The Role of the SARS-CoV-2 S-Protein Glycosylation in the Interaction of SARS-CoV-2/ACE2 and Immunological Responses

The current pandemic is caused by the coronavirus disease 2019 (COVID-19), which is, in turn, induced by a novel coronavirus (SARS-CoV-2) that triggers an acute respiratory disease. In recent years, the emergence of SARS-CoV-2 is the third highly pathogenic event and large-scale epidemic affecting the human population. It follows the severe acute respiratory syndrome coronavirus (SARS-CoV) in 2003 and the Middle East respiratory syndrome coronavirus (MERS-CoV) in 2012. This novel SARS-CoV-2 employs the angiotensin-converting enzyme 2 (ACE2) receptor, like SARS-CoV, and spreads principally in the respiratory tract. The viral spike (S) protein of coronaviruses facilities the attachment to the cellular receptor, entrance, and membrane fusion. The S protein is a glycoprotein and is critical to elicit an immune response. Glycosylation is a biologically significant post-translational modification in virus surface proteins. These glycans play important roles in the viral life cycle, structure, immune evasion, and cell infection. However, it is necessary to search for new information about viral behavior and immunological host's response after SARS-CoV-2 infection. The present review discusses the implications of the CoV-2 S protein glycosylation in the SARS-CoV-2/ACE2 interaction and the immunological response. Elucidation of the glycan repertoire on the spike protein can propel research for the development of an appropriate vaccine.

Apart From Rhoptries, Identification of Toxoplasma gondii's O-GlcNAcylated Proteins Reinforces the Universality of the O-GlcNAcome

O-linked β-N-acetylglucosaminylation or O-GlcNAcylation is a widespread post-translational modification that belongs to the large and heterogeneous group of glycosylations. The functions managed by O-GlcNAcylation are diverse and include regulation of transcription, replication, protein's fate, trafficking, and signaling. More and more evidences tend to show that deregulations in the homeostasis of O-GlcNAcylation are involved in the etiology of metabolic diseases, cancers and neuropathologies. O-GlcNAc transferase or OGT is the enzyme that transfers the N-acetylglucosamine residue onto target proteins confined within the cytosolic and nuclear compartments. A form of OGT was predicted for Toxoplasma and recently we were the first to show evidence of O-GlcNAcylation in the apicomplexans Toxoplasma gondii and Plasmodium falciparum. Numerous studies have explored the O-GlcNAcome in a wide variety of biological models but very few focus on protists. In the present work, we used enrichment on sWGA-beads and immunopurification to identify putative O-GlcNAcylated proteins in Toxoplasma gondii. Many of the proteins found to be O-GlcNAcylated were originally described in higher eukaryotes and participate in cell shape organization, response to stress, protein synthesis and metabolism. In a more original way, our proteomic analyses, confirmed by sWGA-enrichment and click-chemistry, revealed that rhoptries, proteins necessary for invasion, are glycosylated. Together, these data show that regardless of proteins strictly specific to organisms, O-GlcNAcylated proteins are rather similar among living beings.

[Bone mineral density and 17 beta-estradiol correlation in postmenopausal women]

BACKGROUND

With the increased life-expectancy reached during 20th century, women will spend a very important part of their lives in the estrogenic deficiency state accompanying menopause.

OBJECTIVES

To detect serum 17beta-estradiol levels, bone mineral density values, and to see the correlation between both parameters as well as with postmenopausal period.

MATERIAL AND METHODS

A transversal study with ambulatory, community-dwelling postmenopausal women from Oaxaca de Juárez, Oax. was performed.

RESULTS

We studied 70 women with spontaneous menopause, medium values were: age, 55.9 +/- 5.4 yr; menopause age, 48 +/- 3 yr; postmenopausal period, 7.9 +/- 5.3 yr; body mass index, 28.3 +/- 5.4, and serum 17beta-estradiol by radioimmunoassay, 62.78 +/- 25.83 pg/mL. Quantitative calcaneous ultrasound was used to measure bone mineral density and we found 30 women with normal level (-1.0 to 1.4 SD), 29 with osteopenia (-1.1 to -2.3 SD) and only 2 subjects with osteoporosis (-2.7 to 2.8 SD).

CONCLUSIONS

Statistical analysis shows that bone mineral density and postmenopausal period were significantly correlated (p<0.05) as well as serum 17beta-estradiol levels with postmenopausal period; nevertheless, no correlation between bone mineral density and serum 17beta-estradiol or body mass index (p>0.05) was found. On the other hand, it is remarkable high serum 17beta-estradiol levels found in this group, related with postmenopausal status. These latter results are different from those reported in the literature.

[Bibliographic review. The role of hypoestrogenism in postmenopausal osteoporosis--new perspectives]

Estrogen deficiency following menopause results in a significative bone loss, which is thought to be the result of an imbalance in bone remodeling process between formation activity and resorption, where the later is functionally higher than normal and could develop osteopenia or osteoporosis type I. Although it has been made a lot of scientific investigations to explain the way by hypoestrogenism affect skeleton, the renal mechanism remains unclear and it seems to be multifactorial. Therefore, the purpose of this review is to analyze the new perspectives about the effects of serum estradiol levels on bone tissue; special emphasize is made concerning the role of: estrogen receptors, cytokines, RANKL/RANK/OPG system, PTH and PTHrP, bone turnover markers, osteocytes apoptosis, estrogens serum levels and its metabolic pathways.

Re-evaluation of antibiotic and mercury resistance in Escherichia coli populations isolated in 1978 from Amazonian rubber tree tappers and Indians

A study was carried out to assess the stability of antimicrobial susceptibility of wild isolates upon long-term storage using fifty-three Escherichia coli strains isolated in 1978 from feces of healthy children from the Amazon region in Brazil, exposed to low levels of antimicrobial agents, and examined for resistance to mercury and four antibiotics. All of the strains were kept in Lignières medium at room temperature and were transferred to fresh media four times during this period. Thirty-five out of the 53 strains analyzed in 1978 were viable. Upon recovery, antibiotic and mercury resistance was estimated. All of the 35 strains maintained their original phenotype in a stable fashion, except for one multiresistant strain which became susceptible to kanamycin. Fifty-four percent of the strains exhibited a resistance phenotype, among which 47% had conjugative plasmids.

[Candidiasis in AIDS patients]

A total of 35 in patients admitted at Emilio Ribas Hospital--São Paulo, Brazil, with digestive candidiasis and AIDS clinical diagnostic were evaluated 10 month later, being 29 male and 6 female; white outnumbering black with age ranged from 30 to 50 years old. Agar Sabouraud culture and tube germinative tests identified 28 (80%) Candida albicans out 35 strains. Minimum inhibitory concentration (MIC) 50% was against azoles (ketoconazole = 2.2 micrograms/ml; itraconazole = 21.0 micrograms/ml and fluconazole = 19.0 micrograms/ml); polyenes (nystatin = 50.0 micrograms/ml and amphotericin B = 0.12 micrograms/ml) and 5 fluorocytosine = 1.6 micrograms/ml. Siegel tests showed significant Candida albicans proportions in strains isolated from 35 AIDS patients. There was no significant relation between AMB doses and early or late death.

CONCLUSIONS

candidiasis in AIDS patients showed high MIC 50% to azoles and nystatin and significant Candida albicans proportion in all strains isolated from AIDS patients. Previous amphotericin B therapy had no influence in early or late death in 30 patients. Previous therapy possibly explained MIC 50% increases in Candida strains.

[Paracoccidioidomycosis: radiologic and pulmonary study in 58 cases]

Spirometric and haemogasimetric tests were performed in 52 patients with unifocal and multifocal progressive Paracoccidioidomycosis pulmonary diseases, in 5 patients with juvenile and 1 female internal genital forms. The age ranged from 20 to 74 years old and the duration of disease from 3 to 25 years. Dyspnea, cough, tegumentary and lymphatic manifestations were the most predominant signs observed. Fourteen of them was developed Cor pulmonale. Impaired renal function was recorded in 19 patients, cardiac symptoms were described in 7 and hyporeactor adrenal activity was showed in 13 patients. Radiological studies demonstrated mild in 16, moderate in 24 and severe pulmonary lesions types in 18 patients. The pulmonary function revealed: normal spyrographic findings in 17, pure obstructive type in 32 and mixed form in 9 of them. Hyperventilation was described in 54 individuals and all of them showed an increasing of the alveolo-arterial difference. PaO2 less than 80 mm/Hg observed in 36 of them. Statistical analysis demonstrated significative association between clinical evolution and radiological interpretation. Similar data were obtained in radiology evaluations, clinical evolutive studies and pulmonary functions described in these patients. The granulomatous reaction due to Paracoccidioidomycosis, in heavy smokers patients, gave origin to the alterations in small airways predisposing the interalveolar dissemination an impaired alveolo-arterial diffusion.

[Pulmonary function in 35 patients with paracoccidioidomycosis]

Lesões pulmonares observadas na paracoccidioidomicose (pbmicose) pela radiologia foram designadas: leve, moderada e grave de acordo com critério estabelecido pelos autores. Lesões infiltrativas intersticiais bilaterais nddulo fibrolineares e cotonosas foram identificadas respectivamente em 34 e em 23 doentes. Formas leve, moderada e grave assinaladas respectivamente em 6 10 e 19 mostraram à análise radiológica evolutiva melhora em 2, piora em 15 e manutenção do padrão da lesão em 18 doentes. Testes de função pulmonar realizados nos doentes durante o retorno ambulatorial evidenciaram: 12 com padrão espirográfico normal, 20 obstrutivos e 3 mistos; 34 doentes estavam hiperventilando e todos apresentaram aumento da diferença alvéolo arterial. Os resultados obtidos permitiram supor que a fibrose residual descrita nos padrões radiológicos; manutenção e piora de 33 deles aliada à doença obstrutiva crônica verificada pelas provas de função pulmonar constituíram subsídios para o desenvolvimento do Cor pulmonale assinalado

[Aggressive pulmonary paracoccidioidomycosis, stenosing endotracheitis and subacute cor pulmonale. Description of a case]

A paracoccidioidomicose (Pbmicose) atinge os pulmões pela via inalatória, onde se estabelece o complexo primário semelhante ao da tuberculose. A traquéia comprometida pela via tubohemolinfática desenvolveria reação inflamatória em processo granulomatoso levando à obstrução estenosante com asíixia. Acompanhou-se um doente, masculino, 32 anos, branco, natural de Sarutaiá (SP), lavrador, que há 8 meses desenvolveu tosse expectorativa branco-amarelada, diária, sem fatores de melhora ou piora e dispnéia inicial discreta. Há 4 meses, anorexia, fraqueza e astenia. Há 1 mês a dispneia se agravou. Perdeu 15 kg. Tabagista e etilista há 16 anos. Exame físico revelou: PA — 10/7 mmHg, FR = 28 bpm, peso 31 kg, hipocratismo digital e hipotrofia muscular Tórax enfisematoso e síndrome obstrutivo aos testes de função pulmonar. Coração: P2 desdobrada e hiperfonética. Hepatesplenomegalia. Desenvolveu cor-pulmonale e insuficiência adrenal à internação, evoluindo após 45 dias para óbito em insuficiência respiratória aguda asfixiante, apesar da terapia antifúngica ter sido completa. A literatura médica revista não mostrou registro de caso semelhante de cor-pulmonale e insuficiência adrenal de evolução subaguda.

[Female genital paracoccidioidomycosis. Report of a clinical case]

A paracoccidioidomicose é doença sistêmica que atinge mais o sexo masculino do que o feminino. Modelos experimentais mostram maior sensibilidade dos machos do que as fêmeas à dsseminação da doença. A literatura médica é rica em relatos de casos de Pbmicose do trato genital masculino. A raridade da Pbmicose sistêmica na mulher devido à ação hormonal tornou inusitada a descrição de um caso com envolvimneto genital. Paciente de 57 anos, branca, procedente de Conchas (SP), queixando-se de dor abdominal há 10 anos, difusa, seguida de eólica periumbelical periódica, com diarréia e obstipação alternadas. Piorou desse quadro e evoluiu para abdome agudo cirúrgico. O anátomo patológico revelou Pbmicose no epiplon e ovário direito. A biópsia do endométrio mostrou endometrite crônica granulomatosa. A radiologia e a planigrafia revelaram nódulo parahilar direito. Os achados clínicos e laboratoriais permitiram explicar a provável origem do envolvimento genital.