bluuebunny/crossref_metadata_2025 huggingface dataset:
Mitochondria form an apical calcium signaling domain in renal cortical collecting duct cells
Authors: Galarza‐Paez Laura , Eaton Douglas , Lam Ho Yin , Al Khalili Otor , Duke Billie Jeanne , Bao Hui Fang , Ma Heping , Thai Tiffany
Published: June 2021

In several epithelia, Mitochondria sequester intracellular Ca2+ to create Ca2+ signaling domains. We asked whether mitochondria could form barriers to Ca2+ diffusion in renal cortical collecting duct (CCD) cells. We began by staining each of two cell lines (from Xenopus and mouse) with mitotracker red. Mitochondria in both cell lines were localized in bands with a prominent band near the apical surface and a weaker band at the basal pole. To determine the proximity of the apical band to the membrane, we fluorescently tagged PIP2 to label the apical membrane and found that the apical mitochondrial band was localized just beneath the membrane. Many apical membrane proteins are regulated by endoplasmic reticular Ca2+ release. If mitochondria do sequester calcium to create an apical membrane Ca2+ signaling domain, the ER must be able to cross the mitochondrial barrier at certain points so that release of Ca2+ from the ER can reach its desired targets. Cells co‐stained with mitotracker red and ERtracker blue showed that ER crossed the mitochondrial barrier in many places. Next we sought to determine whether mitochondrial bands can prevent movement of intracellular Ca2+ from one pole to another. Live cells stained with the mitochondrial Ca2+ dye Rhodamine 2‐AM showed Ca2+ uptake in the apical but not basal band after treatment with the Ca2+ ionophore ionomycin. Cells transfected with a membrane‐tethered intracellular Ca2+ sensor showed increased Ca2+ at the apical but not basal pole following apical ionomycin. These data suggest that mitochondrial bands in the CCD create an apical signaling domain for Ca2+ regulation of membrane proteins. This work was supported by NIH R37‐DK037963 and T32‐ DK07656 and AHA 13POST16820072.
Genes involved in the development of cardiovascular disease: A genomic study of human arteries
Authors: Lu Tzongshi , Ho Li‐Lun , Liu Qinghua , Molostvov Guerman , Dong Ling‐Shen , Hiemstra Thomas , Zehnder Daniel , Hsiao Li‐Li
Published: June 2021

Cardiovascular disease (CVD) is the leading pandemic health problem globally. In particular arteriosclerosis results in increased cardiac work and reduced coronary flow with the consequence of heart failure. In this study, we explore differential gene expressions and molecular mechanisms in arteries of patients with CVD and healthy control using RNA sequencing technology.

Our data showed that among the 14 up‐regulated genes, hemoglobin‐β (HBB), hemoglobin‐α 2 (HBA2) and hemoglobin‐α 1 (HBA1) that involve in oxygen transport have the highest changes of expression (7.4, 5.0 and 4.6 folds changes, respectively). In addition, two up‐regulated genes, CD36 (3.56 folds) and fatty acid binding protein 4 (FABP4, 3.13 folds), are involved in fat and adipocyte metabolism and PPAR signaling pathway. Conversely, three highest changes genes among the 8 down‐regulated genes are: pentraxin 3 (PTX3, 3.9 folds) is associated with the regulation of inflammatory reactions; sodium channel, voltage‐gated, type VII, alpha subunit (SCN7A, 3.57 folds) is involved in the Adrenergic signaling in cardiomyocytes and heat shock protein A6 (HSPA6, 3.39 folds) plays important protective roles in maintaining normal protein folding under stress.

In conclusion, we identified genes that are unique in patients with CVD when compared with healthy individuals, which may serve as genomic markers in the development of CVD.
A Link between Mitophagy and Apoptosis in Endothelial Cells: Exosomal Delivery of Mfn‐2 siRNA
Authors: Familtseva Anastasia , Chaturvedi Pankaj , Kalani Anuradha , Tyagi Neetu , Tyagi Suresh
Published: June 2021

Exosomes are lipid‐bilayer vesicles (50‐100 nm) derived from many cell types including endothelial cells that are a promising delivery vehicle for small interfering ribonucleic acid (siRNA). Exosomes have the ability to fuse with cell membranes, avoid phagocytosis and be less immunogenic compared to other carriers. We have previously described the beneficial effects of mitochondrial fusion regulated by mitofusin‐2 (Mfn‐2) and the detrimental effects of excessive mitochondrial fission controlled by dynamin related protein (Drp‐1) on endothelial cell loss in vivo. We hypothesize that in vitro delivery of Mfn‐2 siRNA encapsulated with exosomes decreases Mfn‐2 protein expression in mice aortic endothelial cells (MAEC), triggering excessive mitochondrial fragmentation, activation of mitochondrial apoptotic cascade with Bax, Caspase 9 and Caspase 3 up regulation contributing to endothelial cell loss. In our current study, we isolated and purified exosomes from cultured mice aortic endothelial cell medium (MAEC exosomes). The round shape morphology and exosome size were defined by transmission electron microscopy. Western blotting and Flow Cytometry further validated the expression of three exosome markers: CD63, Flotillin‐1 and tumor susceptibility gene (Tsg101). Immunohistochemistry using PKH67 labeling showed the presence of MAEC exosomes in MAEC. In conclusion, our data suggests that Mfn‐2 siRNA encapsulated with MAEC exosomes silenced Mfn‐2 protein expression in MAEC that triggers excessive mitochondrial fragmentation, activation of mitochondrial apoptotic cascade with Bax, Caspase 9 and Caspase 3 up regulation inducing endothelial cell apoptosis.
Aurora Kinase A is critical for the Nkx6.1 mediated β‐cell proliferation pathway
Authors: Tessem Jeffery , Hobson Amanda , Draney Carrie
Published: June 2021

Type 1 and type 2 diabetes are ultimately characterized by depleted β‐cell mass. Characterization of the molecular pathways that control β‐cell proliferation could be harnessed to restore these cells. The homeobox β‐cell transcription factor Nkx6.1 induces β‐cell proliferation by activating the orphan nuclear receptors Nr4a1 and Nr4a3. Here, we demonstrate that Nkx6.1 localizes to the promoter of the mitotic kinase AURKA (Aurora Kinase A) and induces its expression. Adenovirus mediated overexpression of AURKA is sufficient to induce proliferation in primary rat islets while maintaining glucose stimulated insulin secretion. Furthermore, AURKA is necessary for Nkx6.1 mediated β‐cell proliferation as demonstrated by shRNA mediated knock down and pharmacological inhibition of AURKA kinase activity. AURKA preferentially induces DNA replication in β‐cells as measured by BrdU incorporation, and enhances the rate of histone H3 phosphorylation in primary β‐cells, demonstrating that AURKA induces the replicative and mitotic cell cycle phases in rat β‐cells. Finally, overexpression of AURKA results in phosphorylation of the cell cycle regulator p53, which targets p53 for degradation and permits cell cycle progression. These studies define a pathway by which AURKA upregulation by Nkx6.1 results in phosphorylation and degradation of p53, thus removing a key inhibitory factor and permitting engagement of the β‐cell proliferation pathway.
Effects of Iron Deficiency in the Production of Oxidative Stress Biomarkers in the Central Nervous System and Spleen of BALB / c Mice
Authors: Martinez Anabella , Contreras Irazú , Pliego Bernardo , Estrada José Antonio
Published: June 2021

Objective

To determine the production of oxidative stress biomarkers in nervous system and spleen cells of iron deficient mice.

Methods: 2 groups of BALB / c mice 60 days old were established (control and iron deficient). Iron deficiency was established in utero and sustained until its sacrifice. CNS and spleen samples from both groups were obtained to freeze and also to purify leukocytes. Frozen tissue samples were used for analysis with the kit for spectrophotometricall detection of thiobarbituric acid reactive substances (TBARS). Purified cells were cultured in duplicate under standard conditions at a density of 5x10 6 cells / cm 3 for the spleen and 0.5 x 10 6 cells / cm 3 for the CNS. A simultaneous test was performed with stimulated cells (LPS 1 µg / µL) and non stimulated cells to determine the production of nitric oxide by the method of Griess

Results: No significant differences were found in the spleen and CNS lipid peroxidation; however, it can be seen a lower production of malondialdehyde (MDA) in the CNS of iron deficient mice. The nitric oxide production was not significantly different.

Conclusion As There is no statistically significant difference but mathematical in the expression of oxidative stress biomarkers between groups it is suggested increasing the sample size for more relevant results. It is possible that some compensatory mechanisms against oxidative stress, such as increased levels of antioxidant enzymes and antioxidants are overexpressed in the iron‐ deficient group
Prolonged use of Chloramphenicol Induces Aplastic Anemia and Oxidative Stress in Broiler Chicken
Authors: Azeez Odunayo , Iji Oluwafikemi , Akinrinde Adeleye
Published: June 2021

In an attempt to combat bacterial infections in domestic poultry production in developing countries, poultry producers use antibiotics without recourse to its side effects. We investigated the effects of prolonged use of Chloramphenicol in the broilers and the antioxidant potential of four commercially available antioxidants and ascorbic acid.
Two hundred and ten day old broilers were randomly divided into seven groups of thirty birds per group. Group A, (control) received Chloramphenicol for the first six days while all the other groups received it for six weeks. Group B did not receive any antioxidant. Group C received Vitamin C, Group D Selcon Forte, Group E Stressroak, Group F Superliv and Group G, Livestovit in drinking water.
Blood samples were collected after six weeks in three replicates for haematological parameters and erythrocyte osmotic fragility, plasma ALT, AST and GGT. Five birds were culled from each group for the determination of the total GSH, H2O2 and lipid peroxidation in the liver, kidney and the cerebrum.
Those birds that received Chloramphenicol alone presented with aplastic anemia, elevated erythrocyte osmotic fragility and increased AST, ALT and GGT values. The levels of GSH, H2O2 and lipid peroxidation also increased significantly. The anemia and oxidative stress was however corrected in the antioxidants groups.
This study demonstrated that prolonged use of chloramphenicol induced non‐regenerative anaemia and oxidative stress, even at normal recommended dosage.
Comparative effects of intramuscular and intravenous administration of diminazene aceturate on blood pressure and lead‐II electrocardiogram of dogs.
Authors: Adejumobi Olumuyiwa , Abiola John , Adediran David , Omobowale Temidayo
Published: June 2021

Diminazene aceturate (DIAC), has been used extensively in Veterinary practice as a potent antiprotozoal drug. The drug has also been reported to be a small molecule which is capable of activating angiotensin‐converting enzyme‐2 and thereby, having some cardio‐protective effect. We investigated the possible effects of DIAC when administered through the intramuscular (i/m) or intravenous (i/v) routes of dogs on cardiovascular function using blood pressure measurements and electrocardiography as clinical indices. Ten apparently normal dogs were divided into 2 groups of 5 dogs each. DIAC was administered intramuscularly at 3.5mg/kg weight to one group while the other group was treated intravenously using the same dosage. Blood pressure parameters (SBP, DBP and MAP) and lead II ECG were used to assess physiological function. Parameters were measured prior to administration and also at 10 min, 30min, 1hr, 2hrs, 3hrs. 4hrs, 6hrs, 12hrs and 24 hrs afterwards. DIAC caused a statistically significant (p<0.05) reduction in SBP and MAP at 10 and 30 min post administration in both treatment groups. The i/v DIAC also caused a significant (p<0.05) reduction in SDP at 10min, 6hrs and 12hrs post administration. Administration of the drugs through either routes had no significant effect on QTc (Bazett) however, there was a slight increase in QTc (fridericia) values after 30 min of i/v administration when compared with pre‐administration values. This study shows that administration of DIAC through either the i/m or i/v routes caused transient hypotension which was however restored by 1 hour post administration. Electrocardiographic assessment also did not show much remarkable aftermath.
Deletion of Protein Tyrosine Phosphatase 1b (Ptp1b) in Proopiomelanocortin (POMC) Neurons Reduces Sympathetic Tone and Protects Mice from Leptin‐Induced High Blood Pressure
Authors: Bruder‐Nascimento Thiago , Benjamin Butler , Bence Kendra , Belin de Chantemelle Eric
Published: June 2021

Ptp1b is a negative regulator of leptin signaling. Deletion of Ptp1b in POMC neurons increases energy expenditure and protects mice from obesity and type 2 diabetes. However, whether POMC‐Ptp1b deletion sensitizes the cardiovascular system to leptin is unknown. We addressed this question by analyzing the cardiovascular phenotype of flox/flox (WT) and POMC‐Ptp1b KO mice (KO), at baseline and after 7 days of chronic leptin infusion. Conscious blood pressure (BP) and heart rate recordings revealed that POMC‐Ptp1b deletion did not affect baseline BP [WT: 118.3±4.1 vs KO: 117.9± 4.2 mmHg]. However KO mice exhibit a lower BP response to ganglionic blockade [WT: ‐30±4 vs KO: ‐15±6 % drop, P<0.05] that suggests a decreased neurogenic control of BP. Reduced sympathetic tone was further confirmed by showing that KO mice exhibit low plasma catecholamine levels [WT: 3765±483 vs KO: 2113±521 pg/mL, P<0.05, HPLC] compared to WT mice and a compensatory increase in vascular adrenergic tone (increased vascular constriction to phenylephrine) and a1 adrenergic receptors expression (qRT‐PCR). Furthermore chronic sympatho‐activation for 7 days via phenylephrine infusion restored vascular adrenergic tone in KO mice. POMC‐Ptp1b deletion abolished leptin‐induced increase in BP [WT: +13±2.5 mmHg, P<0.05 vs baseline; KO: +4±1.9 mmHg, NS]. However chronic leptin infusion restored vascular adrenergic tone in POMC‐Ptp1b KO mice by increasing vascular sympathoactivation. These data suggests that deletion of Ptp1b in POMC neurons protects from leptin‐induced high BP by reducing neurogenic control of blood pressure.
OVLT Neurons Exhibit Exquisite Osmosensitivity to Elevated NaCl Concentrations
Authors: Kinsman Brian , Browning Kirsteen , Stocker Sean
Published: June 2021

The brain responds to changes in osmolarity through specialized osmosensitive neurons of the organum vasculosum of the lamina terminalis (OVLT). However, prior studies assessed OVLT neuronal responses to supraphysiologic changes in osmolarity (~5 ‐ 15%). Therefore, this study aimed to establish that OVLT neurons are sensitive to physiologic 5 ‐ 10mOsm elevations (~1.5 ‐ 3.5%) in bath NaCl using whole‐cell recordings of adult OVLT neurons in slices. We measured changes in action potential (AP) discharge frequency to 5 mOsm increases in NaCl. 56% of OVLT neurons (9/16) were osmosensitive as defined by a 25% increase in discharge frequency. Osmosensitive neurons' (n = 9) peak AP discharge increased significantly from a 295 mOsm baseline (0.88±0.25 Hz) by 154% to 300 mOsm (1.66±0.33 Hz; p < 0.05) and by 252% to 305 mOsm (1.97±0.34 Hz; p < 0.05) stimuli. Conversely, non‐osmosensitive neurons' (n = 7) peak AP discharge did not significantly change from a 295 mOsm baseline (0.51±0.16 Hz) to 300 mOsm (0.73±0.24 Hz) and 305 mOsm (0.57±0.22 Hz) stimuli (p > 0.05). Linear regression analysis showed that osmosensitive neurons exhibited concentration‐dependent increases in discharge frequency to hyperosmotic challenges (r2 = 0.284), but non‐osmosensitive neurons did not (r2 = 0.00374). Still, osmosensitive and non‐osmosensitive neurons did not differ with regard to input resistance, AP threshold, AP duration, afterhyperpolarization magnitude or repolarization rate. These data demonstrate, for the first time, that OVLT neurons exhibit exquisite sensitivity to 1‐3% increases in osmolarity, and may initiate homeostasis to physiologic elevations in circulating sodium.
Exertional vs. Passive Heat Stroke: Altered Time Course of Cytokine Expression in Plasma and Skeletal Muscle
Authors: King Michelle , Morse Deb , Clanton Thomas
Published: June 2021

Exertional heat stroke (EHS) is a unique model where hyperthermia, exhaustive exercise, and other signals place simultaneous demands on the innate immune system. We hypothesized that when heat was superimposed on exercise there would be an exaggerated stress response due to the cumulative effect of these factors. To explore this, we determined cytokine protein expression in plasma and changes in skeletal muscle gene expression post EHS, passive heat stroke (PHS), exercise sham controls (EXC), and exhaustive exercise (EE) and compared these to naïve controls (NC). Gene expression was evaluated using qRT‐PCR in the diaphragm (DIA), soleus (SOL), and gastrocnemius (GASTROC) at 0.5, 3, 24, and 96 hrs after treatment. Plasma cytokine proteins were determined using Luminex. In EHS and in EXC, peak plasma IL‐6 was observed at 0.5 hr recovery; by 3 hrs it was not different from NC. Contrastingly, following PHS, IL‐6 reached a peak at 3 hrs. IL‐10 was also significantly elevated at 3 hrs in PHS, whereas in EXC and EHS there were no elevations. In EHS, IL‐6 mRNA in the SOL and DIA was increased 0.5 hr post treatment while IL‐10 was only increased in the DIA. In PHS, 30 min post, IL‐6 and IL‐10 mRNA were greatly elevated. Importantly, 30 min after EE or EXC, IL‐6 and IL‐10 mRNA in SOL and GASTROC were significantly suppressed relative to NC. SOCS3 (a downstream response to IL‐6 and IL‐10 receptor activation via JAK/STAT3) was measured as a possible mechanism for suppression of IL‐6 and IL‐10. In EHS SOCS3 was elevated at 30 min in SOL, implying cytokine signaling events began early during exercise or heat exposure. In conclusion, exercise superimposed on heat blunts overall cytokine production and shifts expression to earlier points in time.
Effects of exercise on vasomotor function and vascular distensibility in angiotensin II‐induced hypertension
Authors: Pham Duc , Thalji Nassir , Smith Leslie , Hagler Michael , Zhang Bin , Roos Carolyn , LeBrasseur Nathan , Miller Jordan
Published: June 2021

Activation of NADPH oxidase is a major contributor to hypertension, reactive oxygen species generation, endothelial dysfunction and increased vascular distensibility in angiotensin II (AngII)‐induced hypertension. Since exercise has been associated with increased antioxidant enzyme expression in blood vessels, we hypothesized that exercise training would improve endothelial function and vascular distensibility in mice with AngII‐induced hypertension. C57BL/6J mice received saline or AngII (1000 ng/kg/min) via osmotic minipumps, and were assigned to sedentary or treadmill exercise groups (13 m/min for 30 minutes, 5 days/week) for 14 days. Endothelium‐dependent relaxation in response to acetylcholine and arterial distensibility were assessed in carotid arteries using a pressurized arteriograph system. Gene expression was examined by qRT‐PCR. In AngII‐treated sedentary mice, endothelium‐dependent relaxation was impaired, while distensibility was higher than in saline‐infused sedentary mice. Compared to AngII‐infused sedentary mice, however, endothelium‐dependent relaxation was partially improved, and distensibility normalized in AngII‐infused exercised mice. In response to exercise, mRNA levels of SOD1 and SOD2 in aorta were increased, while mRNA levels of NOX2 were reduced. We conclude that exercise training can dramatically improve endothelial dysfunction and reverse derangements in carotid distensibility following prolonged AngII‐induced hypertension. Additional work examining mechanisms underlying our observed transcriptional changes will be critical to development of novel therapeutic targets.
Docosahexaenoic Acid Inhibits White Adipogenesis and Enhances Mitochondrial Biogenesis through SIRT1 and Hh Signaling
Authors: Chen Yu‐Jen , Kuo Wen‐Hong , Chang Yun‐Tsui , Huang Chao‐Wei , Liu Hui‐Yu , Cheng Ying‐Hong , Mersmann Harry , Ding Shih‐Torng
Published: June 2021

Obesity has emerged as a worldwide phenomenon and leads to related diseases including cardiovascular diseases, type‐2 diabetes, and cancer. We previously demonstrated that docosahexaenoic acid (DHA), an ω‐3 fatty acids (PUFA) rich in fish oils known to reduce inflammation‐driven metabolic syndrome, inhibits forkhead box O1 expression in the liver and adipose tissues to reduce hepatic triglyceride synthesis. To further uncover the beneficial effects of DHA on adipocyte physiology related to adipogenesis and mitochondrial biogenesis, human adipose‐derived stem cells (hADSC) from subcutaneous fat depots were treated with different FA (saturated or unsaturated) during adipocyte differentiation. Strikingly, DHA‐treated hADSCs showed strong inhibition in white adipogenesis and increased characteristics of thermogenic beige adipocytes such as UCP1, PRDM16, TMEM26, and CD137 (browning of white fat). Mechanistically, this inhibition is resulted from activation of sirtuin 1 (SIRT1) and hedgehog (Hh) signaling. DHA also increased mitochondrial biogenesis in adipocytes through peroxisome proliferator‐activated receptor γ. Therefore, the renowned benefits of DHA on the amelioration of obesity‐ or inflammation‐ induced metabolic syndrome may be in part by the reduced adiposity of white adipose tissues and increased mitochondria biogenesis in mature beige adipocytes. Activation of SIRT1 or Hh signaling phenocopying effects of DHA could be potential therapeutics to treat metabolic diseases.
Brown Adipocyte Dysfunction in UCP1 Knockout Mice leads to Age‐Dependent Development of Type 2 Diabetes
Authors: Thoonen Robrecht , Hindle Allyson , Bezerra Miranda Alexandre , Yao Vincent , Tainsh Robert , Buys Emmanuel , Bloch Kenneth , Scherrer‐Crosbie Marielle
Published: June 2021

Since the discovery of functional brown adipose tissue (BAT) in adult humans, an inverse correlation between aging, type 2 diabetes and the amount and activity of the BAT‐depots have been reported. Upon activation, BAT converts the energy of free fatty acids and glucose oxidation into heat through the mitochondrial carrier protein,uncoupling protein 1 (UCP1). BAT has recently been demonstrated to increase triglyceride uptake and insulin sensitivity. Although the thermogenic responses of UCP1 KO mice have been well studied, little is known about the short and long term effects of UCP1 deficiency and how it affects BAT function and metabolism in general.

We used RNAseq to analyze and compare the BAT transcriptome of WT and UCP1 KO mice, under thermoneutral conditions at baseline and after catecholamine induced activation. The effects of aging on glucose and insulin tolerance and molecular markers of type 2 diabetes were investigated in WT and UCP1 KO mice in thermoneutrality for up to 1 year.

Whole transcriptome analysis, followed by qPCR and immunoblotting, revealed marked dysfunction of key metabolic pathways in activated BAT from UCP1KO mice compared to WT mice, while at baseline thermoneutral conditions the BAT transcriptome from UCP1KO and WT mice were similar. Further, UCP1KO mice age‐dependently develop hallmarks of type 2 diabetes, such as impaired glucose tolerance and increased insulin resistance, without developing an obesity phenotype.

We conclude that UCP1 KO mice are a model of severe BAT dysfunction. Long‐term BAT dysfunction is associated with age‐dependent development of hallmarks of type 2 diabetes.
c‐Fos increases functional β‐cell mass
Authors: Ray Jason , Bitner Ben , Kener Kyle , Walker Brent , Tessem Jeffery
Published: June 2021

β‐cell mass is lost in both major forms of diabetes. Mature β‐cells have restricted proliferative capacity. Studies aimed at increasing β‐cell mass frequently have the unwanted side effects of decreased glucose stimulated insulin secretion (GSIS) or increased apoptotic rates. Understanding the molecular pathways that enhance β‐cell mass while maintaining or improving GSIS and the response to apoptotic stimuli could be used as a treatment for diabetes. Overexpression of the β‐cell transcription factor Nkx6.1 induces β‐cell proliferation, enhances GSIS and protects against apoptosis. Nkx6.1 induces expression of VGF, which is necessary for enhanced GSIS and apoptotic resistance. Nr4a1 and Nr4a3 are also induced in the Nkx6.1 molecular pathway, and are necessary for β‐cell proliferation. Microarray analysis of Nkx6.1 expressing primary rat islets demonstrates upregulation of c‐Fos at 24 and 48 hours after adenoviral transduction. We have shown that c‐Fos upregulates expression of VGF, Nr4a1 and Nr4a3. In addition c‐Fos is sufficient to induce β‐cell proliferation. Finally, preliminary data suggest that c‐Fos modulates GSIS and the β‐cell response to apoptotic insults. We present a model by which c‐Fos is necessary for Nkx6.1 mediated β‐cell proliferation, enhanced GSIS and protection from apoptosis by inducing expression of Nr4a1, Nr4a3 and VGF.
Loss of Pancreatic Mitogen‐inducible Gene 6 Protects Mice Against Streptozotocin‐induced Diabetes
Authors: Fong Kimberley , Chen Yi‐Chun , Fueger Patrick
Published: June 2021

Type 1 diabetes (T1D) is caused by autoimmune‐mediated beta cell destruction. Following destruction, the pancreas attempts to mount a cellular repair/regenerative program, although this response is unable to fully restore functional beta cell mass. Epidermal growth factor receptor signaling (EGFR) is one component of the regenerative program. We previously demonstrated that a negative feedback inhibitor of EGFR, Mitogen‐inducible gene 6 (Mig6), is induced by pro‐inflammatory cytokines thought to participate in T1D‐mediated beta cell destruction, which may explain the inability to mount successful beta cell restoration in T1D. Thus, we hypothesized that a loss of Mig6 in the pancreas would confer resistance to a chemically‐induced form of diabetes. To this end, wetreated mice lacking pancreatic Mig6 (PKO) and their wild‐type littermates (WT) with multiple low doses of streptozotocin (STZ) to induce beta cell death and diabetes. We found that whereas STZ‐treated WT mice became hyperglycemic and glucose intolerant, STZ‐treated PKO mice remained euglycemic and fully glucose tolerant. We also demonstrated that pro‐inflammatory cytokines suppress EGFR activation, which can be partially corrected by siRNA‐mediated suppression of Mig6. Further, nitric oxide itself, the downstream toxic component of cytokines, induces Mig6, and nitric oxide synthase inhibition blocks the induction of Mig6 and EGFR signaling impairment mediated by cytokines. These data demonstrate that ablation of Mig6 promotes beta cell damage repair, thus abating the progression to T1D. Our work suggests that Mig6 may be a novel therapeutic target for T1D.
Clathrin and TOM1L1 regulate Epidermal Growth Factor Receptor Signaling at the Plasma Membrane
Authors: Judge Gurjeet , Garay Camilo , Lucarelli Stefanie , Bautista Stephen , Pandey Rohan , Antonescu Costin
Published: June 2021

Epidermal growth factor (EGF) receptor (EGFR) controls many aspects of cell physiology via the activation of intracellular signaling pathways. Ligand‐bound EGFR elicits phosphorylation of Gab1, which activates phosphatidylinositol‐3‐kinase (PI3K), which in turn leads to Akt phosphorylation and activation, controlling cell survival and metabolism. Rapidly upon binding EGF, the receptor is recruited to clathrin‐coated pits (CCPs), eventually leading to EGFR endocytosis. As such, receptor‐proximal EGFR signaling occurs while the receptor is enriched with clathrin‐coated plasma membrane microdomains. Whether and how clathrin microdomains may control EGFR signaling at the plasma membrane leading to Gab1 and Akt phosphorylation remains poorly understood. Using several specific molecular perturbations, we found that clathrin is required for EGF‐stimulated phosphorylation of Akt. Similar perturbations of dynamin were without effect on EGF‐stimulated Akt phosphorylation. This indicates that clathrin microdomains regulate EGFR signaling at the plasma membrane.

Clathrin interacts with and recruits numerous proteins to the plasma membrane including TOM1L1. We have examined the role of TOM1L1, which interacts with clathrin, EGFR and Src‐family kinases (SFKs). SiRNA gene silencing of TOM1L1 impairs EGF‐stimulated Akt phosphorylation. Using fluorescent labeling of clathrin, TOM1L1 and other signaling intermediates coupled to total internal reflection fluorescence microscopy, we have examined the hierarchy of the recruitment of EGFR signals to clathrin‐coated plasma membrane microdomains. Our findings suggest that TOM1L1 has a clathrin‐localized regulatory role in EGF‐stimulated Akt phosphorylation.
Understanding the p53 Aggregation Process through its Activators Resveratrol and PRIMA‐1
Authors: Silva Jerson , Costa Danielly , Campos Nathali , Costa Caroline , Rangel Luciana
Published: June 2021

Among other functions, p53 acts as a transcription factor and is involved in cell cycle control, leading to apoptosis or to the arrest of the cell cycle for DNA damage repair. It is mutated in around 50% of all tumors. In general, mutations occur on the DNA‐binding domain, leading to its loss of function as a transcription factor. It has been postulated that mutant p53 can form aggregates that are related to loss‐of‐function and cancer development. Also, new data have contributed to the spread the application of the prion concept on different amyloid diseases. In this work, we show that the effect of mutant p53 on wild type p53 aggregation occurs in a prion‐like fashion. We have also observed that resveratrol, a natural polyphenol known for its p53 activation properties, and PRIMA‐1, a classical stabilizer and reactivator of mutant p53 structure and function, exert their effects on aggregated mutant p53. Also, resveratrol and 2‐methylene‐3‐quinuclidinone hydrate (MQ), the major PRIMA‐1 active metabolite, have been shown to inhibit WT and mutant p53 core domain (p53C) aggregation at 37oC. The p53 WT form has been protected in a lower degree. MQ has also been shown to inhibit the seeding promoted by mutant p53 cellular extract on WTp53C. The same seeding inhibition effect was observed for extracts from cells treated with PRIMA‐1. Altogether, these findings indicate that prion‐like aggregation of p53 is a good therapeutic target in cancer. Supported by FAPERJ and CNPq.
Nir2 Plays a Central Role in ER‐PM Junctions Maintaining Phosphoinositide Signaling Competence
Authors: Kim Yeun ju , Guzman‐Hernandez Maria , Wisniewski Eva , Balla Tamas
Published: June 2021

During phospholipase C activation, large amounts of phosphoinositide lipids are consumed while generating the second messengers, diacylglycerol (DG) and InsP3. The small PtdIns(4,5)P2 pool is turned over multiple times and it has been evident that the plasma membrane (PM) inositide pools need to be replenished for sustained signaling with newly synthesized phosphatidylinositol (PtdIns) originating from the ER. Conversely, phosphatidic acid (PtdOH) generated via DG in the PM has to return to the ER where it is utilized for PtdIns synthesis. Although PtdIns transfer protein has been postulated to transport PtdIns from the ER to the PM, the protein responsible for PtdOH transport in the other direction has remained elusive. In this study we used a combination of methods all based on intact cells and found that depletion of Nir2, a homolog of the Drosophila RdgB protein, which has previously been identified as a PtdIns transfer protein, causes a defect both in the utilization of PtdOH at the PM and the synthesis of PtdIns in the ER during PLC activation. Conversely, overexpression of Nir2 facilitates PtdOH removal from the PM and its conversion to PtdIns in agonist‐stimulated cells. These data together with the agonist‐induced translocation of Nir2 into ER‐PM contact sites suggest that Nir2 plays a critical role in the recycling of the lipid products of PLC activation and that the agonist‐induced increased turnover of PtdIns described several decades ago is spatially confined to ER‐PM contact zones.
Transgenerational Effects on the Feeding Behavior of the Offspring
Authors: Silva‐Filha Elizabete , Costa Tamires , Farias Bruna , Santos Polyana , Santana Michael , Macedo Fabricio , Santos Robervan , Santana‐Filho Valter
Published: June 2021

The aim was evaluate if the alterations promoted by the insertion of a western diet during the perinatal period can be transgenerational. 4 female rats mated in the ratio 2:1. After pregnancy confirmation, a western on control diet was offered until the weaning of the pups. Pups of both groups were accompanied until complete 90 days, and then were placed to mate. After pregnancy confirmation, all rats were fed with a standard rodent diet. After weaning, rats were divided in 2 groups: second‐generation control offspring (2ºCO) and second‐generation western offspring (2ºWO), both fed with the same standard diet. Offspring body weight (BW) was measured weakly until the 90th day, dietary intake (DI) and calorie consumption (CC) was accompanied during a period of 10 days between the 30th and 40th day (young stage ‐YS) and the 60th and 70th day (adult stage ‐ AS). Offspring fasting glucose was evaluated with 30, 60 and 90 days. 2ºWO pups born with increased BW (2ºCO 5.41 ± 0.08 vs 2ºWO 6.82 ± 0.11) and maintained higher until 90th day(2ºCO 222 ± 5.11 vs 2ºWO 277 ± 4.6). In addition, 2ºWO pups had increased DI and CC in both periods, YS (DI: 2ºCO 121.3 ± 2.75 vs 2ºWO 132.6 ± 3.12) ‐ (CC: 2ºCO 552.14 ± 12.48 vs 2ºWO 603.42 ± 8.24) and AS (DI: 2ºCO 202.1 ± 6.42 vs 2ºWO 220 ± 2.64) ‐ (CC: 2ºCO 641.01 ± 21.11 vs 2ºWO 700.38 ± 14.11). In relation to fasting glucose, no change was observed in any of the periods (30 days: 2ºCO 84.83 ± 2.01 vs 2ºWO 89.5 ± 1.87; 60 days: 2ºCO 87.83 ± 3.88 vs 2ºWO 82.67 ± 2.60; 90 days: 2ºCO 93.83 ± 2.54 vs 2ºWO 82.66 ± 1.87). In conclusion, these findings suggests that dietary patterns influence directly the feeding behavior of future generations.
Lung Cancer Cellular Apoptosis Induced by Recombinant Human Endostatin Gold Nanoshell‐Mediated Near‐Infrared Thermal Therapy
Authors: Luo Haiqing , Xu Meng , Zhu Xinhai , Zhao Jianfu , Man Shiqing , Zhang Haoran
Published: June 2021

Recombinant human endostatin (rhES)can inhibit tumor cell proliferation and apoptosis. The effect of proliferation and apoptosis of A549 lung cancer cells induced by gold nanoshell particles of recombinant human endostatin (G‐rhES) with near‐infrared (NIR) irradiation was studied. Gold nanoshell particles were prepared. Endostatin was connected with the bond A‐U through surface modification by bioconjugation of core‐shell structured gold nanoshells. Proliferation of A549 lung cancer cells induced by G‐rhES was detected by MTT. Cellular apoptosis was researched by flow cytometry. Mitochondrial membrane potential was investigated using a confocal microscope. Morphological changes were studied by atomic force microscopy. Under irradiation in the 820 nm NIR, the proliferation of A549 lung cancer cells was significantly induced by G‐rhES. NIR gold nanoshell particles showed synergism with endostatin, which may be related to hyperthermia‐increased apoptotic effect of endostatin. Our study results suggest that G‐rhES can inhibit lung cancer cells proliferation.The new treatment strategy of G‐rhES combined with thermal therapy may lead to lung cancer remission.

Concentration (ug/ml)
24h
48h
72h

Inhibition rate (%)
Inhibition rate (%)
Inhibition rate (%)

0
‐
‐
‐

2.5
1.2
2.4
3.4

5
4.0
5.9
6.3

10
4.4
6.3
10.2

20
13.7
15.8
17.8

40
16.8
18.5
25.1

80
20.7
25.6
30.1

Concentration (ug/ml)
Apoptotic rate (%)

0
0.9+—0.1

10
5.4+—2.3

20
15.9+—4.9

40
21.4+—2.8

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Effects of Raspberry on Biomarkers of Diabetes, Cardiovascular Disease (CVD) and Oxidative Stress in Obese Diabetic (db/db) Mice
Authors: Atienza Liezl , Garcia Perez Enrique , Noratto Giuliana
Published: June 2021

Diabetes and its complications are considered major health problems worldwide. Oxidative stress associated with diabetes increases the risk of developing CVD. Red raspberry contains bioactive compounds such as polyphenols which may prevent and treat these diseases. The study investigated the effects of raspberry (Wakefield red raspberries) on diabetes, cardiovascular risk factors and oxidative stress in db/db mice. Thirty male db/db mice were divided into two groups and fed ad libitum for 8 weeks with standard diet (control group) and isocaloric standard diet containing 10% freeze dried raspberry (raspberry group). At the end of the study mice were euthanized; tissue and blood were collected and analyzed using standard techniques. Results indicate that raspberry consumption did not decrease significantly (p>0.05) the blood triglycerides and total cholesterol; though abdominal fat decreased by 38% (p > 0.05). Raspberry increased the plasma high density lipoprotein cholesterol by 1.5‐fold, whereas low density lipoprotein cholesterol decreased by 0.3‐fold. Moreover, the insulin tolerance test showed a trend to increase insulin sensitivity in the raspberry group; this was accompanied by a 19% decrease in reactive oxygen species measured in blood erythrocytes. These findings may suggest the potential role of raspberry in decreasing cardiovascular risk in diabetics.
Quality of Diet and Body Mass Index are Factors Involved in DNA Damage in Human Lymphocytes
Authors: Corrêa Camila , Talon Lidiana , Pierine Damiana , Francisqueti Fabiane , Minatel Igor , Santos Klinsmann , Nunes Vânia , Ferreira Ana Lucia , Corrente José
Published: June 2021

The aim was to evaluate the nutritional status and quality of diet on DNA damage in peripheral lymphocytes. 80 women were attended in Clinical Hospital, Brazil and classified according with body mass index (BMI). Group 1 (G1, control) 36 (18.5 and 24.9 kg/m2); group 2 (G2, overweight) 21 (25 to 29.9 kg/m2); group 3 (G3, Metabolic syndrome) 23 (BMI e 30 kg/m2 and three had BMI of 25 to 29.9 kg/m2). Dietary intake; plasma antioxidant capacity (TAP) and malondialdehyde (MDA); carotenoids, retinol and α‐tocopherol and the comet assay. The G1 had lower values of MDA, DNA damage and oxidized purines than G2 and G3. Pyrimidines were greater in G2 and TAP was higher in G3 compared to G1. Dietary intake differed significantly among groups: G2 and G3 consumed more protein and less vitamin C than G1; G2 had lower iron intake and increased sodium intake; and G3 ingested less calcium than G1. Alpha‐carotene in G2 and G3 was decreased, the G3 group showed lower values for cryptoxanthin and β‐carotene and higher values for retinol. Uric acid was proportional increasing BMI. Linear regression showed that greater vitamin D consumption and lower serum levels of α‐carotene were related to higher BMI. In addition, a greater consumption of protein and sodium correlated with higher BMI, and calcium appeared to provide a protection from DNA damage. Worsened nutritional status influences in metabolic and oxidative stress and DNA damage and the diet quality and BMI are the factors that most influenced changes in these parameters. Financial support FAPESP: 2011/08373‐5 and 2014/23450‐4.
Comparison of Phenolic Acids on Alleviating High‐Fat and High‐Fructose Diet‐Induced Metabolic Dysfunctions
Authors: Wang Ou , Zhang Di , Cheng Qian , Liu Jia , Guo Xiaoxuan , Ji Baoping
Published: June 2021

Phenolic acids, one of the major kinds of polyphenols, widely present in edible plants and have many health benefits. This study compares the alleviation effects of six kinds of common phenolic acids on high‐fat and high‐fructose diet (HFFD)‐induced metabolic dysfunctions. Male Sprague‐Dawley rats were fed on normal diet, HFFD, and HFFD supplemented with equimolar of phenolic acids (2.6 mmol/kg diet) for 13 weeks. Lipid and glucose metabolism, insulin resistance (IR) index, hepatic functions, inflammation levels, serum antioxidant capacity were analyzed at the end of the experiment. Results showed that gallic acid and ρ‐coumaric acid treatments showed potential better effects in lowering liver index and inhibiting hepatic fat accumulation, but gallic acid failed to improve serum antioxidant capacity. Caffeic acid treatment could not inhibit the HFFD‐induced body weight gain and liver index increase significantly, but it ranked highly among all the groups in markedly lowering serum lipids levels, normalizing hepatic functions, enhancing antioxidant capacity and improving IR. Chlorogenic acid and ellagic acid exhibited significant effects in lowering C‐reaction protein and interleukin‐6 levels and increasing adiponectin concentration, which were better than the other groups. Protocatechuic acid was the least effective one among these groups as less significant effect was observed. The results suggest that under the same applied dosage, phenolic acids alleviate different deleterious effects of HFFD.
Increased Ferric Iron Species in Lactic Fermented Vegetables May Improve Iron Absorption
Authors: Scheers Nathalie , Rossander‐Hulthen Lena , Torsdottir Inga , Sandberg Ann‐Sofie
Published: June 2021

The objective of the present study was to investigate if the absorption of iron from a vegetable mix was improved by lactic fermentation and to propose a mechanism for such an event. We have conducted human studies, in vitro cell studies, and iron speciation measurements (voltammetry). In human subjects, we observed that lactic fermented vegetables served with both a high‐phytate and low‐phytate meal increased the absorption of iron. In vitro digested fermented vegetables were able to provoke a greater hepcidin response than fresh vegetables, indicating that Fe in the fermented mixes was more bioavailable, independent on the soluble Fe content. We measured that hydrated Fe3+ species were increased after the lactic fermentation while there was no significant change in hydrated Fe2+. Furthermore, lactate addition to Caco‐2 cells did not affect ferritin formation in response to Fe, nor did lactate affect the hepcidin response in the Caco‐2/HepG2 cell system. The mechanism for the increased absorption of iron from lactic fermented vegetables is likely to be an effect of the increase in ferric iron (Fe3+) species.
Disruption and Proteome Alterations of Escherichia coli Induced by a Novel Antimicrobial Peptide from Tibetan Kefir
Authors: Miao Jianyin , Liu Guo , Chen Feilong , Duan Shan , Chen Yunjiao , Gao Xiangyang , Dixon William , Xiao Hang , Cao Yong
Published: June 2021

Our previous study has demonstrated the broad spectrum of antibacterial activities of a novel peptide F1 against fungi, gram‐positive and gram‐negative bacteria. F1 was produced by Lactobacillus paracasei subsp. Tolerans FX‐6 isolated from Tibetan kefir. This study was aimed to reveal the mechanisms for the antibacterial effects of F1 on Escherichia coli using transmission electron microscope and iTRAQ‐based quantitative proteomic analysis. The ultrastructural observation showed that the Escherichia coli cells shrunk after being treated with F1 for 0.5 h or 1 h, suggesting that there was a large extent of cytoplasmic leak. After 2 h, the cell was completely deformed and lysed. The results from iTRAQ‐based quantitative proteomic analysis showed that among 280 identified proteins in Escherichia coli, there were 31 proteins with significantly altered expression levels in response to the treatment of antimicrobial peptide F1, including 10 down‐regulated proteins and 21 up‐regulated proteins. Each of these proteins has different molecular functions according to the Kyoto Encyclopedia of Genes and Genomes pathways. Specifically, the tricarboxylic acid cycle, oxidative phosphorylation, glycerophospholipid metabolism, and cell cycle‐caulobacter pathways, which are associated with Escherichia coli cell death, were affected to the largest extent by the antimicrobial peptide F1. Overall, our study demonstrated a global response of Escherichia coli to the antimicrobial peptide F1, which provides novel insights on the mechanisms of antimicrobial peptides.
Effects of Zinc Supplementation on Cardiac Remodeling After Experimental Myocardial Infarction
Authors: Gonçalves Andrea , Santos P , Rafacho B , Silva R , Batista D , Claro R , Bazan S , Okoshi K , Polegato B , Gaiolla P , Minicucci M , Paiva S , Chiuso‐Minicucci F , Zornoff L
Published: June 2021

Objective

To analyze the effects of zinc supplementation on cardiac remodeling after myocardial infarction. Methods: After experimental infarction, Wistar rats were allocated in two groups: Infarction Control (IC, n=23), that received saline IP every other day, and Infarction Zinc (IZ, n=24), with zinc supplementation (0.5mg/kilo) IP every other day. Sham animals were included and divided in two groups: Sham Control (SC; n=15), treated with saline, and Sham Zinc (SZ; n=15), with zinc supplementation. After 3 months, the animals were submitted to echocardiogram. The effect of infarction (I), Zinc (Z) and the interaction between the factors (IxZ) were analyzed by two way ANOVA. Results and conclusion: Zinc attenuated remodeling by reducing systolic area (SC: 22.6 ± 3.7; SZ: 11.2 ± 3.7; IC: 50.1 ± 2.6; IZ: 44 ± 2.6; p(I) <0.001, p(Z) 0.007, p(IxZ) 0.401) and diastolic area (SC: 50.8 ± 4.7; SZ: 40.1 ± 4.7; IC:79.4 ± 3.2; IZ: 74.9 ± 3.2; p(I) <0.001, p(Z) 0.057, p (IxZ) 0.43) and improving systolic function (shortening velocity of posterior wall SC: 55.6 ± 2.5; SZ: 64 ± 2.5; IC: 36 ± 1.6; IZ: 39.2 ± 1.6; p(I) <0.001, p(Z) 0.01, p(IxZ) 0.245) and diastolic function (E/E'= SC: 13.2 ± 1; SZ: 11.9 ± 1; IC: 17.6 ± 0.7; IZ: 15.5 ± 0.7; p(I) <0.001, p(Z) 0.052, p(IxZ) 0.598). Financial support: Fapesp: 13/06862‐4; 12/14500‐2.
The Effects of Recovery Time from Heat Stress on Circulating Bioenergetic Variables and Biomarkers of Leaky Gut
Authors: Abuajamieh M , Laughlin E , Lei S , Stoakes S , Mayorga E , Seibert J , Nolan E , Sanz‐Fernandez M , Ross J , Selsby J , Rhoads R , Baumgard L
Published: June 2021

The metabolic consequences of heat stress (HS) are atypical (i.e. hyperinsulinemia) considering the animal's nutritional status and a compromised intestinal barrier may initiate the pathophysiological consequences of HS. However, the temporal pattern of metabolic and leaky gut variables during HS recovery is not well‐understood. Female pigs (n=32; 19.5±1.3 kg BW) were sacrificed following exposure to one of four environmental protocols: 1) constant thermoneutral conditions (TN; 24.2°C and 57.2% RH), 2) no TN recovery following 3 d of HS (0d), 3) 3 d of TN recovery post 3 d of HS (3d), 4) 7 d of TN recovery post 3 d of HS (7d). The HS protocol was cyclical (33.6 to 37.4°C, 29.5% RH). All pigs were fed ad libitum. During the heat load, HS increased rectal temperature (P<0.01; 1.0ºC), and respiration rate (P<0.01; 63 bpm), but decreased feed intake (P<0.01; 24%) and growth (P<0.01; 33%) compared to TN controls. Blood glucose was decreased (P<0.05; 10%) for the 0 d pigs, but returned to TN levels by 3 and 7d. Recovery length did not affect circulating NEFA (P>0.73), insulin concentrations or the insulin:glucose (P=0.80). However, the insulin:feed intake was increased in the 0d compared to the TN controls (P=0.06; 49%). Lipopolysaccharide binding‐protein was markedly increased (P<0.05) with advancing recovery time: 67, 110, and 150% in 0, 3, and 7d pigs compared to TN controls, respectively. In summary, HS did not have a lasting effect on energetic variables, but advancing recovery length was associated with progressively increased biomarkers of leaky gut.