bluuebunny/crossref_metadata_2025_split huggingface dataset:
Enzymes Running in Reverse: Catalytic Studies on Isocitrate Dehydrogenase Mutations Implicated in Cancer
Authors: Sohl Christal , Matteo Diego Avellaneda , Grunseth Adam , Anselmo Stacy , Gonzalez Eric , Kennedy Madison 
Published: November 2023

While it has been nearly a century since metabolic alterations in tumors were first described, only relatively recently have mutations in metabolic enzymes been implicated in cancer. Isocitrate dehydrogenase 1 and 2 (IDH1 and IDH2), the enzymes responsible for the NADP+– dependent oxidation of isocitrate (ICT) to α‐ketoglutarate (αKG), are mutated in over 80% of adult grade II and grade III gliomas and secondary glioblastomas, and up to 20% of acute myeloid leukemias. These mutations have tumor suppressive properties in that they are significantly deficient in the normal oxidation reaction. Surprisingly, a class of these mutations can also serve as oncoproteins in that they can catalyze a new reduction reaction, generating the proposed oncometabolite 2‐hydroxyglutarate (2HG). This suggests intriguing catalytic and structural mechanisms are at work in both types of mutations. By using kinetic and structural methods, we are exploring the molecular mechanisms of dysfunction of mutations identified in tumors that are proposed to serve as either oncoproteins or tumor suppressors depending on their ability to catalyze 2HG formation. Through these structure‐function relationships, we can understand the catalytic attributes that result in these dysfunctional activities that can promote tumorigenesis.Support or Funding InformationThis work is supported by NIH R00CA187594.
New Insights into the Anatomy of the Bulbospongiosus Muscle and Its Role in the Composition of the External Anal Sphincter in Humans
Authors: Hall Margaret , Plochocki Jeffrey H , Adrian Brent , Rodriguez‐Sosa Jose R. 
Published: November 2023

Traditional descriptions of the bulbospongiosus muscle in males and females describe a striated muscle overlying the most proximal portion of the corpus spongiosus, the bulb of the penis in males, and the bulbs of the vestibule in females. Likewise, in both sexes the bulbospongiosus muscle and the superficial transverse perineal muscles are described as inserting at the midline on the perineal body. In dissections of forty (40) human cadavers we found both of these descriptions do not accurately characterize the anatomy. In all forty cadavers examined, as suggested by the embryology literature, the adult bulbospongiosus continues from the urogenital triangle to the anal triangle as an uninterrupted ring of muscle that forms the superficial portion of the external anal sphincter and passes deep and lateral to the perineal body without insertion. Additionally, the superficial transverse perineal muscle passes anteriorly and superiorly to insert onto the bulbospongiosus muscle, and does not follow traditional descriptions asserting that this muscle continues medially from the ischial tuberosities to the perineal body. The perineal body is inferior to the rest of the perineum and in the great majority of cadavers we did not observe any muscle fibers inserting on the perineal body, again contradicting the published literature. Dissections of the external anal sphincter demonstrate that the subcutaneous external anal sphincter has a different fiber direction and is not continuous with the superficial external anal sphincter. Also, the deep external anal sphincter is continuous with the puborectalis muscle and is located deep to and separate from the superficial external anal sphincter. Therefore, we suggest that the traditionally conceived external anal sphincter, with three parts of a single muscle, is more usefully described as three individual muscles.Support or Funding InformationMidwestern University Intramural Funds
Mitochondrial Calcium Entry Induces Mitochondrial Reactive Oxygen Species Production by ATP Synthase‐uncoupled, But Proton Leak‐coupled Mechanism – A New System of How Atherogenic Stimuli Activate Aortic Endothelial Cells without Compromising Endothelial Cell Survival
Authors: Li Xinyuan , Fu Hangfei , Fang Pu , Koch Walter J , Wang Hong , Yang Xiao‐Feng 
Published: November 2023

Previously considered as toxic byproducts of cellular metabolism, it was recently discovered that mitochondrial reactive oxygen species (mtROS) are in fact signaling molecules, which drive inflammatory cytokine production and T cell activation. In addition, pathological conditions as diverse as cancer, autoimmune diseases, and cardiovascular diseases all share common feature of increased mtROS production above basal levels. MtROS are generated from the partial oxygen reduction in the electron transport chain and a number of factors have been linked to mtROS production, including mitochondrial calcium (Ca2+), mitochondrial membrane potential, and proton leak. However, since mtROS and ATP production are both coupled to electron transport chain activity, it is unclear whether mitochondrial ROS could be induced independently from ATP synthesis in the cell. By using Seahorse XF96 mitochondrial function analyzer and other molecular biology approaches, we found that during endothelial cell (EC) activation process induced by proatherogenic stimuli lysophosphatidylcholine (lysoPC), mitochondrial calcium entry mediates proton leak‐coupled, but ATP‐synthesis‐uncoupled mitochondrial respiratory chain acceleration and increased mtROS production. By doing this, EC could upregulate mtROS production without compromising mitochondrial membrane potential and ATP generation, and consequently without causing mitochondrial damage and endothelial cell death. Thus, we uncovered a novel pathophysiological role of proton leak in fine‐tuning mtROS production for endothelial activation purpose without compromising endothelial cell survival. This new working model explains how mtROS could be increasingly generated independently from ATP synthesis. Our finding is significant towards the development of novel mitochondrial ROS‐modulating therapies to combat cardiovascular inflammatory diseases, atherosclerosis, autoimmune diseases and cancers.Support or Funding InformationNIH RO1 HL 108910‐01
Hypoglycaemic Activity of the aqueous extract of Costus afer stems alone and in combination with metformin
Authors: Monago Comfort , Anacletus Francis Chukwuma , Nwauche ThankGod Kelechi 
Published: November 2023

Medicinal plants are reservoirs of natural products with anti‐diabetic potentials. In the present study we screened Costus afer for the presence of plant products and to study the effects of the aqueous stem extract of the plant on fasting blood glucose of streptozotocin induced diabetic male rats. Adult male wistar strain albino rats were given graded doses (500, 1000 and 1500mg/kg) of the aqueous stem extract of Costus afer, and a standard hypoglycaemic drug, metformin was co‐administered with 500mg/kg of the plant extract for a period of 3, 6 and 9 weeks. The statistical analysis was carried out using one way ANOVA followed by post hoc LSD multiple comparison on SPSS 19. Costus afer showed significant hypoglycaemic effect (p<0.05) compared to glucose level of the normal control rats. Also, a combination of plant extract and metformin caused a significant reduction in fasting blood sugar of the streptozotocin induced diabetic rats. In histological evaluation of the pancreas, the islet cells of the Langerhan of the pancreas were repopulated and preserved in all the groups treated with the plant extract and its combination with metformin against the diabetic control group whose islet cells were reduced. The results validate the use of Costus afer as a hypoglycaemic plant in native medicine. Costus afer could be a promising plant for the development of anti‐diabetic drugs.Support or Funding InformationResearch was funded by the authors.
Sub‐Acute Administration of Ethanol Extracts of Erythrophloem suavolens Induced Hepatotoxicity and Oxidative Stress in Wistar Strain Albino Rats
Authors: ADISA RAHMAT ADETUTU , NWALIOBA COSMOS U , AKUJOBI SYLVIA , ORIBABOR JUDE 
Published: November 2023

Erythrophloem suavolens is a known poisonous plant to livestock, insects and humans. However, there is no known scientific basis for the toxic effects of this specie. The present study was designed to investigate the hepatotoxic and antioxidative effects of 28 days sub‐acute administration of ethanol extracts of E. suavolens stem bark (EESB) to albino rats. Graded doses of EESB (50, 100, 150, 200 mg/kg) were administered to each of groups II – V of 5 animals each for 28 days, respectively. Group I served as control and received distilled water. Hepatotoxicity, hepatic antioxidant status and levels of plasma lipid profile were determined. Sub‐acute administration of EESB decreased the activities of superoxide dismutase and catalase as well as levels of glutathione in liver homogenate, post‐mitochondrial and mitochondrial fractions, respectively. The amount of malondialdehyde produced increased significantly (p<0.05, p<0.01) and dose‐dependently in all the hepatic fractions, respectively compared to control. The activities of alkaline phosphatase, alanine and aspartate amino transferases were decreased non‐significantly (p>0.05, p>0.01), respectively compared to control animals. Low density lipoprotein, total cholesterol and triglyceride levels decreased non‐significantly but markedly at 200 mg/kg of EESB. Non‐significant increase in level of high density lipoprotein was observed in the EESB‐treated animals. Plasma albumin and total protein concentrations of EESB‐treated group were not significantly different from control. Photomicrographs of liver sections showed necrotic lesions at 200 mg/kg dose.These findings suggest that sub‐acute administration of EESB is hepatotoxic which seems mediated by induction of oxidative stress.
The Role of Semen‐Derived Exosomes on Acute HIV Infection in T Lymphocytes
Authors: Moricz Bridget , Madison M. Nia , Welch Jennifer , Okeoma Chioma 
Published: November 2023

About 35 million people are infected with HIV and even with antiretroviral therapy, the infected individuals are still not living a normal life expectancy. Exosomes, nanovesicles with host proteins and small RNAs, have been shown to possess antiviral properties including suppression of HIV infection. However, these studies were performed in a short‐term setting within 24–48 hours post infection. Here we sought to determine the role of semen exosomes on HIV infection in a longer setting, up to ten days post infection. Semen exosomes were added to acutely infected Jurkat cells and aliquots of the cells and media were taken every two days. The samples were then analyzed for viral integration, replication and fitness either by qPCR, gel electrophoresis or reverse transcriptase assays. Based on the results, exosomes decrease HIV integration, replication and progeny fitness.Support or Funding InformationNSF REU in Microbiology at The University of Iowa through grant number DBI‐1262222
Uncovering the mechanism of trogocytosis in Entamoeba histolytica
Authors: Feeney Shea E. , Ralston Katherine S. 
Published: November 2023

Entamoeba histolytica (histolytica: tissue dissolving) is a eukaryotic pathogen that is the causative agent of amoebiasis. Amoebiasis is a global concern that is responsible for 50 million cases of diarrheal infections, and 100,000 deaths per year primarily in developing countries. This infection causes diarrhea and can also lead to invasive colitis and extraintestinal disease. In some cases, amoebae can spread to the liver and cause abscesses. Killing of human cells by the amoebae is likely to drive this tissue destruction. Our lab recently showed that the amoebae kill human cells by nibbling off bites via trogocytosis (trogo‐: nibble) and discard dead cell corpses, whereas dead cells are ingested whole via phagocytosis. While trogocytosis also occurs in a variety of other microbes and multicellular organisms, the mechanism is not known. In immune cell trogocytosis, two small GTPases have been identified that are involved in its regulation, and one has been shown to be specific to trogocytosis. Thus although trogocytosis and phagocytosis may share some mechanistic components, there are likely to be unique proteins specifically involved in trogocytosis that have not yet been identified. Therefore, I propose that amoebic trogocytosis in E. histolytica requires specific signaling machinery that is distinct from phagocytosis. The discovery of genes involved in amoebic trogocytosis in E. histolytica is not only relevant to the pathogenesis of amoebiasis, but also to the many other organisms that nibble. Two complementary approaches are being utilized to address this hypothesis, a forward genetic screen and transcriptomics analysis, to identify genes uniquely involved in trogocytosis that are not involved in phagocytosis. I am taking advantage of the endogenous RNAi pathway in E. histolytica in order to perform two different forward screens to isolate trogocytosis or phagocytosis mutants. Preliminary studies provide proof of principle that ingestion mutants can be isolated by selection. Since there is evidence that both phagocytosis and trogocytosis are transcriptionally regulated in E. histolytica, I am also performing RNA‐seq analysis to examine differential gene expression in amoebae undergoing trogocytosis versus phagocytosis. My preliminary results with imaging flow cytometry have shown a method to quantify and optimize the number of amoebae performing either trogocytosis or phagocytosis respectively. These results will help to define the mechanism for trogocytosis, an important cellular function in a variety of unicellular and multicellular organisms.Support or Funding InformationNIH MCB T32 GM007377; NIH NIAID K22 Career Transition Award Al108814
Culture Of Urine Sediment Reveals Differences Between Patients With Overactive Bladder (OAB) And Controls: Are Changes In The Bladder Microbiome Responsible For Symptoms Of OAB?
Authors: Krska Louise , Balachandran Aswini , Caballero Nadine , Curtiss Natasha , Peppiatt‐Wildman Claire , Strutt Matthew , Duckett Jonathan , Wildman Scott S.P. 
Published: November 2023

Overactive bladder (OAB) is a common syndrome characterized by increased frequency, urinary urgency, urinary incontinence and nocturia. The cause of idiopathic OAB is unknown, however, a recent investigation has shown that antibiotics may reduce the symptoms of OAB in some patients (1). There is also an increasing body of evidence to suggest that the human bladder has a microbiome, missed by conventional urinalysis and culture (2). Consequently, infection may be a possible cause for the symptoms of OAB in some patients affected by this syndrome.We hypothesise that changes in the urinary tract microbiome are responsible for the symptoms of OAB. The aim of this investigation is to compare the species of bacteria in the urine of patients with OAB and age‐matched controls.Urine samples (5 ml), taken from females aged 35–87 via MSU sampling techniques, were centrifuged, re‐suspended and plated on chocolate agar plates in aerobic and anaerobic conditions for 7 days. Purity plating was performed and isolates identified by sequencing of the 16s rRNA gene.Sediment culture of MSU samples reveals a variety of species of bacteria in urine of both patients with OAB and controls. The average number of species, as identified by our methodology, is 5 per patient in both groups. In controls, the most notable species are Staphylococcus, Streptococcus and Lactobacillus. With increased age, these notable species decrease and other species such as Escherichia coli (E.coli), Campylobacter and Bifidobacterium increase in prevalence. Comparing the microbiome of age‐matched controls with that of patients with OAB, shows that the incidence of E.coli, Campylobacter, Enterococcus and Proteus are further increased.In an attempt to confirm that the bacteria observed was not a contamination artefact of using MSU samples, we performed similar analysis on CSU samples. Preliminary data indicates a trend for increases in the incidence of E.coli and Comamonadaceae and a decrease in Gardnerella and Staphylococcus in patients with OAB.Evidence presented here supports recent observation that the bladder has a microbiome and urine is not sterile. Furthermore, there appears to be differences in the bladder microbiome between patients with OAB and controls, and these differences become more apparent in the aged. A more thorough analysis of the microbiome, including antibiotic protection assays on each sample, is now under way.Support or Funding InformationKidney Research UK
Novel cancer‐oocyte biomarker SAS1B as a potential target in head and neck squamous cell carcinoma (HNSCC)
Authors: Lee Christina Ju , Anderson‐Knapp Kiley , Pires Eusebio , Jameson Mark , Herr John 
Published: November 2023

Head and neck squamous cell carcinoma (HNSCC) is the most common cancer of the head and neck region with a low overall 5‐year survival rate of 50%, highlighting the need for more effective therapeutics. A novel cancer‐oocyte biomarker, SAS1B (sperm acrosomal SLLP1 binding protein), presents substantial opportunities for development of novel diagnostics and therapeutics for patients with HNSCC. SAS1B has been recently discovered as a membrane‐associated zinc metalloprotease expressed in growing oocytes housed in the secondary follicle stage through ovulation, and is virtually absent in other tissues. SAS1B has been identified in approximately 77% uterine tumors including 74% endometrioid and 87% malignant mixed Mullerian tumors (MMMT). Given the range of cancers expressing SAS1B, probing for SAS1B gene and protein may increase the number of possible cancer patients in which a therapeutic method targeting SAS1B would potentially be beneficial. Twenty‐four primary human tumor specimens and eight HNSCC human‐derived cell lines were analyzed for ASTL message and SAS1B protein. A PCR assay unique to ASTL/SAS1B, excluding all of the other 134 human metalloproteases, has been developed with validated primers to amplify various domains of ASTL/SAS1B transcripts. SAS1B was identified in all samples of cell lines and primary tumors [100% incidence] using primers spanning a part of the c‐terminus of SAS1B. In addition, 46kDa and 65kDa SAS1B isoforms have been identified by Western blot using anti‐SAS1B polyclonal antibodies. To test the possibility of SAS1B as an immunotherapeutic target for HNSCC, live cell staining of an HNSCC cell line, OSC19 was carried out using indirect immunofluorescence with anti‐SAS1B polyclonal antibodies revealing cell surface localization of SAS1B. Future experiments will focus on in‐vitro cell killing assays using a duocarmycin‐conjugated antibody to test internalization of the antibody drug conjugate and subsequent growth arrest capabilities. The restricted localization of SAS1B presents opportunities for development of novel diagnostics and highly selective treatment approaches that spare both normal tissues and the ovarian reserve, thus potentially preventing unwanted negative side effects common in currently available therapeutics.Support or Funding Informationn/A
Galangin‐induced cell arrest and apoptosis of nasopharyngeal carcinoma cells through suppression of PI3K/Akt signaling pathway
Authors: Lee Chuan‐Chun , Lin Meng‐Liang , Meng Meng‐Hsiao , Chen Shih‐Shun 
Published: November 2023

Aberrant activation of phosphatidylinositol 3‐kinase (PI3K)–(protein kinase B) Akt signaling is associated with nasopharyngeal carcinoma (NPC) cells resistance to conventional chemo/radiotherapy. We show that natural active compound 3, 5, 7‐trihydroxyflavone (galangin), a type of bioflavonoid extracted from the galangal root (Alpinia galangal), can induce apoptosis and S‐phase arrest of NPC cells through p53‐medulated expression of Bax and p21. Using cell cycle synchronization techniques, we demonstrated that S‐phase synchronized NPC cells were more sensitive to galangin‐induced apoptosis. In ATP‐competitive inhibition assay and thin‐layer chromatography separation of the γ‐32P‐labeled phosphatidylinositol 3, 4, 5‐triphosphate product of kinase reaction with purified recombinant p85α and p110α proteins, we found that galangin might be an ATP‐competitive inhibitor by competing ATP binding site on PI3K catalytic subunit p110 alpha with ATP. Our results indicate that galangin induces p53‐mediated cell cycle arrest and apoptosis of NPC cells by interaction with ATP binding site on p110 alpha catalytic domain of PI3K.Support or Funding Information
Exosomes Secreted by Inflammatory Cytokine Stimulated Glioma Cells Carry a Repertoire of Proteins Which Influence Progression of Glioblastoma Multiforme
Authors: Kore Rajshekhar A , Abraham Edathara C , Griffin Robert J 
Published: November 2023

Astrocytes constitutively secrete exosomes, a set of distinct nanovesicles (30–100 nm) of endosomal origin. In glioblastoma multiforme (GBM), exosomes are involved in mediating intercellular communication by their ability to deliver potentially oncogenic cargo leading to modulation of tissue microenvironment and progression of GBM. Inflammation and oxidative stress have been demonstrated to be connected in the development of GBM. Additionally, pro‐inflammatory cytokines like interleukin‐1 beta (IL‐1β) and tumor necrosis factor‐alpha (TNF‐α) are upregulated in the brain and elevated in serum following radiation therapy in patients with primary GBM tumors. Among others, these cytokines play an important role in progression of neuroinflammation and inflammation driven tumor re‐growth after treatment.MethodsMedia from cultured glial cell lines was subjected to sequential centrifugation to isolate exosomes. Exosomes were characterized by presence of exosomal markers and electron microscopy (EM). Exosomal proteins were analyzed by mass spectrometry (MS). Cell based assays were used to investigate the effect of exosomes secreted by cytokine stimulated cells.ResultsHere we present evidence showing that exosomes (~70–80nm in size) secreted by cytokine‐stimulated glioma cells rescue both glial and neuronal cells from oxidative stress induced cell death. Our MS analysis demonstrates profound changes in exosomal proteome following IL‐1β and TNF‐α stimulation of glioma cells which may explain how GBM tumors manipulate their microenvironment to grow and respond to treatment. Many of the proteins identified are involved in pathways promoting remodeling of extracellular matrix (ECM), biological adhesion, developmental processes and progression of inflammation leading to cancer growth and development.ConclusionsIncreases in cytokine levels in GBM patient brains, either due to disease or radiation, lead to qualitative and quantitative changes in the exosomal proteome. The role and function of proteins present in exosomes secreted by cytokine stimulated cells, in part, explains aggressiveness, resistance to anti‐cancer therapies and high incidence of recurrence of GBM. Our study demonstrates the role of the tissue microenvironment in dictating exosomal content secreted by glioma cells, in the aggressive progression of GBM and their ability to determine the fate of target or recipient cells.Support or Funding InformationNIH/NEI EY011352‐14