The incidence of multiple cancer types is increasing in younger generations, with the underlying causes being debated. Here, we propose that environmentally-driven organ enlargement is a novel mechanism contributing to the observed increase in intergenerational cancer risk. All other things being equal, cancer risk will be higher in larger organs composed of more constituent cells, due to the lifetime accumulation of stochastic genomic replication errors. Importantly, the size of certain organs is affected by factors such as diet and lifestyle. Could distinct environmental conditions between generations, therefore, drive organ enlargement, and as a secondary effect, increase cancer risk? Average height and weight-which correlate to the size of internal organs-have clearly been increasing in more recent generations. Recent studies have also found that socio-economic factors are associated with increased brain volume. Research to examine the validity and applicability of the proposed hypothesis could be highly important for public health policy.
The 1985 confirmation by Mejia and MacKenzie of mammalian NAD-dependent methylenetetrahydrofolate dehydrogenase activity launched four decades of research on methylenetetrahydrofolate dehydrogenase (NAD+-dependent), methenyltetrahydrofolate cyclohydrolase 2 (MTHFD2). This review provides a retrospective on four decades of advancements on MTHFD2 that have revealed its key roles in the folate pathway, amino acid and redox homeostasis, and the metabolism of cancer and immune cells. We trace the initial biochemical characterization of the enzyme, highlight pivotal discoveries regarding MTHFD2's metabolic and non-canonical roles, and discuss the current state of knowledge and future prospects.
N-terminal acetyltransferases (NAT) are the protein complexes that deposit the abundant N-terminal acetylation (Nt-Ac) on eukaryotic proteins, with seven human complexes currently identified. Despite the increasing recognition of their biological and clinical importance, NAT regulation remains elusive. In this study, we performed a bioinformatic investigation to identify transcriptional and post-transcriptional processes that could be involved in the regulation of human NAT complexes. First, co-expression analysis of independent transcriptomic datasets revealed divergent pathway associations for human NAT, which are potentially connected to their distinct cellular functions. One interesting connection uncovered was the coordinated regulation of the NatA and proteasomal genes in cancer and immune cells, confirmed by analysis of multiple datasets and in isolated primary T cells. Another distinctive association was of NAA40 (NatD) with DNA replication, in cancer and non-cancer settings. The link between NAA40 transcription and DNA replication is potentially mediated through E2F1, which we have experimentally shown to bind the promoter of this NAT. Second, the coupled examination of transcriptomic and proteomic datasets revealed a much greater intra-complex concordance of NAT subunits at the protein compared to the transcript level, indicating the predominance of post-transcriptional processes for achieving their coordination. In agreement with this concept, we also found that the effects of somatic copy number alterations affecting NAT genes are attenuated post-transcriptionally. In conclusion, this study provides novel insights into the regulation of human NAT complexes.
N-alpha-acetyltransferase 40 (NAA40) is an evolutionarily conserved N-terminal acetyltransferase (NAT) linked to oncogenesis and chemoresistance. A recent study reported the generation of a second, shorter NAA40 isoform (NAA40S) through alternative translation, which we proceeded to further characterise. Notably, recombinant NAA40S had a greater in vitro enzymatic activity and affinity towards its histone H2A/H4 substrates compared to full-length NAA40 (NAA40L). Within cells, NAA40S was enzymatically active, based on its ability to suppress the H2A/H4S1Ph antagonistic mark in CRISPR-generated NAA40 knockout cells. Finally, we show that in addition to alternative translation, the NAA40S isoform could be derived from a primate and testis-specific transcript, which may align with the “out-of-testis” origin of recently evolved genes and isoforms. To summarise, our data reveal an even greater functional divergence between the two NAA40 isoforms than had been previously recognised.
Scorpion venom peptides are generally classified into two main groups: the disulfide bridged peptides (DBPs), which usually target membrane-associated ion channels, and the non-disulfide bridged peptides (NDBPs), a smaller group with multifunctional properties. In the past decade, these peptides have gained interest because most of them display functions that include antimicrobial, anticancer, haemolytic, and anti-inflammatory activities. Our current study focuses on the short (9–19 amino acids) antimicrobial linear scorpion peptides. Most of these peptides display a net positive charge of 1 or 2, an isoelectric point at pH 9–10, a broad range of hydrophobicity, and a Grand Average of Hydropathy (GRAVY) Value ranging between −0.05 and 1.7. These features allow these peptides to be attracted toward the negatively charged phospholipid head groups of the lipid membranes of target cells, a force driven by electrostatic interactions. This review outlines the antimicrobial potential of short-chained linear scorpion venom peptides. Additionally, short linear scorpion peptides are in general more attractive for large-scale synthesis from a manufacturing point of view. The structural and functional diversity of these peptides represents a good starting point for the development of new peptide-based therapeutics.
SARS-CoV-2 is the virus that causes the infectious disease known as Corona Virus Disease 2019 (COVID-19). The severe impact of the virus on humans is undeniable, which is why effective vaccines were highly anticipated. As of 12 January 2022, nine vaccines have obtained Emergency Use Listing by the World Health Organization (WHO), and four of these are approved or authorized by the Centers for Disease Control and Prevention (CDC) in the United States. The initial clinical trials studying COVID-19 vaccine efficacy excluded pregnant and lactating individuals, meaning that data on the effects of the vaccine on breast milk were lacking. Until today, none of the authorized vaccines have been approved for use in individuals under six months. During the first months of life, babies do not produce their own antibodies; therefore, antibodies contained in their mothers’ breastmilk are a critical protective mechanism. Several studies have shown the presence of SARS-CoV-2 antibodies in the breast milk of women who have been vaccinated or had been naturally infected. However, whether these are protective is still unclear. Additionally, research on the BNT162b2 mRNA vaccine developed by Pfizer-BioNTech and the mRNA-1273 vaccine developed by Moderna suggests that these vaccines do not release significant amounts, if any, of mRNA into breast milk. Hence, there is no evidence that vaccination of the mother poses any risk to the breastfed infant, while the antibodies present in breast milk may offer protection against the virus. The primary objective of this systematic review is to summarize the current understanding of the presence of immunoglobulins in human milk that are elicited by SARS-CoV-2 vaccines and to evaluate their ability to neutralize the virus. Additionally, we aim to quantify the side effects experienced by lactating mothers who have been vaccinated, as well as the potential for adverse effects in their infants. This study is critical because it can help inform decision-making by examining the current understanding of antibody secretion in breastmilk. This is particularly important because, although the virus tends to be less severe in younger individuals, infants who contract the disease are at a higher risk of requiring hospitalization compared to older children.
The novel coronavirus disease 2019 (COVID-19) is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and poses significant complications for cardiovascular disease (CVD) patients. MicroRNAs (miRNAs) are small non-coding RNAs that regulate gene expression and influence several physiological and pathological processes, including CVD. This critical review aims to expand upon the current literature concerning miRNA deregulation during the SARS-CoV-2 infection, focusing on cardio-specific miRNAs and their association with various CVDs, including cardiac remodeling, arrhythmias, and atherosclerosis after SARS-CoV-2 infection. Despite the scarcity of research in this area, our findings suggest that changes in the expression levels of particular COVID-19-related miRNAs, including miR-146a, miR-27/miR-27a-5p, miR-451, miR-486-5p, miR-21, miR-155, and miR-133a, may be linked to CVDs. While our analysis did not conclusively determine the impact of SARS-CoV-2 infection on the profile and/or expression levels of cardiac-specific miRNAs, we proposed a potential mechanism by which the miRNAs mentioned above may contribute to the development of these two pathologies. Further research on the relationship between SARS-CoV-2, CVDs, and microRNAs will significantly enhance our understanding of this connection and may lead to the use of these miRNAs as biomarkers or therapeutic targets for both pathologies.
Nutrition during early life plays a crucial role in determining a child’s long-term health [...]
Lactate dehydrogenase (LDH) is an enzyme that catalyzes the reversible conversion of lactate to pyruvate while reducing NAD+ to NADH (or oxidizing NADH to NAD+). Due to its central role in the Warburg effect, LDH-A isoform has been considered a promising target for treating several types of cancer. However, research on inhibitors targeting LDH-B isoform is still limited, despite the enzyme's implication in the development of specific cancer types such as breast and lung cancer. This study aimed to identify small-molecule compounds that specifically inhibit LDH-B. Our in silico analysis identified eight commercially available compounds that may affect LDH-B activity. The best five candidates, namely tucatinib, capmatinib, moxidectin, rifampicin, and acetyldigoxin, were evaluated further in vitro. Our results revealed that two compounds, viz., tucatinib and capmatinib, currently used for treating breast and lung cancer, respectively, could also act as inhibitors of LDH-B. Both compounds inhibited LDH-B activity through an uncompetitive mechanism, as observed in in vitro experiments. Molecular dynamics studies further support these findings. Together, our results suggest that two known drugs currently being used to treat specific cancer types may have a dual effect and target more than one enzyme that facilitates the development of these types of cancers. Furthermore, the results of this study could be used as a new starting point for identifying more potent and specific LDH-B inhibitors.
There is a strong link between the rate of cell division and the lifetime cancer risk for a given tissue. This relationship is a consequence of the random occurrence of genetic mutations with each cell division, which can potentially disrupt oncogenes and tumour suppressor genes. Consequently, tissues with a high rate of cell division, such as the colon and breast, have a higher risk of developing tumours than tissues with lower rates such as the heart or brain. Erythrocytes, or red blood cells, are generated at an immense rate of about two million per second in normal adults. Mammalian erythrocytes are also distinguished by the fact that uniquely in this lineage, they have evolved to eject their nucleus during their formation, a process known as enucleation. Since erythrocytes lack a nucleus, they also do not contain the genetic material that can become mutated and give rise to cancer. Therefore, erythrocyte cancer burden is minimal compared to malignancy of other blood lineages. Although cancer is often considered evolutionarily neutral, multicellular organisms have actually evolved several tumour suppressive mechanisms. We propose here that the repression of the tumour burden arising from the erythrocyte lineage is an unappreciated benefit and a driver for the evolution of erythrocyte enucleation in mammals. A prediction emerging from our hypothesis is that non-mammalian lineages which retain the ancestral nucleated erythrocyte state will either experience greater rates of cancers originating from this lineage or will have evolved alternative and distinct tumour suppressive mechanisms. A greater understanding and appreciation of animal tumour suppressive mechanisms at the species level may also offer insights into cancer prevention and treatments for humans.
BACKGROUND:Breast cancer (BC) is the second leading cause of cancer-related mortality among women. Beyond the established tumourigenic role of genetic mutations, metabolic reprogramming is another key cancer hallmark. Glucose metabolism in particular is known to be prominently altered in tumours, in order to support biomass accumulation and cancer cell survival. The tumor suppressor microRNA (miRNA) miR-22 has been previously associated with a plethora of BC phenotypes such as growth, invasion-metastasis, and regulation of metabolic phenotypes such as lipid and folate metabolism. In this study, we aimed to investigate the role of miR-22 in the regulation of glucose metabolism in BC cells.METHODS AND RESULTS:Here we examined how miR-22 affects glucose metabolism in the MCF-7 BC cells. We found that over-expression of miR-22 caused a reduced glycolytic rate in these cells. Moreover, the miRNA also rendered MCF-7 cells more sensitive to lower glucose levels. We next unbiasedly screened the transcript levels of 84 genes relevant to glucose metabolism using the Human Glucose RT2 Profiler PCR Array. Interestingly, the strongest effect identified by this screen was the upregulation of genes involved in glycogen synthesis and the repression of gene involved in glycogen catabolism. Examination of publicly available transcriptomic datasets confirmed the correlations between expression of miR-22 and these glycogen metabolism genes in BC cells.CONCLUSION:This study has generated evidence for a regulatory role of miR-22 in glucose and glycogen metabolism, expanding the involvement of this miRNA in BC metabolic reprogramming.
Ankylosing spondylitis (AS) is an inflammatory disease leading to spine ankylosis; however, the mechanisms behind new bone formation are still not fully understood. Single Nucleotide Polymorphisms (SNPs) in PTGER4, encoding for the receptor EP4 of prostaglandin E2 (PGE2), are associated with AS. Since the PGE2-EP4 axis participates in inflammation and bone metabolism, this work aims at investigating the influence of the prostaglandin-E2 axis on radiographic progression in AS. In 185 AS (97 progressors), baseline serum PGE2 predicted progression, and PTGER4 SNP rs6896969 was more frequent in progressors. Increased EP4/PTGER4 expression was observed in AS circulating immune cells, synovial tissue, and bone marrow. CD14highEP4 + cells frequency correlated with disease activity, and when monocytes were cocultured with mesenchymal stem cells, the PGE2/EP4 axis induced bone formation. In conclusion, the Prostaglandin E2 axis is involved in bone remodelling and may contribute to the radiographic progression in AS due to genetic and environmental upregulation.
Monitoring the levels of IgG antibodies against the SARS-CoV-2 is important during the coronavirus disease 2019 (COVID-19) pandemic, to plan an adequate and evidence-based public health response. After this study we report that the plasma levels of IgG antibodies against SARS-CoV-2 spike protein were higher in individuals with evidence of prior infection who received at least one dose of either an mRNA-based vaccine (Comirnaty BNT162b2/Pfizer-BioNTech or Spikevax mRNA-1273/Moderna) or an adenoviral-based vaccine (Vaxzervia ChAdOx1 nCoV-19 /Oxford-Astra Zeneca) (n = 39) compared to i) unvaccinated individuals with evidence of prior infection with SARS-CoV-2 (n = 109) and ii) individuals without evidence of prior infection with SARS-CoV-2 who received one or two doses of one of the aforementioned vaccines (n = 342). Our analysis also revealed that regardless of the vaccine technology (mRNA-based and adenoviral vector-based) two doses achieved high anti- SARS-CoV-2 IgG responses. Our results indicate that vaccine-induced responses lead to higher levels of IgG antibodies compared to those produced following infection with the virus. Additionally, in agreement with previous studies, our results suggest that among individuals previously infected with SARS-CoV-2, even a single dose of a vaccine is adequate to elicit high levels of antibody response.
In the past half century, humanity has experienced two devastating pandemics; the HIV-1 pandemic and the recent pandemic caused by SARS-CoV-2.Both emerged as zoonotic pathogens.Interestingly, SARS-CoV-2 has rapidly migrated all over the world in less than two years, much as HIV-1 did almost 40 years ago.Despite these two RNA viruses being different in their mode of transmission as well as the symptoms they generate, recent evidence suggests that they cause similar immune responses.In this mini review, we compare the molecular basis for CD4 + T cell lymphopenia and other effects on the immune system induced by SARS-CoV-2 and HIV-1 infections.We considered features of the host immune response that are shared with HIV-1 and could account for the lymphopenia and other immune effects observed in COVID-19.The information provided herein, may cast the virus-induced lymphopenia and cytokine storm associated with the acute SARS-CoV-2 infection and pathogenesis in a different light for further research on host immune responses.It can also provide opportunities for the identification of novel therapeutic targets for COVID-19.Furthermore, we provide some basic information to enable a comparative framework for considering the overlapping sets of immune responses caused by HIV-1 and SARS-CoV-2.
Four vaccines that have been authorized in the European Union offer different levels of protection against SARS-CoV-2 by generating immune responses against the spike receptor-binding domain (RBD) of the virus. Monitoring the levels of IgG antibodies against the SARS-CoV-2 is important during the coronavirus disease 2019 (COVID-19) pandemic to plan an adequate and evidence-based public health response. We compared the levels of serum IgG antibodies against SARS-CoV-2 spike protein in three groups: i) individuals without evidence of prior infection with SARS-CoV-2 who received one or two doses of either an mRNA-based (Comirnaty BNT162b2/Pfizer-BioNTech or Spikevax mRNA-1273/Moderna) or an adenoviral-based vaccine (Vaxzervia ChAdOx1 nCoV-19 /Oxford-Astra Zeneca) (n=227), ii) unvaccinated individuals with evidence of prior infection with SARS-CoV-2 (n=109), and iii) individuals with evidence of prior infection with SARS-CoV-2 who received at least one dose of a vaccine (n=30). Unvaccinated individuals without evidence of prior infection with SARS-CoV-2 were used as a control group (n=211). Our results indicate that vaccine-induced responses lead to higher levels of IgG antibodies compared to those produced following infection with the virus. In agreement with previous studies, our results suggest that among individuals previously infected with SARS-CoV-2, even a single dose of a vaccine is adequate to elicit high levels of humoral immunity.