine Oxidation: Applications in Neurodegenerative Diseases.

Oxidative stress appears to be a key feature of many neurodegenerative diseases either as a cause or consequence of disease. A range of molecules are subject to oxidation, but in particular, proteins are an important target and measure of oxidative stress. Proteins are subject to a range of oxidative modifications at reactive cysteine residues, and depending on the level of oxidative stress, these modifications may be reversible or irreversible. A range of experimental approaches has been developed to characterize cysteine oxidation of proteins. In particular, mass spectrometry-based proteomic methods have emerged as a powerful means to identify and quantify cysteine oxidation sites on a proteome scale; however, their application to study neurodegenerative diseases is limited to date. Here we provide a guide to these approaches and highlight the under-exploited utility of these methods to measure oxidative stress in neurodegenerative diseases for biomarker discovery, target engagement and to understand disease mechanisms.

Study on the Synthesis of Chabazite Zeolites via Interzeolite Conversion of Faujasites.

The interzeolite conversion of faujasite (FAU-type) zeolites to chabazite (CHA-type) zeolite in the presence of N,N,N-trimethyladamantammonium and N,N,N-dimethylethylcyclohexylammonium cations was investigated over a large compositional range by carefully controlling the reaction mixture compositions. Highly crystalline CHA zeolites were also obtained by the transformation of several zeolite types including EMT, LTL, LEV, RTH, and MFI frameworks. The formation of CHA zeolite from FAU zeolite precursors was substantially faster than that from zeolite L with a similar composition. High-silica CHA zeolites were also produced successfully using a mixture of TMAda with a number of less expensive organic structure-directing agents. The CHA zeolite materials have been synthesized with high crystallinity and with a Si/Al ratio ranging from 5 to 140. Our data support the importance of structural similarity between the zeolite precursors, nucleation/crystallization processes, and the zeolite product in the interzeolite conversion compared to conventional amorphous aluminosilicate gels. Our synthetic methods could be used to prepare other 8-membered ring zeolites such as AEI and AFX frameworks, potential candidates for selective catalytic reduction of NOx, light olefin production, and CO2 abatement.

Endoscopic Orbital Decompression for Graves' Orbitopathy - A Vietnam Study.

PURPOSE: To evaluate the efficacy and safety of endoscopic orbital decompression in patients with Graves' orbitopathy. PATIENTS AND METHODS: This is a prospective study in Hanoi Medical University and a Military Hospital from December 2017 to December 2018. Twenty-eight orbits of fifteen patients were undergoing endoscopic orbital decompression for Graves' orbitopathy. Indications for surgery were proptosis in twenty-two orbits and compressive optic neuropathy in six orbits. The outcome measures were proptosis reduction, visual acuity, visual field test and diplopia. Post-operative complications including cerebrospinal fluid leakage, haemorrhage, lacrimal duct impairment, worsening diplopia, sinusitis and cellulitis were collected. RESULTS: The mean proptosis reduction was 2.23 mm. Visual acuity and medium deviation in the Humphrey visual field were significantly improved in four of six eyes with compressive optic neuropathy. There was one patient with intra-operative excessive bleeding which resolved without affecting visual outcome. Post-operatively, two patients developed a new onset of diplopia and two others worsened diplopia; three have already undergone successful strabismus surgery and moderate proptosis reduction. CONCLUSION: Endoscopic orbital decompression surgery was effectively and safely to manage compressive optic neuropathy of Graves' orbitopathy and moderately reduce proptosis in a group of Vietnamese patients.

Exposure to 1-Butanol Exemplifies the Response of the Thermoacidophilic Archaeon Sulfolobus acidocaldarius to Solvent Stress.

Sulfolobus acidocaldarius is a thermoacidophilic crenarchaeon with optimal growth at 80°C and pH 2 to 3. Due to its unique physiological properties, allowing life at environmental extremes, and the recent availability of genetic tools, this extremophile has received increasing interest for biotechnological applications. In order to elucidate the potential of tolerating process-related stress conditions, we investigated the response of S. acidocaldarius toward the industrially relevant organic solvent 1-butanol. In response to butanol exposure, biofilm formation of S. acidocaldarius was enhanced and occurred at up to 1.5% (vol/vol) 1-butanol, while planktonic growth was observed at up to 1% (vol/vol) 1-butanol. Confocal laser-scanning microscopy revealed that biofilm architecture changed with the formation of denser and higher tower-like structures. Concomitantly, changes in the extracellular polymeric substances with enhanced carbohydrate and protein content were determined in 1-butanol-exposed biofilms. Using scanning electron microscopy, three different cell morphotypes were observed in response to 1-butanol. Transcriptome and proteome analyses were performed comparing the response of planktonic and biofilm cells in the absence and presence of 1-butanol. In response to 1% (vol/vol) 1-butanol, transcript levels of genes encoding motility and cell envelope structures, as well as membrane proteins, were reduced. Cell division and/or vesicle formation were upregulated. Furthermore, changes in immune and defense systems, as well as metabolism and general stress responses, were observed. Our findings show that the extreme lifestyle of S.acidocaldarius coincided with a high tolerance to organic solvents. This study provides what may be the first insights into biofilm formation and membrane/cell stress caused by organic solvents in S. acidocaldariusIMPORTANCEArchaea are unique in terms of metabolic and cellular processes, as well as the adaptation to extreme environments. In the past few years, the development of genetic systems and biochemical, genetic, and polyomics studies has provided deep insights into the physiology of some archaeal model organisms. In this study, we used S. acidocaldarius, which is adapted to the two extremes of low pH and high temperature, to study its tolerance and robustness as well as its global cellular response toward organic solvents, as exemplified by 1-butanol. We were able to identify biofilm formation as a primary cellular response to 1-butanol. Furthermore, the triggered cell/membrane stress led to significant changes in culture heterogeneity accompanied by changes in central cellular processes, such as cell division and cellular defense systems, thus suggesting a global response for the protection at the population level.

Phosphopeptide enrichment for phosphoproteomic analysis - A tutorial and review of novel materials.

Significant technical advancements in phosphopeptide enrichment have enabled the identification of thousands of p-peptides (mono and multiply phosphorylated) in a single experiment. However, it is still not possible to enrich all p-peptide species in a single step. A range of new techniques and materials has been developed, with the potential to provide a step-change in phosphopeptide enrichment. The first half of this review contains a tutorial for new potential phosphoproteomic researchers; discussing the key steps of a typical phosphoproteomic experiment used to investigate canonical phosphorylation sites (serine, threonine and tyrosine). The latter half then show-cases the latest developments in p-peptide enrichment including: i) Strategies to mitigate non-specific binding in immobilized metal ion affinity chromatography and metal oxide affinity chromatography protocols; ii) Techniques to separate multiply phosphorylated peptides from monophosphorylated peptides (including canonical from non-canonical phosphorylated peptides), or to simultaneously co-enrich other post-translational modifications; iii) New hybrid materials and methods directed towards enhanced selectivity and efficiency of metal-based enrichment; iv) Novel materials that hold promise for enhanced phosphotyrosine enrichment. A combination of well-understood techniques and materials is much more effective than any technique in isolation; but the field of phosphoproteomics currently requires benchmarking of novel materials against current methodologies to fully evaluate their utility in peptide based proteoform analysis.

BH4 activates CaMKK2 and rescues the cardiomyopathic phenotype in rodent models of diabetes.

Diabetic cardiomyopathy (DCM) is a major cause of mortality/morbidity in diabetes mellitus patients. Although tetrahydrobiopterin (BH4) shows therapeutic potential as an endogenous cardiovascular target, its effect on myocardial cells and mitochondria in DCM and the underlying mechanisms remain unknown. Here, we determined the involvement of BH4 deficiency in DCM and the therapeutic potential of BH4 supplementation in a rodent DCM model. We observed a decreased BH4:total biopterin ratio in heart and mitochondria accompanied by cardiac remodeling, lower cardiac contractility, and mitochondrial dysfunction. Prolonged BH4 supplementation improved cardiac function, corrected morphological abnormalities in cardiac muscle, and increased mitochondrial activity. Proteomics analysis revealed oxidative phosphorylation (OXPHOS) as the BH4-targeted biological pathway in diabetic hearts as well as BH4-mediated rescue of down-regulated peroxisome proliferator-activated receptor-γ coactivator 1-α (PGC-1α) signaling as a key modulator of OXPHOS and mitochondrial biogenesis. Mechanistically, BH4 bound to calcium/calmodulin-dependent protein kinase kinase 2 (CaMKK2) and activated downstream AMP-activated protein kinase/cAMP response element binding protein/PGC-1α signaling to rescue mitochondrial and cardiac dysfunction in DCM. These results suggest BH4 as a novel endogenous activator of CaMKK2.

Exercise-Induced Circulating Irisin Level Is Correlated with Improved Cardiac Function in Rats.

Irisin, a recently identified myokine, plays an important physiological role in modulating energy homeostasis. However, the role of irisin in cardiac function during exercise has not been evaluated. In this study, we investigated the effect of exercise on irisin, pro-inflammatory cytokines, and cardiac function during 12 weeks of exercise in rats. Eight-week-old Sprague-Dawley male rats were randomly divided into two groups (n = 9 per group): sedentary control (CON) and exercise (EXE) groups. The EXE group was trained on a motorized treadmill at 20 m/min, for 60 min/day, five times/week for 12 weeks. The EXE group showed a decrease in abdominal visceral fat (p < 0.05), epididymal fat (p < 0.01), and total cholesterol (TC) (p < 0.05) and an increase in irisin levels (p < 0.01). Irisin negatively correlated with abdominal visceral (p < 0.05) and epididymal fat (p < 0.05) and positively correlated with the ejection fraction (p < 0.05), fractional shortening (p < 0.05), and cardiac output (p < 0.05). In conclusion, exercise decreases the abdominal visceral and epididymal fat and TC levels, possibly caused by elevated irisin levels, thus improving the cardiac function. This suggests that exercise-induced circulating irisin levels correlate with improved cardiac function in rats.