IUBMB Life最新文献

Cryomyces antarcticus, a melanized cryptoendolithic fungus endemic to Antarctica, can tolerate environmental conditions as severe as those in space. Particularly, its ability to withstand ionizing radiation has been attributed to the presence of thick and highly melanized cell walls, which-according to a previous investigation-may contain both 1,8-dihydroxynaphthalene (DHN) and L-3,4 dihydroxyphenylalanine (L-DOPA) melanin. The genes putatively involved in the synthesis of DHN melanin were identified in the genome of C. antarcticus. Most important is capks1 encoding a non-reducing polyketide synthase (PKS) and being the ortholog of the functionally characterized kppks1 from the rock-inhabiting fungus Knufia petricola. The co-expression of CaPKS1 or KpPKS1 with a 4'-phosphopantetheinyl transferase in Saccharomyces cerevisiae resulted in the formation of a yellowish pigment, suggesting that CaPKS1 is the enzyme providing the precursor for DHN melanin. To dissect the composition and function of the melanin layer in the outer cell wall of C. antarcticus, non-melanized mutants were generated by CRISPR/Cas9-mediated genome editing. Notwithstanding its slow growth (up to months), three independent non-melanized Δcapks1 mutants were obtained. The mutants exhibited growth similar to the wild type and a light pinkish pigmentation, which is presumably due to carotenoids. Interestingly, visible light had an adverse effect on growth of both melanized wild-type and non-melanized Δcapks1 strains. Further evidence that light can pass the melanized cell walls derives from a mutant expressing a H2B-GFP fusion protein, which can be detected by fluorescence microscopy. In conclusion, the study reports on the first genetic manipulation of C. antarcticus, resulting in non-melanized mutants and demonstrating that the melanin is rather of the DHN type. These mutants will allow to elucidate the relevance of melanization for surviving extreme conditions found in the natural habitat as well as in space.

Osteoporosis (OP) is a systemic metabolic bone disease resulting in reduced bone strength and increased susceptibility to fractures, making it a significant public health and economic problem worldwide. The clinical use of anti-osteoporosis agents is limited because of their serious side effects or the high cost of long-term use. The Xianlinggubao (XLGB) formula is an effective traditional Chinese herbal medicine commonly used in orthopedics to treat osteoporosis; however, its mechanism of action remains unclear. In this study, we screened 40 small RNAs derived from XLGB capsules and found that XLGB28-sRNA targeting TNFSF11 exerted a significant anti-osteoporosis effect in vitro and in vivo by simultaneously promoting osteogenesis and inhibiting osteoclastogenesis. Oral administration of bencaosome [16:0 Lyso PA+XLGB28-sRNA] effectively improved bone mineral density and reduced the damage to the bone microstructure in mice. These results suggest that XLGB28-sRNA may be a novel oligonucleotide drug that promotes osteogenesis and inhibits osteoclastogenesis in mice.

Clinical data from over two decades, involving more than 3000 treated patients, demonstrate that adeno-associated virus (AAV) gene therapy is a safe, effective, and well-tolerated therapeutic method. Clinical trials using AAV-mediated gene delivery to accessible tissues have led to successful treatments for numerous monogenic disorders and advancements in tissue engineering. Although the US Food and Drug Administration (FDA) has approved AAV for clinical use, systemic administration remains a significant challenge. In this review, we delve into AAV biology, focusing on current manufacturing technologies and transgene engineering strategies. We examine the use of AAVs in ongoing clinical trials for ocular, neurological, and hematological disorders, as well as cancers. By discussing recent advancements and current challenges in the field, we aim to provide valuable insights for researchers and clinicians navigating the evolving landscape of AAV-based gene therapy.

Aegerolysin proteins are involved in various interactions by recognising a molecular receptor in the target organism. The formation of pores in combination with larger, non-aegerolysin-like protein partners (such as membrane attack complex/perforin proteins [MACPFs]) is one of the possible responses in the presumed competitive exclusion of other organisms from the ecological niche. Bicomponent pairs are already observed at the gene level. Fungi growing under extreme conditions can be divided into ubiquitous and extremotolerant generalists which can compete with mesophilic species and rare, isolated extremophilic and extremotolerant specialists with narrow ecological amplitude that cannot compete. Under extreme conditions, there are fewer competitors, so fungal specialists generally produce less diverse and complicated profiles of specialised molecules. Since extremotolerant and extremophilic fungi have evolved in numerous branches of the fungal tree of life and aegerolysins are unevenly distributed across fungal genomes, we investigated whether aegerolysins, together with their partner proteins, contribute to the extreme survival ecology of generalists and specialists. We compiled a list of 109 thermo-, psihro-, acido-, alkali-, halo-, metallo- and polyextremo-tolerant/-philic fungal species. Several challenges were identified that affected the outcome: renaming fungal species, defining extremotolerant/extremophilic traits, identifying extremotolerant/extremophilic traits as metadata in databases and linking fungal isolates to fungal genomes. The yield of genomes coding aegerolysins or MACPFs appears to be lower in extremotolerant/extremophilic fungi compared to all fungal genomes. No candidates for pore-forming gene pairs were identified in the genomes of extremophilic fungi. Aegerolysin and MACPFs partner pairs were identified in only two of 69 species with sequenced genomes, namely in the ubiquitous metallotolerant generalists Aspergillus niger and A. foetidus. These results support the hypothesised role of these pore-forming proteins in competitive exclusion.

DNA–protein crosslinks (DPC) are common DNA lesions induced by various external and endogenous agents. One of the sources of DPC is the apurinic/apyrimidinic site (AP site) and proteins interacting with it. Some proteins possessing AP lyase activity form covalent complexes with AP site-containing DNA without borohydride reduction (suicidal crosslinks). We have shown earlier that tyrosyl-DNA phosphodiesterase 1 (TDP1) but not AP endonuclease 1 (APE1) is able to remove intact OGG1 from protein–DNA adducts, whereas APE1 is able to prevent the formation of DPC by hydrolyzing the AP site. Here we demonstrate that TDP1 can remove intact PARP2 but not XRCC1 from covalent enzyme–DNA adducts with AP-DNA formed in the absence of APE1. We also analyzed an impact of APE1 and TDP1 on the efficiency of DPC formation in APE1^−/− or TDP1^−/− cell extracts. Our data revealed that APE1 depletion leads to increased levels of PARP1–DNA crosslinks, whereas TDP1 deficiency has little effect on DPC formation.

tRNAs are not only essential for decoding the genetic code, but their abundance also has a strong impact on the rate of protein production, folding, and on the stability of the translated messenger RNAs. Plasmodium expresses a unique surface protein called tRip, involved in the import of exogenous tRNAs into the parasite. Comparative proteomic analysis of the blood stage of wild-type and tRip-KO variant of P. berghei parasites revealed that downregulated proteins in the mutant parasite are distinguished by a bias in their asparagine content. Furthermore, the demonstration of the possibility of charging host tRNAs with Plasmodium aminoacyl-tRNA synthetases led us to propose that imported host tRNAs participate in parasite protein synthesis. These results also suggest a novel mechanism of translational control in which import of host tRNAs emerge as regulators of gene expression in the Plasmodium developmental cycle and pathogenesis, by enabling the synthesis of asparagine-rich regulatory proteins that efficiently and selectively control the parasite infectivity.

Type 2 diabetes mellitus is a prevalent metabolic disease, posing a considerable threat to public health. Oligonucleotide drugs have proven to be a promising field of therapy for the diseases. In this study, we reported that a herbal small RNA (sRNA), JGL-sRNA-h7 (B34735529, F1439.L002444.A11), could exhibit potent hypoglycemic effects by targeting glucose-6-phosphatase. Oral administration of sphingosine (d18:1)-JGL-sRNA-h7 bencaosomes ameliorated hyperglycemia and diabetic kidney injury better than metformin in db/db mice. Furthermore, glucose tolerance was also improved in sphingosine (d18:1)-JGL-sRNA-h7 bencaosomes-treated beagle dogs. Our study indicates that JGL-sRNA-h7 could be a promising hypoglycemic oligonucleotide drug.

To date, SARS-CoV-2 has caused millions of deaths, but the choice of treatment is limited. We previously established a platform for identifying Food and Drug Administration (FDA)-approved repurposed drugs for avian influenza A virus infections that could be used for coronavirus disease 2019 (COVID-19) treatment. In this study, we analyzed blood samples from two cohorts of 63 COVID-19 patients, including 19 patients with severe disease. Among the 39 FDA-approved drugs we identified for COVID-19 therapy in both cohorts, 23 drugs were confirmed by literature mining data, including 14 drugs already under COVID-19 clinical trials and 9 drugs reported for COVID-19 treatments, suggesting the remaining 16 FDA-approved drugs may be candidates for COVID-19 therapy. Additionally, we previously reported that herbal small RNAs (sRNAs) could be effective components in traditional Chinese medicine (TCM) for treating COVID-19. Based on the abundance of sRNAs, we screened the 245 TCMs in the Bencao (herbal) sRNA Atlas that we had previously established, and we found that the top 12 TCMs for COVID-19 treatment was consistent across both cohorts. We validated the efficiency of the top 30 sRNAs from each of the top 3 TCMs for COVID-19 treatment in poly(I:C)-stimulated human non-small cell lung cancer cells (A549 cells). In conclusion, our study recommends potential COVID-19 remedies using FDA-approved repurposed drugs and herbal sRNAs from TCMs.

Parecoxib, a well-recognized nonsteroidal anti-inflammatory drug, has been reported to possess anticancer properties in various tumor types. In this work, we aimed to investigate the potential anticancer effects of parecoxib on hepatocellular carcinoma (HCC) cells. To assess the impact of parecoxib on HCC cell proliferation, we employed Cell Counting Kit-8, colony formation, and 5-ethynyl-2′-deoxyuridine assays. Hoechst/propidium iodide (PI) double staining and flow cytometry were performed to evaluate apoptosis and cell cycle analysis. Wound healing and transwell assays were utilized to assess cell migration and invasion. Tube formation assay was employed to analyze angiogenesis. Protein levels were determined using western blotting, and mRNA expression levels were assessed using quantitative real-time polymerase chain reaction (PCR). A xenograft mouse model was used to confirm the antitumor effects of parecoxib on HCC tumors in vivo. Our data demonstrated that parecoxib effectively inhibited the proliferation of HCC cells in a dose- and time-dependent manner. In addition, parecoxib induced cell cycle arrest in the G2 phase and promoted apoptosis. Moreover, parecoxib hindered tumor migration and invasion by impeding the epithelial–mesenchymal transition process. Further investigation showed that parecoxib could significantly suppress angiogenesis through the inhibition of extracellular signal-regulated kinase (ERK)–vascular endothelial growth factor (VEGF) axis. Notably, treatment with the ERK activator phorbol myristate acetate upregulated the expression of matrix metalloproteinase (MMP)-2, MMP-9, and VEGF and reversed the function of parecoxib in HCC cells. Besides, parecoxib displayed its antitumor efficacy in vivo. Collectively, our results suggest that parecoxib ameliorates HCC progression by regulating proliferation, cell cycle, apoptosis, migration, invasion, and angiogenesis through the ERK–VEGF/MMPs signaling pathway.

Multiple sclerosis (MS) is a common autoimmune illness that is difficult to treat. The upregulation of Th17 cells is critical in the pathological process of MS. Hederagenol (Hed) has been shown to lower IL-17 levels, although its role in MS pathophysiology is uncertain. In this study, we explore whether Hed could ameliorate MS by modulating Th17 cell differentiation, with the goal of identifying new treatment targets for MS. The experimental autoimmune encephalomyelitis (EAE) mouse model was conducted and Hed was intraperitoneally injected into mice. The weight was recorded and the clinical symptom grade was assessed. Hematoxylin-eosin staining was carried out to determine the extent of inflammation in the spinal cord and liver. The luxol Fast Blue staining was performed to detect the pathological changes in the myelin sheath. Nerve damage was detected using NeuN immunofluorescence staining and terminal deoxynucleotidyl transferase dUTP nick-end labeling staining. Immunohistology approaches were used to study alterations in immune cells in the spinal cord. The proportions of T cell subsets in the spleens were analyzed by flow cytometry. RORγt levels were measured using quantitative real-time PCR or Western blot. The activity of the RORγt promoter was analyzed by Chromatin immunoprecipitation. Hed administration reduced the clinical symptom grade of EAE mice, as well as the inflammatory infiltration, demyelination, and cell disorder of the spinal cord, while having no discernible effect on the mouse weight. In addition, Hed treatment significantly reduced the number of T cells, particularly Th17 cells in the spinal cord and spleen-isolated CD4⁺ T cells. Hed lowered the RORγt levels in spleens and CD4⁺ T cells and overexpression of RORγt reversed the inhibitory effect of Hed on Th17 differentiation. Hed decreased nerve injury by modulating Th17 differentiation through the RORγt promoter. Hed regulates Th17 differentiation by reducing RORγt promoter activity, which reduces nerve injury and alleviates EAE.