Pentraxin 3 mediates neurogenesis and angiogenesis after cerebral ischaemia.

BACKGROUND: The acute phase protein pentraxin 3 (PTX3) is a new biomarker of stroke severity and is a key regulator of oedema resolution and glial responses after cerebral ischaemia, emerging as a possible target for brain repair after stroke. Neurogenesis and angiogenesis are essential events in post-stroke recovery. Here, we investigated for the first time the role of PTX3 in neurogenesis and angiogenesis after stroke. METHODS: PTX3 knockout (KO) or wild-type (WT) mice were subjected to experimental cerebral ischaemia (induced by middle cerebral artery occlusion (MCAo)). Poststroke neurogenesis was assessed by nestin, doublecortin (DCX) and bromodeoxyuridine (BrdU) immunostaining, whereas angiogenesis was assessed by BrdU, vascular endothelial growth factor receptor 2 (VEGFR2) and PECAM-1 immunostaining. In vitro neurogenesis and angiogenesis assays were carried out on neurospheres derived from WT or interleukin-1ß (IL-1ß) KO mice, and mouse endothelial cell line bEnd.5 respectively. Behavioural function was assessed in WT and PTX3 KO mice using open-field, motor and Y-maze tests. RESULTS: Neurogenesis was significantly reduced in the dentate gyrus (DG) of the hippocampus of PTX3 KO mice, compared to WT mice, 6 days after MCAo. In addition, recombinant PTX3 was neurogenic in vitro when added to neurospheres, which was mediated by IL-1ß. In vivo poststroke angiogenesis was significantly reduced in PTX3 KO mice compared to WT mice 14 days after MCAo, as revealed by reduced vascular density, less newly formed blood vessels and decreased expression of VEGFR2. In vitro, recombinant PTX3 induced marked endothelial cellular proliferation and promoted formation of tube-like structures of endothelial cell line bEnd.5. Finally, a lack of PTX3 potentiated motor deficits 14 days after MCAo. CONCLUSIONS: These results indicate that PTX3 mediates neurogenesis and angiogenesis and contributes to functional recovery after stroke, highlighting a key role of PTX3 as a mediator of brain repair and suggesting that PTX3 could be used as a new target for stroke therapy.

What Training, Support, and Resourcing Do Health Professionals Need to Support People Using a Closed-Loop System? A Qualitative Interview Study with Health Professionals Involved in the Closed Loop from Onset in Type 1 Diabetes (CLOuD) Trial.

Background: We explored health professionals' views about the training, support, and resourcing needed to support people using closed-loop technology in routine clinical care to help inform the development of formal guidance. Methods: Interviews were conducted with health professionals (n = 22) delivering the Closed Loop from Onset in Type 1 Diabetes (CLOuD) trial after they had ≥6 months' experience of supporting participants using a closed-loop system. Data were analyzed descriptively. Results: Interviewees described how, compared with other insulin regimens, teaching and supporting individuals to use a closed-loop system could be initially more time-consuming. However, they also noted that after an initial adjustment period, users had less need for initiating contact with the clinical team compared with people using pumps or multiple daily injections. Interviewees highlighted how a lessened need for ad hoc clinical input could result in new challenges; specifically, they had fewer opportunities to reinforce users' diabetes knowledge and skills and detect potential psychosocial problems. They also observed heightened anxiety among some parents due to the constant availability of data and unrealistic expectations about the system's capabilities. Interviewees noted that all local diabetes teams should be empowered to deliver closed-loop system care, but stressed that health professionals supporting closed-loop users in routine care will need comprehensive technology training and standardized clinical guidance. Conclusion: These findings constitute an important starting point for the development of formal guidance to support the rollout of closed-loop technology. Our recommendations, if actioned, will help limit the potential additional burden of introducing closed-loop systems in routine clinical care and help inform appropriate user education and support.