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This paper confirms the damaging effects produced by MP and Cd on testicular activity in the rat. Oral treatment with both chemicals resulted in testicular damage, documented by biomolecular and histological alterations, particularly by impaired morphometric parameters, increased apoptosis, reduced testosterone synthesis, and downregulation of the steroidogenic enzyme 3β-HSD. We also demonstrated, for the first time, that both MP and Cd can affect the protein level of PTMA, a small peptide that regulates germ cell proliferation and differentiation. Interestingly, the cytoarchitecture of testicular cells was also altered by the treatments, as evidenced by the impaired expression and localization of DAAM1 and PREP, two proteins involved in actin- and microtubule-associated processes, respectively, during germ cells differentiation into spermatozoa, impairing normal spermatogenesis. Finally, we showed that the effect of simultaneous treatment with MP and Cd were more severe than those produced by MP alone and less harmful than those of Cd alone. This could be due to the different ways of exposure of the two substances to rats (in drinking water for Cd and in oral gavage for MP), since being the first contact in the animals’ gastrointestinal tract, MP can adsorb Cd, reducing its bioavailability through the Trojan-horse effect.

Nutritional pancreatic atrophy (NPA) is a classical Se/vitamin E deficiency disease of chicks. To reveal molecular mechanisms of its pathogenesis, we fed day-old chicks a practical, low-Se diet (14 μg Se/kg), and replicated the typical symptoms of NPA including vesiculated mitochondria, cytoplasmic vacuoles, and hyaline bodies in acinar cells of chicks as early as day 18. Target pathway analyses illustrated a > 90% depletion (P

The new and increasingly studied concept of immunogenic cell death (ICD) revealed a previously unknown perspective of the various regulated cell death (RCD) modalities, elucidating their immunogenic properties and rendering obsolete the notion that immune stimulation is solely the outcome of necrosis. A distinct characteristic of ICD is the release of danger-associated molecular patterns (DAMPs) by dying and/or dead cells. Thus, several members of the DAMP family, such as the well-characterized heat shock proteins (HSPs) HSP70 and HSP90, the high-mobility group box 1 protein and calreticulin, and the thymic polypeptide prothymosin α (proTα) and its immunoreactive fragment proTα(100–109), are being studied as potential diagnostic tools and/or possible therapeutic agents. Here, we present the basic aspects and mechanisms of both ICD and other immunogenic RCD forms; denote the role of DAMPs in ICD; and further exploit the relevance of human proTα and proTα(100–109) in ICD, highlighting their possible clinical applications. Furthermore, we present the preliminary results of our in vitro studies, which show a direct correlation between the concentration of proTα/proTα(100–109) and the levels of cancer cell apoptosis, induced by anticancer agents and γ-radiation. [ABSTRACT FROM AUTHOR]

The inhibition of retinal ischemia-induced damage by post-ischemic prothymosin alpha (ProTα) was not affected in toll-like receptor 4 knockout (TLR4−/−) mice but blocked by the pretreatment with antibody against F0/F1 ATPase α- or β-subunit, novel candidate for ProTα-receptor. In addition to the previous observation of ProTα-induced ATP release from cells, the present study showed a ProTα-induced enhancement of ATP hydrolysis activity of recombinant ATP5A1/5B complex. As the protection of retinal function by post-ischemic ProTα was abolished by anti-P2Y12 antibody, the activation of F0/F1 ATPase and subsequent P2Y12 receptor system may play roles in beneficial actions by post-ischemic ProTα.

Prothymosin alpha (ProTα) is involved in multiple cellular processes. Upon serum-free stress, ProTα lacking a signal peptide sequence is non-classically released from C6 glioma cells as a complex with Ca2+-binding cargo protein S100A13. Thus, ProTα and S100A13 are conceived to be members of damage-associated molecular patterns (DAMPs)/alarmins. However, it remains to be determined whether stress-induced release of ProTα and S100A13 involves SNARE proteins in the mechanisms underlying membrane tethering of the multiprotein complex. In the present study, we used C6 glioma cells as a model of ProTα release. In pull-down assay, p40 synaptotagmin-1 (Syt-1), a vesicular SNARE, formed a hetero-oligomeric complex with homodimeric S100A13 in a Ca2+-dependent manner. The interaction between p40 Syt-1 and S100A13 was also Ca2+-dependent in surface plasmon resonance (SPR). Immunoprecipitation using conditioned medium (CM) revealed that p40 Syt-1 was co-released with ProTα and S100A13 upon serum-free stress. In in situ proximity ligation assay (PLA), Syt-1 interacted with S100A13 upon serum-free stress in C6 glioma cells. The intracellular delivery of anti-Syt-1 IgG blocked serum free-induced release of ProTα and S100A13. Serum free-induced ProTα-EGFP release was significantly blocked by botulinum neurotoxin/C1 (BoNT/C1), which cleaves target SNARE syntaxin-1 (Stx-1). In immunocytochemistry, the cellular loss of ProTα-EGFP, S100A13, and Syt-1 was also blocked by BoNT/C1. Furthermore, the intracellular delivery of anti-Stx-1 IgG or Stx-1 siRNA treatment blocked Syt-1, S100A13 and ProTα release from C6 glioma cells. All these findings suggest that SNARE proteins play roles in stress-induced non-classical release of DAMPs/alarmins proteins, ProTα and S100A13 from C6 glioma cells. [ABSTRACT FROM AUTHOR]

Tissue plasminogen activator (tPA) administration beyond 4.5 h of stroke symptoms is beneficial for patients but has an increased risk of cerebral hemorrhage. Thus, increasing the therapeutic window of tPA is important for stroke recovery. We previously showed that prothymosin alpha (ProTα) or its mimetic hexapeptide (P6Q) has anti‐ischemic activity. Here, we examined the beneficial effects of ProTα or P6Q against delayed tPA‐induced brain damage following middle cerebral artery occlusion (MCAO) or photochemically induced thrombosis in mice. Brain hemorrhage was observed by tPA administration during reperfusion at 4.5 and 6 h after MCAO. Co‐administration of ProTα with tPA at 4.5 h inhibited hemorrhage and motor dysfunction 2–4 days, but not 7 days after MCAO. ProTα administration at 2 and 4.5 h after MCAO significantly inhibited tPA (4.5 h)‐induced motor dysfunction and death more than 7 days. Administration of tPA caused the loss of tight junction proteins, zona occulden‐1 and occludin, and up‐regulation of matrix metalloproteinase‐2/9, in a ProTα‐reversible manner. P6Q administration abolished tPA (4.5 h)‐induced hemorrhage and reversed tPA (6 h)‐induced vascular damage and matrix metalloproteinase‐2 and 9 up‐regulation. Twice administrations of P6Q at 2 h alone and 6 h with tPA significantly improved motor dysfunction more than 7 days. In photochemically induced thrombosis ischemia, similar vascular leakage and neuronal damage (infarction and motor dysfunction) by late tPA (4.5 or 6 h) were also inhibited by P6Q. Thus, these studies suggest that co‐administration with ProTα or P6Q would be beneficial to inhibit delayed tPA‐induced hemorrhagic mechanisms in acute ischemic stroke. [ABSTRACT FROM AUTHOR]

Background: Prothymosin alpha (ProTα) is a nuclear protein expressed in virtually all mammalian tissues. Previous studies have shown that ProTα exhibits protective effects against ischemia-induced cell death in various cell types. Recently, the 6-residue peptide P6Q (NEVDQE), the modified form of the active 6-residue core (51–56) in ProTα, has also been shown to have protective effects against retinal ischemia. However, it remains to be elucidated whether P6Q is effective against acute kidney injury (AKI). Therefore, we investigated the renoprotective effect of P6Q on cisplatin-induced AKI. Methods: Cultured HK-2 cells were treated with cisplatin for 24 h and pretreatment with ProTα or P6Q was carried out 30 min before cisplatin treatment. Cell viability was evaluated using the MTT assay. In an in vivo study, 8-week-old male Wistar rats were divided into control, cisplatin treated, and cisplatin treated with P6Q injection groups. In the last of these, P6Q was injected intravenously before cisplatin treatment. Then, we evaluated the renoprotective effect of P6Q. Results: In the study on cultured cells, pretreatment with ProTα or P6Q prevented cisplatin-induced cell death. In the in vivo study, pretreatment with P6Q significantly attenuated cisplatin-induced increase in serum creatinine and blood urea nitrogen levels, renal tubular cell injury, and apoptosis. Moreover, P6Q attenuated the mitochondrial apoptotic pathway and accelerated Akt phosphorylation after cisplatin-induced renal damage. Conclusion: Taken together, our findings indicate that P6Q can attenuate cisplatin-induced AKI and suppress the mitochondrial apoptotic pathway via Akt phosphorylation. These data suggest that P6Q has potential as a preventative drug for cisplatin-induced AKI. [ABSTRACT FROM AUTHOR]

We previously showed that prothymosin alpha (ProTα) improves cerebral ischemia-induced motor dysfunction. Our recent study also demonstrated that heterozygous ProTα deletion exhibited an enhanced anxiety-like behavior in mice. However, it remains elusive which brain regions or cells are related to these phenotypes. Here we generated conditional Gγ7-specific ProTα knockout mice using G protein γ7 subunit gene (Gng7)-cre promoter to see the brain robustness roles of ProTα in the striatum and hippocampus. The younger conditional ProTα (Gng7) knockout mice at the age of 10 weeks showed no significant phenotypes in motor dysfunction in the Rotarod test and locomotor activity in the open-field test, whereas significant motor dysfunction was obtained by 15 min transient middle cerebral artery occlusion (tMCAO)-induced cerebral ischemia. The aged conditional ProTα (Gng7) knockout mice at the age of 20 weeks showed hypolocomotor activity with less center time in the open-field test and impaired motor coordination in the Rotarod test without ischemia. Thus, this study suggests that ProTα has important roles in the maintenance of motor coordination and anxiety-like behavior. • We generated Gγ7-specific conditional prothymosin alpha (ProTα) knockout mice. • Younger ProTα (Gng7) knockout mice showed motor dysfunction under cerebral ischemia. • Aged conditional ProTα (Gng7) knockout mice exhibit motor dysfunction and anxiety. • This study suggests that ProTα plays roles in maintenance of motor function or anxiety. [ABSTRACT FROM AUTHOR]

Prothymosin alpha (ProTα) suppresses stress-induced necrosis of cultured cortical neurons. As neuroprotection alone could not explain the long-lasting protective actions against cerebral ischemia by ProTα, we further examined whether ProTα, in addition to neuroprotective effects, has other anti-ischemic activities. When recombinant mouse ProTα (rmProTα) at 0.3 mg/kg was intravenously (i.v.) given 2 h after the start of tMCAO, all mice survived for more than 14 days. In evaluation of CD31- and tomato lectin-labeling as well as IgG and Evans blue leakage, rmProTα treatment (0.1 mg/kg) largely blocked ischemia-induced vascular damages. Therefore, rmProTα has novel beneficial effects against ischemia-induced brain damage through vascular mechanisms.

Abstract pH-induced structural changes of the synthetic homopolypeptides poly-E, poly-K, poly-R, and intrinsically disordered proteins (IDPs) prothymosin α (ProTα) and linker histone H1, in concentrated PEG solutions simulating macromolecular crowding conditions within the membrane-less organelles, were characterized. The conformational transitions of the studied poly-amino acids in the concentrated PEG solutions depend on the polymerization degree of these homopolypeptides, the size of their side chains, the charge distribution of the side chains, and the crowding agent concentration. The results obtained for poly-amino acids are valid for IDPs having a significant total charge. The overcrowded conditions promote a significant increase in the cooperativity of the pH-induced coil–α-helix transition of ProTα and provoke histone H1 aggregation. The most favorable conditions for the pH-induced structural transitions in concentrated PEG solutions are realized when the charged residues are grouped in blocks, and when the distance between the end of the side group carrying charge and the backbone is small. Therefore, the block-wise distribution of charged residues within the IDPs not only plays an important role in the liquid–liquid phase transitions, but may also define the expressivity of structural transitions of these proteins in the overcrowded conditions of the membrane-less organelles. [ABSTRACT FROM AUTHOR]

Prothymosin-α is a small, multifunctional intrinsically disordered protein associated with cell survival and proliferation which binds multiple Zn2+ ions and undergoes partial folding. The interaction between prothymosin-α and at least two of its protein targets is significantly enhanced in the presence of Zn2+ ions, suggesting that Zn2+ binding plays a role in the protein's function. The primary sequence of prothymosin-α is highly acidic, with almost 50% comprised of Asp and Glu, and is unusual for a Zn2+-binding protein as it lacks Cys and His residues. To gain a better understanding of the nature of the Zn2+-prothymosin-α interactions and the protein's ability to discriminate Zn2+ over other divalent cations (e.g., Ca2+, Co2+, Mg2+) we synthesized a set of three model peptides and characterized the effect of metal binding using electrospray ionization mass spectrometry (ESI MS) and circular dichroism (CD) spectroscopy. ESI MS data reveal that the native peptide model of the glutamic acid rich region binds 4 Zn2+ ions with apparent, stepwise Kd values that are, at highest, in the tens of micromolar range. A peptide model with the same amino acid composition as the native sequence, but with the residues arranged randomly, showed no evidence of structural change by CD upon introduction of Zn2+. These results suggest that the high net negative charge of the glutamic acid-rich region of prothymosin-α is not a sufficient criterion for Zn2+ to induce a structural change; rather, Zn2+ binding to prothymosin-α is sequence specific, providing important insight into the behavior of intrinsically disordered proteins. [ABSTRACT FROM AUTHOR]

NUPR1 is a protumoral multifunctional intrinsically disordered protein (IDP), which is activated during the acute phases of pancreatitis. It interacts with other IDPs such as prothymosin α, as well as with folded proteins such as the C-terminal region of RING1-B (C-RING1B) of the Polycomb complex; in all those interactions, residues around Ala33 and Thr68 (the 'hot-spot' region) of NUPR1 intervene. Its paralogue, NUPR1L, is also expressed in response to DNA damage, it is p53-regulated, and its expression downregulates that of the NUPR1 gene. In this work, we characterized the conformational preferences of isolated NUPR1L and its possible interactions with the same molecular partners of NUPR1. Our results show that NUPR1L was an oligomeric IDP from pH 2.0 to 12.0, as judged by steady-state fluorescence, circular dichroism (CD), dynamic light scattering, 1D 1H-NMR (nuclear magnetic resonance), and as indicated by structural modelling. However, in contrast with NUPR1, there was evidence of local helical- or turn-like structures; these structures were not rigid, as judged by the lack of sigmoidal behaviour in the chemical and thermal denaturation curves obtained by CD and fluorescence. Interestingly enough, NUPR1L interacted with prothymosin α and C-RING1B, and with a similar affinity to that of NUPR1 (in the low micromolar range). Moreover, NUPR1L hetero-associated with NUPR1 with an affinity of 0.4 mM and interacted with the 'hotspot' region of NUPR1. Thus, we suggest that the regulation of NUPR1 gene by NUPR1L does not only happen at the DNA level, but it could also involve direct interactions with NUPR1 natural partners. [ABSTRACT FROM AUTHOR]

The present study aimed to investigate the expression patterns of prothymosin-a (PTMA) and parathymosin (PTMS) in patients with squamous cell carcinoma (SCC), adenosquamous cell carcinoma (ASC) and adenocarcinoma (AC) of the gallbladder, and to assess their association with the clinicopathological characteristics and prognosis of the patients. A retrospective analysis of data pertaining to patients with SCC/ASC (n=46) and AC (n=80) of the gallbladder, who were treated with surgical resection, was conducted. Kaplan-Meier survival analysis was also performed to assess the correlation of the expression pattern with survival. The results revealed a higher percentage of patients with a large tumor diameter (>3 cm) in the SCC/ASC group as compared with those in the AC group (P<0.05). No significant differences were observed between patients with SCC/ASC and those with AC with respect to the patient sex, presence of gallstones, TNM stage, lymph node metastasis, invasive growth into anatomically contiguous structures, surgical methods used, survival rate, and the expression levels of PTMA and PTMA (P>0.05). However, positive expression of PTMA and PTMA was associated with tumor size, TNM stage, lymph node metastasis, locally invasive growth, and treatment with radical resection in patients with SCC/ASC and AC (P<0.05). In addition, positive expression of PTMA and PTMA was observed in a significantly lower number of patients with advanced AC as compared with those in early AC (P<0.05), while these expression levels were also associated with shorter survival in the SCC/ASC group and AC group (P<0.05). Cox multivariate analysis also demonstrated a negative correlation between PTMA and PTMA levels, and the postoperative survival rate in the two groups. In conclusion, the present study indicated that the expression levels of PTMA and PTMA were closely associated with the tumorigenesis and progression of SCC, ASC and AC of the gallbladder. Positive expression of PTMA and PTMA may serve as a valuable prognostic factor in these patients. [ABSTRACT FROM AUTHOR]

Prothymosin α (ProTα) is an acidic protein with a nuclear role related to the chromatin activity through its interaction with histones in mammalian cells. ProTα acts as an anti-apoptotic factor involved in the control of the apoptosome activity in the cytoplasm, however the mechanisms underlying this function are still known. ProTα shares similar biological functions with acidic nuclear-cytoplasmic shuttling proteins included in SET and ANP32 family members. Using affinity chromatography, co-immunoprecipitation and chemical cross-linking, we demonstrate that ProTα interacts with SET, ANP32A and ANP32B proteins. The study by mass spectrometry of the complexes stabilized by chemical cross-linking showed that associations of ProTα consist of six highly acidic ProTα-complexes, which corresponds to differentiated interactions of ProTα either with SET or ANP32 proteins. The presence in the ProTα-complexes of cytoplasmic proteins involved in membrane remodeling and proteins implicated in the mitochondrial permeability, seems to indicate that they could be related to a cytoplasmic-mitochondrial activity. According to the cellular function of the characterized targets of ProTα, and the evolution in the composition of the diverse ProTα-complexes when proliferation activity was reduced or apoptosis induced, leads to hypothesized that ProTα interactions might be related to the proliferation activity and control of the cell survival. [ABSTRACT FROM AUTHOR]

Prothymosin alpha (PTMA) is a highly acidic, intrinsically disordered protein that was first extracted from rat thymus and characterized as an immunogenic factor but soon detected in a variety of mammalian tissues. The presence of a nuclear localization signal and the adoption of a peculiar randomcoil conformation are among the reasons behind its interaction with several molecular partners, hence at this time PTMAis known to be a very conserved and widely expressed molecule, involved in numerous and diverse biological processes. Only few studies have tried to weigh its possible involvement in reproduction, specifically in male gametogenesis: first reports have suggested that PTMA might be associated with the proliferative and early-meiotic phases of mammal spermatogenesis. Some years later, a comparative project on vertebrate spermatogenesis reported the isolation, for the first time, of prothymosin in a non-mammalian species, the amphibian Pelophylax esculentus. PTMA transcript and protein are localized in the germinal compartment, from spermatocytes to spermatozoa. A congruent pattern has been highlighted in studies on the fish Torpedo marmorata and Danio rerio, and in the mammal Rattus norvegicus, in which the expression of PTMA has been found in meiotic and post-meiotic germ cells inside testicular cysts and tubules. Moreover, its presence has been confirmed in rat and human spermatozoa (associated with the acrosome); its retention in the apical region of the head after the acrosome reaction revealed a striking conservation of the pattern during phylogenesis and suggested a possible role for the protein in gametogenesis and in fertilization. [ABSTRACT FROM AUTHOR]

Prothymosin alpha (ProTα) is a highly conserved mammalian polypeptide (109 amino acids in man) exerting in vitro and in vivo immunoenhancing activities. Recently, our team has developed a 99m Tc-radiolabeled derivative of the C-terminal bioactive decapeptide of ProTα ([ 99m Tc] C1 ) and employed it in in vitro studies, the results of which support the existence of binding sites on human neutrophils that recognize [ 99m Tc] C1 , intact ProTα as well as the C-terminal decapeptide of ProTα and presumably involve Toll-like receptor 4. In the present work, [ 99m Tc] C1 was administered to Swiss albino mice with experimentally-induced inflammation for in vivo biodistribution and imaging studies, in parallel with a suitable negative control, which differs from [ 99m Tc] C1 only in bearing a scrambled version of the ProTα decapeptide. The biodistribution data obtained with [ 99m Tc] C1 demonstrated fast clearance of radioactivity from blood, heart, lungs, normal muscle, and predominantly urinary excretion. Most importantly, slow clearance of radioactivity from the inflammation focus was observed, resulting in a high ratio of inflamed/normal muscle tissue (9.15 at 30 min post injection, which remained practically stable up to 2 h). The inflammation-targeting capacity of [ 99m Tc] C1 was confirmed by imaging studies and might be attributed to neutrophils, which are recruited at the inflamed areas and bear binding sites for [ 99m Tc] C1 . In this respect, apart from being a valuable tool for further studies on ProTα in in vitro and in vivo systems, [ 99m Tc] C1 merits further evaluation as a radiopharmaceutical for specific imaging of inflammation foci. [ABSTRACT FROM AUTHOR]

Prothymosin alpha (ProTα) is expressed in various mammalian organs including the neuronal nuclei in the brain, and is involved in multiple functions, such as chromatin remodeling, transcriptional regulation, cell proliferation, and survival. ProTα has beneficial actions against ischemia-induced necrosis and apoptosis in the brain and retina. However, characterizing the physiological roles of endogenous ProTα in the brain without stress remains elusive. Here, we generated ProTα-deficiency mice to explore whether endogenous ProTα is involved in normal brain functions. We successfully generated heterozygous ProTα knockout (ProTα+/−) mice, while all homozygous ProTα knockout (ProTα−/−) offspring died at early embryonic stage, suggesting that ProTα has crucial roles in embryonic development. In the evaluation of different behavioral tests, ProTα+/− mice exhibited hypolocomotor activity in the open-field test and enhanced anxiety-like behaviors in the light/dark transition test and the novelty induced hypophagia test. ProTα+/− mice also showed impaired learning and memory in the step-through passive avoidance test and the KUROBOX test. Depression-like behaviors in ProTα+/− mice in the forced swim and tail suspension tests were comparable with that of wild-type mice. Furthermore, adult hippocampal neurogenesis was significantly decreased in ProTα+/− mice. ProTα+/− mice showed an impaired long-term potentiation induction in the evaluation of electrophysiological recordings from acute hippocampal slices. Microarray analysis revealed that the candidate genes related to anxiety, learning/memory-functions, and neurogenesis were down-regulated in ProTα+/− mice. Thus, this study suggests that ProTα has crucial physiological roles in the robustness of brain. [ABSTRACT FROM AUTHOR]

Cisplatin is a potent chemotherapeutic drug widely used for the treatment of human cancer. However, its efficacy against hepatocellular carcinoma (HCC) is poor for reasons that remain unclear. We show here that prothymosin-alpha (PTMA) is overexpressed in HCC cell lines. Silencing PTMA using short-hairpin RNA sensitizes HCC cells to cisplatin, while ectopic expression of PTMA induces cell resistance to the drug. Cisplatin inhibits both the JNK pathway and PTMA in a dose-dependent manner. Treatment with a JNK inhibitor also reduces PTMA protein stability and sensitizes HCC cells to cisplatin. Notably, the effects of PTMA silencing and JNK inhibition can be reversed by ectopic expression of PTMA. We show that PTMA silencing induces translocation of proapoptotic Bax to mitochondria and enhances cisplatin-induced cytochrome c release and caspase-9 activation. Conversely, ectopic expression of PTMA reverses these effects. Our results indicate that PTMA is positively regulated by JNK and protects HCC cells against cisplatin-induced cell death. The JNK/PTMA axis may thus represent a novel target for chemotherapy against HCC. [ABSTRACT FROM AUTHOR]

Prothymosin α (PTMA) is a highly acidic, intrinsically disordered protein, which is widely expressed and conserved throughout evolution; its uncommon features are reflected by its involvement in a variety of processes, including chromatin remodelling, transcriptional regulation, cell proliferation and death, immunity. PTMA has also been implicated in spermatogenesis: during vertebrate germ cell progression in the testis the protein is expressed in meiotic and post-meiotic stages, and it is associated with the acrosome system of the differentiating spermatids in mammals. Then, it finally localizes on the inner acrosomal membrane of the mature spermatozoa, suggesting its possible role in both the maturation and function of the gametes. In the present work we studied PTMA expression during the spermatogenesis of the adult zebrafish, a species in which two paralogs have been described. Our data show that ptma transcripts are expressed in the testis, and localize in meiotic and post-meiotic germ cells, namely spermatocytes and spermatids. Consistently, the protein is expressed in spermatocytes, spermatids, and spermatozoa: its initial perinuclear distribution is extended to the chromatin region during cell division and, in haploid phases, to the cytoplasm of the developing and final gametes. The nuclear localization in the acrosome-lacking spermatozoa suggests a role for PTMA in chromatin remodelling during gamete differentiation. These data further provide a compelling starting point for the study of PTMA functions during vertebrate fertilization. [ABSTRACT FROM AUTHOR]

Background: Prothymosin α (ProTα) (isoform 2: iso2) is a widely distributed, small acidic protein with intracellular and extracellular-associated functions. Recently, we identified two new ProTα variants with potent anti-HIV activity from CD8+ T cells and cervicovaginal lavage. The first is a splice variant of the ProTα gene known as isoB and the second is the product of ProTα pseudogene 7 (p7). Similarly to iso2, the anti-HIV activity of both variants is mediated by type I IFN. Here we tested whether the immunomodulatory activity of isoB and p7 are also TLR4 dependent and determined their kinetic of release in response to HIV-1 infection. Methods: Type I, type III, TNF-α and IL-6 mRNA inducing activity was determined in macrophages from wild type and TLR4 knockout mice treated with recombinant ProTα variants. Supernatants from mock and HIV infected cells were analyzed by mass spectrometry in positive and negative modes for the presence of ProTα variants. In silico structural and functional analysis of ProTα variants were performed. Results: We show that both isoB and p7 upregulate IFN-β, IFN-λ1, IL-6, TNF-α and RANTES mRNAs in primary human macrophages. The potent stimulation of IFN-β by the recombinant ProTα variants in human macrophages is dependent on the TLR4 pathway, whereas the induction of TNF-α and IL-6 may also occur independently of TLR4, suggesting the interaction of ProTα variants with other signaling molecules/receptors. In silico analyses confirmed that the novel isoB and p7 variants are intrinsically disordered proteins, which lack the NLS and mass spectrometry showed release of ProTα variants within minutes post HIV-1 infection. These features are consistent with the function of ProTα variants as damage associate molecular patterns (DAMPs). Conclusions: Our findings indicate that ProTα variants strongly inhibit viral replication mainly, but not exclusively, through TLR4 signaling and that they are released within minutes of viral infection suggesting that they may function as DAMPs. [ABSTRACT FROM AUTHOR]

We consider a flexible chain with internal friction in a harmonic confinement and extend it to include the effects of solvent quality at the mean field level by introducing a Flory type exponent ν . The strength of the harmonic confinement ( k c ) accounts for the denaturant concentration and connects to the internal friction of the chain ( ξ i n t ) through an ansatz. Our calculated reconfiguration times falling in the range of 5–50 ns are found out to be within 10%–15% of the experimentally measured reconfiguration times of the folded cold shock protein and the intrinsically disordered protein prothymosin α . In addition, our calculations show that the reconfiguration time scales with the chain length N as ∼ N α , where α depends weakly on the internal friction but has rather stronger dependence on the solvent quality. In the absence of any internal friction, α = 2 ν + 1 and it goes down in the presence of internal friction, but chain reconfiguration slows down in general. On the contrary, in a poorer solvent chain reconfiguration and looping become faster even though the internal friction is higher in the collapsed state. [ABSTRACT FROM AUTHOR]

[Ca 2+ ] i alterations are vital in signaling pathways of cell activation. We tried to detect such changes, in intracellular signaling pathways downstream TLR4 in immune cells, following stimulation with prothymosin alpha (proTα) and its decapeptide proTα(100–109). Human leukocytes were activated with LPS, proTα or proTα(100–109), directly or after 24 h stimulation, while neutrophils were directly challenged. Cells were loaded with Fluo-4 and cytoplasmic Ca 2+ alterations were recorded by flow cytometry. Direct challenge with 20 μg/mL LPS induced a measurable [Ca 2+ ] i increase in macrophages and neutrophils. Monocytes and macrophages incubated for 24 h with LPS, proTα or proTα(100–109) and challenged with LPS, displayed a robust response. Lymphocytes and iDCs exhibited no alterations. Conclusively, we assessed a flow cytometry-based method for monitoring Ca 2+ ion influx changes in immune cells. Their stimulation with proTα or proTα(100–109) generates an activating background, similar to LPS, allowing for the detection of [Ca 2+ ] i alterations induced upon subsequent challenge. [ABSTRACT FROM AUTHOR]

Prothymosin alpha (ProTα) has robustness roles against brain and retinal ischemia or serum-starvation stress. In the ProTα sequence, the active core 30-amino acid peptide/P 30 (a.a.49–78) is necessary for the original neuroprotective actions against ischemia. Moreover, the 9-amino acid peptide sequence/P 9 (a.a.52–60) in P 30 still shows neuroprotective activity against brain and retinal ischemia, though P 9 is less potent than P 30 . As the previous structure–activity relationship study for ProTα may not be enough, the possibility still exists that any sequence smaller than P 9 retains potent neuroprotective activity. When different P 9 - and P 30 -related peptides were intravitreally injected 24 h after retinal ischemia in mice, the 6-amino acid peptide/P 6 (NEVDEE, a.a.51–56) showed potent protective effects against ischemia-induced retinal functional deficits, which are equipotent to the level of P 30 peptide in electroretinography (ERG) and histological damage in Hematoxylin and Eosin (HE) staining. Further studies using ERG and HE staining suggested that intravitreal or intravenous (i.v.) injection with modified P 6 peptide/P 6 Q (NEVDQE) potently inhibited retinal ischemia-induced functional and histological damage. In an immunohistochemical analysis, the ischemia-induced loss of retinal ganglion, bipolar, amacrine and photoreceptor cells were inhibited by a systemic administration with P 6 Q peptide 24 h after the ischemic stress. In addition, systemic post-treatment with P 6 Q peptide significantly inhibited retinal ischemia-induced microglia and astrocyte activation in terms of increased ionized calcium-binding adaptor molecule 1 (Iba-1) and glial fibrillary acidic protein (GFAP) intensity, respectively, as well as their morphological changes, increased number and migration. Thus, this study demonstrates the therapeutic significance of modified P 6 peptide P 6 Q (NEVDQE) derived from 6-amino acid peptide (P 6 ) in ProTα against ischemic damage. [ABSTRACT FROM AUTHOR]

Background: The cell type, cell status and specific localization of Prothymosin a (PTMA) within cells seemingly determine its function. PTMA undergoes 2 types of protease proteolytic modifications that are useful in elucidating its interactions with other molecules; a factor that typifies its roles. Preferably a nuclear protein, PTMA has been shown to function in the cytoplasm and extracellularly with much evidence leaning on pathognomonic status. As such, determination of its cellular distribution under normal physiological context while utilizing varied techniques is key to illuminating prospective validation of its distinct functions in different tissues. Differential distribution insights at normal physiology would also portent better basis for further clarification of its interactions and proteolytic modifications under pathological conditions like numerous cancer, ischemic stroke and immunomodulation. We therefore raised an antibody against the C terminal of PTMA to use in tandem with available antibody against the N terminal in a murine model to explicate the differences in its distribution in brain cell types and major peripheral organs through western blotting and immunohistochemical approaches. Results: The newly generated antibody was applied against the N-terminal antibody to distinguish truncated versions of PTMA or deduce possible masking of the protein by other interacting molecules. Western blot analysis indicated presence of a truncated form of the protein only in the thymus, while immunohistochemical analysis showed that in brain hippocampus the full-length PTMA was stained prominently in the nucleus whereas in the stomach full-length PTMA staining was not observed in the nucleus but in the cytoplasm. Conclusion: Truncated PTMA could not be detected by western blotting when both antibodies were applied in all tissues examined except the thymus. However, immunohistochemistry revealed differential staining by these antibodies suggesting possible masking of epitopes by interacting molecules. The differential localization patterns observed in the context of nucleic versus cytoplasmic presence as well as punctate versus diffuse pattern in tissues and cell types, warrant further investigations as to the forms of PTMA interacting partners. [ABSTRACT FROM AUTHOR]

Introduction: Prothymosin alpha (PTMA), a nuclear oncoprotein involved in cell cycle regulation, is used as a prognostic marker in many cancers. The histopathology of pituitary carcinomas and locally invasive adenomas is indistinguishable from that of benign tumors. A new marker is needed to differentiate these lesions. We evaluated PTMA in pituitary adenomas to determine its usefulness as a prognostic factor of tumor proliferation. Material/Methods: We conducted a retrospective analysis of a group of 27 patients, including 15 females (56%) and 12 males (44%) with a mean age of 58.6±12 years, who underwent pituitary tumor surgery between 2003 and 2012. The Ki-67 and PTMA-nuclear (PTMA-n) and PTMA-cytoplasmic (PTMA- -c) indices were determined by immunohistochemical staining. We studied histopathological features, clinical symptoms, and magnetic resonance imaging or computed tomography performed before surgery and one year following surgery to evaluate tumor size and progression. Results: The expression of Ki-67 was revealed in 77.8% of adenomas, PTMA-n in 81.5% and PTMA-c in 92.6%. The mean value of the Ki-67 index was 1.8%, PTMA-n was 1.84%, and PTMA-c was 35.6%. There was a significant positive correlation between Ki-67 and PTMA-n (p=0.009). We did not find any correlation between Ki-67, PTMA-c, and tumor progression. PTMA-n was found to be correlated with tumor size (p=0.045) and was higher in the case of gonadotropinomas (p=0.026). Conclusions: The positive nuclear expression of Ki-67 and PTMA was observed in the majority of pituitary adenomas. Neither the expression of Ki-67 nor that of PTMA-c was related to tumor recurrence or local invasion. [ABSTRACT FROM AUTHOR]

Prothymosin-alpha protects the brain and retina from ischemic damage. Although prothymosin-alpha contributes to toll-like receptor (TLR4)-mediated immnunopotentiation against viral infection, the beneficial effects of prothymosin-alpha-TLR4 signaling in protecting against ischemia remain to be elucidated. In this study, intravitreal administration of prothymosinalpha 48 h before induction of retinal ischemia prevented retinal cellular damage as evaluated by histology, and retinal functional deficits as evaluated by electroretinography. Prothymosin- alpha preconditioning completely prevented the ischemia- induced loss of ganglion cells with partial survival of bipolar and photoreceptor cells, but not amacrine cells, in immunohistochemistry experiments. Prothymosin-alpha treatment in the absence of ischemia caused mild activation, proliferation, and migration of retinal microglia, whereas the ischemia-induced microglial activation was inhibited by prothymosin-alpha preconditioning. All these preventive effects of prothymosin-alpha preconditioning were abolished in TLR4 knock-out mice and by pre-treatments with anti-TLR4 antibodies or minocycline, a microglial inhibitor. Prothymosinalpha preconditioning inhibited the retinal ischemia-induced up-regulation of TLR4-related injury genes, and increased expression of TLR4-related protective genes. Furthermore, the prothymosin-alpha preconditioning-induced prevention of retinal ischemic damage was abolished in TIR-domain-containing adapter-inducing interferon-p knock-out mice, but not in myeloid differentiation primary response gene 88 knock-out mice. Taken together, the results of this study suggest that prothymosin-alpha preconditioning selectively drives TLR4-TIR-domain-containing adapter-inducing interferon-p signaling and microglia in the prevention of retinal ischemic damage. [ABSTRACT FROM AUTHOR]

Prothymosin alpha (ProTα) is a small protein that in mammals is known to participate in diverse biological processes including immunomodulation. In teleost, the immunological function of ProTα is unknown. In the current study, we investigated the expression and function of the ProTα (named CsProTα) from the teleost fish tongue sole ( Cynoglossus semilaevis ). We found that CsProTα expression was abundant in immune relevant tissues and upregulated by megalocytivirus infection. Immunoblot detected secretion of CsProTα by peripheral blood leukocytes. Recombinant CsProTα (rCsProTα) as well as the C-terminal 11-residue (Ct11) were able to bind head kidney monocytes (HKM) and induce immune gene expression; however, the induction patterns caused by rCsProTα and Ct11 differed considerably. When introduced in vivo , rCsProTα and Ct11 significantly reduced megalocytivirus infection in fish tissues, whereas rCsProTα antibody significantly promoted viral replication. Blocking of Myd88 activity abolished the virus-inhibitory effect of rCsProTα but not Ct11. Taken together, these results demonstrate for the first time that both the intact protein and the C-terminal segment of a teleost ProTα can act like cytokines and induce antiviral immunity via, however, distinct signaling pathways that differ in the requirement of Myd88. [ABSTRACT FROM AUTHOR]

Soluble factors from CD8+ T cells and cervicovaginal mucosa of women are recognized as important in controlling human immunodeficiency virus type 1 (HIV-1) infection and transmission. Previously, we have shown the strong anti-HIV-1 activity of prothymosin α (ProTα) derived from CD8+ T cells. ProTα is a small acidic protein with wide cell distribution, to which several functions have been ascribed, depending on its intracellular or extracellular localization. To date, activities of ProTα have been attributed to a single protein known as isoform 2. Here we report the isolation and identification of 2 new ProTα variants from CD8+ T cells and cervicovaginal lavage with potent anti-HIV-1 activity. The first is a splice variant of the ProTα gene, known as isoform CRA-b, and the second is the product of a ProTα gene, thus far classified as a pseudogene 7. Native or recombinant ProTα variants potently restrict HIV-1 replication in macrophages through the induction of type I interferon. The baseline expression of interferon-responsive genes in primary human cervical tissues positively correlate with high levels of intracellular ProTα, and the knockdown of ProTα variants by small interfering RNA leads to downregulation of interferon target genes. Overall, these findings suggest that ProTα variants are innate immune mediators involved in immune surveillance. [ABSTRACT FROM AUTHOR]

Prothymosin alpha ( ProTα ) and thymosin beta ( Tβ ) belong to thymosin family, which consists of a series of highly conserved peptides involved in stimulating immune responses. ProTα b and Tβ are still poorly studied in teleost. Here, the full-length cDNAs of ProTα b and Tβ-like ( Tβ-l ) were cloned and identified in common carp ( Cyprinus carpio L.). The expressions of carp ProTα b and Tβ-l exhibited rise-fall pattern and then trended to be stable during early development. After spring viraemia of carp virus (SVCV) infection, the carp ProTα b and Tβ-l transcripts were significantly up-regulated in some immune-related organs. When transiently over-expressed carp ProTα b and Tβ-l in zebrafish, these two proteins up-regulated the expressions of T lymphocytes-related genes ( Rag 1, TCR-γ, CD4 and CD8α ). These results suggest that carp ProTα b and Tβ may ultimately enhance the immune response during viral infection and modulate the development of T lymphocytes in teleost. [ABSTRACT FROM AUTHOR]

Prothymosin alpha (PTMA) is overexpressed in various human tumors, including hepatocellular carcinoma (HCC). The significance of PTMA overexpression and its underlying mechanism remain unclear. We show here that silencing PTMA sensitizes HCC cells to the kinase inhibitor sorafenib. In contrast, ectopic expression of PTMA induces cell resistance to the drug. While inhibitors targeting JNK, ERK or PI3K reduce PTMA expression, only ERK activation is suppressed by sorafenib. In addition, inhibition of ERK produces a dramatic decrease in both endogenous PTMA level and promoter activation. Ectopic expression of active MKK1/2 considerably induces PTMA expression. We also identify a sorafenib-responsive segment lying 1000–1500-bp upstream of the PTMA transcription start site and observe that it is controlled by c-Myc and ERK. Mutation in the PTMA promoter at the predicted c-Myc binding site and silencing of c-Myc both abrogate sorafenib's effect on PTMA transcription. We also find that silencing PTMA potentiates Bax translocation to mitochondria in response to sorafenib and this is associated with increased cytochrome c release from mitochondria and enhanced caspase-9 activation. These results indicate that PTMA is positively regulated by the oncoprotein c-Myc and protects HCC cells against sorafenib-induced cell death, thus identifying PTMA as a new target for chemotherapy against HCC. [ABSTRACT FROM AUTHOR]

Abstract: Objectives: To determine the plasma levels of thymosin-α1 (TA1) and prothymosin-α (PTMA) proteins in renal cell carcinoma (RCC) or urothelial carcinoma (UC) patients, and explore the potential of these 2 molecules as biomarkers. Materials and methods: Blood samples were taken from 50 consecutive patients with RCC, 97 with UC, and 55 with benign urologic diseases before surgery. Their clinical characteristics were obtained from medical record review. Plasma TA1 and PTMA levels were measured using enzyme-linked immunosorbent assay and their correlation with tumor grade, pathologic stage, and survival were explored. Results: Plasma TA1 levels were significantly lower in RCC patients than in UC or benign patients, particularly in UC of the renal pelvis patients (P < 0.0001). Plasma PTMA levels were also significantly lower in UC patients compared with RCC patients and benign patients (P < 0.05). Plasma TA1 levels inversely correlated with pathologic stage both in bladder cancer and RCC patients (P = 0.03 and 0.02, respectively). Both plasma TA1 and PTMA did not correlate with tumor grade. Plasma TA1 was a prognostic indicator for progression-free and disease-specific overall survival in bladder cancer patients (P = 0.008 and 0.04, respectively). Conclusions: Plasma TA1 level may be a biomarker for differentiating between UC and RCC. It may also be a prognostic factor for disease progression and disease-specific survival in bladder cancer patients. These findings warrant more studies for validation. [Copyright &y& Elsevier]

The human prothymosin alpha (PTα) gene encodes a 12.5 kDa highly acidic nuclear protein that is widely expressed in mammalian tissues including the heart and importantly, is detectable also in blood serum. During apoptosis or necrosis, PTα changes its nuclear localization and is able to exert an important cytoprotective effect. Since the role of PTα in the heart has never been evaluated, the aim of the present study was to investigate the effects of PTα on cardiomyocytes during ischemic injury. Our data show that seven after myocardial infarction (MI), PTα expression levels are significantly increased both in blood serum and in cardiac tissue, and notably we observe that PTα translocates from the nuclei to cytoplasm and plasma membrane of cardiomyocytes following MI. Furthermore, in vitro experiments in cardiomyocytes, confirm that after 6 h of simulated ischemia (SI), PTα protein levels are upregulated compared to normoxic cells. Importantly, treatment of cardiomyocytes with a recombinant PTα (rPTα), during SI results in a significant decrease in the apoptotic response and in a robust increase in cell survival. Moreover, these effects are accompanied to a significant preservation of the activated levels of the anti-apoptotic serine-threonine kinase Akt. Consistent with our in vitro observation, rPTα-treated MI mice exhibit a strong reduction in infarct size at 24 h, compared to the MI control group and at the molecular level, PTα treatment induces activation of Akt. The present study provides for the first time the demonstration that PTα offers cardioprotection against ischemic injury by an Akt-dependent mechanism. [ABSTRACT FROM AUTHOR]

Abstract: Apoptosis is characterized by a series of discrete biochemical events, among which is the truncation of the nuclear polypeptide prothymosin alpha (proTα) by activated caspase-3. This early apoptotic event results in the generation of a carboxy-terminal fragment of proTα, the immunoactive decapeptide proTα(100–109). We hypothesized that the detection of increased levels of proTα(100–109) in serum can be directly correlated with the induction of massive cell apoptosis, resulting from a severe bacterial infection. Thus, using high-affinity-purified polyclonal antibodies (Abs), raised in rabbits and a prototype antibody-capture system, we developed a highly sensitive and specific competitive ELISA for proTα(100–109). The sensitivity of the ELISA (0.1ng/mL to 10μg/mL) is acceptable for the quantification of the decapeptide in serum samples. To assess our initial hypothesis, we determined the concentration of proTα(100–109) in the sera of mice infected with the bacterium Streptococcus pyogenes over the course of the infection. We show that serum concentration of proTα(100–109) was marginal to undetectable before infection, increased over time and peaked at 72h postinfection. In silico analysis suggests that the Abs generated are unlikely to cross-react with any other unrelated mouse or bacterial protein. Further validation of our ELISA using serum samples from humans, infected with bacteria, may provide a useful tool to differentiate the causative agent of a potentially lethal septic infection. [Copyright &y& Elsevier]

Background: Active cancer immunotherapies are beginning to yield clinical benefit, especially those using peptidepulsed dendritic cells (DCs). Different adjuvants, including Toll-like receptor (TLR) agonists, commonly co-administered to cancer patients as part of a DC-based vaccine, are being widely tested in the clinical setting. However, endogenous DCs in tumor-bearing individuals are often dysfunctional, suggesting that ex vivo educated DCs might be superior inducers of anti-tumor immune responses. We have previously shown that prothymosin alpha (proTα) and its immunoreactive decapeptide proTα(100–109) induce the maturation of human DCs in vitro. The aim of this study was to investigate whether proTα- or proTα(100–109)-matured DCs are functionally competent and to provide preliminary evidence for the mode of action of these agents. Results: Monocyte-derived DCs matured in vitro with proTα or proTα(100–109) express co-stimulatory molecules and secrete pro-inflammatory cytokines. ProTα- and proTα(100–109)-matured DCs pulsed with HER-2/neu peptides induce TH1-type immune responses, prime autologous naïve CD8-positive (+) T cells to lyse targets expressing the HER-2/neu epitopes and to express a polyfunctional profile, and stimulate CD4+ T cell proliferation in an HER-2/neu peptide-dependent manner. DC maturation induced by proTα and proTα(100–109) is likely mediated via TLR-4, as shown by assessing TLR-4 surface expression and the levels of the intracellular adaptor molecules TIRAP, MyD88 and TRIF. Conclusions: Our results suggest that proTα and proTα(100–109) induce both the maturation and the T cell stimulatory capacity of DCs. Although further studies are needed, evidence for a possible proTα and proTα(100–109) interaction with TLR-4 is provided. The initial hypothesis that proTα and the proTα-derived immunoactive decapeptide act as “alarmins”, provides a rationale for their eventual use as adjuvants in DC-based anti-cancer immunotherapy. [ABSTRACT FROM AUTHOR]

Prothymosin α (PTMA) is a highly acidic intrinsically unstructured protein. Its expression in male gonads is evolutionary conserved; in rat testis it is specifically localized in the cytoplasm of post-meiotic germ cells, in association with the developing acrosome system. In the present paper we investigated on PTMA localization inside the head of mammalian spermatozoa (SPZ). We chose a confocal approach to ascertain whether PTMA is expressed in the acrosome or in the perinuclear theca, two regions that are tightly linked and partially overlapped in the mature haploid cells. The obtained results showed that PTMA is specifically localized in the acrosome of rat epididymal SPZ; the same experimental approach evidenced, for the first time, PTMA presence in human ejaculated SPZ. A Western blot analysis on protein extracts from human sperm head fractions confirmed the confocal data and demonstrated that the peptide is specifically associated with the inner acrosomal membrane fraction. Finally, when the acrosome reaction was induced in vitro by progesterone treatment on both rat and human sperm, PTMA signal was retained in the apical region of reacted SPZ. In conclusion, this study confirms the conservation of PTMA distribution in vertebrate male gametes and strongly supports a role for this polypeptide in their physiology. J. Cell. Physiol. 228: 1629-1637, 2013. © 2013 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Phosphorylation of prothymosin α (ProTα) appears not to affect its influence on chromatin remodelling. To determine whether it affects nuclear import or cytosolic antiapoptotic activity, cells were transfected with vectors generating tagged recombinant ProTα (rProTα), either wild-type (rProTα-wt), which is partially phosphorylated posttranslation or the nonphosphorylatable rProTα-T7A. Immunofluorescence microscopy showed the predominant location of native ProTα, rProTα-wt, and rProTα-T7A in the nucleus. The activity of caspases 9 and 3 following apoptosis induction treatment (staurosporine) indicated reduction of apoptosis by rProTα-wt but not by rProTα-T7A. It is concluded that phosphorylation of ProTα is required for its antiapoptotic activity, but it does not affect its nuclear import. [ABSTRACT FROM AUTHOR]

The thymus gland, as a primary lymphoid organ, plays a crucial role in the normal development and appropriate functioning of the immune system, contributing to the maturation and differentiation of T lymphocytes. The first biologically active extract isolated from the thymus was named thymosin fraction V (TFV). The fractionation of TFV led to the isolation of a series of immunoreactive polypeptides, termed thymosins, the most important and well-studied of which are thymosin a1 (Ta1) and its precursor molecule, prothymosin a (proTa). Although the precise molecular mechanism of action of these polypeptides has not yet been fully elucidated, it is thought that they have a potential use in medical practice, both as cancer biomarkers and as immunotherapeutic agents for the treatment of cancer patients. ProTa is ubiquitously expressed in all tissues and plays a dual role; intracellularly, it participates in the regulation of the cell cycle, while extracellularly it acts as an immunomodulator. This review focuses on proTa and the data accumulated to date with respect to its role in cancer, and specifically its potential clinical utility, both as a biomarker for cancer prognosis and monitoring, and as an immunotherapeutic tool for the activation of immune responses against tumor cells. Based on the results derived from clinical trials of Ta1 in patients with cancer, the eventual use of proTa in similar studies in humans is discussed, aiming at the enhancement of the functions of the immune system and, ultimately, at cancer regression. [ABSTRACT FROM AUTHOR]

Prothymosin alpha (ProTα), a nuclear protein, is implicated in the inhibition of ischemia-induced necrosis as well as apoptosis in the brain and retina. Although ProTα has multiple biological functions through distinct regions in its sequence, it has remained which region is involved in this neuroprotection. This study reported that the active core peptide sequence P30 (amino acids 49-78) of ProTα exerts its full survival effect in cultured cortical neurons against ischemic stress. Our in vivo study revealed that intravitreous administration of P30 at 24 h after retinal ischemia significantly blocks the ischemia-induced functional damages of retina at day 7. In addition, P30 completely rescued the retinal ischemia-induced ganglion cell damages at day 7 after the ischemic stress, along with partial blockade of the loss of bipolar, amacrine, and photoreceptor cells. On the other hand, intracerebroventricular (3 nmol) or systemic (1 mg/kg; i.v.) injection of P30 at 1 h after cerebral ischemia (1 h tMCAO) significantly blocked the ischemia-induced brain damages and disruption of blood vessels. Systemic P30 delivery (1 mg/kg; i.v.) also significantly ameliorated the ischemic brain caused by photochemically induced thrombosis. Taken together, this study confers a precise demonstration about the novel protective activity of ProTα-derived small peptide P30 against the ischemic damages in vitro and in vivo. [ABSTRACT FROM AUTHOR]

Abstract: Background: Tumour-associated lymphocytes (TALs) present in effusions of ovarian cancer patients exhibit impaired activities, due to the immunosuppressive environment of the ascites. Means to enhance their cytotoxicity against autologous tumour cells are of clinical importance. The immunomodulator prothymosin alpha (proTα) increases the specific lysis of tumour cells by activated CD8+ T-lymphocytes and its immunoreactivity is exerted by the carboxy-terminal decapeptide, proTα(100-109). These two molecules were studied on TALs in vitro, and in SCID mice bearing human ovarian tumours. Methods: TALs and tumour cells were isolated from 41 ovarian cancer patients and co-cultured in the presence of proTα or proTα(100-109). The cytotoxicity of peptide-stimulated TALs was tested against autologous tumour cells and K562. Ex vivo peptide-stimulated TALs from three patients were adoptively transferred intraperitoneally in SCID mice, previously inoculated with each patient’s autologous tumour cells. Results: ProTα and its immunoreactive peptide proTα(100-109), enhanced the cytotoxic activity of TALs against autologous tumour cells in vitro, but marginally affected the lysis of K562. The effect of proTα and proTα(100-109) was higher after 7–14days of stimulation, whereas TAL cytotoxicity was significantly decreased after 21days. Mice administered TALs, ex vivo activated with proTα or proTα(100-109) for 7days, showed a relatively lower tumour increase rate and a prolongation of their survial, compared to controls. Conclusion: Our data demonstrate that, in the presence of tumour antigens, proTα and proTα(100-109) enhance the depressed cytotoxicity of TALs against autologous tumour cells in vitro and retard tumour growth in vivo. [Copyright &y& Elsevier]

Highlights: [•] Neuroprotective action of 9-amino acid peptide/P9 derived from prothymosin alpha. [•] P9-induced amelioration of ischemic damages in retina and brain. [•] Blockade of ischemia-induced cerebral blood vessels disruption by P9. [Copyright &y& Elsevier]

Abstract: Neutrophils are short-lived leukocytes and major components of the innate immune system. They are key players in the body''s defense against pathogens, but their contribution to tumor growth and metastasis is controversial. Nevertheless, improving the functions of neutrophils in cancer patients, particularly in those undergoing chemotherapy, is of clinical significance. In this study, we investigated the ability of the immunoreactive fragment of the polypeptide prothymosin alpha (proTα), i.e., the decapeptide proTα(100–109), to enhance the functions of neutrophils isolated from the peripheral blood of breast cancer patients in comparison with those from healthy donors. Activation of neutrophils from both groups with proTα(100–109) significantly increased phagocytosis and the production of intracellular reactive oxygen species (ROS) compared to controls. The release of extracellular ROS and oxidative burst of proTα(100–109)-stimulated neutrophils were less improved. Most importantly, upon activation with proTα(100–109), neutrophils from breast cancer patients showed significantly enhanced cytotoxicity against tumor cell targets. Using a scrambled peptide as a control, we showed that the proTα(100–109)-induced effects were sequence-specific and comparable to those exerted by the parental molecule proTα. The responsiveness of neutrophils to proTα(100–109) or intact proTα did not correlate with the tumor grade or other established tumor characteristics. Our results suggest that proTα(100–109) activates neutrophils, particularly those derived from breast cancer patients, and these effects could potentially be used to improve some functions of neutrophils in the clinical setting. [Copyright &y& Elsevier]

Little is known about the cellular mechanisms modulating the shift in balance from a state of survival to cell death by caspase-mediated apoptosis in response to a lethal stress. Here we show that the RNA-binding protein HuR has an important function in mediating this switch. During caspase-mediated apoptosis, HuR is cleaved to generate two cleavage products (CPs). Our data demonstrate that the cleavage of HuR switches its function from being a prosurvival factor under normal conditions to becoming a promoter of apoptosis in response to a lethal stress. In the absence of an apoptotic stimuli, HuR associates with and promotes the expression of caspase-9 and prothymosin α (ProT) mRNAs, and pro- and antiapoptotic factors, respectively, both of which have been characterized as important players in determining cell fate. During the early steps of caspase-mediated apoptosis, however, the level of caspase-9 protein increases, while ProT remains unchanged. Under these conditions, the two HuR-CPs selectively bind to and stabilize caspase-9 mRNA, but do not bind to ProT. Hence, taken together, our data show that by maintaining a threshold of expression of proapoptotic factors such as caspase-9 in response to a lethal stress, the HuR-CPs help a cell to switch from resisting death to undergoing apoptosis. [ABSTRACT FROM AUTHOR]