Profilin: many facets of a small protein

Aggregates associated with amyotrophic lateral sclerosis sequester the actin-binding protein profilin 2

Amyotrophic Lateral Sclerosis (ALS) is a devastating neurodegenerative disease characterized by the degeneration of upper and lower motoneurons. The four most frequently mutated genes causing familial ALS (fALS) are C9orf72, FUS, SOD1, and TARDBP. Some of the related wild-type proteins comprise intrinsically disordered regions (IDRs) which favor their assembly in liquid droplets-the biophysical mechanism behind the formation of physiological granules such as stress granules (SGs). SGs assemble and dissolve dependent on the cellular condition. However, it has been suggested that transition from reversible SGs to irreversible aggregates contributes to the toxic properties of ALS-related mutated proteins. Sequestration of additional proteins within these aggregates may then result in downstream toxicity. While the exact downstream mechanisms remain elusive, rare ALS-causing mutations in the actin binding protein profilin 1 suggest an involvement of the actin cytoskeleton. Here, we hypothesize that profilin isoforms become sequestered in aggregates of ALS-associated proteins which induce subsequent dysregulation of the actin cytoskeleton. Interestingly, localization of neuronal profilin 2 in SGs was more pronounced compared with the ubiquitously expressed profilin 1. Accordingly, FUS and C9orf72 aggregates prominently sequestered profilin 2 but not profilin 1. Moreover, we observed a distinct sequestration of profilin 2 and G-actin to C9orf72 aggregates in different cellular models. On the functional level, we identified dysregulated actin dynamics in cells with profilin 2-sequestering aggregates. In summary, our results suggest a more common involvement of profilins in ALS pathomechanisms than indicated from the rarely occurring profilin mutations.

Profilin Pfy1 is critical for cell wall integrity and virulence in Candida albicans

Profilin is a small actin-binding protein that plays an important role in actin polymerization. However, its functions in Candida albicans, the most prevalent fungal pathogen, remain unclear. Here, we report that profilin plays a crucial role in C. albicans morphogenesis and virulence. Deletion of profilin results in abnormal morphogenesis and impaired hyphal development. Furthermore, pfy1Δ/Δ is hypersensitive to cell wall stress and displays thicker cell wall than wild-type cells, indicative of a critical function of Pfy1 in cell wall integrity. In addition, our findings demonstrate that profilin is required for the virulence of C. albicans in a murine model of systemic infection. In conclusion, our work provides a promising target for developing antifungal drugs.IMPORTANCEOur research revealed Pfy1 is not only involved in hyphal development but also essential for pseudohyphal formation in response to DNA damage agents methyl methanesulfonate (MMS) and H2O2. The disruption of PFY1 resulted in striking morphological defects in both yeast and hyphal forms. Further investigation suggested that profilin plays a role in polarized growth of Candida albicans via binding with Act1, and contributes to cell wall remodeling. Both hyphal growth and cell wall integrity are the important virulence factors of C. albicans. Thus, pfy1Δ/Δ strains significantly reduced mortality rates in mice. These findings suggested that profilin could serve as a target for developing new antifungal drugs possibly for use in combination therapies with caspofungin, for treating invasive candidiasis.

Survival strategies of cancer cells: the role of macropinocytosis in nutrient acquisition, metabolic reprogramming, and therapeutic targeting

Macropinocytosis is a nonselective form of endocytosis that allows cancer cells to largely take up the extracellular fluid and its contents, including nutrients, growth factors, etc. We first elaborate meticulously on the process of macropinocytosis. Only by thoroughly understanding this entire process can we devise targeted strategies against it. We then focus on the central role of the MTOR (mechanistic target of rapamycin kinase) complex 1 (MTORC1) in regulating macropinocytosis, highlighting its significance as a key signaling hub where various pathways converge to control nutrient uptake and metabolic processes. The article covers a comprehensive analysis of the literature on the molecular mechanisms governing macropinocytosis, including the initiation, maturation, and recycling of macropinosomes, with an emphasis on how these processes are hijacked by cancer cells to sustain their growth. Key discussions include the potential therapeutic strategies targeting macropinocytosis, such as enhancing drug delivery via this pathway, inhibiting macropinocytosis to starve cancer cells, blocking the degradation and recycling of macropinosomes, and inducing methuosis - a form of cell death triggered by excessive macropinocytosis. Targeting macropinocytosis represents a novel and innovative approach that could significantly advance the treatment of cancers that rely on this pathway for survival. Through continuous research and innovation, we look forward to developing more effective and safer anti-cancer therapies that will bring new hope to patients.Abbreviation: AMPK: AMP-activated protein kinase; ASOs: antisense oligonucleotides; CAD: carbamoyl-phosphate synthetase 2, aspartate transcarbamylase, and dihydroorotase; DC: dendritic cell; EGF: epidermal growth factor; EGFR: epidermal growth factor receptor; ERBB2: erb-b2 receptor tyrosine kinase 2; ESCRT: endosomal sorting complex required for transport; GAP: GTPase-activating protein; GEF: guanine nucleotide exchange factor; GRB2: growth factor receptor bound protein 2; LPP: lipopolyplex; MTOR: mechanistic target of rapamycin kinase; MTORC1: mechanistic target of rapamycin kinase complex 1; MTORC2: mechanistic target of rapamycin kinase complex 2; NSCLC: non-small cell lung cancer; PADC: pancreatic ductal adenocarcinoma; PDPK1: 3-phosphoinositide dependent protein kinase 1; PI3K: phosphoinositide 3-kinase; PIK3C3: phosphatidylinositol 3-kinase catalytic subunit type 3; PtdIns(3,4,5)P3: phosphatidylinositol-(3,4,5)-trisphosphate; PtdIns(4,5)P2: phosphatidylinositol-(4,5)-bisphosphate; PTT: photothermal therapies; RAC1: Rac family small GTPase 1; RPS6: ribosomal protein S6; RPS6KB1: ribosomal protein S6 kinase B1; RTKs: receptor tyrosine kinases; SREBF: sterol regulatory element binding transcription factor; TFEB: transcription factor EB; TNBC: triple-negative breast cancer; TSC2: TSC complex subunit 2; ULK1: unc-51 like autophagy activating kinase 1; UPS: ubiquitin-proteasome system.

Polyphenolic and Immunometric Profiling of Wheat Varieties: Impact of Organic and Conventional Farming on Allergenic and Bioactive Compounds

This study investigates the impact of organic and conventional farming on the allergenic and bioactive properties of wheat. The primary aim was to assess the immunometric parameters and polyphenolic composition in four varieties of winter and four varieties of spring wheat cultivated under both farming systems. Immunometric assays focused on gluten content, the allergenic QQQPP peptide, and the panallergenic profilin Tri a 12. While gluten levels (15-20 g/kg) showed no clear dependence on farming type, organic wheat exhibited a mild yet significant increase in QQQPP-dependent immunoreactivity in five samples (>20 µg/g). However, all organic wheat samples demonstrated a notable reduction in profilin content (<0.6 µg/g), suggesting that the type of wheat cultivation could influence allergenic risk for individuals with wheat-related allergies. Polyphenolic profiling revealed that kaempferol, p-coumaric acid, and gallic acid were the predominant compounds, with organic wheat displaying slightly higher polyphenol levels on average. Despite these differences, the variations were insufficient to determine a superior cultivation method. These findings highlight the potential allergenic and nutritional implications of organic versus conventional wheat farming.

CqProfilin enhances WSSV infection by promoting viral intracellular transport through binding to both viral nucleocapsid and actin cytoskeleton

White spot syndrome virus (WSSV) is a large nuclear-replicating DNA virus of crustaceans such as shrimp and crayfish; however, the molecular mechanisms facilitating its transport from the invasion site to the cell nucleus have not yet been well elucidated. In this study, a CqProfilin (CqPFN) with a conserved PROF domain was identified from the red claw crayfish Cherax quadricarinatus. CqPFN was ubiquitously expressed in all examined tissues and hemocyte, with the highest levels in the hemocyte, followed by hematopoietic tissue (Hpt) from which the hemocyte were derived in crayfish. The transcript of WSSV genes such as IE1 and VP28 was obviously decreased both in vivo in hemocyte and Hpt, as well as in vitro in cultured Hpt cells, after CqPFN gene silencing; in contrast, the expression of viral genes was significantly increased by the introduction of a recombinant CqPFN protein in Hpt cells in vitro. Moreover, CqPFN was clearly colocalized with the main viral nucleocapsid protein VP664 and F-actin cytoskeleton, respectively, during the early stage of WSSV infection in Hpt cells. In addition, CqPFN was confirmed to interact with a truncated VP6642,405-2,535 and another viral nucleocapsid protein VP15 of WSSV and Cqβ-Actin from Hpt by co-immunoprecipitation assays. Further studies found that VP664 also colocalized with F-actin in the Hpt cell cytoplasm after WSSV infection, suggesting that the actin cytoskeleton was involved in the intracellular transport of incoming viral nucleocapsid. Taken together, CqPFN might combine with the actin cytoskeleton to promote WSSV infection through binding with viral nucleocapsid proteins VP664 and VP15, promoting intracellular transport of viral incoming nucleocapsid for further releasing genome into the nucleus for transcription. Collectively, these results provided an understanding of the WSSV pathogenesis, which will contribute to the development of an antiviral strategy against WSSV disease.

Computational discovery of tripeptide inhibitors targeting monkeypox virus A42R profilin-like protein

Monkeypox is an infectious disease caused by the monkeypox virus (MPXV), a member of the Orthopoxvirus genus closely related to smallpox. The structure of the A42R profilin-like protein is the first and only available structure among MPXV proteins. Biochemical studies of A42R were conducted in the 1990s and later work also analyzed the protein's function in viral replication in cells. This study aims to screen tripeptides for their potential inhibition of the A42R profilin-like protein using computational methods, with implications for MPXV therapy. A total of 8000 tripeptides underwent molecular docking simulations, resulting in the identification of 20 compounds exhibiting strong binding affinity to A42R. To validate the docking results, molecular dynamics simulations and free energy perturbation calculations were performed. These analyses revealed two tripeptides with sequences TRP-THR-TRP and TRP-TRP-TRP, which displayed robust binding affinity to A42R. Markedly, electrostatic interactions predominated over van der Waals interactions in the binding process between tripeptides and A42R. Three A42R residues, namely Glu9, Ser12, and Arg38, appear to be pivotal in mediating the interaction between A42R and the tripeptide ligands. Notably, tripeptides containing two or three tryptophan residues demonstrate a pronounced binding affinity, with the tripeptide comprising three tryptophan amino acids showing the highest level of affinity. These findings offer valuable insights for the selection of compounds sharing a similar structure and possessing a high affinity for A42R, potentially capable of inhibiting its enzyme activity. The study highlights a structural advantage and paves the way for the development of targeted therapies against MPXV infections.

Alpha-Mangostin and its nano-conjugates induced programmed cell death in Acanthamoeba castellanii belonging to the T4 genotype

Acanthamoeba are free living amoebae that are the causative agent of keratitis and granulomatous amoebic encephalitis. Alpha-Mangostin (AMS) is a significant xanthone; that demonstrates a wide range of biological activities. Here, the anti-amoebic activity of α-Mangostin and its silver nano conjugates (AMS-AgNPs) were evaluated against pathogenic A. castellanii trophozoites and cysts in vitro. Amoebicidal assays showed that both AMS and AMS-AgNPs inhibited the viability of A. castellanii dose-dependently, with an IC50 of 88.5 ± 2.04 and 20.2 ± 2.17 μM, respectively. Both formulations inhibited A. castellanii-mediated human keratinocyte cell cytopathogenicity. Functional assays showed that both samples caused apoptosis through the mitochondrial pathway and reduced mitochondrial membrane potential and ATP production, while increasing reactive oxygen species (ROS) and nicotinamide adenine dinucleotide phosphate (NADPH) cytochrome-c reductase in the cytosol. Whole transcriptome sequencing of A. castellanii showed the expression of 826 genes, with 447 genes being up-regulated and 379 genes being down-regulated post treatment. The Kyoto Encyclopedia of Genes and Genomes analysis showed that the majority of genes were linked to apoptosis, autophagy, RAP1, AGE-RAGE and oxytocin signalling pathways. Seven genes (PTEN, H3, ARIH1, SDR16C5, PFN, glnA GLUL, and SRX1) were identified as the most significant (Log2 (FC) value 4) for molecular mode of action in vitro. Future in vivo studies with AMS and nanoconjugates are needed to realize the clinical potential of this work.

The role of actin cytoskeleton CFL1 and ADF/cofilin superfamily in inflammatory response

Actin remodeling proteins are important in immune diseases and regulate cell cytoskeletal responses. These responses play a pivotal role in maintaining the delicate balance of biological events, protecting against acute or chronic inflammation in a range of diseases. Cofilin (CFL) and actin depolymerization factor (ADF) are potent actin-binding proteins that cut and depolymerize actin filaments to generate actin cytoskeleton dynamics. Although the molecular mechanism by which actin induces actin cytoskeletal reconstitution has been studied for decades, the regulation of actin in the inflammatory process has only recently become apparent. In this paper, the functions of the actin cytoskeleton and ADF/cofilin superfamily members are briefly introduced, and then focus on the role of CFL1 in inflammatory response.

Protein Profiles and Novel Molecular Biomarkers of Schizophrenia Based on 4D-DIA Proteomics

Schizophrenia is a severe psychological disorder. The current diagnosis mainly relies on clinical symptoms and lacks laboratory evidence, which makes it very difficult to make an accurate diagnosis especially at an early stage. Plasma protein profiles of schizophrenia patients were obtained and compared with healthy controls using 4D-DIA proteomics technology. Furthermore, 79 DEPs were identified between schizophrenia and healthy controls. GO functional analysis indicated that DEPs were predominantly associated with responses to toxic substances and platelet aggregation, suggesting the presence of metabolic and immune dysregulation in patients with schizophrenia. KEGG pathway enrichment analysis revealed that DEPs were primarily enriched in the chemokine signaling pathway and cytokine receptor interactions. A diagnostic model was ultimately established, comprising three proteins, namely, PFN1, GAPDH and ACTBL2. This model demonstrated an AUC value of 0.972, indicating its effectiveness in accurately identifying schizophrenia. PFN1, GAPDH and ACTBL2 exhibit potential as biomarkers for the early detection of schizophrenia. The findings of our studies provide novel insights into the laboratory-based diagnosis of schizophrenia.

Role of Protein Phosphatases in Tumor Angiogenesis: Assessing PP1, PP2A, PP2B and PTPs Activity

Tumor angiogenesis, the formation of new blood vessels to support tumor growth and metastasis, is a complex process regulated by a multitude of signaling pathways. Dysregulation of signaling pathways involving protein kinases has been extensively studied, but the role of protein phosphatases in angiogenesis within the tumor microenvironment remains less explored. However, among angiogenic pathways, protein phosphatases play critical roles in modulating signaling cascades. This review provides a comprehensive overview of the involvement of protein phosphatases in tumor angiogenesis, highlighting their diverse functions and mechanisms of action. Protein phosphatases are key regulators of cellular signaling pathways by catalyzing the dephosphorylation of proteins, thereby modulating their activity and function. This review aims to assess the activity of the protein tyrosine phosphatases and serine/threonine phosphatases. These phosphatases exert their effects on angiogenic signaling pathways through various mechanisms, including direct dephosphorylation of angiogenic receptors and downstream signaling molecules. Moreover, protein phosphatases also crosstalk with other signaling pathways involved in angiogenesis, further emphasizing their significance in regulating tumor vascularization, including endothelial cell survival, sprouting, and vessel maturation. In conclusion, this review underscores the pivotal role of protein phosphatases in tumor angiogenesis and accentuate their potential as therapeutic targets for anti-angiogenic therapy in cancer.

Yeast profilin mutants inhibit classical nuclear import and alter the balance between actin and tubulin levels

Profilin is a small protein that controls actin polymerization in yeast and higher eukaryotes. In addition, profilin has emerged as a multifunctional protein that contributes to other processes in multicellular organisms. This study focuses on profilin (Pfy1) in the budding yeast Saccharomyces cerevisiae. The primary sequences of yeast Pfy1 and its metazoan orthologs diverge vastly. However, structural elements of profilin are conserved among different species. To date, the full spectrum of Pfy1 functions has yet to be defined. The current work explores the possible involvement of yeast profilin in nuclear protein import. To this end, a panel of well-characterized yeast profilin mutants was evaluated. The experiments demonstrate that yeast profilin (i) regulates nuclear protein import, (ii) determines the subcellular localization of essential nuclear transport factors, and (iii) controls the relative abundance of actin and tubulin. Together, these results define yeast profilin as a moonlighting protein that engages in multiple essential cellular activities.

Detection of Bet v 1 Homologous Proteins and Plant Profilins by Indirect ELISA

Allergies are an ever-increasing health problem in developed societies. Cross-allergies caused by panallergens are a particularly difficult issue. Proteins similar to the main birch pollen Bet v 1 allergen and profilin are some of the most common allergens. These proteins have a very conservative structure and are present in many distinct organisms. Hence, the knowledge of their natural occurrence is very important for the prevention of allergic reactions. The immunometric method is the most useful approach for determining these allergens. The requirement of reliability and simplicity is fulfilled by enzyme-linked immunosorbent assay (ELISA). In this chapter, detailed procedures are described for the determination of Bet v 1 homologous proteins and plant profilins with the use of indirect, noncompetitive ELISA.

The loss of profilin1 is catastrophic to podocytes

Profilin1 belongs to a family of small monomeric actin-binding proteins with diverse roles in fundamental actin-dependent cellular processes required for cell survival. Podocytes are postmitotic visceral epithelial cells critical for the structure and function of the kidney filtration barrier. There is emerging evidence that the actin-related mode of cell death known as mitotic catastrophe is an important pathway involved in podocyte loss. In this issue of the JCI, Tian, Pedigo, and colleagues demonstrate that profilin1 deficiency in podocytes triggered cell cycle reentry, resulting in abortive cytokinesis with a loss in ribosomal RNA processing that leads to podocyte loss and glomerulosclerosis. This study demonstrates the essential role of actin dynamics in mediating this fundamental mode of podocyte cell death.

Profilin1 is required for prevention of mitotic catastrophe in murine and human glomerular diseases

The progression of proteinuric kidney diseases is associated with podocyte loss, but the mechanisms underlying this process remain unclear. Podocytes reenter the cell cycle to repair double-stranded DNA breaks. However, unsuccessful repair can result in podocytes crossing the G1/S checkpoint and undergoing abortive cytokinesis. In this study, we identified Pfn1 as indispensable in maintaining glomerular integrity - its tissue-specific loss in mouse podocytes resulted in severe proteinuria and kidney failure. Our results suggest that this phenotype is due to podocyte mitotic catastrophe (MC), characterized histologically and ultrastructurally by abundant multinucleated cells, irregular nuclei, and mitotic spindles. Podocyte cell cycle reentry was identified using FUCCI2aR mice, and we observed altered expression of cell-cycle associated proteins, such as p21, p53, cyclin B1, and cyclin D1. Podocyte-specific translating ribosome affinity purification and RNA-Seq revealed the downregulation of ribosomal RNA-processing 8 (Rrp8). Overexpression of Rrp8 in Pfn1-KO podocytes partially rescued the phenotype in vitro. Clinical and ultrastructural tomographic analysis of patients with diverse proteinuric kidney diseases further validated the presence of MC podocytes and reduction in podocyte PFN1 expression within kidney tissues. These results suggest that profilin1 is essential in regulating the podocyte cell cycle and its disruption leads to MC and subsequent podocyte loss.

Chromatin meets the cytoskeleton: the importance of nuclear actin dynamics and associated motors for genome stability

The actin cytoskeleton is of fundamental importance for numerous cellular processes, including intracellular transport, cell plasticity, and cell migration. However, functions of filamentous actin (F-actin) in the nucleus remain understudied due to the comparatively low abundance of nuclear actin and the resulting experimental limitations to its visualization. Owing to recent technological advances such as super-resolution microscopy and the development of nuclear-specific actin probes, essential roles of the actin cytoskeleton in the context of genome maintenance are now emerging. In addition to the contributions of monomeric actin as a component of multiple important nuclear protein complexes, nuclear actin has been found to undergo polymerization in response to DNA damage and DNA replication stress. Consequently, nuclear F-actin plays important roles in the regulation of intra-nuclear mobility of repair and replication foci as well as the maintenance of nuclear shape, two important aspects of efficient stress tolerance. Beyond actin itself, there is accumulating evidence for the participation of multiple actin-binding proteins (ABPs) in the surveillance of genome integrity, including nucleation factors and motor proteins of the myosin family. Here we summarize recent findings highlighting the importance of actin cytoskeletal factors within the nucleus in key genome maintenance pathways.

Effect of embelin on inhibition of cell growth and induction of apoptosis in Acanthamoeba castellanii

Acanthamoeba castellanii is the causative agent of fatal encephalitis and blinding keratitis. Current therapies remain a challenge, hence there is a need to search for new therapeutics. Here, we tested embelin (EMB) and silver nanoparticles doped with embelin (EMB-AgNPs) against A. castellanii. Using amoebicidal assays, the results revealed that both compounds inhibited the viability of Acanthamoeba, having an IC50 of 27.16 ± 0.63 and 13.63 ± 1.08 μM, respectively, while causing minimal cytotoxicity against HaCaT cells in vitro. The findings suggest that both samples induced apoptosis through the mitochondria-mediated pathway. Differentially expressed genes analysis showed that 652 genes were uniquely expressed in treated versus untreated cells, out of which 191 were significantly regulated in the negative control vs. conjugate. Combining the analysis, seven genes (ARIH1, RAP1, H3, SDR16C5, GST, SRX1, and PFN) were highlighted as the most significant (Log2 (FC) value ± 4) for the molecular mode of action in vitro. The KEGG analysis linked most of the genes to apoptosis, the oxidative stress signaling pathway, cytochrome P450, Rap1, and the oxytocin signaling pathways. In summary, this study provides a thorough framework for developing therapeutic agents against microbial infections using EMB and EMB-AgNPs.

A RhoA-mediated biomechanical response in Schwann cells modulates peripheral nerve myelination

Myelin improves axonal conduction velocity and is essential for nerve development and regeneration. In peripheral nerves, Schwann cells depend on bidirectional mechanical and biochemical signaling to form the myelin sheath but the mechanism underlying this process is not understood. Rho GTPases are integrators of "outside-in" signaling that link cytoskeletal dynamics with cellular architecture to regulate morphology and adhesion. Using Schwann cell-specific gene inactivation in the mouse, we discovered that RhoA promotes the initiation of myelination, and is required to both drive and terminate myelin growth at different stages of peripheral myelination, suggesting developmentally-specific modes of action. In Schwann cells, RhoA targets actin filament turnover, via Cofilin 1, actomyosin contractility and cortical actin-membrane attachments. This mechanism couples actin cortex mechanics with the molecular organization of the cell boundary to target specific signaling networks that regulate axon-Schwann cell interaction/adhesion and myelin growth. This work shows that RhoA is a key component of a biomechanical response required to control Schwann cell state transitions for proper myelination of peripheral nerves.

Morphological alterations in corneal nerves of patients with dry eye and associated biomarkers

The purposes of the present study were to (1) identify the relationship between dry eye symptoms and morphological changes in corneal subbasal nerves/ocular surfaces, and (2) discover tear film biomarkers indicating morphological changes in the subbasal nerves. This was a prospective cross-sectional study conducted between October and November 2017. Adults with dry eye disease (DED, n = 43) and healthy eyes (n = 16) were evaluated based on their subjective symptoms and ophthalmological findings. Corneal subbasal nerves were observed using confocal laser scanning microscopy. Nerve lengths, densities, branch numbers, and nerve fiber tortuosity were analyzed using ACCMetrics and CCMetrics image analysis systems; tear proteins were quantified by mass spectroscopy. Compared with the control group, the DED group had significantly lower tear breakup times (TBUT) and pain tolerance capacity, and significantly higher corneal nerve branch density (CNBD) and corneal nerve total branch density (CTBD). CNBD and CTBD showed significant negative correlations with TBUT. Six biomarkers (cystatin-S, immunoglobulin kappa constant, neutrophil gelatinase-associated lipocalin, profilin-1, protein S100-A8, and protein S100-A9) showed significant positive correlations with CNBD and CTBD. The significantly higher CNBD and CTBD in the DED group suggests that DED is associated with morphological alterations in corneal nerves. The correlation of TBUT with CNBD and CTBD further supports this inference. Six candidate biomarkers that correlate with morphological changes were identified. Thus, morphological changes in corneal nerves are a hallmark of DED, and confocal microscopy may help in the diagnosis and treatment of dry eyes.

Metabolic responses in blood-stage malaria parasites associated with increased and decreased sensitivity to PfATP4 inhibitors

BACKGROUND

Spiroindolone and pyrazoleamide antimalarial compounds target Plasmodium falciparum P-type ATPase (PfATP4) and induce disruption of intracellular Na+ homeostasis. Recently, a PfATP4 mutation was discovered that confers resistance to a pyrazoleamide while increasing sensitivity to a spiroindolone. Transcriptomic and metabolic adaptations that underlie this seemingly contradictory response of P. falciparum to sublethal concentrations of each compound were examined to understand the different cellular accommodation to PfATP4 disruptions.

METHODS

A genetically engineered P. falciparum Dd2 strain (Dd2A211V) carrying an Ala211Val (A211V) mutation in PfATP4 was used to identify metabolic adaptations associated with the mutation that results in decreased sensitivity to PA21A092 (a pyrazoleamide) and increased sensitivity to KAE609 (a spiroindolone). First, sublethal doses of PA21A092 and KAE609 causing substantial reduction (30-70%) in Dd2A211V parasite replication were identified. Then, at this sublethal dose of PA21A092 (or KAE609), metabolomic and transcriptomic data were collected during the first intraerythrocytic developmental cycle. Finally, the time-resolved data were integrated with a whole-genome metabolic network model of P. falciparum to characterize antimalarial-induced physiological adaptations.

RESULTS

Sublethal treatment with PA21A092 caused significant (p < 0.001) alterations in the abundances of 91 Plasmodium gene transcripts, whereas only 21 transcripts were significantly altered due to sublethal treatment with KAE609. In the metabolomic data, a substantial alteration (≥ fourfold) in the abundances of carbohydrate metabolites in the presence of either compound was found. The estimated rates of macromolecule syntheses between the two antimalarial-treated conditions were also comparable, except for the rate of lipid synthesis. A closer examination of parasite metabolism in the presence of either compound indicated statistically significant differences in enzymatic activities associated with synthesis of phosphatidylcholine, phosphatidylserine, and phosphatidylinositol.

CONCLUSION

The results of this study suggest that malaria parasites activate protein kinases via phospholipid-dependent signalling in response to the ionic perturbation induced by the Na+ homeostasis disruptor PA21A092. Therefore, targeted disruption of phospholipid signalling in PA21A092-resistant parasites could be a means to block the emergence of resistance to PA21A092.

Structure of the Monkeypox virus profilin-like protein A42R reveals potential functional differences from cellular profilins

The infectious disease human monkeypox is spreading rapidly in 2022, causing a global health crisis. The genomics of Monkeypox virus (MPXV) have been extensively analyzed and reported, although little is known about the virus-encoded proteome. In particular, there are no reported experimental MPXV protein structures other than computational models. Here, a 1.52 Å resolution X-ray structure of the MPXV protein A42R, the first MPXV-encoded protein with a known structure, is reported. A42R shows structural similarity to profilins, which are cellular proteins that are known to function in the regulation of actin cytoskeletal assembly. However, structural comparison of A42R with known members of the profilin family reveals critical differences that support prior biochemical findings that A42R only weakly binds actin and does not bind poly(L-proline). In addition, the analysis suggests that A42R may make distinct interactions with phosphatidylinositol lipids. Overall, the data suggest that the role of A42R in the replication of orthopoxviruses may not be readily determined by comparison to cellular profilins. Furthermore, these findings support the need for increased efforts to determine high-resolution structures of other MPXV proteins to inform physiological studies of the poxvirus infection cycle and to reveal potential new strategies to combat human monkeypox should this emerging infectious disease with pandemic potential become more common in the future.

Taro raphide-associated proteins: Allergens and crystal growth

Calcium oxalate raphide crystals are found in bundles in intravacuolar membrane chambers of specialized idioblasts cells of most plant families. Aroid raphides are proposed to cause acridity in crops such as taro (Colocasia esculenta (L.) Schott). Acridity is irritation that causes itchiness and pain when raw/insufficiently cooked tissues are eaten. Since raphides do not always cause acridity and since acridity can be inactivated by cooking and/or protease treatment, it is possible that a toxin or allergen-like compound is associated with the crystals. Using two-dimensional (2D) gel electrophoresis and mass spectrometry (MS) peptide sequencing of selected peptides from purified raphides and taro apex transcriptome sequencing, we showed the presence on the raphides of peptides normally associated with mitochrondria (ATP synthase), chloroplasts (chaperonin ~60 kDa), cytoplasm (actin, profilin), and vacuole (V-type ATPase) that indicates a multistage biocrystallation process ending with possible invagination of the tonoplast and addition of mucilage that may be derived from the Golgi. Actin might play a crucial role in the generation of the needle-like raphides. One of the five raphide profilins genes was highly expressed in the apex and had a 17-amino acid insert that significantly increased that profilin's antigenic epitope peak. A second profilin had a 2-amino acid insert and also had a greater B-cell epitope prediction. Taro profilins showed 83% to 92% similarity to known characterized profilins. Further, commercial allergen test strips for hazelnuts, where profilin is a secondary allergen, have potential for screening in a taro germplasm to reduce acridity and during food processing to avoid overcooking.

Functional Recognition Theory and Type 2 Immunity: Insights and Uncertainties

Type 2 immunity plays an important role in host defense against helminths and toxins while driving allergic diseases. Despite progress in understanding the biology of type 2 immunity, the fundamental mechanisms regulating the type 2 immune module remain unclear. In contrast with structural recognition used by pattern recognition receptors, type 2 immunogens are sensed through their functional properties. Functional recognition theory has arisen as the paradigm for the initiation of type 2 immunity. However, the vast array of structurally unrelated type 2 immunogens makes it challenging to advance our understanding of type 2 immunity. In this article, we review functional recognition theory and organize type 2 immunogens into distinct classes based on how they fit into the concept of functional recognition. Lastly, we discuss areas of uncertainty in functional recognition theory with the goal of providing a framework to further define the logic of type 2 immunity in host protection and immunopathology.

Bioinformatic prediction of putative conveyers of O-GlcNAc transferase intellectual disability

Protein O-GlcNAcylation is a dynamic posttranslational modification that is catalyzed by the enzyme O-GlcNAc transferase (OGT) and is essential for neurodevelopment and postnatal neuronal function. Missense mutations in OGT segregate with a novel X-linked intellectual disability syndrome, the OGT congenital disorder of glycosylation (OGT-CDG). One hypothesis for the etiology of OGT-CDG is that loss of OGT activity leads to hypo-O-GlcNAcylation of as yet unidentified, specific neuronal proteins, affecting essential embryonic, and postnatal neurodevelopmental processes; however, the identity of these O-GlcNAcylated proteins is not known. Here, we used bioinformatic techniques to integrate sequence conservation, structural data, clinical data, and the available literature to identify 22 candidate proteins that convey OGT-CDG. We found using gene ontology and PANTHER database data that these candidate proteins are involved in diverse processes including Ras/MAPK signaling, translational repression, cytoskeletal dynamics, and chromatin remodeling. We also identify pathogenic missense variants at O-GlcNAcylation sites that segregate with intellectual disability. This work establishes a preliminary platform for the mechanistic dissection of the links between protein O-GlcNAcylation and neurodevelopment in OGT-CDG.

Multiple roles for the cytoskeleton in ALS

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease caused by more than sixty genes identified through classic linkage analysis and new sequencing methods. Yet no clear mechanism of onset, cure, or effective treatment is known. Popular discourse classifies the proteins encoded from ALS-related genes into four disrupted processes: proteostasis, mitochondrial function and ROS, nucleic acid regulation, and cytoskeletal dynamics. Surprisingly, the mechanisms detailing the contribution of the neuronal cytoskeletal in ALS are the least explored, despite involvement in these cell processes. Eight genes directly regulate properties of cytoskeleton function and are essential for the health and survival of motor neurons, including: TUBA4A, SPAST, KIF5A, DCTN1, NF, PRPH, ALS2, and PFN1. Here we review the properties and studies exploring the contribution of each of these genes to ALS.

Visualizing molecules of functional human profilin

Profilin-1 (PFN1) is a cytoskeletal protein that regulates the dynamics of actin and microtubule assembly. Thus, PFN1 is essential for the normal division, motility, and morphology of cells. Unfortunately, conventional fusion and direct labeling strategies compromise different facets of PFN1 function. As a consequence, the only methods used to determine known PFN1 functions have been indirect and often deduced in cell-free biochemical assays. We engineered and characterized two genetically encoded versions of tagged PFN1 that behave identical to each other and the tag-free protein. In biochemical assays purified proteins bind to phosphoinositide lipids, catalyze nucleotide exchange on actin monomers, stimulate formin-mediated actin filament assembly, and bound tubulin dimers (kD = 1.89 µM) to impact microtubule dynamics. In PFN1-deficient mammalian cells, Halo-PFN1 or mApple-PFN1 (mAp-PEN1) restored morphological and cytoskeletal functions. Titrations of self-labeling Halo-ligands were used to visualize molecules of PFN1. This approach combined with specific function-disrupting point-mutants (Y6D and R88E) revealed PFN1 bound to microtubules in live cells. Cells expressing the ALS-associated G118V disease variant did not associate with actin filaments or microtubules. Thus, these tagged PFN1s are reliable tools for studying the dynamic interactions of PFN1 with actin or microtubules in vitro as well as in important cell processes or disease-states.

Profilin 1 Induces Tumor Metastasis by Promoting Microvesicle Secretion Through the ROCK 1/p-MLC Pathway in Non-Small Cell Lung Cancer

Profilin 1 (PFN1), an actin-binding protein, plays contrasting roles in the metastasis of several cancers; however, its role in non-small cell lung cancer (NSCLC) metastasis remains unclear. Here, PFN1 expression was upregulated in metastatic NSCLC tissues. PFN1 overexpression significantly promotes NSCLC metastasis in vitro and in vivo. Proteomics analysis revealed PFN1 involvment in microvesicles (MVs) secretion. In vitro experiments confirmed that PFN1 overexpression increased secretion of MVs. MVs are important mediators of metastasis. Here, we show an increased abundance of MVs in the sera of patients with metastatic NSCLC compared to that in the sera of patients with non-metastatic NSCLC. Both in vitro and in vivo experiments revealed that PFN1 could increase MV secretion, and MVs derived from PFN1-overexpressing cells markedly promoted NSCLC metastasis. We then elucidated the mechanisms underlying PFN1-mediated regulation of MVs and found that PFN1 could interact with ROCK1 and enhance its kinase activity to promote myosin light chain (MLC) phosphorylation for MV secretion. Inhibition of ROCK1 decreased MV secretion and partially reversed the PFN1-induced promotion of NSCLC metastasis. Collectively, these findings show that PFN1 regulates MV secretion to promote NSCLC metastasis. PFN1 and MVs represent potential predictors or therapeutic targets for NSCLC metastasis.

Profilin is involved in G1 to S phase progression and mitotic spindle orientation during Leishmania donovani cell division cycle

Profilin is a multi-ligand binding protein, which is a key regulator of actin dynamics and involved in regulating several cellular functions. It is present in all eukaryotes, including trypanosomatids such as Leishmania. However, not much is known about its functions in these organisms. Our earlier studies have shown that Leishmania parasites express a single homologue of profilin (LdPfn) that binds actin, phosphoinositides and poly- L- proline motives, and depletion of its intracellular pool to 50%of normal levels affects the cell growth and intracellular trafficking. Here, we show, employing affinity pull-down and mass spectroscopy, that LdPfn interacted with a large number of proteins, including those involved in mRNA processing and protein translation initiation, such as eIF4A1. Further, we reveal, using mRNA Seq analysis, that depletion of LdPfn in Leishmania cells (LdPfn^+/-) resulted in significantly reduced expression of genes which encode proteins involved in cell cycle regulation, mRNA translation initiation, nucleosides and amino acids transport. In addition, we show that in LdPfn^+/- cells, cellular levels of eIF4A1 protein were significantly decreased, and during their cell division cycle, G1-to-S phase progression was delayed and orientation of mitotic spindle altered. These changes were, however, reversed to normal by episomal expression of GFP-LdPfn in LdPfn^+/- cells. Taken together, our results indicate that profilin is involved in regulation of G1-to-S phase progression and mitotic spindle orientation in Leishmania cell cycle, perhaps through its interaction with elF4A1 protein.

CORO1A regulates lipoprotein uptake in Leydig cells exposed to cadmium

Cadmium (Cd) is one of the most common environmental pollutants, which has a long biological half-life. Maternal Cd-exposure in the natural environment causes steroidogenesis defects resulting in spermatogenesis disorder in male offspring. For better understanding its underlying mechanism, we have employed iTRAQ to screen the differentially expressed protein and found that the expression of CORO1A and Cofilin 1 was up-regulated approximately 2 fold in Leydig cells of maternal Cd-exposure offspring. As the major source of steroid hormone, cholesterol is transported to cells via receptor-mediated endocytosis which relies on the remodel of cytoskeleton, then stores in lipid droplets (LDs). However, few studies have focused on the role of cytoskeleton in abnormal steroidogenesis. This study was performed to explore the role of CORO1A in androgen deficiency caused by Cd exposure and its involvement of low-density lipoprotein (LDL) uptake and effects on LDs. We found that Cd resulted in the up-regulation of CORO1A and Cofilin 1, and down-regulation of Profilin 1 in the testis of male offspring with maternal exposure. The structure of filamentous actin was broken, disordered and even crumpled up in Cd-treated R2C cells. F-actin disassembly led to a low uptake of LDL with a reduced number of LDs, followed by decreased total cholesterol and low progesterone production. When CORO1A was silenced, the expression of Cofilin 1 was down-regulated and Profilin 1 was up-regulated in Cd-treated R2C cells. The filamentous actin was rescued and the integrated cytoskeleton prompted LDL uptake, which resulted in the increased total cholesterol and high progesterone production. These findings highlight the crucial role of CORO1A as a cytoskeleton regulatory protein in steroidogenesis, which may help to better understand Cd-induced steroid hormone deficiency in children.

Profilin-1 prevents psoriasis pathogenesis through IκBζ regulation

Profilin-1 (PFN-1) is an actin-binding protein that regulates actin polymerization, cell proliferation, apoptosis, angiogenesis, and carcinogenesis. Its dysregulation has been reported in diverse pathologic diseases; however, the role of PFN-1 in psoriasis has not yet been elucidated. In this study, we demonstrate that PFN-1 expression is increased in both skin and serum of patients with psoriasis. PFN-1 was markedly expressed in the epidermis of psoriatic lesions and its expression positively correlated with psoriasis severity. IL-17A treatment of keratinocytes increased the PFN-1 expression, whereas TNF-α induced the PFN-1 expression and secretion. In addition, knockdown of PFN-1 with shRNA resulted in an altered expression of psoriasis-associated inflammatory markers, HBD-2, S100A7, S100A9, and Ki67, and recombinant PFN-1 suppressed the IL-17A-induced inflammatory response in keratinocytes. Interestingly, recombinant PFN-1 also suppressed IL-17A-induced IκBζ, an important player in immune response in psoriasis. Collectively, our results show that PFN-1 acts as a negative regulator of psoriatic inflammation through suppression of IκBζ, and the balanced level of PFN-1 is important for the IκBζ regulation. Thus, the expression of PFN-1 can be used as a biomarker for psoriasis severity, and it can be considered as a possible target for the treatment of psoriasis.

Biochemical characterization of actin assembly mechanisms with ALS-associated profilin variants

Eight separate mutations in the actin-binding protein profilin-1 have been identified as a rare cause of amyotrophic lateral sclerosis (ALS). Profilin is essential for many neuronal cell processes through its regulation of lipids, nuclear signals, and cytoskeletal dynamics, including actin filament assembly. Direct interactions between profilin and actin monomers inhibit actin filament polymerization. In contrast, profilin can also stimulate polymerization by simultaneously binding actin monomers and proline-rich tracts found in other proteins. Whether the ALS-associated mutations in profilin compromise these actin assembly functions is unclear. We performed a quantitative biochemical comparison of the direct and formin mediated impact for the eight ALS-associated profilin variants on actin assembly using classic protein-binding and single-filament microscopy assays. We determined that the binding constant of each profilin for actin monomers generally correlates with the actin nucleation strength associated with each ALS-related profilin. In the presence of formin, the A20T, R136W, Q139L, and C71G variants failed to activate the elongation phase of actin assembly. This diverse range of formin-activities is not fully explained through profilin-poly-L-proline (PLP) interactions, as all ALS-associated variants bind a formin-derived PLP peptide with similar affinities. However, chemical denaturation experiments suggest that the folding stability of these profilins impact some of these effects on actin assembly. Thus, changes in profilin protein stability and alterations in actin filament polymerization may both contribute to the profilin-mediated actin disruptions in ALS.

Transcriptional loss of domestication-driven cytoskeletal GhPRF1 gene causes defective floral and fiber development in cotton (Gossypium)

Constitutive- and fiber-specific RNAi of GhPRF1 gene illustrated strong correlation between domestication-driven profilin genes and floral/fiber architecture in cotton. During morpho-transformation of short-fuzz of wild cotton into the elongating spinnable fibers under the millennia of human selection, actin-polymerizing cytoskeletal profilin genes had undergone significant sequence alterations and spatiotemporal shift in their transcription levels. To comprehend the expression dynamics of profilin genes with their phenotypic implications, transgenic expression modulation of cotton profilin 1 (GhPRF1) gene was performed in the constitutive- and fiber-specific manner in Coker 310FR cotton cultivar. The constitutive GhPRF1-RNAi lines (35S:GhPRF1-RNAi) exhibited distorted 'monadelphous' staminal-tube, reduced pollen-viability and poorly developed fibers, whereas floral and fiber development of fiber-specific GhPRF1-RNAi lines showed no abnormalities. Moreover, the fiber-specific GhPRF1 overexpression lines (FBP7:GhPRF1-Ox) showed increased emergence of fiber-initials on the ovule surface, on the contrary to no fiber-initials in fiber-specific RNAi lines (FBP7:GhPRF1-RNAi). Interestingly, the average seed weight and fiber weight of FBP7:GhPRF1-Ox lines increased > 60% and > 38%, respectively, compared with FBP7:GhPRF1-RNAi lines and untransformed control seeds. On a molecular basis, the aberrant floral and fiber development of 35S:GhPRF1-RNAi lines was largely associated with sugar metabolism and hormone-signaling mechanisms. These observations illustrated the strong correlation between domestication-driven GhPRF genes, and floral/fiber development in cotton. Also, the enhanced agronomic traits in GhPRF1-Ox lines of cotton empowered us to recognize their imperative roles, and their future deployment for the sustainable cotton crop improvement.

Effect of profilin-1 on the asymmetric dimethylarginine-induced vascular lesion-associated hypertension

Previous studies have demonstrated that the levels of asymmetric dimethylarginine (ADMA), an endogenous inhibitor of nitric oxide (NO) synthesis, are strongly associated with hypertension, diabetes, and cardiovascular diseases. Profilin-1, an actin-binding protein, has been documented to be involved in endothelial injury and in the proliferation of vascular smooth muscle cells resulting from hypertension. However, the role of profilin-1 in ADMA-induced vascular injury in hypertension remains largely unknown. Forty healthy subjects and forty-two matched patients with essential hypertension were enrolled, and the related indexes of vascular injury in plasma were detected. Rat aortic smooth muscle cells (RASMCs) were treated with different concentrations of ADMA for different periods of time and transfected with profilin-1 small hairpin RNA to interrupt the expression of profilin-1. To determine the role of the Janus kinase 2/signal transducer and activator of transcription 3 (JAK2/STAT3) pathway, RASMCs were pretreated with AG490 or rapamycin. The expression of profilin-1 was tested using real-time polymerase chain reaction (PCR) and western blot analysis. Cell proliferation was measured by flow cytometry and 3-(4,5-dimethylthiazol-2yl)-2,5-diphenyltetrazoliumbromide assays. Compared with healthy subjects, the levels of ADMA and profilin-1 were markedly elevated in hypertensive individuals, while the levels of NO were significantly decreased (p < 0.05). In vitro, studies showed ADMA-induced profilin-1 expression in a concentration- and time-dependent manner in RASMCs (p < 0.05), concomitantly with promoting the proliferation of RASMCs. Furthermore, ADMA-mediated proliferation of RASMCs and upregulation expression of profilin-1 were inhibited by blockade of the JAK2/STAT3 pathway or knockdown of profilin-1. Profilin-1 implicated in the ADMA-mediated vascular lesions in hypertension.

A novel proteomic-based screening method for ovarian cancer using cervicovaginal fluids: A window into the abdomen

OBJECTIVE

Our objective is to develop a site-specific proteomic-based screening test for ovarian cancer(OC) using the mucus of the cervix and vagina and evaluate a potential means for home testing.

METHODS

Cervicovaginal fluid samples were obtained from ovarian cancer and normal control patients for LC-mass spectrometry(MS) proteomic evaluation. Statistical modeling determined the protein panel with the highest penetrance across ovarian cancer samples. A subcohort of patients consented to provide self-collected vaginal samples at home with questionnaire on feasibility. Cohen's kappa methodology was utilized to determine agreement between physician-collected and patient-collected samples.

RESULTS

A total of 83 consecutive patient samples were collected prospectively (33 ovarian cancer & 50 controls). Thirty patients consented for self-collection. Using LC-MS, 30 peptides demonstrated independent statistical significance for detecting ovarian cancer. Using statistical modeling, the protein panel that determined the best predictor for detecting OC formed a "fingerprint" consisting of 5 proteins: serine proteinase inhibitor A1; periplakin; profilin1; apolipoprotein A1; and thymosin beta4-like protein. These peptides demonstrated a significant increase probability of detecting ovarian cancer with the ROC curve having an AUC of 0.86 (p = 0.00001). Physician-collected and patient-collected specimens demonstrated moderate agreement with kappa average of 0.6 with upper bound of 0.75.

CONCLUSIONS

Using novel site-specific collection methods, we identified an OC "fingerprint" with adequate sensitivity and specificity to warrant further evaluation in a larger cohort. Agreement of physician-collected and patient-collected samples were encouraging and could improve access to screening with a home self-collection if this screening test is validated in future studies.

Signaling Enzymes and Ion Channels Being Modulated by the Actin Cytoskeleton at the Plasma Membrane

A cell should deal with the changing external environment or the neighboring cells. Inevitably, the cell surface receives and transduces a number of signals to produce apt responses. Typically, cell surface receptors are activated, and during this process, the subplasmalemmal actin cytoskeleton is often rearranged. An intriguing point is that some signaling enzymes and ion channels are physically associated with the actin cytoskeleton, raising the possibility that the subtle changes of the local actin cytoskeleton can, in turn, modulate the activities of these proteins. In this study, we reviewed the early and new experimental evidence supporting the notion of actin-regulated enzyme and ion channel activities in various cell types including the cells of immune response, neurons, oocytes, hepatocytes, and epithelial cells, with a special emphasis on the Ca²⁺ signaling pathway that depends on the synthesis of inositol 1,4,5-trisphosphate. Some of the features that are commonly found in diverse cells from a wide spectrum of the animal species suggest that fine-tuning of the activities of the enzymes and ion channels by the actin cytoskeleton may be an important strategy to inhibit or enhance the function of these signaling proteins.

Profilin Isoforms in Health and Disease - All the Same but Different

Profilins are small actin binding proteins, which are structurally conserved throughout evolution. They are probably best known to promote and direct actin polymerization. However, they also participate in numerous cell biological processes beyond the roles typically ascribed to the actin cytoskeleton. Moreover, most complex organisms express several profilin isoforms. Their cellular functions are far from being understood, whereas a growing number of publications indicate that profilin isoforms are involved in the pathogenesis of various diseases. In this review, we will provide an overview of the profilin family and "typical" profilin properties including the control of actin dynamics. We will then discuss the profilin isoforms of higher animals in detail. In terms of cellular functions, we will focus on the role of Profilin 1 (PFN1) and Profilin 2a (PFN2a), which are co-expressed in the central nervous system. Finally, we will discuss recent findings that link PFN1 and PFN2a to neurological diseases, such as amyotrophic lateral sclerosis (ALS), Fragile X syndrome (FXS), Huntington's disease and spinal muscular atrophy (SMA).

Serum levels of cytoskeleton remodeling proteins and their mRNA expression in tumor tissue of metastatic laryngeal and hypopharyngeal cancers

Actin-binding proteins (ABPs) and various signaling systems are involved in the process of squamous cell carcinoma of the larynx and hypopharynx (SCCLH) metastasis. The clinical significance of these proteins has not yet been determined. We analyzed the relationship between the mRNA levels of cofilin 1 (CFL1), profilin 1 (PFN1), adenylyl cyclase-associated protein 1 (CAP1), SNAI1 and RND3 and SCCLH metastasis. The serum levels of the above ABPs were estimated and the relationship between them and their mRNA expressions was analyzed. The expression levels of ABP mRNAs were measured by real-time RT-PCR in paired tissue samples taken from 54 patients with SCCLH (T1-4N0-1M0). Expression analysis was performed using the 2^-ΔΔCT method. The levels of ABPs in the blood serum were measured by ELISA. Statistical analysis was carried out using the SPSS Statistica 20.0 software package. No significant difference in the mRNA gene expression in tumor tissue of patients with T1-3N0M0 SCCLH and patients with T2-4N1-2M0 SCCLH was found. High expression of RND3 mRNA was accompanied by an increase in mRNA expression of all studied ABPs. In the blood serum of T2-4N1-2M0 patients, the level of PFN1 was lower by 21% and the level of CAP1 was higher by 75% than those observed in T1-4N0M0 patients. The data obtained showed that RND3 is involved in the regulation of molecular cascades of SCCLH metastasis. PFN1 and CAP1 serum levels can be good classifiers of metastases in patients with SCCLH.

The role of profilin-1 in cardiovascular diseases

Dynamic remodeling of the actin cytoskeleton is an essential feature for virtually all actin-dependent cellular processes, including cell migration, cell cycle progression, chromatin remodeling and gene expression, and even the DNA damage response. An altered actin cytoskeleton is a structural hallmark associated with numerous pathologies ranging from cardiovascular diseases to immune disorders, neurological diseases and cancer. The actin cytoskeleton in cells is regulated through the orchestrated actions of a myriad of actin-binding proteins. In this Review, we provide a brief overview of the structure and functions of the actin-monomer-binding protein profilin-1 (Pfn1) and then discuss how dysregulated expression of Pfn1 contributes to diseases associated with the cardiovascular system.

Biophysical Reviews: 2020-looking back, going forward

After first describing the issue contents (Biophysical Reviews-Volume 12 Issue 6), this Editorial goes on to provide a short round-up of the activities of the journal in 2020. Directly following this Editorial are two obituaries marking the recent deaths of Prof. Fumio Oosawa (Japan) and Dr. Herbert Tabor (USA)-two major figures in Biophysical/Biochemical science from the last 100 years.

Profilin-1 is dysregulated in endometroid (type I) endometrial cancer promoting cell proliferation and inhibiting pro-inflammatory cytokine production

Endometrial cancer (EC) is the most common gynaecological malignancy. Alarmingly its incidence and mortality rate is increasing particularly in younger women of reproductive age. Despite this, there are limited treatment options for EC. Profilin-1 (PFN1) regulates tumorigenesis in numerous cancers, but the role of PFN1 in EC has not been investigated. We hypothesized that PFN1 would have altered expression in EC and contribute to the development of EC. We quantified PFN1 in type 1 EC and benign/normal endometrium by RT-qPCR and IHC. The effect of silencing PFN1 on cell adhesion and proliferation was investigated using 2 EC cell lines (HEC1A and AN3CA). The effect of recombinant PFN1 (100 μM) on pro-inflammatory cytokine gene expression was investigated using THP1 monocyte cell line. PFN1 immunolocalized to glandular epithelial cells, vascular endothelial cells and leukocytes in the stromal compartment of normal endometrium and EC. PFN1 immunostaining intensity was significantly elevated in grade (G)I EC compared to normal endometrium, GI-II and GIII EC. In endometrial epithelial cancer cells alone, PFN1 immunostaining intensity was significantly reduced in GII and III EC compared to normal endometrium and GI EC. The stromal compartment of EC had strong PFN1 expression compared to benign and normal endometrium. Silencing PFN1 in the AN3CA endometrial epithelial cancer cell line significantly enhanced cell adhesion and proliferation. PFN1 treatment significantly down-regulated TNFα and IL1β mRNA expression by THP1 cells. This study demonstrated that whilst PFN1 production is retained in the stromal compartment of EC, PFN1 production is lost in endometrial epithelial cancer cells with increasing cancer grade. PFN1 may play a role in the tumorigenesis of EC. Loss of PFN1 in GII and GIII endometrial epithelial cancer cells associated with sustained PFN1 by infiltrating immune cells may promote EC tumorigenesis due to increased endometrial epithelial cancer cell proliferation coupled with a pro-tolerance tumor microenvironment.

Biophysics of human anatomy and physiology-a Special Issue in honor of Prof. Cristobal dos Remedios on the occasion of his 80th birthday

In 2001, Cristobal dos Remedios was made Professor of Anatomy (now emeritus) within Australia's highest-ranked university (University of Sydney). For the majority of his career, he has examined the biomechanics and biophysics of human muscle contraction. To coincide with the occasion of his 80th birthday, this Special Issue has commissioned a collection of review articles from experts exploring biophysical subjects within the general areas of human anatomy and physiology. After introducing the scope and contents of the Issue, we provide a short scientific biography, placing his scientific achievements within the context of the course of his life's developments.