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1.
J Gen Intern Med ; 2024 Jul 17.
Article in English | MEDLINE | ID: mdl-39020226

ABSTRACT

BACKGROUND: The COVID-19 pandemic disproportionately affected people from structurally vulnerable communities. There was a need to improve COVID-19 testing in these communities to reduce viral spread and connect to treatment. OBJECTIVE: We created a partnership between an academic medical center and three community-based organizations (CBOs) to offer low-barrier COVID-19 walk-up testing clinics in Portland, Maine. Our objective was to examine whether the co-created testing clinics reached structurally vulnerable populations. DESIGN: The clinics offered COVID-19 rapid antigen tests three times a week outside CBO sites from January 2022 to May 2023. Clinic staff administered a brief survey on reason for testing and then instructed participants on how to self-swab. While staff processed the test, participants were invited to complete an additional survey about their demographics and testing perceptions. PARTICIPANTS: Adults seeking COVID-19 testing with specific outreach to people who are unhoused, immigrants, and low-income and/or uninsured. MAIN MEASURES: Number of tests conducted and result, reasons for testing, and testing perceptions. KEY RESULTS: Of 246 completed tests, 18 were positive for COVID-19 (7%). Participants sought testing for a variety of reasons, including symptoms (60%), close contact exposure (29%), and/or need for a negative test result to access services or an activity (33%). Overall, people primarily tested due to symptoms with only 7% testing due to close contact exposure alone. The clinics reached vulnerable populations. Among the 130 people completing the participant survey, 39% were unhoused, 22% spoke a language other than English at home, 23% were uninsured, and 46% earned less than $20,000 in 2019. Qualitative field notes captured key elements of clinics that influenced reach, and how this collaboration with CBOs helped build trust with our target populations. CONCLUSIONS: Providing low-barrier walk-up clinics partnering with trusted CBOs was observed to be helpful in reaching structurally vulnerable populations for COVID-19 testing.

2.
PLoS Pathog ; 20(5): e1012225, 2024 May.
Article in English | MEDLINE | ID: mdl-38739655

ABSTRACT

Biofilm formation by the fungal pathogen Candida albicans is the basis for its ability to infect medical devices. The metabolic gene ERG251 has been identified as a target of biofilm transcriptional regulator Efg1, and here we report that ERG251 is required for biofilm formation but not conventional free-living planktonic growth. An erg251Δ/Δ mutation impairs biofilm formation in vitro and in an in vivo catheter infection model. In both in vitro and in vivo biofilm contexts, cell number is reduced and hyphal length is limited. To determine whether the mutant defect is in growth or some other aspect of biofilm development, we examined planktonic cell features in a biofilm-like environment, which was approximated with sealed unshaken cultures. Under those conditions, the erg251Δ/Δ mutation causes defects in growth and hyphal extension. Overexpression in the erg251Δ/Δ mutant of the paralog ERG25, which is normally expressed more weakly than ERG251, partially improves biofilm formation and biofilm hyphal content, as well as growth and hyphal extension in a biofilm-like environment. GC-MS analysis shows that the erg251Δ/Δ mutation causes a defect in ergosterol accumulation when cells are cultivated under biofilm-like conditions, but not under conventional planktonic conditions. Overexpression of ERG25 in the erg251Δ/Δ mutant causes some increase in ergosterol levels. Finally, the hypersensitivity of efg1Δ/Δ mutants to the ergosterol inhibitor fluconazole is reversed by ERG251 overexpression, arguing that reduced ERG251 expression contributes to this efg1Δ/Δ phenotype. Our results indicate that ERG251 is required for biofilm formation because its high expression levels are necessary for ergosterol synthesis in a biofilm-like environment.


Subject(s)
Biofilms , Candida albicans , Candidiasis , Fungal Proteins , Biofilms/growth & development , Candida albicans/metabolism , Candida albicans/genetics , Candida albicans/physiology , Fungal Proteins/metabolism , Fungal Proteins/genetics , Animals , Candidiasis/microbiology , Candidiasis/metabolism , Hyphae/metabolism , Mice , Gene Expression Regulation, Fungal , Ergosterol/metabolism , Transcription Factors/metabolism , Transcription Factors/genetics , Mutation
3.
Brain ; 2024 Apr 23.
Article in English | MEDLINE | ID: mdl-38650574

ABSTRACT

Obesity is a chronic disease caused by excessive fat accumulation that impacts the body and brain health. Insufficient leptin or leptin receptor (LepR) are involved in the disease pathogenesis. Leptin is involved with several neurological processes, and it has critical developmental roles. We have previously demonstrated that leptin deficiency in early life leads to permanent developmental problems, including energy homeostasis imbalance, melanocortin and reproductive system alterations and brain mass reduction in young adult mice. Since in humans, obesity has been associated with brain atrophy and cognitive impairment, it is important to determine the long-term consequences of early life leptin deficiency in brain structure and memory function. Here, we demonstrate that leptin-deficient mice (LepOb) exhibit altered brain volume, decreased neurogenesis and memory impairment. Similar effects were observed in animals that do not express the LepR (LepRNull). Interestingly, restoring the expression of LepR in 10-week-old mice reverses brain atrophy, as well as neurogenesis and memory impairments in older animals. Our findings indicate that leptin deficiency impairs brain development and memory, which are reversible by restoring leptin signaling in adulthood.

4.
Microbiol Spectr ; 12(6): e0396723, 2024 Jun 04.
Article in English | MEDLINE | ID: mdl-38647345

ABSTRACT

Acylhydrazone (AH) derivatives represent a novel category of anti-fungal medications that exhibit potent activity against Sporothrix sp., both in vitro and in a murine model of sporotrichosis. In this study, we demonstrated the anti-fungal efficacy of the AH derivative D13 [4-bromo-N'-(3,5-dibromo-2-hydroxybenzylidene)-benzohydrazide] against both planktonic cells and biofilms formed by Sporothrix brasiliensis. In a clinical study, the effect of D13 was then tested in combination with itraconazole (ITC), with or without potassium iodide, in 10 cats with sporotrichosis refractory to the treatment of standard of care with ITC. Improvement or total clinical cure was achieved in five cases after 12 weeks of treatment. Minimal abnormal laboratory findings, e.g., elevation of alanine aminotransferase, were observed in four cats during the combination treatment and returned to normal level within a week after the treatment was ended. Although highly encouraging, a larger and randomized controlled study is required to evaluate the effectiveness and the safety of this new and exciting drug combination using ITC and D13 for the treatment of feline sporotrichosis. IMPORTANCE: This paper reports the first veterinary clinical study of an acylhydrazone anti-fungal (D13) combined with itraconazole against a dimorphic fungal infection, sporotrichosis, which is highly endemic in South America in animals and humans. Overall, the results show that the combination treatment was efficacious in ~50% of the infected animals. In addition, D13 was well tolerated during the course of the study. Thus, these results warrant the continuation of the research and development of this new class of anti-fungals.


Subject(s)
Antifungal Agents , Cat Diseases , Drug Therapy, Combination , Itraconazole , Sporothrix , Sporotrichosis , Cats , Animals , Itraconazole/therapeutic use , Itraconazole/administration & dosage , Itraconazole/pharmacology , Sporotrichosis/drug therapy , Sporotrichosis/veterinary , Antifungal Agents/therapeutic use , Antifungal Agents/pharmacology , Antifungal Agents/administration & dosage , Cat Diseases/drug therapy , Cat Diseases/microbiology , Sporothrix/drug effects , Hydrazones/therapeutic use , Hydrazones/pharmacology , Female , Male , Microbial Sensitivity Tests , Biofilms/drug effects , Treatment Outcome
5.
BMC Med Educ ; 23(1): 735, 2023 Oct 06.
Article in English | MEDLINE | ID: mdl-37803366

ABSTRACT

BACKGROUND: The popularity of short-term global health experiences amongst US medical students has been increasing. However, it remains a challenge for medical schools to comprehensively prepare students to work in an international environment and to contribute in ethically responsible and meaningful ways. Students of the Global Medicine program (GMED) of the UIC College of Medicine Center for Global Health set out to develop a pre-and-post travel curriculum that addresses some of these challenges. METHODS: The students surveyed the literature of 66 published global health curricula and identified aspects of pre-and-post travel training that were found to be under-addressed. They then developed a curriculum in conjunction with GMED faculty that incorporated these identified aspects of pre-and-post travel training. RESULTS: Five aspects of pre-and-post travel training were identified as being under-addressed in the literature while traveling. These domains include: [1] examining power relations associated with neo-colonization between and within countries; [2] training for bi-directional learning; [3] examining motivations and goals for participating in global health; [4] addressing personal resiliency and psychosocial wellbeing related to students' travel, and; [5] reflecting on the challenging aspects of the fieldwork experience. CONCLUSIONS: The student-driven curriculum is being integrated into the GMED program through structured didactic sessions, one-on-one mentor meetings and small group discussions. Once students have traveled, the curriculum will be evaluated with the foreign partners they visited.


Subject(s)
Education, Medical , Students, Medical , Humans , Curriculum , Learning , Mentors , Global Health
6.
Biochim Biophys Acta Mol Cell Biol Lipids ; 1868(11): 159384, 2023 11.
Article in English | MEDLINE | ID: mdl-37673393

ABSTRACT

Fungal pathogens have been under the spotlight as their expanding geographic range combined with their potential harm to vulnerable populations turns them into increasingly threats to public health. Therefore, it is ultimately important to unveil the mechanisms associated with their infection process for further new treatment discovery. With this purpose, sphingolipid-based research has gained attention over the last years as these molecules have key properties that can regulate fungal pathogenicity. Here we discuss some of these properties as well as their role in fungal diseases, focusing on the subgroup of glycosphingolipids, as they represent promising molecules for drug discovery and for the development of fungal vaccines.


Subject(s)
Glycosphingolipids , Sphingolipids , Host-Pathogen Interactions
8.
Cytokine ; 169: 156299, 2023 09.
Article in English | MEDLINE | ID: mdl-37451115

ABSTRACT

Mouse mammary tumor virus (MMTV) is a retrovirus that has been associated with the development of breast cancer (BC) in mice. The identification of a 95% homologous gene sequence to MMTV in human BC samples has increased interest in this hypothesis. This virus in humans received the name of mouse mammary tumor virus-like (MMTV-like). Several cytokines may be involved in the interactions between MMTV and the immune system, such as interferon-gamma (IFN-γ), which can enhance Th1-mediated antitumor immune response but it can also play a protumorigenic role by transmitting antiapoptotic and proliferative signals. Little is known about the antiviral immune response in a microenvironment with the presence of MMTV-like in BC patients. Therefore, the purpose of the present study was to quantify the plasma levels of IFN-γ in the peripheral blood of 123 neoplasia-free donors and 98 BC patients of different molecular subtypes, by enzyme-linked immunosorbent assay (ELISA), and evaluate the association of these plasma levels with the detection of the MMTV-like env gene in tumor tissue. Correlation analyzes involving IFN-γ plasma levels and clinical-pathological parameters were performed by Kendall Tau-c test. In our study, a decrease in IFN-γ levels was observed in the group of BC patients (30.85 ± 57.49 pg/ml) compared to the control group (115.00 ± 176.80 pg/ml) (p < 0.0001). In the analysis by stratified BC molecular subtypes, Luminal-A (30.79 ± 61.04 pg/ml; p < 0.0001), Luminal-B (24.74 ± 25.78 pg/ml; p = 0.0188) and triple-negative (23.95 ± 40.45 pg/ml; p = 0.0005) had a lower plasma level compared to control group. There was no significant difference between IFN-γ plasma levels of MMTV-like DNA positive samples compared to MMTV-negative samples (p = 0.2056). In general BC, patients with larger tumor size had higher IFN-γ plasma levels (Tau-c = 0.202; p = 0.019). By analyzing the MMTV-like env negative samples, we could identify that IFN-γ plasma levels were higher in larger tumor size (Tau-c = 0.222; p = 0.020) and with greater lymph node involvement (Tau-c = 0.258; p = 0.042). Also, higher IFN-γ plasma levels were observed in patients with higher histopathological grades (Tau-c = 0.384; p = 0.019) in MMTV-like env positive samples. For the first time, we assessed the association between plasma levels of IFN-γ and the presence of the MMTV-like env gene in BC samples. However, more studies are needed to clarify whether the high levels of IFN-γ in MMTV-like env positive samples are reflecting a possible antiviral immune response or whether this cytokine is promoting tumor growth.


Subject(s)
Breast Neoplasms , Humans , Animals , Mice , Female , Breast Neoplasms/genetics , Breast Neoplasms/pathology , Mammary Tumor Virus, Mouse/genetics , Interferon-gamma/genetics , Genes, env , Antiviral Agents , Tumor Microenvironment
9.
J Toxicol Environ Health A ; 86(13): 446-457, 2023 07 03.
Article in English | MEDLINE | ID: mdl-37219520

ABSTRACT

Chimarrão is a typical beverage made from the infusion of dried and ground leaves and stems of Ilex paraguariensis (popularly known as Yerba mate or mate herb) which is widely consumed in parts of South America. The aim of this study was to examine the effects of the chimarrão against nephrotoxicity and oxidative stress induced by the potassium dichromate (PD) salt in male Wistar rats. The experiment lasted 17 days, and in the first 15 days animals ingested a chimarrão infusion or control drinking water and then submitted to an intraperitoneal injection (15 mg/kg) of PD (or saline solution) and euthanized after 48 hr at which time animals still received infusion or drinking water. Blood plasma and 24 hr-urine samples were collected to measure creatinine levels as an estimate of glomerular filtration rate (GFR). Concomitantly oxidative stress was determined in the kidneys as evidenced by levels of carbonyl groups, malondialdehyde (MDA) and antioxidant capacity against peroxyl radicals. Potassium dichromate induced oxidative stress in the kidneys and reduced GFR. Treatment with chimarrão during the 15 days prior to PD injection reduced PD salt-mediated oxidative stress. Further, treatment with post-injection chimarrão to PD-administered rats improved the GFR. Our findings support that the use of the chimarrão beverage may be considered as an important nephroprotective substance.


Subject(s)
Drinking Water , Ilex paraguariensis , Male , Rats , Animals , Potassium Dichromate/toxicity , Rats, Wistar , Plant Extracts/pharmacology , Oxidative Stress
10.
Microbiol Spectr ; 11(3): e0162723, 2023 06 15.
Article in English | MEDLINE | ID: mdl-37195179

ABSTRACT

Thermotolerance is a remarkable virulence attribute of Aspergillus fumigatus, but the consequences of heat shock (HS) to the cell membrane of this fungus are unknown, although this structure is one of the first to detect changes in ambient temperature that imposes on the cell a prompt adaptative response. Under high-temperature stress, fungi trigger the HS response controlled by heat shock transcription factors, such as HsfA, which regulates the expression of heat shock proteins. In yeast, smaller amounts of phospholipids with unsaturated fatty acid (FA) chains are synthesized in response to HS, directly affecting plasma membrane composition. The addition of double bonds in saturated FA is catalyzed by Δ9-fatty acid desaturases, whose expression is temperature-modulated. However, the relationship between HS and saturated/unsaturated FA balance in membrane lipids of A. fumigatus in response to HS has not been investigated. Here, we found that HsfA responds to plasma membrane stress and has a role in sphingolipid and phospholipid unsaturated biosynthesis. In addition, we studied the A. fumigatus Δ9-fatty acid desaturase sdeA and discovered that this gene is essential and required for unsaturated FA biosynthesis, although it did not directly affect the total levels of phospholipids and sphingolipids. sdeA depletion significantly sensitizes mature A. fumigatus biofilms to caspofungin. Also, we demonstrate that hsfA controls sdeA expression, while SdeA and Hsp90 physically interact. Our results suggest that HsfA is required for the adaptation of the fungal plasma membrane to HS and point out a sharp relationship between thermotolerance and FA metabolism in A. fumigatus. IMPORTANCE Aspergillus fumigatus causes invasive pulmonary aspergillosis, a life-threatening infection accounting for high mortality rates in immunocompromised patients. The ability of this organism to grow at elevated temperatures is long recognized as an essential attribute for this mold to cause disease. A. fumigatus responds to heat stress by activating heat shock transcription factors and chaperones to orchestrate cellular responses that protect the fungus against damage caused by heat. Concomitantly, the cell membrane must adapt to heat and maintain physical and chemical properties such as the balance between saturated/unsaturated fatty acids. However, how A. fumigatus connects these two physiological responses is unclear. Here, we explain that HsfA affects the synthesis of complex membrane lipids such as phospholipids and sphingolipids and controls the enzyme SdeA, which produces monounsaturated fatty acids, raw material for membrane lipids. These findings suggest that forced dysregulation of saturated/unsaturated fatty acid balance might represent novel strategies for antifungal therapy.


Subject(s)
Aspergillus fumigatus , Thermotolerance , Humans , Aspergillus fumigatus/genetics , Aspergillus fumigatus/metabolism , Thermotolerance/physiology , Heat Shock Transcription Factors/metabolism , Fatty Acids/metabolism , Saccharomyces cerevisiae/metabolism , Phospholipids/metabolism , Membrane Lipids/metabolism , Sphingolipids/metabolism , Fungal Proteins/genetics , Fungal Proteins/metabolism
11.
Brain Commun ; 5(2): fcad059, 2023.
Article in English | MEDLINE | ID: mdl-37013172

ABSTRACT

Obesity is defined as abnormal or excessive fat accumulation that may impair health and is a risk factor for developing other diseases, such as type 2 diabetes and cardiovascular disorder. Obesity is also associated with structural and functional alterations in the brain, and this condition has been shown to increase the risk of Alzheimer's disease. However, while obesity has been associated with neurodegenerative processes, its impact on brain cell composition remains to be determined. In the current study, we used the isotropic fractionator method to determine the absolute composition of neuronal and non-neuronal cells in different brain regions of the genetic mouse models of obesity Lepob/ob and LepRNull/Null . Our results show that 10- to 12-month-old female Lepob/ob and LepRNull/Null mice have reduced neuronal number and density in the hippocampus compared to C57BL/6 wild-type mice. Furthermore, LepRNull/Null mice have increased density of non-neuronal cells, mainly glial cells, in the hippocampus, frontal cortex and hypothalamus compared to wild-type or Lepob/ob mice, indicating enhanced inflammatory responses in different brain regions of the LepRNull/Null model. Collectively, our findings suggest that obesity might cause changes in brain cell composition that are associated with neurodegenerative and inflammatory processes in different brain regions of female mice.

12.
mBio ; 14(2): e0033923, 2023 04 25.
Article in English | MEDLINE | ID: mdl-36877042

ABSTRACT

Invasive fungal infections are a leading cause of death in immunocompromised patients. Current therapies have several limitations, and innovative antifungal agents are critically needed. Previously, we identified the fungus-specific enzyme sterylglucosidase as essential for pathogenesis and virulence of Cryptococcus neoformans and Aspergillus fumigatus (Af) in murine models of mycoses. Here, we developed Af sterylglucosidase A (SglA) as a therapeutic target. We identified two selective inhibitors of SglA with distinct chemical scaffolds that bind in the active site of SglA. Both inhibitors induce sterylglucoside accumulation and delay filamentation in Af and increase survival in a murine model of pulmonary aspergillosis. Structure-activity relationship (SAR) studies identified a more potent derivative that enhances both in vitro phenotypes and in vivo survival. These findings support sterylglucosidase inhibition as a promising antifungal approach with broad-spectrum potential. IMPORTANCE Invasive fungal infections are a leading cause of death in immunocompromised patients. Aspergillus fumigatus is a fungus ubiquitously found in the environment that, upon inhalation, causes both acute and chronic illnesses in at-risk individuals. A. fumigatus is recognized as one of the critical fungal pathogens for which a substantive treatment breakthrough is urgently needed. Here, we studied a fungus-specific enzyme, sterylglucosidase A (SglA), as a therapeutic target. We identified selective inhibitors of SglA that induce accumulation of sterylglucosides and delay filamentation in A. fumigatus and increase survival in a murine model of pulmonary aspergillosis. We determined the structure of SglA, predicted the binding poses of these inhibitors through docking analysis, and identified a more efficacious derivative with a limited SAR study. These results open several exciting avenues for the research and development of a new class of antifungal agents targeting sterylglucosidases.


Subject(s)
Aspergillosis , Invasive Fungal Infections , Pulmonary Aspergillosis , Animals , Mice , Aspergillus fumigatus/genetics , Antifungal Agents/pharmacology , Disease Models, Animal , Aspergillosis/drug therapy , Aspergillosis/microbiology , Pulmonary Aspergillosis/drug therapy
13.
Pathogens ; 12(1)2023 Jan 16.
Article in English | MEDLINE | ID: mdl-36678496

ABSTRACT

The aim of this study was to determine the incidence of infections and cytological abnormalities and to investigate possible predisposing factors such as sociodemographic characteristics, sexual behavioral habits, and gynecological and obstetric backgrounds. Between 2013 and December 2016, a cross-sectional study was conducted among 429 consenting women, from whom cervical samples were tested for the presence of Human papillomavirus (HPV) by polymerase chain reaction (PCR). Susceptibility to HPV infection was assessed by binary logistic regression in light of possible predisposing factors, which were collected using a questionnaire. In our sample population, the prevalence of HPV infection was 49%; high-risk types had a higher prevalence of 89.1%. A larger proportion of HPV-infected women were under 25 years of age, were single, and had monthly incomes up to minimum wage. Multivariate binary logistic regression analysis showed that age younger than 25 years increased the odds of infection fivefold, while a monthly income of one to three minimum wages provided protection against HPV infection, even if the women were married or had a cohabiting partner. In the HPV-positive group, squamous intraepithelial lesions (SIL) occurred more frequently in women who earned up to one minimum wage monthly, but a monthly income of one to three minimum wages protected against the development of SIL. The results suggest that age, marital status, and monthly income are important cofactors for HPV infection and the development of SIL.

15.
Rev Assoc Med Bras (1992) ; 68(9): 1191-1198, 2022 Sep.
Article in English | MEDLINE | ID: mdl-36228250

ABSTRACT

OBJECTIVE: Bronchiectasis is a chronic respiratory disease characterized by inflammation, irreversible dilation of the bronchi, and recurrent pulmonary infections, with a high morbidity and mortality rate, but is less studied from the point of view of its prevalence and associated factors not directly related to respiratory prognosis. As it is a disease related to the exacerbation of the inflammatory process and oxidative stress, this study searched to investigate the micronucleus frequency in patients with and without bronchiectasis treated at a specialized pulmonology service in a hospital in the extreme south of Brazil. METHODS: Patients with a confirmed tomographic diagnosis of bronchiectasis were defined as cases. Mutagenicity was evaluated by the micronucleus test in patients' oral mucosa cells. Data collection was performed through a questionnaire containing socioeconomic, demographic, lifestyle, and health condition information. RESULTS: Of the 95 patients involved in this study, 21 (22.1%) were diagnosed with bronchiectasis aged between 12 and 89 years. There was no significant difference in the frequency of micronucleus between patients with and without bronchiectasis. There was a significant positive association between age and frequency of micronucleus among patients with bronchiectasis, but this association does not occur among patients without the disease. CONCLUSION: This is the first study to investigate data on the prevalence and clinical and epidemiological aspects of this chronic disease in Brazil, especially those related to the genotoxicity outcome.


Subject(s)
Bronchiectasis , Pulmonary Medicine , Adolescent , Adult , Aged , Aged, 80 and over , Brazil/epidemiology , Bronchiectasis/diagnosis , Bronchiectasis/epidemiology , Child , Hospitals , Humans , Middle Aged , Mutagens/therapeutic use , Young Adult
16.
mBio ; 13(5): e0232822, 2022 10 26.
Article in English | MEDLINE | ID: mdl-36066100

ABSTRACT

Aspergillus fumigatus causes invasive aspergillosis (IA) in immunocompromised patients, resulting in high mortality rates. Currently, no vaccine formulations to promote immune protection in at-risk individuals have been developed. In this work, we deleted the sterylglucosidase-encoding gene, sglA, in Aspergillus fumigatus and investigated its role in fungal virulence and host vaccine protection. The ΔsglA mutant accumulated sterylglucosides (SGs), newly studied immunomodulatory glycolipids, and exhibited reduced hyphal growth and altered compositions of cell wall polysaccharides. Interestingly, the ΔsglA mutant was avirulent in two murine models of IA and was fully eliminated from the lungs. Both corticosteroid-induced immunosuppressed and cyclophosphamide-induced leukopenic mice vaccinated with live or heat-killed ΔsglA conidia were fully protected against a lethal wild-type A. fumigatus challenge. These results highlight the potential of SG-accumulating strains as safe and promising vaccine formulations against invasive fungal infections. IMPORTANCE Infections by Aspergillus fumigatus occur by the inhalation of environmental fungal spores called conidia. We found that live mutant conidia accumulating glycolipids named sterylglucosides are not able to cause disease when injected into the lung. Interestingly, these animals are now protected against a secondary challenge with live wild-type conidia. Remarkably, protection against a secondary challenge persists even with vaccination with heat-killed mutant conidia. These results will significantly advance the field of the research and development of a safe fungal vaccine for protection against the environmental fungus A. fumigatus.


Subject(s)
Aspergillosis , Invasive Fungal Infections , Mice , Animals , Aspergillus fumigatus , Spores, Fungal , Hot Temperature , Aspergillosis/microbiology , Immunocompromised Host , Vaccination , Glycolipids , Cyclophosphamide
17.
Rev. Assoc. Med. Bras. (1992, Impr.) ; 68(9): 1191-1198, Sept. 2022. tab, graf
Article in English | LILACS-Express | LILACS | ID: biblio-1406646

ABSTRACT

SUMMARY OBJECTIVE: Bronchiectasis is a chronic respiratory disease characterized by inflammation, irreversible dilation of the bronchi, and recurrent pulmonary infections, with a high morbidity and mortality rate, but is less studied from the point of view of its prevalence and associated factors not directly related to respiratory prognosis. As it is a disease related to the exacerbation of the inflammatory process and oxidative stress, this study searched to investigate the micronucleus frequency in patients with and without bronchiectasis treated at a specialized pulmonology service in a hospital in the extreme south of Brazil. METHODS: Patients with a confirmed tomographic diagnosis of bronchiectasis were defined as cases. Mutagenicity was evaluated by the micronucleus test in patients' oral mucosa cells. Data collection was performed through a questionnaire containing socioeconomic, demographic, lifestyle, and health condition information. RESULTS: Of the 95 patients involved in this study, 21 (22.1%) were diagnosed with bronchiectasis aged between 12 and 89 years. There was no significant difference in the frequency of micronucleus between patients with and without bronchiectasis. There was a significant positive association between age and frequency of micronucleus among patients with bronchiectasis, but this association does not occur among patients without the disease. CONCLUSION: This is the first study to investigate data on the prevalence and clinical and epidemiological aspects of this chronic disease in Brazil, especially those related to the genotoxicity outcome.

19.
Nat Commun ; 13(1): 3634, 2022 06 25.
Article in English | MEDLINE | ID: mdl-35752611

ABSTRACT

Fungal infections cause more than 1.5 million deaths annually. With an increase in immune-deficient susceptible populations and the emergence of antifungal drug resistance, there is an urgent need for novel strategies to combat these life-threatening infections. Here, we use a combinatorial screening approach to identify an imidazopyrazoindole, NPD827, that synergizes with fluconazole against azole-sensitive and -resistant isolates of Candida albicans. NPD827 interacts with sterols, resulting in profound effects on fungal membrane homeostasis and induction of membrane-associated stress responses. The compound impairs virulence in a Caenorhabditis elegans model of candidiasis, blocks C. albicans filamentation in vitro, and prevents biofilm formation in a rat model of catheter infection by C. albicans. Collectively, this work identifies an imidazopyrazoindole scaffold with a non-protein-targeted mode of action that re-sensitizes the leading human fungal pathogen, C. albicans, to azole antifungals.


Subject(s)
Azoles , Fluconazole , Animals , Antifungal Agents/pharmacology , Antifungal Agents/therapeutic use , Azoles/pharmacology , Biofilms , Candida albicans , Drug Resistance, Fungal , Fluconazole/pharmacology , Homeostasis , Microbial Sensitivity Tests , Rats
20.
Microbiol Spectr ; 10(4): e0196122, 2022 08 31.
Article in English | MEDLINE | ID: mdl-35758748

ABSTRACT

Sphingolipids are essential building blocks of eukaryotic membranes and important signaling molecules that are regulated tightly in response to environmental and physiological inputs. While their biosynthetic pathway has been well-described, the mechanisms that facilitate the perception of sphingolipid levels at the plasma membrane remain to be uncovered. In Saccharomyces cerevisiae, the Nce102 protein has been proposed to function as a sphingolipid sensor as it changes its plasma membrane distribution in response to sphingolipid biosynthesis inhibition. We show that Nce102 redistributes specifically in regions of increased sphingolipid demand, e.g., membranes of nascent buds. Furthermore, we report that the production of Nce102 increases following sphingolipid biosynthesis inhibition and that Nce102 is internalized when excess sphingolipid precursors are supplied. This finding suggests that the total amount of Nce102 in the plasma membrane is a measure of the current need for sphingolipids, whereas its local distribution marks sites of high sphingolipid demand. The physiological role of Nce102 in the regulation of sphingolipid synthesis is demonstrated by mass spectrometry analysis showing reduced levels of hydroxylated complex sphingolipids in response to heat stress in the nce102Δ deletion mutant. We also demonstrate that Nce102 behaves analogously in the widespread human fungal pathogen Candida albicans, suggesting a conserved principle of local sphingolipid control across species. IMPORTANCE Microorganisms are challenged constantly by their rapidly changing environment. To survive, they have developed diverse mechanisms to quickly perceive stressful situations and adapt to them appropriately. The primary site of both stress sensing and adaptation is the plasma membrane. We identified the yeast protein Nce102 as a marker of local sphingolipid levels and fluidity in the plasma membrane. Nce102 is an important structural and functional component of the membrane compartment Can1 (MCC), a plasma membrane microdomain stabilized by a large cytosolic hemitubular protein scaffold, the eisosome. The MCC/eisosomes are widely conserved among fungi and unicellular algae. To determine if Nce102 carries out similar functions in other organisms, we analyzed the human fungal pathogen Candida albicans and found that Nce102 responds to sphingolipid levels also in this organism, which has potential applications for the development of novel therapeutic approaches. The presented study represents a valuable model for how organisms regulate plasma membrane sphingolipids.


Subject(s)
Saccharomyces cerevisiae Proteins , Sphingolipids , Candida albicans , Cell Membrane/metabolism , Fungal Proteins/metabolism , Saccharomyces cerevisiae/genetics , Saccharomyces cerevisiae/metabolism , Saccharomyces cerevisiae Proteins/analysis , Saccharomyces cerevisiae Proteins/genetics , Saccharomyces cerevisiae Proteins/metabolism , Sphingolipids/analysis , Sphingolipids/metabolism
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