Papel de los tejidos orales durante la infección por SARS-CoV-2 / Role of oral tissues in SARS-CoV-2 infection

La actual pandemia de COVID-19 provocada por el virus SARS-CoV-2 es un problema de salud que afecta a la población globalmente. Su desarrollo puede ser asintomático o exhibir manifestaciones clínicas moderadas o severas dependiendo en gran medida de la respuesta inmune de quien la padece. Esta enfermedad afecta principalmente a los pulmones a través del desarrollo del síndrome respiratorio agudo severo (SRAS), tanto como por la «tormenta de citocinas¼, una respuesta inflamatoria exacerbada que podría provocar una falla multisistémica y, en casos severos, la muerte. Se conoce que la enzima convertidora de angiotensina 2 (ECA-2), presente en diversos tejidos del cuerpo, actúa como receptor funcional del virus SARS-CoV-2 facilitando la entrada de éste a las células. Se ha demostrado la presencia de dicho receptor en varios tejidos orales, por lo que se puede considerar a la cavidad bucal como una vía latente de infección por dicho coronavirus, ya que su mecanismo de transmisión es a través de la inhalación de partículas virales, ya sea por vía nasal u oral. Así mismo, la presencia de carga vírica en la saliva y algunos de los síntomas de la COVID-19, por ejemplo la ageusia, pueden indicar la presencia de contagio viral en etapas tempranas. La presente revisión muestra evidencia que sugiere que diversos tejidos en la cavidad oral podrían ser considerados sitios potenciales de contagio por el SARS-CoV-2, teniendo un papel importante en el mecanismo de transmisión y en el desarrollo de coinfecciones (AU)

The COVID-19 pandemic caused by the SARS-CoV-2 virus is currently a global healthcare problem. The onset of this disease can exhibit several clinical manifestations ranging from mild to severe symptoms, depending on the individual's immune response. COVID-19 primarily affects the lungs by developing the Severe Acute Respiratory Syndrome (SARS) and the «cytokine storm¼, an exacerbated inflammatory reaction that can lead to multiorgan failure and consequently death. The angiotensin-converting enzyme 2 (ACE-2), present in several tissues in the human body, is known to act as the functional receptor of the SARS-CoV-2 germ facilitating its entrance into the cells. Such receptor is also present in diverse oral cavity tissues, indicating a latent route of infection due to its influence in the transmission mechanism by inhalation, either oral or nasal, of virus particles. Also, viral load in saliva and taste disorder symptoms like ageusia could indicate a viral infection in its early stages. This article presents evidence suggesting that several tissues in the oral cavity can be considered potential sites of SARS-CoV-2 infection, thus playing an essential role in the transmission mechanism and development of co-infections (AU)

Self-Assembling Peptides as an Emerging Platform for the Treatment of Metabolic Syndrome.

Metabolic syndrome comprises a cluster of comorbidities that represent a major risk of developing chronic diseases, such as type II diabetes, cardiovascular diseases, and stroke. Alarmingly, metabolic syndrome reaches epidemic proportions worldwide. Today, lifestyle changes and multiple drug-based therapies represent the gold standard to address metabolic syndrome. However, such approaches face two major limitations: complicated drug therapeutic regimes, which in most cases could lead to patient incompliance, and limited drug efficacy. This has encouraged scientists to search for novel routes to deal with metabolic syndrome and related diseases. Within such approaches, self-assembled peptide formulations have emerged as a promising alternative for treating metabolic syndrome. In particular, self-assembled peptide hydrogels, either as acellular or cell-load three-dimensional scaffoldings have reached significant relevance in the biomedical field to prevent and restore euglycemia, as well as for controlling cardiovascular diseases and obesity. This has been possible thanks to the physicochemical tunability of peptides, which are developed from a chemical toolbox of versatile amino acids enabling flexibility of designing a wide range of self-assembled/co-assembled nanostructures forming biocompatible viscoelastic hydrogels. Peptide hydrogels can be combined with several biological entities, such as extracellular matrix proteins, drugs or cells, forming functional biologics with therapeutic ability for treatment of metabolic syndrome-comorbidities. Additionally, self-assembly peptides combine safety, tolerability, and effectivity attributes; by this presenting a promising platform for the development of novel pharmaceuticals capable of addressing unmet therapeutic needs for diabetes, cardiovascular disorders and obesity. In this review, recent advances in developing self-assembly peptide nanostructures tailored for improving treatment of metabolic syndrome and related diseases will be discussed from basic research to preclinical research studies. Challenges facing the development of approved medicinal products based on self-assembling peptide nanomaterials will be discussed in light of regulatory requirement for clinical authorization.

Evaluation of the immunogenic capability of the BCG strains BCGΔBCG1419c and BCGΔBCG1416c in a three-dimensional human lung tissue model.

Tuberculosis (TB) still remains as an unmet global threat. The current vaccine is not fully effective and novel alternatives are needed. Here, two vaccine candidate strains derived from BCG carrying deletions in the BCG1416c or BCG1419c genes were analysed for their capacity to modulate the cytokine/chemokine profile and granuloma formation in a human lung tissue model (LTM). We show that the clustering of monocytes, reminiscent of early granuloma formation, in LTMs infected with BCG strains was similar for all of them. However, BCGΔBCG1419c, like M. tuberculosis, was capable of inducing the production of IL-6 in contrast to the other BCG strains. This work suggests that LTM could be a useful ex vivo assay to evaluate the potential immunogenicity of novel TB vaccine candidates.