Type-2 diabetes (T2D) worsens stroke recovery, amplifying post-stroke disabilities. Currently, there are no therapies targeting this important clinical problem. Sodium-glucose cotransporter 2 inhibitors (SGLT2i) are potent anti-diabetic drugs that also efficiently reduce cardiovascular death and heart failure. In addition, SGLT2i facilitate several processes implicated in stroke recovery. However, the potential efficacy of SGLT2i to improve stroke recovery in T2D has not been investigated. Therefore, we determined whether a post-stroke intervention with the SGLT2i Empagliflozin could improve stroke recovery in T2D mice. T2D was induced in C57BL6J mice by 8 months of high-fat diet feeding. Hereafter, animals were subjected to transient middle cerebral artery occlusion and treated with vehicle or the SGLTi Empagliflozin (10 mg/kg/day) starting from 3 days after stroke. A similar study in non diabetic mice was also conducted. Stroke recovery was assessed using the forepaw grip strength test. To identify potential mechanisms involved in the Empagliflozin-mediated effects, several metabolic parameters were assessed. Additionally, neuronal survival, neuroinflammation, neurogenesis and cerebral vascularization were analyzed using immunohistochemistry/quantitative microscopy. Empagliflozin significantly improved stroke recovery in T2D but not in non-diabetic mice. Improvement of functional recovery was associated with lowered glycemia, increased serum levels of fibroblast growth factor-21 (FGF-21), and the normalization of T2D-induced aberration of parenchymal pericyte density. The global T2D-epidemic and the fact that T2D is a major risk factor for stroke are drastically increasing the number of people in need of efficacious therapies to improve stroke recovery. Our data provide a strong incentive for the potential use of SGLT2i for the treatment of post-stroke sequelae in T2D.

Background: Post-stroke functional recovery is severely impaired by type 2 diabetes (T2D). This is an important clinical problem since T2D is one of the most common diseases. Because weight loss-based strategies have been shown to decrease stroke risk in people with T2D, we aimed to investigate whether diet-induced weight loss can also improve post-stroke functional recovery and identify some of the underlying mechanisms. Methods: T2D/obesity was induced by 6 months of high-fat diet (HFD). Weight loss was achieved by a short- or long-term dietary change, replacing HFD with standard diet for 2 or 4 months, respectively. Stroke was induced by middle cerebral artery occlusion and post-stroke recovery was assessed by sensorimotor tests. Mechanisms involved in neurovascular damage in the post-stroke recovery phase, i.e. neuroinflammation, impaired angiogenesis and cellular atrophy of GABAergic parvalbumin (PV)+ interneurons were assessed by immunohistochemistry/quantitative microscopy. Results: Both short- and long-term dietary change led to similar weight loss. However, only the latter enhanced functional recovery after stroke. This effect was associated with pre-stroke normalization of fasting glucose and insulin resistance, and with the reduction of T2D-induced cellular atrophy of PV+ interneurons. Moreover, stroke recovery was associated with decreased T2D-induced neuroinflammation and reduced astrocyte reactivity in the contralateral striatum. Conclusion: The global diabetes epidemic will dramatically increase the number of people in need of post-stroke treatment and care. Our results suggest that diet-induced weight loss leading to pre-stroke normalization of glucose metabolism has great potential to reduce the sequelae of stroke in the diabetic population.

Aims/hypothesis: Type 2 diabetes is associated with worsened stroke outcome and lasting disability. The underlying mechanisms are undetermined, and no therapy is available. We experimentally investigated whether pharmacologically targeting obesity, which is highly prevalent in type 2 diabetes, before stroke enhances neurological recovery in type 2 diabetes. To induce weight loss, we employed the glucagon-like peptide 1 receptor (GLP-1R) agonist semaglutide and the neuropeptide Y receptor Y2 (NPY2R) agonist BI8271, which potentiates GLP-1R-mediated weight loss. We also investigated potential acute neuroprotective effects induced by these treatments, independently of metabolic regulation. Methods: C57BL/6J mice were fed with a high-fat diet for 5 months to induce obesity and features of type 2 diabetes (i.e. hyperglycaemia and insulin resistance). Weight loss was induced by 4-week administration of semaglutide and/or BI8271. As a control for the effect of weight loss, a vehicle (PBS)-treated group was switched to standard diet to achieve the same weight range and the same percentage weight loss within the same time frame as those receiving semaglutide/BI8271. Thereafter, mice were subjected to stroke by transient middle cerebral artery occlusion (tMCAO). Stroke recovery (the primary outcome) was assessed by measuring the recovery of grip strength and the lateralised sensorimotor integration. Brains and serum were collected, and stroke volume and serum IGF-1 levels were quantified (secondary outcomes). In additional studies, type 2 diabetic mice were subjected to tMCAO and injected with semaglutide and/or BI8271 1 and 24 h after reperfusion. Acute neuroprotection (the primary outcome) was assessed by a grip strength test and by quantifying stroke volume and the number of surviving neuronal nuclear marker (NeuN)-positive neurons. Results: We report that pre-stroke weight loss by GLP-1R activation, and more potently by dual co-activation of GLP-1 and NPY2 receptors, is a pharmacologically targetable mechanism, upstream of glycaemic regulation, through which post-stroke recovery is achieved. Moreover, we show that post-stroke recovery in type 2 diabetes is inversely associated with peripheral IGF-1 levels. Finally, GLP-1R and NPY2R activation can also improve stroke recovery through acute neuroprotection if they are given acutely after stroke, independently of their metabolic effects. Conclusions/interpretation: The diabetes and obesity epidemics are increasing the incidence of stroke, and consequently the need for treatments to improve stroke outcome. Our results indicate that clinically used type 2 diabetes treatments could be employed in a preventive role to improve stroke outcome by exerting dual pharmacological action: weight loss and acute neuroprotection. These findings could have novel therapeutic implications for many people. Graphical

Intestinal alkaline phosphatase 3 (AKP3) is an enzyme that was reported to play a role in lipid metabolism and to prevent high fat diet-induced metabolic syndrome in mice. To investigate a potential functional role of AKP3 in diet-induced adiposity and metabolic health, we have kept male and female wild-type or AKP3 deficient mice on a high fat diet for 15 weeks to induce obesity and compared those with mice kept on standard fat diet. Body weight as well as adipose tissue mass were statistically significantly higher upon high fat diet feeding for mice of both genders and genotypes. Female mice of either genotype kept on high fat diet gained less weight, resulting in smaller adipose tissue depots with smaller adipocytes. However, AKP3 deficiency had no significant effect on body weight gain or adipose tissue mass and did not affect adipocyte size or density. Gene expression analysis revealed no effect of the genotype on inflammatory parameters in adipose tissue, except for tumor necrosis factor alpha, which was higher in mesenteric adipose tissue of female obese mice. Plasma glucose and insulin levels were also not affected in obese AKP3 deficient mice. Overall, our data do not support a functional role of AKP3 in adipose tissue development, or insulin sensitivity.

Type 2 diabetes (T2D) impairs post-stroke recovery, and the underlying mechanisms are unknown. Insulin resistance (IR), a T2D hallmark that is also closely linked to aging, has been associated with impaired post-stroke recovery. However, whether IR worsens stroke recovery is unknown. We addressed this question in mouse models where early IR, with or without hyperglycemia, was induced by chronic high-fat diet feeding or sucrose supplementation in the drinking water, respectively. Furthermore, we used 10-month-old mice, spontaneously developing IR but not hyperglycemia, where IR was normalized pharmacologically pre-stroke with Rosiglitazone. Stroke was induced by transient middle cerebral artery occlusion and recovery was assessed by sensorimotor tests. Neuronal survival, neuroinflammation and the density of striatal cholinergic interneurons were also assessed by immunohistochemistry/quantitative microscopy. Pre-stroke induction and normalization of IR, respectively, worsened and improved post-stroke neurological recovery. Moreover, our data indicate a potential association of this impaired recovery with exacerbated neuroinflammation and a decreased density of striatal cholinergic interneurons. The global diabetes epidemic and population aging are dramatically increasing the percentage of people in need of post-stroke treatment/care. Our results suggest that future clinical studies should target pre-stroke IR to reduce stroke sequelae in both diabetics and elderly people with prediabetes.

Background/objectives: Being overweight increases the predisposition to obesity and type 2 diabetes (T2D), which significantly elevate stroke risk and the likelihood of severe post-stroke disability. Dietary nitrate (NO₃⁻) supplementation can mitigate obesity and metabolic impairments, making it a promising approach to halt overweight people from developing overt obesity/T2D, thereby potentially also improving stroke outcome. We determined whether NO3⁻ supplementation prevents overweight mice from progressing into obesity and T2D and whether this intervention improves stroke outcome. Methods: An overweight condition was induced via 6 weeks of a high-fat diet (HFD), after which animals were randomized to either a HFD or a HFD with NO₃⁻ supplementation. After 24 weeks, when HFD-mice without NO₃⁻ developed obesity and T2D, all animals were subjected to transient middle cerebral artery occlusion and stroke outcome was assessed via behavioral testing and infarct size. The effect of NO₃⁻ on post-stroke neuroinflammation, neurogenesis, and neovascularization was analyzed by immunohistochemistry. Results: Sustained NO₃⁻ supplementation in overweight mice did not prevent obesity or insulin resistance. However, it attenuated weight gain, prevented hyperglycemia, and significantly improved functional recovery after stroke, without affecting infarct size. Moreover, NO₃⁻ decreased post-stroke neuroinflammation by reducing microglial infiltration. NO₃⁻ did not affect stroke-induced neurogenesis or vascularization. Conclusion: These results highlight the potential of NO₃⁻ supplementation to prevent metabolic impairment in the overweight population and improve stroke prognosis in this large group of people at risk of stroke and severe stroke sequelae.