© 2019 the Authors. Reviews in Aquaculture Published by John Wiley. &. Sons Australia, Ltd Antimicrobial resistance (AMR) is a growing threat to global public health, and the overuse of antibiotics in animals has been identified as a major risk factor. With high levels of international trade and direct connectivity to the aquatic environment, shrimp aquaculture may play a role in global AMR dissemination. The vast majority of shrimp production occurs in low- and middle-income countries, where antibiotic quality and usage is widely unregulated, and where the integration of aquaculture with family livelihoods offers many opportunities for human, animal and environmental bacteria to come into close contact. Furthermore, in shrimp growing areas, untreated waste is often directly eliminated into local water sources. These risks are very different to many other major internationally-traded aquaculture commodities, such as salmon, which is produced in higher income countries where there are greater levels of regulation and well-established management practices. Assessing the true scale of the risk of AMR dissemination in the shrimp industry is a considerable challenge, not least because obtaining reliable data on antibiotic usage is very difficult. Combating the risks associated with AMR dissemination is also challenging due to the increasing trend towards intensification and its associated disease burden, and because many farmers currently have no alternatives to antibiotics for preventing crop failure. In this review, we critically assess the potential risks the shrimp industry poses to AMR dissemination. We also discuss some of the possible risk mitigation strategies that could be considered by the shrimp industry as it strives for a more sustainable future in production.

One of the key strategic objectives of the World Health Organisation's global antimicrobial resistance (AMR) action plan is to improve public awareness and understanding of this issue. Very few AMR awareness campaigns have targeted the animal production sector, particularly in low- and middle-income countries (LMICs) where rural communities can be geographically difficult to access via traditional face-to-face community engagement methods. Aquaculture is a major food production industry in Bangladesh and across Asia, an area which poses a significant risk to global AMR dissemination. In this pilot study, we sought to investigate the potential for digital communication materials to rapidly and effectively communicate AMR messages to rural aquaculture farmers in Bangladesh. Working with stakeholders from the Bangladesh aquaculture industry, we developed a 4-minute digital animation designed specifically for this audience and assessed its capacity to engage and communicate AMR messages to farmers. We then conducted a small-scale social media campaign, to determine the potential for rapidly disseminating AMR awareness materials to a large audience across Bangladesh, where there is an extensive 4 G internet network and an ever-increasing proportion of the population (57% as of December 2019) have mobile internet access. Thirty-six farmers were surveyed: all of them liked this method of communication and 97% said it would change the way they use antibiotics in the future. Through the social media campaign, the animation received 9,100 views in the first 2 weeks alone. Although preliminary, these results demonstrate the huge potential for digital communication methods for the rapid and widespread communication of AMR awareness materials to rural aquaculture communities in Bangladesh and across Asia. Our results support the need for more research into the most appropriate and effective content of AMR awareness campaigns for aquaculture communities and question the need for explaining the science underlying AMR in such communication materials.

Nucleophosmin-anaplastic lymphoma kinase (NPM-ALK) is a tyrosine kinase oncogene responsible for the pathogenesis of the majority of human ALK-positive lymphomas. We recently reported that it activated the Rac1 GTPase in anaplastic large-cell lymphoma (ALCL), leading to Rac-dependent formation of active invadopodia required for invasiveness. Herein, we went further into the study of this pathway and used the inhibitor of Rac, NSC23766, to validate its potential as a molecular target in ALCL in vitro and in vivo in a xenograft model and in a conditional model of NPM-ALK transgenic mice. Our data demonstrate that Rac regulates important effectors of NPM-ALK-induced transformation such as Erk1/2, p38 and Akt. Moreover, inhibition of Rac signaling abrogates NPM-ALK-elicited disease progression and metastasis in mice, highlighting the potential of small GTPases and their regulators as additional therapic targets in lymphomas.

The chimera nucleophosmin-anaplastic lymphoma kinase (NPM-ALK), the tyrosine kinase activity of which is constitutively upregulated, is the causative agent of 75% of the anaplastic large-cell lymphomas (ALCLs). We have demonstrated that NPM-ALK induces the production of reactive oxygen species (ROS) by a pathway involving the arachidonic acid-metabolizing enzymes of the lipoxygenase (LOX) family. The use of the LOX inhibitor nordihydroguaiaretic acid (NDGA) and of the anti-oxidant N-acetylcysteine (NAC) demonstrated that ROS are important in maintaining the ALK kinase active. Consistent with this, NDGA treatment resulted in the inhibition of key pathways, such as Akt, signal transducer and activator of transcription factor 3 (STAT3) and extracellular signal-regulated kinase (ERK), which are involved in NPM-ALK antiapoptotic and pro-mitogenic functions. Conversely, the stress-activated kinase p38, described in some instances as a mediator of apoptosis, was activated. Interestingly, 5-LOX, an isoform involved in many cancers, was found to be activated in NPM-ALK(+) cells. Functional studies have shown that transforming properties, namely proliferation and resistance to apoptosis, were abrogated by treatment with either NDGA or the 5-LOX inhibitor (N-(3-phenoxycinnamyl)-acetohydroxamic acid) (BW A4C). Together, these data point to the ROS/LOX pathway as a potential new target for therapy in NPM-ALK-positive tumors.

BACKGROUND: Increasing evidence suggests that individual isoforms of protein kinase C (PKC) play distinct roles in regulating platelet activation. METHODOLOGY/PRINCIPAL FINDINGS: in this study, we focus on the role of two novel PKC isoforms, PKCdelta and PKCepsilon, in both mouse and human platelets. PKCdelta is robustly expressed in human platelets and undergoes transient tyrosine phosphorylation upon stimulation by thrombin or the collagen receptor, GPVI, which becomes sustained in the presence of the pan-PKC inhibitor, Ro 31-8220. In mouse platelets, however, PKCdelta undergoes sustained tyrosine phosphorylation upon activation. In contrast the related isoform, PKCepsilon, is expressed at high levels in mouse but not human platelets. There is a marked inhibition in aggregation and dense granule secretion to low concentrations of GPVI agonists in mouse platelets lacking PKCepsilon in contrast to a minor inhibition in response to G protein-coupled receptor agonists. This reduction is mediated by inhibition of tyrosine phosphorylation of the FcRgamma-chain and downstream proteins, an effect also observed in wild-type mouse platelets in the presence of a PKC inhibitor. CONCLUSIONS: These results demonstrate a reciprocal relationship in levels of the novel PKC isoforms delta and epsilon in human and mouse platelets and a selective role for PKCepsilon in signalling through GPVI.

Integrins are the major receptor type known to facilitate cell adhesion and lamellipodia formation on extracellular matrix proteins. However, collagen-related peptide and thrombin have recently been shown to mediate platelet lamellipodia formation when presented as immobilized surfaces. The aims of this study were to establish if there exists a role for the platelet integrin alpha(IIb)beta(3) in this response; and if so, whether signalling from the integrin is required for lamellipodia formation on these surfaces. Real-time analysis was used to compare platelet morphological changes on surfaces of fibrinogen, collagen-related peptide or thrombin in the presence of various pharmacological inhibitors and platelets from 'knockout' mice. We demonstrate that collagen-related peptide and thrombin stimulate distinct patterns of platelet lamellipodia formation and elevation of intracellular Ca(2+) to that induced by the integrin alpha(IIb)beta(3) ligand, fibrinogen. Nevertheless, lamellipodia formation on collagen-related peptide and thrombin is dependent upon engagement of alpha(IIb)beta(3), consistent with release of alpha(IIb)beta(3) ligand(s) from platelet granules. However, the requirement for signalling by the integrin on fibrinogen can be bypassed by the addition of thrombin to the solution. These observations reveal a critical role for alpha(IIb)beta(3) in forming lamellipodia on collagen-related peptide and thrombin which is dependent on its ability to function as an adhesive receptor but not necessarily on its ability to signal. These results suggest that integrins may play an important role in lamellipodia formation triggered by nonintegrin ligands in platelets and possibly in other cell types.