Low-Density Lipoproteins Increase Proliferation, Invasion, and Chemoresistance via an Exosome Autocrine Mechanism in MDA-MB-231 Chemoresistant Cells.

Dyslipidemias involving high concentrations of low-density lipoproteins (LDLs) increase the risk of developing triple-negative breast cancer (TNBC), wherein cholesterol metabolism and protein translation initiation mechanisms have been linked with chemoresistance. Doxorubicin (Dox) treatment, a member of the anthracycline family, represents a typical therapeutic strategy; however, chemoresistance remains a significant challenge. Exosomes (Exs) secreted by tumoral cells have been implicated in cell communication pathways and chemoresistance mechanisms; the content of exosomes is an outcome of cellular cholesterol metabolism. We previously induced Dox resistance in TNBC cell models, characterizing a variant denominated as variant B cells. Our results suggest that LDL internalization in parental and chemoresistant variant B cells is associated with increased cell proliferation, migration, invasion, and spheroid growth. We identified the role of eIF4F translation initiation factor and the down-regulation of tumor suppressor gene PDCD4, an inhibitor of eIF4A, in chemoresistant variant B cells. In addition, the exomes secreted by variant B cells were characterized by the protein content, electronic microscopy, and cell internalization assays. Critically, exosomes purified from LDL-treated variant B cell promoted cell proliferation, migration, and an increment in lactate concentration. Our results suggest that an autocrine phenomenon induced by exosomes in chemoresistant cells may induce modifications on signaling mechanisms of the p53/Mdm2 axis and activation of p70 ribosomal protein kinase S6. Moreover, the specific down-regulated profile of chaperones Hsp90 and Hsp70 secretion inside the exosomes of the chemoresistant variant could be associated with this phenomenon. Therefore, autocrine activation mediated by exosomes and the effect of LDL internalization may influence changes in exosome chaperone content and modulate proliferative signaling pathways, increasing the aggressiveness of MDA-MB-231 chemoresistant cells.

Pseudoachalasia as a paraneoplastic event in a patient with Hodgkin's disease.

Pseudoachalasia or secondary achalasia (5% of achalasias that are deemed primary achalasias) is an esophageal motor disorder with manometric criteria for achalasia, but it appears in the context of an underlying pathology that can be attributed to its origin. Usually appears in >60 years with rapid evolution of symptoms (<1 year). The main cause of pseudoachalasia is neoformative etiology, but there are others. Our patient started with rapid progression dysphagia and was diagnosed with type II achalasia within a Hodgkin's lymphoma. In the radiological-metabolic studies, disease involvement was ruled out as an extrinsic compression of the esophagogastric junction as well as signs of its activity at this level. Chemotherapy has not been shown to play a role in the development of this pathology. On the other hand, radiotherapy has been associated with an esophageal motor disorder, but, in our case, it was after its onset. Therefore, we propose that the mechanism of pseudoachalasia in our case is a paraneoplastic event. This hypothesis is related to other similar cases reported, and it reflects the importance of continuing to investigate this clinical condition that is indistinguishable by manometry from primary achalasia. In addition, it usually presents differential clinical characteristics whose early recognition has implications for the diagnostic, therapeutic, and prognostic management of the patient.

Pseudoachalasia as a paraneoplastic event in a patient with Hodgkin’s disease

Pseudoachalasia or secondary achalasia (5% of achalasias that are deemed primary achalasias) is an esophageal motor disorder with manometric criteria for achalasia, but it appears in the context of an underlying pathology that can be attributed to its origin. Usually appears in >60 years with rapid evolution of symptoms (<1 year). The main cause of pseudoachalasia is neoformative etiology, but there are others. Our patient started with rapid progression dysphagia and was diagnosed with type II achalasia within a Hodgkin's lymphoma. In the radiological-metabolic studies, disease involvement was ruled out as an extrinsic compression of the esophagogastric junction as well as signs of its activity at this level. Chemotherapy has not been shown to play a role in the development of this pathology. On the other hand, radiotherapy has been associated with an esophageal motor disorder, but, in our case, it was after its onset. Therefore, we propose that the mechanism of pseudoachalasia in our case is a paraneoplastic event. This hypothesis is related to other similar cases reported, and it reflects the importance of continuing to investigate this clinical condition that is indistinguishable by manometry from primary achalasia. In addition, it usually presents differential clinical characteristics whose early recognition has implications for the diagnostic, therapeutic, and prognostic management of the patient. (AU)

Seasonal heat stress compromises testicular thermoregulation and semen quality of Dorper rams raised in a desert climate.

Dorper rams are widely distributed throughout the world under different climatic conditions, however, little is known about their reproductive performance in desert regions. Ten Dorper rams were individually housed and exposed to thermoneutrality for 35 d in spring (23.6 ± 5.6 °C, mean ± SD) and outdoor heat stress (HS) for 35 d in summer (33.6 ± 2.0 °C) to evaluate the effect of seasonal HS on physiological responses, testicular biometry, and seminal quality under desert climatic conditions. Rectal temperature, respiration rate and coat surface temperatures in different body regions were measured every 7 d (0600, 1200, and 1800 h); also, testicular biometry was registered at 0600 h. Semen was collected via an artificial vagina 3 d after physiological variables were measured and seminal traits were evaluated. Rectal temperature, respiration rate and coat surface temperatures were higher (P < 0.01) at each hour of measurement in summer compared to spring. Overall, scrotal length and circumference, as well as testicular volume were higher (P < 0.01) in summer than in spring. Compared to spring conditions, summer HS caused lower (P ≤ 0.05) sperm concentration and viability combined with a higher percentage of sperm abnormalities without affecting ejaculate volume. Both mass and sperm motility were similar between seasons in the first two sampling weeks, and then decreased (P ≤ 0.03) due to summer HS. In conclusion, Dorper rams developed testicle hyperthermia and, consequently, showed poor semen quality due to the high environmental temperatures prevailing in desert regions.

Recurrent hemobilia secondary to extrahepatic biliary tract cholangiocarcinoma. A diagnostic challenge.

The etiology of hemobilia has mainly iatrogenic (>50%), followed by traumatic causes. Others are biliopathy due to portal high pressure, or neoplastic or infective biliopathy. In the case of non-clear hemobilia, direct-vision-cholangioscopy can change the management in >34% of cases. Our patient had episodes of obstructive hemobilia with secondary cholangitis without objectifying underlying pathology. When she was referred to our center, SpyGlass®-cholangioscopy identified the suspicious lesion compatible with early-stage cholangiocarcinoma despite the diagnostic delay. In conclusion, it is important to keep in mind the neoformative etiology as a potential cause of hemobilia of unclear origin, in which case, cholangioscopy (SpyGlass®) can contribute to the recognition of the signs of malignancy of the lesion and, therefore, to the diagnosis.

A Triazaspirane Derivative Inhibits Migration and Invasion in PC3 Prostate Cancer Cells.

Cancer is a serious health problem due to the complexity of establishing an effective treatment. The purpose of this work was to evaluate the activity of a triazaspirane as a migration and invasion inhibitor in PC3 prostatic tumor cells through a possible negative regulation of the FAK/Src signal transduction pathway and decreased secretion of metalloproteinases 2 and 9. Molecular docking analysis was performed using Moe 2008.10 software. Migration (wound-healing assay) and invasion (Boyden chamber assay) assays were performed. In addition, the Western blot technique was used to quantify protein expression, and the zymography technique was used to observe the secretion of metalloproteinases. Molecular docking showed interactions in regions of interest of the FAK and Src proteins. Moreover, the biological activity assays demonstrated an inhibitory effect on cell migration and invasion, an important suppression of metalloproteinase secretion, and a decrease in the expression of p-FAK and p-Src proteins in treated PC3 cells. Triazaspirane-type molecules have important inhibitory effects on the mechanisms associated with metastasis in PC3 tumor cells.

Mesalazine-induced esophageal ulcers. a rare adverse effect.

31-year-old woman. Diagnosis of ulcerative proctitis in February/2022. Calprotectin 1832 µg/g. Colonoscopy: erythematous, friable and erosive mucosa up to 10 cm from the anal margin. Pathology: compatible with ulcerative colitis with moderate activity. Start of oral mesalazine (3 gr/24 h granules) and topical (1 gr/24 h suppository). After three months, she achieved clinical remission. Calprotectin 57 µg/g. Two months later, she consulted for solid dysphagia, loss of 10 kg, and low-grade fever for a month. Fifteen days before, she went to an emergency room where Prednisone 50 mg/24 h was started. On the day of the assessment, she was receiving 30 mg with no improvement. The next day, gastroscopy showed 6-12 mm esophageal ulcers with non-confluent shallow geographic borders, biopsies were taken. Viral serologies and HLA B51 were requested. Given the severity of the symptoms, empirical treatment was started with Valaciclovir 1 g/12 h. Serologies: IgG for Ebstein Barr virus, cytomegalovirus and herpes virus with negative IgM. Cytomegalovirus viral load: <30 IU/ml. Pathology: acute extensively ulcerated esophagitis, inflammatory infiltrate and some eosinophils with negative histochemical staining for fungi, cytomegalovirus and herpes virus I and II. HLA B51 was negative. Valaciclovir and mesalazine are discontinued after seven days given the known relationship of the latter with low-grade fever and, exceptionally, with esophageal pathology. Three days later, the patient reported clear improvement in dysphagia from the day the mesalazine was discontinued. After eight months, she was still asymptomatic. Upon resolution of the symptoms, control gastroscopy was not performed, and mesalazine has not been reintroduced due to its probable causal association. Mesalazine has an excellent safety profile. Adverse effects include fever, headache, diarrhea and.

Potential Inhibitors of The OTUB1 Catalytic Site to Develop an Anti-Cancer Drug Using In-Silico Approaches.

Background: : Cancer continues worldwide. It has been reported that OTUB1, a cysteine protease, plays a critical role in a variety of tumors and is strongly related to tumor proliferation, migration, and clinical prognosis by its functions on deubiquitination. Drug advances continue against new therapeutic targets. In this study we used OTUB1 to develop a specific pharmacological treatment to regulate deubiquitination by OTUB1. The aim of this research is to regulate OTUB1 functions. Methods: By molecular docking in a specific potential OTUB1 interaction site between Asp88, Cys91, and His26 amino acids, using a chemical library of over 500,000 compounds, we selected potential inhibitors of the OTUB1 catalytic site. Results: Ten compounds (OT1 - OT10) were selected by molecular docking to develop a new anti-cancer drug to decrease OTUB1 functions in cancer processes. Conclusion: OT1 - OT10 compounds could be interacting in the potential site between Asp88, Cys91, and His265 amino acids in OTUB1. This site is necessary for the deubiquitinating function of OTUB1. Therefore, this study shows another way to attack cancer.

Histiocytic sarcoma of the esophagus.

A 20-year-old male with no medical history of interest who goes to the emergency room because of retrosternal pain, odynophagia, dysphagia, and fever. On physical examination: 37.7ºC axillary temperature, bad general condition, and central chest pain on palpation. In the blood test: 16,200x10^6/L white blood cells, 12,800x10^6/L neutrophils, and 11.66mg/dL C reactive protein, with the rest of the complete blood count, coagulation, and biochemistry within normal values.

Ferulic acid supplementation for 40 days in hair ewe lambs experiencing seasonal heat stress: short-term effects on physiological responses, growth, metabolism, and hematological profile.

Free ferulic acid (FA) is a natural compound with antioxidant properties which mitigates the negative effects of cold stress in sheep; however, its impact on thermoregulatory responses in heat-stressed sheep has not been defined. The objective was to evaluate the effects of FA supplementation on physiological responses, serum analyte concentrations, and the hematological profile of heat-stressed hair ewe lambs. Twenty-two Dorper × Katahdin ewe lambs (initial body weight = 23.5 ± 2.8 kg and age = 4 months) were housed in individual pens for 40 days and assigned under a randomized complete block design to the following treatments (n = 11): basal diet with 0 (control) or 250 mg of FA/kg of feed. The FA × sampling day interaction only affected serum concentration of some metabolic hormones; particularly on day 20 of the trial, FA increased (P < 0.01) insulins and the insulin to glucose ratio while decreased (P = 0.05) thyroxine. Overall, supplemental FA did not affect rectal temperature, respiratory rate, most body surface temperatures, feedlot performance, and serum concentrations of metabolites, electrolytes, triiodothyronine, and cortisol. In addition, FA only tended to decrease (P ≥ 0.09) erythrocyte count and plaquetocrit and to increase (P = 0.08) mean corpuscular volume. In conclusion, FA supplementation did not improve the growth nor thermoregulatory capacity of heat-stressed hair ewe lambs. Still, it partially modulated the metabolism to reinforce some energetic adaptive mechanisms when the ambient temperature was ≥ 35 °C.

eIF4A/PDCD4 Pathway, a Factor for Doxorubicin Chemoresistance in a Triple-Negative Breast Cancer Cell Model.

Cells employ several adaptive mechanisms under conditions of accelerated cell division, such as the unfolded protein response (UPR). The UPR is composed of a tripartite signaling system that involves ATF6, PERK, and IRE1, which maintain protein homeostasis (proteostasis). However, deregulation of protein translation initiation could be associated with breast cancer (BC) chemoresistance. Specifically, eukaryotic initiation factor-4A (eIF4A) is involved in the unfolding of the secondary structures of several mRNAs at the 5' untranslated region (5'-UTR), as well as in the regulation of targets involved in chemoresistance. Importantly, the tumor suppressor gene PDCD4 could modulate this process. This regulation might be disrupted in chemoresistant triple negative-BC (TNBC) cells. Therefore, we characterized the effect of doxorubicin (Dox), a commonly used anthracycline medication, on human breast carcinoma MDA-MB-231 cells. Here, we generated and characterized models of Dox chemoresistance, and chemoresistant cells exhibited lower Dox internalization levels followed by alteration of the IRE1 and PERK arms of the UPR and triggering of the antioxidant Nrf2 axis. Critically, chemoresistant cells exhibited PDCD4 downregulation, which coincided with a reduction in eIF4A interaction, suggesting a sophisticated regulation of protein translation. Likewise, Dox-induced chemoresistance was associated with alterations in cellular migration and invasion, which are key cancer hallmarks, coupled with changes in focal adhesion kinase (FAK) activation and secretion of matrix metalloproteinase-9 (MMP-9). Moreover, eIF4A knockdown via siRNA and its overexpression in chemoresistant cells suggested that eIF4A regulates FAK. Pro-atherogenic low-density lipoproteins (LDL) promoted cellular invasion in parental and chemoresistant cells in an MMP-9-dependent manner. Moreover, Dox only inhibited parental cell invasion. Significantly, chemoresistance was modulated by cryptotanshinone (Cry), a natural terpene purified from the roots of Salvia brandegeei. Cry and Dox co-exposure induced chemosensitization, connected with the Cry effect on eIF4A interaction. We further demonstrated the Cry binding capability on eIF4A and in silico assays suggest Cry inhibition on the RNA-processing domain. Therefore, strategic disruption of protein translation initiation is a druggable pathway by natural compounds during chemoresistance in TNBC. However, plasmatic LDL levels should be closely monitored throughout treatment.

LDL Promotes Disorders in ß-Cell Cholesterol Metabolism, Implications on Insulin Cellular Communication Mediated by EVs.

Dyslipidemia is described as a hallmark of metabolic syndrome, promoting a stage of metabolic inflammation (metainflammation) that could lead to misbalances in energetic metabolism, contributing to insulin resistance, and modifying intracellular cholesterol pathways and the renin-angiotensin system (RAS) in pancreatic islets. Low-density lipoprotein (LDL) hypercholesterolemia could disrupt the tissue communication between Langerhans ß-cells and hepatocytes, wherein extracellular vesicles (EVs) are secreted by ß-cells, and exposition to LDL can impair these phenomena. ß-cells activate compensatory mechanisms to maintain insulin and metabolic homeostasis; therefore, the work aimed to characterize the impact of LDL on ß-cell cholesterol metabolism and the implication on insulin secretion, connected with the regulation of cellular communication mediated by EVs on hepatocytes. Our results suggest that ß-cells can endocytose LDL, promoting an increase in de novo cholesterol synthesis targets. Notably, LDL treatment increased mRNA levels and insulin secretion; this hyperinsulinism condition was associated with the transcription factor PDX-1. However, a compensatory response that maintains basal levels of intracellular calcium was described, mediated by the overexpression of calcium targets PMCA1/4, SERCA2, and NCX1, together with the upregulation of the unfolded protein response (UPR) through the activation of IRE1 and PERK arms to maintain protein homeostasis. The LDL treatment induced metainflammation by IL-6, NF-κB, and COX-2 overexpression. Furthermore, LDL endocytosis triggered an imbalance of the RAS components. LDL treatment increased the intracellular levels of cholesterol on lipid droplets; the adaptive ß-cell response was portrayed by the overexpression of cholesterol transporters ABCA1 and ABCG1. Therefore, lipotoxicity and hyperinsulinism induced by LDL were regulated by the natural compound auraptene, a geranyloxyn coumarin modulator of cholesterol-esterification by ACAT1 enzyme inhibition. EVs isolated from ß-cells impaired insulin signaling via mTOR/p70S6Kα in hepatocytes, a phenomenon regulated by auraptene. Our results show that LDL overload plays a novel role in hyperinsulinism, mechanisms associated with a dysregulation of intracellular cholesterol, lipotoxicity, and the adaptive UPR, which may be regulated by coumarin-auraptene; these conditions explain the affectations that occur during the initial stages of insulin resistance.

Matrix metalloproteinase-2 and matrix metalloproteinase-9 serum levels in patients with vertebrobasilar dolichoectasia with and without stroke: case-control study.

PURPOSE: To describe the differences in the serum levels of MMP-2 and MMP-9 of patients with vertebrobasilar dolichoectasia (VBD) with and without acute stroke. METHODS: Case-control study. From an outpatient clinic, we recruited 14 controls and 19 patients with VBD. We also recruited 33 patients with stroke from two emergency departments, 14 without VBD (S/-VBD) and 19 with VBD (S/ + VBD). All the patients underwent serum MMP-2 and MMP-9 measurements and a non-contrast CT scan. Two investigators assessed the intracranial vertebral arteries (VA) and the basilar artery (BA) at the mid-pons. Diagnosis of VBD was made if the BA diameter was ≥ 4.5 mm. RESULTS: The mean age of the 66 patients studied was 57.6 + 16.0 years, 41% female. In the 33 patients with stroke, the median NIHSS was 8 (range 15); there were no differences in the NIHSS scores between both groups with stroke. Median MMP-2 levels were lower in the S/-VBD when compared to controls. Median MMP-9 serum levels were higher in both groups with VBD when compared to controls and the S/-VDB group. Both groups with stroke exhibited higher MMP-9 serum levels than controls but were not statistically different from those found in patients with VBD. Serum levels of MMP-9 were significantly correlated with the diameters of the BA (r = 0.344, p = 0.01) and the left VA (r = 0.305, p = 0.05). CONCLUSION: This study found that high serum levels of MMP-9 are associated with VBD independently of stroke and correlated with the degree of VBD.

Progesterone supplementation in Holstein heifers subjected to cooling and timed AI during summer: physiological and reproductive variables and thyroid hormone concentrations.

Our aim was to evaluate the effects of progesterone supplementation after fixed-time artificial insemination (FTAI) on physiological and reproductive variables and serum thyroid hormone concentrations of cooled Holstein heifers during a hot summer season. Sixty-nine Holstein heifers were randomly assigned to three treatments: (1) heifers under visual estrus detection and inseminated according to AM-PM rule (n = 23; control (C)), (2) heifers subjected to FTAI after estrus synchronization using a CIDR insert (n = 24; FTAI group), and (3) heifers treated as the FTAI group plus progesterone supplementation between the day 4 and 14 post-insemination with a reused CIDR device (n = 22; FTAI+SP4 group). All heifers were cooled daily with misting and fans. Physiological variables were measured; likewise, blood samples were collected to determine serum progesterone, thyroxine, and triiodothyronine concentrations. Both respiration rate and rectal temperature were similar among treatments. Conception rate was greater (P < 0.05) in C (65.2%) and FTAI+SP4 (59.1%) heifers than in FTAI heifers (33.3%). Serum triiodothyronine and progesterone concentrations of FTAI+SP4 heifers were similar to those of C heifers but greater (P < 0.05) than those of FTAI heifers. In conclusion, progesterone supplementation post-insemination increased conception rate and serum progesterone concentrations without affecting thermoregulation capacity in Holstein heifers subjected to FTAI and cooling during a hot summer season.

Free ferulic acid supplementation of heat-stressed hair ewe lambs: Oxidative status, feedlot performance, carcass traits and meat quality.

Twenty-two Katahdin × Dorper ewe lambs (average weight = 23.5 ± 2.8 kg) were individually housed during a 40-d feeding study and then slaughtered to evaluate effects of free ferulic acid (FA; 0 and 250 mg/kg of feed) on oxidative status, feedlot growth, carcass and non-carcass traits, wholesale cut yields and meat quality under heat stress conditions. Overall feeding FA decreased protein oxidation without affecting oxidative stress index, while growth rate and feed efficiency increased only in the hottest period (i.e., 28 to 45 °C). The FA supplementation increased kidney-pelvic-heart and mesenteric fat deposition, as well as yields of forequarter, shoulder, ribs, loin, and breast and flank, but decreased yields of hindquarter, neck, plain loin and leg. Carcass characteristics and meat quality were unaffected by FA. Overall, FA supplementation of heat-stressed hair ewe lambs enhanced feedlot performance under extreme heat stress and increased internal fat reserves, while changing muscle mass deposition, possibly because it prevented protein oxidation.

Isthmin 2 is decreased in preeclampsia and highly expressed in choriocarcinoma.

INTRODUCTION: Isthmin 2 (ISM2) is a protein which expression in humans is almost specific to the placenta. There is no previous report in the literature that investigated this protein in preeclampsia or choriocarcinoma. METHODS: We conducted a prospective, cross-sectional study that included women with preeclampsia, gestational hypertension and normotensive pregnancy. We measured serum concentrations of ISM2 protein and performed immunohistochemistry in placenta tissues. We also performed immunohistochemistry of ISM2 in samples from choriocarcinoma and compare with lung, prostate, colon, gastric and breast cancers. RESULTS: A total of 81 patients were included, 30 with preeclampsia, 21 with gestational hypertension and 30 controls. The ISM2 protein was found to be decreased in patients with preeclampsia compared to the control group (P = 0.036). These results were confirmed by immunohistochemistry. We also found that ISM2 protein was overexpressed in choriocarcinoma. DISCUSSION: Taken together, our results suggest an angiogenic function for ISM2. Its serum level decreased in our patients with preeclampsia could be reflecting that it is involved in the pathogenesis of the disease; on the other hand its high expression in choriocarcinoma, indicates that ISM2 may play an active role in the angiogenesis of this and other cancers.

Lipid Modulation in the Formation of ß-Sheet Structures. Implications for De Novo Design of Human Islet Amyloid Polypeptide and the Impact on ß-Cell Homeostasis.

Human islet amyloid polypeptide (hIAPP) corresponds to a 37-residue hormone present in insulin granules that maintains a high propensity to form ß-sheet structures during co-secretion with insulin. Previously, employing a biomimetic approach, we proposed a panel of optimized IAPP sequences with only one residue substitution that shows the capability to reduce amyloidogenesis. Taking into account that specific membrane lipids have been considered as a key factor in the induction of cytotoxicity, in this study, following the same design strategy, we characterize the effect of a series of lipids upon several polypeptide domains that show the highest aggregation propensity. The characterization of the C-native segment of hIAPP (residues F23-Y37), together with novel variants F23R and I26A allowed us to demonstrate an effect upon the formation of ß-sheet structures. Our results suggest that zwitterionic phospholipids promote adsorption of the C-native segments at the lipid-interface and ß-sheet formation with the exception of the F23R variant. Moreover, the presence of cholesterol did not modify this behavior, and the ß-sheet structural transitions were not registered when the N-terminal domain of hIAPP (K1-S20) was characterized. Considering that insulin granules are enriched in phosphatidylserine (PS), the property of lipid vesicles containing negatively charged lipids was also evaluated. We found that these types of lipids promote ß-sheet conformational transitions in both the C-native segment and the new variants. Furthermore, these PS/peptides arrangements are internalized in Langerhans islet ß-cells, localized in the endoplasmic reticulum, and trigger critical pathways such as unfolded protein response (UPR), affecting insulin secretion. Since this phenomenon was associated with the presence of cytotoxicity on Langerhans islet ß-cells, it can be concluded that the anionic lipid environment and degree of solvation are critical conditions for the stability of segments with the propensity to form ß-sheet structures, a situation that will eventually affect the structural characteristics and stability of IAPP within insulin granules, thus modifying the insulin secretion.