Deubiquitination of MITF-M Regulates Melanocytes Proliferation and Apoptosis

Microphthalmia-associated transcription factor-M (MITF-M) is the key gene in the proliferation and differentiation of melanocytes, which undergoes an array of post-translation modifications. As shown in our previous study, deubiquitinase USP13 is directly involved in melanogenesis. However, it is still ambiguous that the effect of USP13-mediated MITF-M expression on melanocytes proliferation and apoptosis. Herein, we found that MITF-M overexpressing melanocytes showed high cell proliferation, reduced apoptosis, and increased melanin levels. Besides, melanin-related genes, TYR, DCT, GPNMB, and PMEL, were significantly up-regulated in MITF-M overexpressing melanocytes. Furthermore, Exogenous USP13 significantly upregulated the endogenous MITF-M protein level, downregulated USP13 significantly inhibited MITF-M protein levels, without altering MITF-M mRNA expression. In addition, USP13 upregulation mitigated the MITF-M degradation and significantly increased the half-life of MITF-M. Also, USP13 stabilized the exogenous MITF protein levels. In conclusion, the MITF-M level was regulated by USP13 deubiquitinase in melanocytes, affecting melanocytes proliferation and apoptosis. This study provides the theoretical basis for coat color transformation that could be useful in the development of the new breed in fur animals.

Bioassay-Guided Isolation of Antiproliferative Compounds from Limbarda crithmoides (L.) Dumort

Limbarda crithmoides (L.) Dumort (Asteraceae) n-hexane extract displayed high cell proliferation inhibitory activity against acute myeloid leukaemia cells (OCI-AML3) and was therefore subjected to a bioassay-guided multistep separation procedure. Two thymol derivatives, namely 10-acetoxy-8,9-epoxythymol tiglate (1) and 10-acetoxy-9-chloro-8,9-dehydrothymol (2), were isolated and identified by means of NMR spectroscopy. Both of them exhibited a significant dose-dependent inhibition of cell proliferation.

Dynamics of proteins, carbohydrates and global DNA methylation patterns during induction of nodular cluster cultures from seeds of Vriesea reitzii

Tissue culture techniques have been employed for bromeliad mass propagation by means of the morphogenetic route of nodular cluster cultures (NCs). This study aimed to assess protein, carbohydrate and global DNA methylation (GDM) level dynamics during NCs induction from Vriesea reitzii seeds. Seeds were inoculated into Murashige and Skoog (MS) liquid medium supplemented with 4 µM α-naphthaleneacetic acid (NAA) to induce NCs and in culture medium without plant growth regulators to form normal seedlings. Samples collected at 0, 3, 7, 10, 14, and 21 days of culture were analyzed. All parameters assessed showed the same variation pattern. However, seeds inducing NCs showed significantly lower starch (6.0 mg g-1 FM), carbohydrate (10.7 mg g-1 FM) and GDM (11.0%) levels than seeds forming normal seedlings after 21 days in culture. On the other hand, the protein content (9.1 mg g-1 FM) was significantly higher during induction. NCs induction process through seeds is the result of gene reprogramming in the explant, which leads to morphological, biochemical and metabolic alterations. This involves dedifferentiation, high cell proliferation, high energy demand and protein synthesis, which is related to elevated metabolic activity.

Trends in the Uses of Spirulina Microalga: A mini-review

HighlightsTrends in the uses of Spirulina over different decades were critically examinedFindings from surveyed literature indicated that Spirulina utilization was mainly focused on its food and feed potential before the last 20-30 yearsThe review observed that research focused on the health and pharmaceutical uses, biofertilizer, bioplastic, cosmetic, bioenergy and pollution control applications of Spirulina are trends that sprouted out within the last 20-25 years.The review has successfully compiled numerous uses of Spirulina microalga for easy readership by readers since many studies have been performed on the uses Spirulina but reviews of this type spanning through different beneficial aspects of Spirulina are still scarce. Hence, this review fills such gap. AbstractThere is a need to have a single document that summarises the present day uses of Spirulina. In this review, the research trend on the health and other applications of Spirulina microalga was critically evaluated. In terms of the health uses, antioxidant, antibacterial, and immunostimulant effects of Spirulina were emphasized. Other uses of the microalga discussed include the use of Spirulina for human and animal food, bioenergy, pollution and ecotoxicology control, cosmetics, bioplastics and biofertilizers. Literature search revealed that Spirulina polysaccharides, phycocyanin size and content play a role in antioxidant activity and DNA repair. The double bonds and positions of –COOH and –OH in Spirulina phenol content and γ-linolenic fatty acids (γ-LFA) have antimicrobial activity. Some compounds in Spirulina improve immune, increase survival rate and enhance distribution of proteins like hepcidin and TNF-α in animal models. High protein, vitamins, fatty acids (FAs) and glycoproteins in Spirulina are easily digestible due to its lack of cellulose and can improve human and livestock growth. Spirulina produces biodegradable and non-toxic biodiesel and useful co-products. Absorption of heavy metals by chemisorption occurs in Spirulina. Phycocyanin and β-carotene of Spirulina increase skin health, Spirulina also cause high cell proliferation and aids wound healing. Bioplastics produced from Spirulina are biodegradable, non-toxic with high blends. Biofertilizers from Spirulina have little or no residual risks, adds soil Nitrogen through Spirulina Nitrogen fixation ability. In addition, the survey of published works on Spirulina for the past two decades indicates that more research is been carried out in recent years using Spirulina, especially studies involving its health potentials and those concerned with molecular analysis. In conclusion, Spirulina is an exceptional commodity with numerous applications, and probably, some of its compounds causing those effects are yet to be isolated and that is one area for further research.

Defective Osteogenic Differentiation in the Development of Osteosarcoma

Osteosarcoma (OS) is associated with poor prognosis due to its high incidence of metastasis and chemoresistance. It often arises in areas of rapid bone growth in long bones during the adolescent growth spurt. Although certain genetic conditions and alterations increase the risk of developing OS, the molecular pathogenesis is poorly understood. Recently, defects in differentiation have been linked to cancers, as they are associated with high cell proliferation. Treatments overcoming these defects enable terminal differentiation and subsequent tumor inhibition. OS development may be associated with defects in osteogenic differentiation. While early regulators of osteogenesis are unable to bypass these defects, late osteogenic regulators, including Runx2 and Osterix, are able to overcome some of the defects and inhibit tumor propagation through promoting osteogenic differentiation. Further understanding of the relationship between defects in osteogenic differentiation and tumor development holds tremendous potential in treating OS.