Empagliflozin alleviates neuronal apoptosis induced by cerebral ischemia/reperfusion injury through HIF-1α/VEGF signaling pathway

Empagliflozin promotes skin flap survival by activating AMPK signaling pathway

Flaps are widely used in surgical wound repair, yet distal necrosis poses a significant postoperative challenge, stemming from potential factors such as inadequate blood perfusion, inflammation, ischemia/reperfusion (I/R) injury, mitochondrial impairment, and subsequent ferroptosis. Empagliflozin (EMPA), a sodium-glucose cotransporter 2 inhibitor, has pharmacological activities that promote angiogenesis, mitophagy, and inhibit inflammation, I/R injury, and ferroptosis. However, it is unclear whether EMPA can enhance flap survival. Here, we established a modified McFarlane flap model and applied EMPA to demonstrate its mechanism of action. 24 rats were evenly divided into four groups: the control, low-dose EMPA (10 mg/kg), high-dose EMPA (30 mg/kg), and inhibitor groups. Molecular biology experiments demonstrated that EMPA promoted the expression of angiogenesis-related factors vascular endothelial growth factor (VEGF) and CD34. Additionally, it also increased superoxide dismutase (SOD) activity and reduced malondialdehyde (MDA) levels, thus suppressing oxidative stress. EMPA further alleviated inflammation by downregulating the expression of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6). In vitro experiments showed that EMPA promoted the proliferation of human umbilical vein endothelial cells (HUVECs) and reduce their reactive oxygen species (ROS) production. Further investigation demonstrated that EMPA improves flap prognosis by inducing the expression of the adenosine monophosphate-activated protein kinase (AMPK) signaling pathway, further promoting mitophagy and inhibiting ferroptosis. These effects collectively contributed to the survival of the skin flap. Overall, our research elucidates the protective effects of EMPA on flap survival and its specific mechanisms, offering new insights into solving post-transplant flap necrosis.

Electroacupuncture alleviates cerebral ischemia injury by regulating PI3K/AKT/NF-κB signaling in microglia of ischemic stroke rats

This study aimed to investigate the potential of electroacupuncture as an intervention for inducing 'Awakening and Opening of the Brain' in rats with stroke models induced by middle cerebral artery occlusion/reperfusion (MCAO/R). The efficacy of electroacupuncture in alleviating cerebral ischemic injury was evaluated using Longa scores, triphenyl tetrazolium chloride staining, and hematoxylin and eosin staining. Non-targeted metabolomics analysis was conducted to identify differential metabolite changes before and after electroacupuncture treatment in MCAO/R rats. Network pharmacology analysis was then performed to correlate these differential metabolites with ischemic stroke. The PI3K/AKT/NF-κB signaling pathway was identified as a key target. In vivo experiments further validated the mechanism by which electroacupuncture promotes M2 microglial polarization through inhibition of the PI3K/AKT/NF-κB signaling in MCAO/R rats. This study demonstrated that electroacupuncture reduces brain damage and inhibits inflammation in MCAO/R rats by modulating the PI3K/AKT/NF-κB signaling pathway and promoting the polarization of microglia from M1 to M2.

Empagliflozin Mitigates PTZ-Induced Seizures in Rats: Modulating Npas4 and CREB-BDNF Signaling Pathway

Empagliflozin (EMPA) is one of the sodium/glucose cotransporter 2 (SGLT2) inhibitors that has been recently approved for the treatment of diabetes mellitus type II. Recently, EMPA has shown protective effects in different neurological disorders, besides its antidiabetic activity. Kindling is a relevant model to study epilepsy and neuroplasticity. This study aimed to investigate the potential protective effects of EMPA (1 and 3 mg/kg orally) against convulsant effects induced by pentylenetetrazole (PTZ) using a modified window- (win-) PTZ kindling protocol. The biochemical dysfunction and hippocampal damage induced by PTZ were profoundly reversed by EMPA treatment in a dose-dependent manner, as evidenced by the significant increase in reduced glutathione (GSH) and decrease in malondialdehyde (MDA) hippocampal contents. Furthermore, EMPA counteracted PTZ-induced neuronal damage in the hippocampal region, as confirmed by histopathological examination of the hippocampal tissues. EMPA impaired astrocytosis and showed an antiapoptotic effect through a significant reduction of glial fibrillary acidic protein (GFAP) and BCL2-Associated X Protein (BAX) expressions, respectively. Interestingly, EMPA exhibited an antiepileptic effect against PTZ-induced seizures through significantly reducing neuronal PAS domain Protein 4 (Npas4), cyclic adenosine monophosphate (cAMP) response element binding protein (CREB) hippocampal expressions, and enhancing the brain-derived neurotrophic factor (BDNF)-tropomyosin receptor kinase B (TrkB) pathway, which are found to be involved in epileptogenesis, eventually leading to significant improvement of behavioral impairments induced by PTZ. Hence, these results showed further prospective insights for EMPA as a neuroprotective agent.

SGLT-2 Inhibitors' and GLP-1 Receptor Agonists' Influence on Neuronal and Glial Damage in Experimental Stroke

Background: SGLT-2 inhibitors (SGLT-2i) and GLP-1 receptor agonists (GLP-1RA) have demonstrated nephro- and cardioprotective effects, but their neuroprotective properties, especially concerning stroke severity, and mechanisms are not unambiguous. We aimed to study the influence of SGLT-2i with different selectivity and GLP-1RA on brain damage volume and neurological status in non-diabetic and diabetic rats and to investigate the underlying mechanisms. Methods: Non-diabetic Wistar rats were divided into five groups (n = 10 each) and received empagliflozin, canagliflozin, or dulaglutide as study drugs and metformin as comparison drug. Control animals were administered 0.9% NaCl for 7 days before stroke. At 48 h after stroke, we assessed neurological deficit, neuronal and astroglial damage markers, and brain damage volume. We also modeled type 2 DM in Wistar rats using the high-fat diet+nicotinamide/streptozotocin method and established similar treatment groups. After 8 weeks, rats were subjected to stroke with further neurological deficit, neuroglial damage markers, and brain necrosis volume measurement. Results: In non-diabetic rats, all the drugs showed an infarct-limiting effect; SGLT-2i and dulaglutide were more effective than metformin. DULA improved neurological status compared with MET and SGLT-2i treatment. All the drugs decreased neurofilament light chains (NLCs) level and neuronal damage markers, but none of them decreased the glial damage marker S100BB. In DM, similarly, all the drugs had infarct-limiting effects. Neurological deficit was most pronounced in the untreated diabetic rats and was reduced by all study drugs. All the drugs reduced NLC level; dulaglutide and empagliflozin, but not canagliflozin, also decreased S100BB. None of the drugs affected neuron-specific enolase. Conclusions: SGLT-2i and GLP-1RA are neuroprotective in experimental stroke. GLP-1RA might be more effective than SGLT-2i as in non-diabetic conditions it influences both brain damage volume and neurological status. All study drugs decrease neuronal damage, while GLP-1RA and highly selective SGLT-2i EMPA, but not low-selective CANA, also have an impact on neuroglia in diabetic conditions.

Neuroprotective effect of empagliflozin against doxorubicin-induced chemobrain in rats: Interplay between SIRT-1/MuRF-1/PARP-1/NLRP3 signaling pathways and enhanced expression of miRNA-34a and LncRNA HOTAIR

Chemobrain, a challenging side effect of doxorubicin (DOX)-based chemotherapy, impairs cognitive abilities in cancer survivors. DOX triggers chemobrain via oxidative stress, leading to inflammation and apoptosis. Empagliflozin (EMPA), a sodium glucose co-transporter-2 inhibitor, demonstrated neuroprotective effects by reducing reactive oxygen species (ROS) and inflammation, but its protective mechanisms against DOX-induced chemobrain is not fully known. Thus, this study aimed to investigate EMPA's neuroprotective effects on DOX-induced chemobrain in rats and to uncover the underlying protective mechanisms. Fifty male Wistar rats were divided into control, EMPA, DOX (2 mg/kg, IP, once/week for 4 weeks), and two treated groups (DOX+ EMPA 5 and 10 mg/kg/day, PO, for 4 weeks). Behavioral tests showed improved memory, motor performance, and reduced anxiety in EMPA-treated groups compared to DOX, with superior results at the higher dose. Histopathological analysis revealed increased intact neurons in the cortex and hippocampus in EMPA-treated groups, with 346.4 % increase in CA3 (p < 0.0001), 19.1 % in dentate gyrus (p = 0.0006), and 362.6 % in cortex (p < 0.0001) in the high-dose EMPA group. Biochemical investigations of the high-dose EMPA group revealed significant decreases in inflammatory and apoptotic markers (JNK/PARP-1/NLRP3/MuRF-1/FOXO-1), increased SIRT-1 protein expression by 389.9 % (p < 0.0001), and reduced miRNA-34a and LncRNA HOTAIR gene expression (50.4 % and 53.4 % respectively, p < 0.0001) relative to DOX group. Conclusively, EMPA demonstrated superior behavioral and histopathological outcomes particularly at higher dose, positioning it as a promising neuroprotective candidate against DOX-induced chemobrain, possibly through modulating SIRT-1, NF-κb, NLRP3, and oxidative stress pathways.

Empagliflozin-activated AMPK elicits neuroprotective properties in reserpine-induced depression via regulating dynamics of hippocampal autophagy/inflammation and PKCζ-mediated neurogenesis

RATIONALE

Major depression has been an area of extensive research during the last decades, for it represents a leading cause of disability and suicide. The stark rise of depression rates influenced by life stressors, economic threats, pandemic era, and resistance to classical treatments, has made the disorder rather challenging. Adult hippocampal neurogenesis and plasticity are particularly sensitive to the dynamic interplay between autophagy and inflammation. In fact, the intricate balance between the two processes contributes to neuronal homeostasis and survival.

OBJECTIVES

Having demonstrated promising potentials in AMPK activation, a major metabolic sensor and autophagy regulator, empagliflozin (Empa) was investigated for possible antidepressant properties in the reserpine rat model of depression.

RESULTS

While the reserpine protocol elicited behavioral, biochemical, and histopathological changes relevant to depression, Empa outstandingly hindered these pathological perturbations. Importantly, hippocampal autophagic response markedly declined with reserpine which disrupted the AMPK/mTOR/Beclin1/LC3B machinery and, conversely, neuro-inflammation prevailed under the influence of the NLRP3 inflammasome together with oxidative/nitrative stress. Consequently, AMPK-mediated neurotrophins secretion obviously deteriorated through PKCζ/NF-κB/BDNF/CREB signal restriction. Empa restored hippocampal monoamines and autophagy/inflammation balance, driven by AMPK activation. By promoting the atypical PKCζ phosphorylation (Thr403) which subsequently phosphorylates NF-κB at Ser311, AMPK successfully reinforced BDNF/CREB signal and hippocampal neuroplasticity. The latter finding was supported by hippocampal CA3 toluidine blue staining to reveal intact neurons.

CONCLUSION

The current study highlights an interesting role for Empa as a regulator of autophagic and inflammatory responses in the pathology of depression. The study also pinpoints an unusual contribution for NF-κB in neurotrophins secretion via AMPK/PKCζ/NF-κB/BDNF/CREB signal transduction. Accordingly, Empa can have special benefits in diabetic patients with depressive symptoms.

LIMITATIONS

The influence of p-NF-κB (Ser311) on NLRP3 inflammasome assembly and activation has not been investigated, which can represent an interesting point for further research.

The SGLT2 inhibitor empagliflozin exerts neuroprotective effect against hydrogen peroxide-induced toxicity on primary neurons

Oxidative stress has been implicated in several chronic pathological conditions, leading to cell death and injury. Alzheimer's disease (AD) and type 2 diabetes mellitus (T2DM) have several overlapping mechanisms as they are both characterized by increased oxidative stress, inflammation, insulin resistance, and autophagy dysfunction. The objective of this study was to elucidate the possible neuroprotective effect of empagliflozin, a sodium-glucose co-transporter 2 inhibitor (SGLT2i), against hydrogen peroxide-induced neurotoxicity in primary hippocampal neurons derived from wild-type (WT) and transgenic AD rats (TgF344-AD). An in vitro oxidative stress model was established using hydrogen peroxide to induce damage to neurons. Empagliflozin pretreatment was tested on this model initially through a cell viability assay. Flow cytometry and cell sorting were employed to discriminate the apoptotic and necrotic neuronal cell populations. Finally, the morphological and morphometric features of the neurons, including dendritic length and spine density, were evaluated using the SNT ImageJ plug-in following immunostaining with GFP. Sholl analysis was used to evaluate the impact of empagliflozin and hydrogen peroxide on dendritic arborization. Empagliflozin tended to ameliorate hydrogen peroxide-induced toxicity in primary neurons derived from WT rats and led to the preservation of dendritic spine density in both WT and TgF344-AD neurons (one-way ANOVA, p < 0.05). A modest improvement in dendrites' length was also observed. Empagliflozin pretreatment can partially mitigate dendritic and spine alterations induced by hydrogen peroxide in primary neurons. These results underscore the impact of empagliflozin on neuronal morphology and highlight its potential as a candidate for the treatment and/or prevention of AD.

Sodium-Glucose Cotransporter-2 Inhibitors, Dulaglutide, and Risk for Dementia : A Population-Based Cohort Study

BACKGROUND

Both sodium-glucose cotransporter-2 (SGLT2) inhibitors and glucagon-like peptide-1 receptor agonists (GLP-1 RAs) may have neuroprotective effects in patients with type 2 diabetes (T2D). However, their comparative effectiveness in preventing dementia remains uncertain.

OBJECTIVE

To compare the risk for dementia between SGLT2 inhibitors and dulaglutide (a GLP-1 RA).

DESIGN

Target trial emulation study.

SETTING

Nationwide health care data of South Korea obtained from the National Health Insurance Service between 2010 and 2022.

PATIENTS

Patients aged 60 years or older who have T2D and are initiating treatment with SGLT2 inhibitors or dulaglutide.

MEASUREMENTS

The primary outcome was the presumed clinical onset of dementia. The date of onset was defined as the year before the date of dementia diagnosis, assuming that the time between the onset of dementia and diagnosis was 1 year. The 5-year risk ratios and risk differences comparing SGLT2 inhibitors with dulaglutide were estimated in a 1:2 propensity score-matched cohort adjusted for confounders.

RESULTS

Overall, 12 489 patients initiating SGLT2 inhibitor treatment (51.9% dapagliflozin and 48.1% empagliflozin) and 1075 patients initiating dulaglutide treatment were included. In the matched cohort, over a median follow-up of 4.4 years, the primary outcome event occurred in 69 participants in the SGLT2 inhibitor group and 43 in the dulaglutide group. The estimated risk difference was -0.91 percentage point (95% CI, -2.45 to 0.63 percentage point), and the estimated risk ratio was 0.81 (CI, 0.56 to 1.16).

LIMITATION

Residual confounding is possible; there was no adjustment for hemoglobin A1c levels or duration of diabetes; the study is not representative of newer drugs, including more effective GLP-1 RAs; and the onset of dementia was not measured directly.

CONCLUSION

Under conventional statistical criteria, a risk for dementia between 2.5 percentage points lower and 0.6 percentage point greater for SGLT2 inhibitors than for dulaglutide was estimated to be highly compatible with the data from this study. However, whether these findings generalize to newer GLP-1 RAs is uncertain. Thus, further studies incorporating newer drugs within these drug classes and better addressing residual confounding are required.

PRIMARY FUNDING SOURCE

Ministry of Food and Drug Safety of South Korea.

The Interplay between MiR-134/BDNF and LKB1/AMPK/SIRT1 Accentuates the Antidepressant Efficacy of Empagliflozin in Ovariectomized Rats

Major depressive disorder (MDD) is considered a major cause of suicide worldwide. As previous studies revealed that neuroinflammation is a significant factor in the etiology of MDD, this study proposed to unravel the possible antidepressant effect of Empagliflozin (EMPA) through targeting miRNA-134 (miR-134)/brain-derived neurotrophic factor (BDNF) and liver kinase B1 (LKB1)/adenosine 5'-monophosphate-activated protein kinase (AMPK)/silent information regulator 1 (SIRT1) axes in ovariectomized (OVX) female rats. Rats were assigned randomly to four groups: Sham operation (SO), OVX, OVX + EMPA (10 mg/kg/day, p.o.), and OVX + EMPA + Dorsomorphin (DORSO) (25 μg/day/rat, i.v.). Drugs were administered for 28 days after 2 weeks of surgery. EMPA debilitated OVX-induced depressive-like behavior by mitigating the immobility time in the tail suspension test and forced swimming test. Moreover, EMPA curtailed OVX-induced alterations of serum estradiol, hippocampal serotonin, miR-134 expression, as well as BDNF. EMPA also dwindled OVX-induced changes of hippocampal p-LKB1/LKB1, p-AMPK/AMPK, SIRT1, and inflammatory markers (nuclear factor-kappa-B, interleukin-1 beta, interleukin-6, and tumor necrosis factor alpha). Additionally, the EMPA-treated group exhibited marked improvement in different brain regions' histopathology. However, DORSO coadministration reversed most of EMPA's beneficial effects. The current study displayed the modulatory role of EMPA on miR-134/BDNF and LKB1/AMPK/SIRT1 axes, thus offering a partial explanation of its antidepressant efficacy and proposing EMPA as a novel therapeutic avenue for MDD.

[Highly selective sodium-glucose co-transporter type 2 inhibitor empagliflozin as means of brain protection in conditions of chronic brain dyscirculation]

BACKGROUND

Chronic brain dyscirculation is one of the frequent type 2 diabetes mellitus (DM) complications and leads to patients' disability. Sodium-glucose co-transporter type 2 inhibitors (SGLT-2i) have been proven to have advantages for cardiovascular system, but their effect on the central nervous system (CNS) has not been studied enough.

AIM

To study empagliflozin effect on CNS damage functional and laboratory parameters in patients with type 2 DM and, under experimental conditions, to investigate the mechanisms of the drug neurotropic effect.

MATERIALS AND METHODS

The clinical part of the study included patients with type 2 DM on metformin monotherapy (n=39). Patients with a target glycated hemoglobin level formed the "MET" group (n=19), in patients with a non-target glycated hemoglobin level empagliflozin was co-administered for the following 6 months (the "MET+EMPA" group, n=20). Healthy volunteers comprised the control group (n=16). The cognitive status and neuron-specific enolase (NSE) and neurofilament light chains (NLC) concentration were studied. DM was modeled in rats, thereafter the rats were treated with empagliflozin for 8 weeks. Microglia activation was assessed using anti-Iba-1 antibodies and morphological changes in neurons when stained by the Nissl method.

RESULTS

Both in the "MET+EMPA" and the "MET" groups cognitive deficits were observed, according to the Montreal Cognitive Assessment (MOCA) (24.0 (23.0; 27.0) and 25.0 (21.0; 27.0) points) and the Mini-Mental State Examination (MMSE) (23.75 (23.0; 27.0) and 25.0 (21.0; 27.0) points). Empagliflozin therapy led to the cognitive status normalization after 6 months (26.5 (24.0; 27.0) points according to the MOCA scale and 27.5 (24.0; 28.0) points according to the MMSE). Initially, all patients had a significant increase of NSE (3.60 (2.66; 3.76) ng/ml in the "MET" group, 3.22 (2.94; 3.54) ng/ml in the "MET+EMPA» group, 2.72 (2.13; 2.72) ng/ml in the «Control» group) and NLC (4.50 (3.31; 5.56) ng/ml in the «MET» group, 5, 25 (3.75; 6.25) ng/ml in the «MET+EMPA» group comparing with 3.50 (2.25; 3.50) ng/ml in the «Control» group). Empagliflozin therapy led to a significant decrease in NLC already after 3 months (3.80 (3.25; 3.87) ng/ml), without significant influence on the NSE level. In the experiment, DM was characterized by an increased number of activated microgliocytes and destructured neurons and a decreased number of neurons with a normal structure. Empagliflozin therapy was accompanied by a decrease in the number of immunopositive microgliocytes in the CA1 zone of the hippocampus and an increase in the number of structured neurons.

CONCLUSION

Type 2 diabetes mellitus is characterized by functional and biochemical changes in the central nervous system even under satisfactory glycemic control. Therapy with empagliflozin has a neuroprotective effect, manifested in an improvement in cognitive status and a decrease in NLC level. Empagliflozin reduces neuronal damage and abnormal microglial activation.

Neural and Glial Regulation of Angiogenesis in CNS in Ischemic Stroke

CNS diseases associated with compromised blood supply and/or vascular integrity are one of the leading causes of mortality and disability in adults worldwide and are also among 10 most common causes of death in children. Angiogenesis is an essential element of regeneration processes upon nervous tissue damage and can play a crucial role in neuroprotection. Here we review the features of cerebral vascular regeneration after ischemic stroke, including the complex interactions between endothelial cells and other brain cell types (neural stem cells, astrocytes, microglia, and oligodendrocytes). The mechanisms of reciprocal influence of angiogenesis and neurogenesis, the role of astrocytes in the formation of the blood-brain barrier, and roles of microglia and oligodendrocytes in vascular regeneration are discussed. Understanding the mechanisms of angiogenesis regulation in CNS is of critical importance for the development of new treatments of neurovascular pathologies.

Empagliflozin alleviates neuroinflammation by inhibiting astrocyte activation in the brain and regulating gut microbiota of high-fat diet mice

A high-fat diet can modify the composition of gut microbiota, resulting in dysbiosis. Changes in gut microbiota composition can lead to increased permeability of the gut barrier, allowing bacterial products like lipopolysaccharides (LPS) to enter circulation. This process can initiate systemic inflammation and contribute to neuroinflammation. Empagliflozin (EF), an SGLT2 inhibitor-type hypoglycemic drug, has been reported to treat neuroinflammation. However, there is a lack of evidence showing that EF regulates the gut microbiota axis to control neuroinflammation in HFD models. In this study, we explored whether EF could improve neuroinflammation caused by an HFD via regulation of the gut microbiota and the mechanism underlying this phenomenon. Our data revealed that EF alleviates pathological brain injury, reduces the reactive proliferation of astrocytes, and increases the expression of synaptophysin. In addition, the levels of inflammatory factors in hippocampal tissue were significantly decreased after EF intervention. Subsequently, the results of 16S rRNA gene sequencing showed that EF could change the microbial community structure of mice, indicating that the abundance of Lactococcus, Ligilactobacillus and other microbial populations decreased dramatically. Therefore, EF alleviates neuroinflammation by inhibiting gut microbiota-mediated astrocyte activation in the brains of high-fat diet-fed mice. Our study focused on the gut-brain axis, and broader research on neuroinflammation can provide a more holistic understanding of the mechanisms driving neurodegenerative diseases and inform the development of effective strategies to mitigate their impact on brain health. The results provide strong evidence supporting the larger clinical application of EF.

Ferulic Acid Methyl Ester Attenuates Cerebral Ischemia-Reperfusion Injury in Rats by Modulating PI3K/HIF-1α/VEGF Signaling Pathway

Background

Cerebral ischaemia-reperfusion injury (CIRI) could worsen the inflammatory response and oxidative stress in brain tissue. According to previous studies, ferulic acid methyl ester (FAME), as the extract with the strongest comprehensive activity in the traditional Chinese medicine Huang Hua oil dot herb, has significant anti-oxidative stress and neuroprotective functions, and can effectively alleviate CIRI, but its mechanism of action is still unclear.

Methods

Firstly, the pharmacological effects of FAME were investigated by in vitro oxidative stress and inflammatory experiments. Secondly, evaluate the therapeutic effects of FAME in the treatment of CIRI by brain histopathological staining and cerebral infarct area by replicating the in vivo MACO model. Thirdly, RNA-Seq and network pharmacology were utilized to predict the possible targets and mechanisms of FAME for CIRI at the molecular level. Finally, the expression of key target proteins, as well as the key regulatory relationships were verified by molecular docking visualization, Western Blotting and immunohistochemistry.

Results

The results of in vitro experiments concluded that FAME could significantly reduce the content of TNF-α, IL-1β and ROS, inhibiting COX-2 and iNOS protein expression in cells(p<0.01). FAME was demonstrated to have anti-oxidative stress and anti-inflammatory effects. The results of in vivo experiments showed that after the administration of FAME, the area of cerebral infarction in rats with CIRI was reduced, the content of Bcl-2 and VEGF was increased(p<0.05). Network pharmacology and RNA-Seq showed that the alleviation of CIRI by FAME may be through PI3K-AKT and HIF-1 signaling pathway. Enhanced expression of HIF-1α, VEGF, p-PI3K, p-AKT proteins in the brain tissues of rats in the FAME group was verified by molecular docking and Western Blotting.

Conclusion

FAME possesses significant anti-inflammatory and anti-oxidative stress activities and alleviates CIRI through the PI3K/HIF-1α/VEGF signaling pathway.

Neuroprotective Effects of Sodium-Glucose Cotransporter-2 (SGLT2) Inhibitors (Gliflozins) on Diabetes-Induced Neurodegeneration and Neurotoxicity: A Graphical Review

Diabetes is a chronic endocrine disorder that negatively affects various body systems, including the nervous system. Diabetes can cause or exacerbate various neurological disorders, and diabetes-induced neurodegeneration can involve several mechanisms such as mitochondrial dysfunction, activation of oxidative stress, neuronal inflammation, and cell death. In recent years, the management of diabetes-induced neurodegeneration has relied on several types of drugs, including sodium-glucose cotransporter-2 (SGLT2) inhibitors, also called gliflozins. In addition to exerting powerful effects in reducing blood glucose, gliflozins have strong anti-neuro-inflammatory characteristics that function by inhibiting oxidative stress and cell death in the nervous system in diabetic subjects. This review presents the molecular pathways involved in diabetes-induced neurodegeneration and evaluates the clinical and laboratory studies investigating the neuroprotective effects of gliflozins against diabetes-induced neurodegeneration, with discussion about the contributing roles of diverse molecular pathways, such as mitochondrial dysfunction, oxidative stress, neuro-inflammation, and cell death. Several databases-including Web of Science, Scopus, PubMed, Google Scholar, and various publishers, such as Springer, Wiley, and Elsevier-were searched for keywords regarding the neuroprotective effects of gliflozins against diabetes-triggered neurodegenerative events. Additionally, anti-neuro-inflammatory, anti-oxidative stress, and anti-cell death keywords were applied to evaluate potential neuronal protection mechanisms of gliflozins in diabetes subjects. The search period considered valid peer-reviewed studies published from January 2000 to July 2023. The current body of literature suggests that gliflozins can exert neuroprotective effects against diabetes-induced neurodegenerative events and neuronal dysfunction, and these effects are mediated via activation of mitochondrial function and prevention of cell death processes, oxidative stress, and inflammation in neurons affected by diabetes. Gliflozins can confer neuroprotective properties in diabetes-triggered neurodegeneration, and these effects are mediated by inhibiting oxidative stress, inflammation, and cell death.

Exploring the neuropharmacological potential of empagliflozin on nootropic and scopolamine-induced amnesic model of Alzheimer's like conditions in rats

BACKGROUND

Alzheimer's disease (AD) is one of the most challenging and prevalent neurodegenerative disorder globally with a rising prevalence, characterized by progressive cognitive decline, memory loss, and behavioural changes. Current research aims to determine the nootropic and anti-amnesic effect of Empagliflozin (EMPA) against scopolamine-induced amnesia in rats, by modulating the cholinergic and N-Methyl D-Aspartate (NMDA) receptors.

METHODS

Rats were treated once daily with an EMPA (5 and 10 mg/kg) and donepezil (2.5 mg/kg) for successive 26 days. During the final 13 days of treatment, a daily injection of scopolamine (1 mg/kg) was administered to induce cognitive deficits.

RESULTS

EMPA was found to be significantly reduce escape latency, increase time spent in the target quadrant, and enhanced the number of target zone crossings in the Morris water maze (MWM) test, indicating improved spatial memory. Moreover, EMPA increased the recognition index and the number of spontaneous alternations in the novel object recognition (NOR) and Y-maze tests, respectively, suggesting enhanced memory.

DISCUSSION

Interestingly doses of EMPA (5 mg/kg, 10 mg/kg) exhibited memory-enhancing effects even in the absence of scopolamine-induced impairment. Biochemical analysis revealed that EMPA elevated the levels of glutathione (GSH), a potent antioxidant, while decreasing lipid peroxidation (LPO) activity and increasing catalase (CAT) levels, indicating its antioxidative properties. Interestingly molecular docking studies revealed that EMPA fit perfectly in the active sites of M1 muscarinic acetylcholine (mACh) and NMDA receptors. These results indicated that the nootropic and antiamnesic effect of EMPA is possibly mediated via M1 and NMDA receptors and might be a remedy for AD.

The SGLT2 inhibitor Empagliflozin promotes post-stroke functional recovery in diabetic mice

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.

Efficacy of empagliflozin as adjunctive therapy to citalopram in major depressive disorder: a randomized double-blind, placebo-controlled clinical trial

BACKGROUND

Major depressive disorder is one of the most common psychiatric disorders, which is associated with a high disease burden. Current treatments using antidepressants have limitations, so using medication with neuromodulating and anti-inflammatory properties alongside them could be helpful. In a clinical trial, we studied the effectiveness of empagliflozin, a blood sugar-lowering drug, as an adjunctive therapy to reduce the severity of depression symptoms.

METHODS

A number of outpatients with moderate to severe depression (Hamilton Depression Rating Scale (HDRS) > = 17) who were not under related medication or had not taken medication for at least the last two months, had an age range of 18-60 years and had written informed consent to enter the study (N = 90) were randomly divided into two groups receiving placebo or empagliflozin (10 mg daily) combined with citalopram (40 mg daily) based on permuted block randomization method in an 8-week randomized, double-blind, placebo-controlled clinical trial. They were evaluated using the HDRS in weeks 0, 4, and 8.

RESULTS

HDRS scores were equal to 28.42(± 3.83), 20.20(± 3.82), and 13.42(± 3.42) in the placebo group during weeks 0,4, and 8, respectively. These scores were 27.36(± 3.77), 13.76(± 1.40), and 7.00(± 1.13), respectively, for the group treated with empagliflozin. Compared to the control group, patients treated with empagliflozin using repeated-measures ANOVA showed greater improvement in reducing the severity of depression symptoms over time (p value = 0.0001).

CONCLUSIONS

Considering the promising findings in this clinical trial, further study of empagliflozin as adjunctive therapy in MDD with larger sample sizes and longer follow-ups is recommended.

Sanpian decoction ameliorates cerebral ischemia-reperfusion injury by regulating SIRT1/ERK/HIF-1α pathway through in silico analysis and experimental validation

ETHNOPHARMACOLOGICAL RELEVANCE

Cerebral ischemia-reperfusion injury (CIRI) is a complex pathophysiological process involving multiple factors, and becomes the footstone of rehabilitation after ischemic stroke. Sanpian decoction (SPD) has exhibited protective effects against CIRI, migraine, and other cerebral vascular diseases. However, the underlying mechanisms have not been completely elucidated.

AIM OF THE STUDY

This study sought to explore the potential mechanisms underlying the effect of SPD against CIRI.

MATERIALS AND METHODS

High-performance liquid chromatography (HPLC) and ultra-high-performance liquid chromatography (UPLC) were carried out to determine the chemical constituents of SPD. A network pharmacology approach combined with experimental verification was conducted to elucidate SPD's multi-component, multi-target, and multi-pathway mechanisms in CIRI occurrence. The pharmacodynamics of the decoction was evaluated by establishing the rat model of middle cerebral artery occlusion/reperfusion (MCAO/R). In vivo and in vitro experiments were carried out, and the therapeutic effects of SPD were performed using 2,3,5-triphenyltetrazolium chloride (TTC) staining, hematoxylin-eosin (HE) staining, and Nissl staining. We used terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining and flow cytometry to evaluate cortex apoptosis. The quantification of mRNA and corresponding proteins were performed using real-time quantitative reverse transcription polymerase chain reaction (RT-qPCR) and Western blot respectively.

RESULTS

Our research showed that pretreatment with SPD improved neurological function and inhibited CIRI. Network pharmacology revealed that the hypoxia-inducible factor-1 (HIF-1) signaling pathway and mitogen-activated protein kinase (MAPK) signaling pathway-mediated apoptosis may be associated with CIRI. In vivo and in vitro experiments, we confirmed that SPD increased cerebral blood flow, improved neural function, and reduced neural apoptosis via up-regulating the expression of sirtuin 1 (SIRT1) and down-regulating phospho-extracellular regulated protein kinases (p-ERK)/ERK and HIF-1α levels in CIRI rats.

CONCLUSION

Taken together, the present study systematically revealed the potential targets and signaling pathways of SPD in the treatment of CIRI using in silico prediction and verified the therapeutic effects of SPD against CIRI via ameliorating apoptosis by regulating SIRT1/ERK/HIF-1α.

Empagliflozin treatment of cardiotoxicity: A comprehensive review of clinical, immunobiological, neuroimmune, and therapeutic implications

Cancer and cardiovascular disorders are known as the two main leading causes of mortality worldwide. Cardiotoxicity is a critical and common adverse effect of cancer-related chemotherapy. Chemotherapy-induced cardiotoxicity has been associated with various cancer treatments, such as anthracyclines, immune checkpoint inhibitors, and kinase inhibitors. Different methods have been reported for the management of chemotherapy-induced cardiotoxicity. In this regard, sodium-glucose cotransporter-2 inhibitors (SGLT2i), a class of antidiabetic agents, have recently been applied to manage heart failure patients. Further, SGLT2i drugs such as EMPA exert protective cardiac and systemic effects. Moreover, it can reduce inflammation through the mediation of major inflammatory components, such as Nucleotide-binding domain-like receptor protein 3 (NLRP3) inflammasomes, Adenosine 5'-monophosphate-activated protein kinase (AMPK), and c-Jun N-terminal kinase (JNK) pathways, Signal transducer and activator of transcription (STAT), and overall decreasing transcription of proinflammatory cytokines. The clinical outcome of EMPA administration is related to improving cardiovascular risk factors, including body weight, lipid profile, blood pressure, and arterial stiffness. Intriguingly, SGLT2 suppressors can regulate microglia-driven hyperinflammation affecting neurological and cardiovascular disorders. In this review, we discuss the protective effects of EMPA in chemotherapy-induced cardiotoxicity from molecular, immunological, and neuroimmunological aspects to preclinical and clinical outcomes.

Neuroprotective effects of glucose-lowering drugs in rat focal brain ischemia-reperfusion model

Background. Ischemic stroke is one of the leading causes of death in patients with type 2 diabetes mellitus (DM). According to the results of clinical and experimental studies, the ability of glucagon-like peptide-1 receptor agonists (GLP-1RA) to reduce the risk and severity of stroke in DM has been proven; data on the sodium-glucose cotransporter-2 inhibitors (SGLT-2i) effect are scarce. There has been no direct comparative study of the GLP-1RA and SGLT-2i neuroprotective effect.

Objective. To evaluate and to compare the effect of GLP-1RA of varying duration of action and SGLT-2i of varying selectivity on the neurological deficit severity and the brain damage volume in a transient focal brain ischemia model in rats without DM.

Design and methods. Male Wistar rats were divided into groups (n = 10 each) depending on the therapy received: “EMPA” (empagliflozin per os 2 mg/kg once daily), “CANA” (canagliflozin per os 25 mg/kg once daily), “LIRA” (liraglutide 1 mg/kg s. c. once daily), “DULA” (dulaglutide 0,12 mg/kg s. c. every 72 hours), “SEMA” (semaglutide 0,012 mg /kg s. c. once daily), “MET” (metformin per os 200 mg/kg once daily — comparison group), “Control” (administration of 0,9 % NaCl solution s. c. once daily). After 7 days, all groups underwent transient focal 30-minute filament middle cerebral artery occlusion. After 48 hours of reperfusion, neurological deficit was assessed using the Garcia scale, then the brain was collected and sections were stained with 1 % triphenyltetrazolium chloride solution to calculate the damage volume.

Results. Neurological deficit severity in the “LIRA” (14,50 (12,25; 15,25) points) and “SEMA” (14,00 (13,50; 18,00) points) groups was significantly less than in the “Control” group (11.00 (6,75; 12,00) points). The use of both SGLT-2i, as well as metformin, had no effect on the neurological status. At the same time, therapy with all study drugs had an infarct-limiting effect, compared with the “Control” group (damage volume 24,50 (14,69; 30,12) % of the total brain volume). At the same time, the brain damage volume in the “MET” group (12,93 (6,65, 26,66) %) was greater than that in the “EMPA” (6,08 (2,97, 7,63) %), “CANA” (5,11 (3,96; 8,34) %), “LIRA” (3,40 (2,09; 8,08) %), “DULA” (4,37 (2,72; 5,40) %), “SEMA” (5,19 (4,11; 7,83) %) groups.

Conclusions. SGLT-2i of varying selectivity and GLP-1RA of varying duration of action have a similar infarct-limiting effect in acute experimental brain ischemia. At the same time, GLP-1RA neuroprotective potential is higher, as it is characterized by an additional positive effect on the neurological status.

Catalpol Alleviates Ischemic Stroke Through Promoting Angiogenesis and Facilitating Proliferation and Differentiation of Neural Stem Cells via the VEGF-A/KDR Pathway

Stroke is one of the leading causes of disability and death globally with a lack of effective therapeutic strategies. Catalpol is a bioactive compound derived from the traditional Chinese medicine Rehmannia glutinosa and it has been shown to be protective against various neurological diseases. The potential roles of catalpol against ischemic stroke are still not completely clear. In this study, we examined the effect and mechanism of catalpol against ischemic stroke using in vivo rat distal middle cerebral artery occlusion (dMCAO) and in vitro oxygen-glucose deprivation (OGD) models. We demonstrated that catalpol indeed attenuated the neurological deficits caused by dMCAO and improved neurological function. Catalpol remarkably promoted angiogenesis, promoted proliferation and differentiation of neural stem cells (NSCs) in the subventricular zone (SVZ), and prevented neuronal loss and astrocyte activation in the ischemic cortex or hippocampal dentate gyrus (DG) in vivo. The vascular endothelial growth factor receptor 2 (KDR, VEGFR-2) inhibitor SU5416 and VEGF-A shRNA were used to investigate the underlying mechanisms. The results showed that SU5416 administration or VEGF-A-shRNA transfection both attenuated the effects of catalpol. We also found that catalpol promoted the proliferation of cultured brain microvascular endothelial cells (BMECs) and the proliferation and differentiation of NSCs subjected to OGD insult in vitro. Interestingly, the impact of catalpol on cultured cells was also inhibited by SU5416. Moreover, catalpol was shown to protect NSCs against OGD indirectly by promoting BMEC proliferation in the co-cultured system. Taken together, catalpol showed therapeutic potential in cerebral ischemia by promoting angiogenesis and NSC proliferation and differentiation. The protective effects of catalpol were mediated through VEGF-A/KDR pathway activation.

Canagliflozin, an Inhibitor of the Na+-Coupled D-Glucose Cotransporter, SGLT2, Inhibits Astrocyte Swelling and Brain Swelling in Cerebral Ischemia

Brain swelling is a major cause of death and disability in ischemic stroke. Drugs of the gliflozin class, which target the Na+-coupled D-glucose cotransporter, SGLT2, are approved for type 2 diabetes mellitus (T2DM) and may be beneficial in other conditions, but data in cerebral ischemia are limited. We studied murine models of cerebral ischemia with middle cerebral artery occlusion/reperfusion (MCAo/R). Slc5a2/SGLT2 mRNA and protein were upregulated de novo in astrocytes. Live cell imaging of brain slices from mice following MCAo/R showed that astrocytes responded to modest increases in D-glucose by increasing intracellular Na+ and cell volume (cytotoxic edema), both of which were inhibited by the SGLT2 inhibitor, canagliflozin. The effect of canagliflozin was studied in three mouse models of stroke: non-diabetic and T2DM mice with a moderate ischemic insult (MCAo/R, 1/24 h) and non-diabetic mice with a severe ischemic insult (MCAo/R, 2/24 h). Canagliflozin reduced infarct volumes in models with moderate but not severe ischemic insults. However, canagliflozin significantly reduced hemispheric swelling and improved neurological function in all models tested. The ability of canagliflozin to reduce brain swelling regardless of an effect on infarct size has important translational implications, especially in large ischemic strokes.

Diabetes-Alzheimer's connection in older age: SGLT2 inhibitors as promising modulators of disease pathways

Late-onset Alzheimer's disease (LOAD) is the most frequent cause of dementia in older persons. Subjects affected by type 2 diabetes mellitus (T2DM) are at higher risk of vascular disease, cognitive decline, and dementia. LOAD has many characteristics shared with impaired insulin signaling pathways, and substantial evidence has demonstrated a pivotal role in dysregulated glucose metabolism in its pathogenesis. Recent studies have shown that some anti-diabetic drugs, other than regulating the metabolism of peripheral tissues, can also modulate the brain's metabolism, reduce inflammation, and have a direct neuroprotective effect. Sodium-glucose cotransporter-2 inhibitors (SGLT2i) are a newer class with many pleiotropic effects that may have strong neuroprotective potential. After a summary of the principal "anti-diabetic" drugs acting as suitable candidates in treating LOAD, this narrative review explored the potential role of SGLT2i on cognition from pre-clinical to clinical studies.

Crosstalk between Alzheimer's disease and diabetes: a focus on anti-diabetic drugs

Alzheimer's disease (AD) and Type 2 diabetes mellitus (T2DM) are two of the most common age-related diseases. There is accumulating evidence of an overlap in the pathophysiological mechanisms of these two diseases. Studies have demonstrated insulin pathway alternation may interact with amyloid-β protein deposition and tau protein phosphorylation, two essential factors in AD. So attention to the use of anti-diabetic drugs in AD treatment has increased in recent years. In vitro, in vivo, and clinical studies have evaluated possible neuroprotective effects of anti-diabetic different medicines in AD, with some promising results. Here we review the evidence on the therapeutic potential of insulin, metformin, Glucagon-like peptide-1 receptor agonist (GLP1R), thiazolidinediones (TZDs), Dipeptidyl Peptidase IV (DPP IV) Inhibitors, Sulfonylureas, Sodium-glucose Cotransporter-2 (SGLT2) Inhibitors, Alpha-glucosidase inhibitors, and Amylin analog against AD. Given that many questions remain unanswered, further studies are required to confirm the positive effects of anti-diabetic drugs in AD treatment. So to date, no particular anti-diabetic drugs can be recommended to treat AD.

Sericin improves memory and sociability impairments evoked by transient global cerebral ischemia through suppression of hippocampal oxidative stress, inflammation, and apoptosis

Sericin (Ser) is a natural neuroactive macromolecule with diverse pharmacological properties, and our previous findings have shown its neuroprotective potentials. This study aimed to investigate the therapeutic potential of Ser on cognitive dysfunction induced by transient global cerebral ischemia/reperfusion (tGI/R) and its mechanism of action. The tGI/R was induced in BALB/c mice by bilateral occlusion of the common carotid arteries for two 5 min followed by a 10-min reperfusion period. After 24 h, mice were treated with normal saline or different doses of Ser (100, 200, and 300 mg/kg) for 10 days. Cognitive performances were assessed using the Barnes maze and social interaction tasks. Oxidative stress markers including superoxide dismutase (SOD), glutathione peroxidase (GPx), total antioxidant capacity (TAC), and malondialdehyde (MDA) as well as pro-inflammatory cytokines (interleukin (IL)-6 and tumor necrosis factor-alpha) and anti-inflammatory cytokine (IL-10) were assessed in the hippocampus. Markers of apoptosis (pro- and cleaved caspase-9 and 3, Bax, and Bcl-2) were assessed by Western blotting. Besides, transferase-mediated dUTP nick end-labeling assay was used to detect apoptotic cell death. We show here that Ser administration improved tGI/R-induced cognitive deficits, enhanced the activity of SOD and GPx, increased TAC levels, while reduced MDA levels. Notably, Ser decreased neuronal apoptotic cell death in the hippocampal dentate gyrus (DG) region, accompanied by suppression of neuroinflammation, downregulation of pro-apoptotic proteins (caspase-9, caspases-3, and Bax), and upregulation of anti-apoptotic protein, Bcl-2. Taken together, Ser administration protected hippocampal neurons from apoptotic cell death by impeding oxidative stress and inflammatory responses and, in turn, improved cognitive function in the tGI/R mice.

The Brain at High Altitude: From Molecular Signaling to Cognitive Performance

The brain requires over one-fifth of the total body oxygen demand for normal functioning. At high altitude (HA), the lower atmospheric oxygen pressure inevitably challenges the brain, affecting voluntary spatial attention, cognitive processing, and attention speed after short-term, long-term, or lifespan exposure. Molecular responses to HA are controlled mainly by hypoxia-inducible factors. This review aims to summarize the cellular, metabolic, and functional alterations in the brain at HA with a focus on the role of hypoxia-inducible factors in controlling the hypoxic ventilatory response, neuronal survival, metabolism, neurogenesis, synaptogenesis, and plasticity.

A comprehensive review of stroke-related signaling pathways and treatment in western medicine and traditional Chinese medicine

This review provides insight into the complex network of signaling pathways and mechanisms involved in stroke pathophysiology. It summarizes the historical progress of stroke-related signaling pathways, identifying potential interactions between them and emphasizing that stroke is a complex network disease. Of particular interest are the Hippo signaling pathway and ferroptosis signaling pathway, which remain understudied areas of research, and are therefore a focus of the review. The involvement of multiple signaling pathways, including Sonic Hedgehog (SHH), nuclear factor erythroid 2-related factor 2 (Nrf2)/antioxidant response element (ARE), hypoxia-inducible factor-1α (HIF-1α), PI3K/AKT, JAK/STAT, and AMPK in pathophysiological mechanisms such as oxidative stress and apoptosis, highlights the complexity of stroke. The review also delves into the details of traditional Chinese medicine (TCM) therapies such as Rehmanniae and Astragalus, providing an analysis of the recent status of western medicine in the treatment of stroke and the advantages and disadvantages of TCM and western medicine in stroke treatment. The review proposes that since stroke is a network disease, TCM has the potential and advantages of a multi-target and multi-pathway mechanism of action in the treatment of stroke. Therefore, it is suggested that future research should explore more treasures of TCM and develop new therapies from the perspective of stroke as a network disease.

Sodium-Glucose Cotransporter 2 (SGLT2) Inhibitors: Harms or Unexpected Benefits?

There is a need for innovative pharmaceutical intervention in light of the increasing prevalence of metabolic disease and cardiovascular disease. The kidneys' sodium-glucose cotransporter 2 inhibitors (SGLT2) receptors are targeted to reduce glucose reabsorption by SGLT2. Patients with type 2 diabetes mellitus (T2DM) benefit the most from reduced blood glucose levels, although this is just one of the numerous physiological consequences. To establish existing understanding and possible advantages and risks for SGLT2 inhibitors in clinical practice, this article will explore the influence of SGLT2 inhibitors on six major organ systems. In addition, this literature review will discuss the benefits and potential drawbacks of SGLT2 inhibitors on various organ systems and their potential application in therapeutic settings.

A simple but novel glycymicelle ophthalmic solution based on two approved drugs empagliflozin and glycyrrhizin: in vitro/in vivo experimental evaluation for the treatment of corneal alkali burns

A simple but novel ophthalmic solution based on two approved drugs was developed to reposition existing drugs to treat new diseases. This nanoformulation was developed using the phytochemical drug glycyrrhizin as an amphiphilic nanocarrier to micellarly solubilize empagliflozin (EMP), an oral drug that is widely used to control high blood glucose but has poor water solubility. This novel nanoformulation, which we designated the EMP@glycymicelle ophthalmic solution, was obtained using a simple preparation process. The resulting solution was a clear solution with an EMP encapsulation efficiency of 97.91 ± 0.50%, a small glycymicelle size of 6.659 ± 0.196 nm, and a narrow polydispersity index of 0.226 ± 0.059. The optimized formulation demonstrated that EMP was soluble in water up to 18 mg ml^-1 because of its encapsulation within glycymicelles. The EMP@glycymicelle ophthalmic solution exhibited excellent characteristics, including good storage stability, fast in vitro release profiles, improved in vitro antioxidant activity, and no ocular irritation. Ocular permeation evaluation showed that the EMP@glycymicelle ophthalmic solution had strong ocular permeation of EMP, and it reached the posterior segment of mouse eyes after ocular topical administration. The treatment efficacy evaluation showed that the EMP@glycymicelle ophthalmic solution had a significant effect against corneal alkali burns in mice, prompting corneal wound healing, recovering corneal sensitivity, reducing corneal haze, and relieving corneal NV invasion. The mechanism of inhibiting HMGB1 signaling was involved in this strong treatment effect. These results indicated that the EMP@glycymicelle ophthalmic solution provided a new concept of drug repurposing and a promising ocular system for the nano-delivery of EMP with significantly improved in vivo profiles.

Enriched Environment Attenuates Ferroptosis after Cerebral Ischemia/Reperfusion Injury via the HIF-1α-ACSL4 Pathway

Enriched environment (EE) has been proven to be an effective intervention strategy which can improve neurofunctional recovery following cerebral ischemia/reperfusion (I/R) injury. However, it still needs further investigation for the underlying mechanisms. Recently, it has been shown that ferroptosis played an essential role in the pathophysiological development of ischemic stroke (IS). This study is aimed at investigating whether EE plays a neuroprotective role by attenuating ferroptosis after cerebral I/R injury. We used middle cerebral artery occlusion/reperfusion (MCAO/R) to build a model of cerebral I/R injury. To evaluate the effect of EE on neurological recovery, we used the modified neurological severity score (mNSS) and the Morris water maze (MWM). We used the western blot to detect the protein levels of glutathione peroxidase 4 (GPX4), hypoxia-inducible factor-1α (HIF-1α), and acyl-CoA synthetase long-chain family member 4 (ACSL4). We used the quantitative real-time PCR (qRT-PCR) to measure the mRNA levels of ACSL4 and inflammatory cytokines including tumor necrosis factor alpha (TNFα), interleukin-6 (IL-6), and interleukin 1 beta (IL-1β). The occurrence of ferroptosis was detected by TdT-mediated dUTP nick-end labeling (TUNEL) assay, diaminobenzidine- (DAB-) enhanced Perls' staining, iron level assays, and malondialdehyde (MDA) level assays. The results verified that EE enhanced functional recovery and attenuated ferroptosis and neuroinflammation after cerebral I/R injury. EE increased the expression of HIF-1α while inhibited the expression of ACSL4. Our research indicated that EE improved functional recovery after cerebral I/R injury through attenuating ferroptosis, and this might be related to its regulation of the neuroinflammation and HIF-1α-ACSL4 pathway.

Exploring the synergic mechanism of Ligusticum striatum DC. and borneol in attenuating BMECs injury and maintaining tight junctions against cerebral ischaemia based on the HIF-1α/VEGF signalling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Ligusticum striatum DC., also known as Ligusticum chuanxiong Hort. (LCH), is widely used in China for its excellent effect in ischaemic stroke (IS) patients, and borneol (BO) has been confirmed to maintain the blood‒brain barrier (BBB) after stroke. They are often used as a combination in the prescriptions of IS patients. Although the advantage of their combined treatment in improving brain ischaemia has been verified, their synergistic mechanism on BBB maintenance is still unclear.

AIM OF THE STUDY

This study was designed to evaluate the synergistic effect of maintaining the BBB between LCH and BO against IS and to further explore the potential mechanism.

MATERIALS AND METHODS

After primary mouse brain microvascular endothelial cells (BMECs) were extracted and identified, the duration of oxygen-glucose deprivation (OGD) and the doses of LCH and BO were optimized. Then, the cells were divided into five groups: control, model, LCH, BO, and LCH + BO. Cell viability, injury degree, proliferation and migration were detected by CCK-8, LDH, EdU and wound-healing assays, respectively. Hoechst 33342 staining was adopted to detect the apoptosis rate, and western blotting was employed to observe the expressions of Bax, Bcl-2, caspase-3 and cleaved caspase-3. The TEER value and NaF permeability were measured to assess tight junction (TJ) function, while ZO-1, occludin and claudin-5 were also probed by western blotting. Moreover, the HIF-1α/VEGF pathway was observed to explore the underlying mechanism of BBB maintenance. In vivo, global cerebral ischaemia/reperfusion (GCIR) surgery was performed to establish an IS model. After treatment with LCH (200 mg/kg) and/or BO (160 mg/kg), histopathological structure and BMECs repair were observed by HE staining and immunohistochemistry of vWF. Meanwhile, TJ-associated proteins in vivo were also detected by western blotting.

RESULTS

Basically, LCH and BO had different emphases. LCH significantly attenuated the vacuolar structure, nuclear pyknosis and neuronal loss of GCIR mice, while BO focused on promoting BMECs proliferation and angiogenesis and inhibiting the degradation of TJ-associated proteins in vivo after IS. Interestingly, their combination further enhanced these effects. OGD injury markedly reduced the viability, proliferation and migration of primary BMECs; decreased the ratio of Bcl-2/Bax, TEER value, and the expressions of ZO-1, occludin and claudin-5; induced LDH release and apoptosis; and increased the cleaved caspase-3/caspase-3 ratio and NaF permeability. Meanwhile, BO might be the main contributor to the combinative treatment in ameliorating OGD-induced damage of BMECs and degradation of TJ-related proteins, and the potential mechanism might be involved in upregulating the HIF-1α/VEGF signalling pathway. Although LCH showed no obvious improvement, it could enhance the therapeutic effect of BO. Interestingly, their combination even produced some new improvements, including the reduction of cleaved caspase-3 and increase in TEER value, none of which were exhibited in their monotherapies.

CONCLUSIONS

LCH and BO exhibited complementary therapeutic features in alleviating cerebral ischaemic injury by inhibiting BMECs apoptosis, maintaining the BBB and attenuating the loss of neurons. LCH preferred to protect ischaemic neurons, while BO played a key role in protecting BMECs, maintaining the BBB and TJs by activating the HIF-1α/VEGF signalling pathway.

Effects of breviscapine on cerebral ischemia-reperfusion injury and intestinal flora imbalance by regulating the TLR4/MyD88/NF-κB signaling pathway in rats

ETHNOPHARMACOLOGICAL RELEVANCE

The plant Erigeron breviscapus (Vant.) Hand.-Mazz.,a Chinese herbal medicine with multiple pharmacological effects and clinical applications, has been traditionally used in the treatment of paralysis caused by stroke and joint pain from rheumatism by the Yi minority people of Southwest China for generations.However, its mechanism involves many factors and has not been fully clarified.

AIM OF THE STUDY

Taking intestinal flora as the target, the protective effect of extract(breviscapine) of E. breviscapus on cerebral ischemia and its possible mechanism were discussed from the perspective of brain inflammatory pathway and intestinal CYP3A4, which depends on intestinal flora.

MATERIALS AND METHODS

In this study, we first verified the binding ability between major active ingredient of Erigeron breviscapus and the core target TLR4 protein by molecular docking using Vina software.We established a rat model of cerebral ischemia-reperfusion injury in vivo.The neurological function of rats was scored by Bederson score table, the cerebral infarction volume was detected by TTC staining, and the serum NSE level was detected by ELASA. 16S rRNA sequencing was used to detect the intestinal flora of rats in each group.The expression levels of cerebral TLR4/MyD88/NF-κB and CYP3A4 mRNA and protein in different intestinal segments were detected by qRT-PCR and Western blot.

RESULTS

Compared with the model group, the neurological injury score, infarct volume and serum NSE concentration of breviscapine low, medium and high dose groups and nimodipine groups decreased significantly. Meanwhile, breviscapine could significantly reduce the expression level of the TLR4/MyD88/NF-κB in brain tissue and CYP3A4 in different intestinal segments of rats with cerebral ischemia-reperfusion injury. In addition, breviscapine also significantly ameliorated intestinal flora dysbiosis of rats with cerebral ischemia-reperfusion injury.

CONCLUSIONS

Breviscapine can protect rats from cerebral ischemia-reperfusion injury by regulating intestinal flora, inhibiting brain TLR4/MyD88/NF-κB inflammatory pathway and intestinal CYP3A4 expression.

Effect of Dl-3-n-butylphthalide on mitochondrial Cox7c in models of cerebral ischemia/reperfusion injury

Several studies have demonstrated the protective effect of dl-3-n-Butylphthalide (NBP) against cerebral ischemia, which may be related to the attenuation of mitochondrial dysfunction. However, the specific mechanism and targets of NBP in cerebral ischemia/reperfusion remains unclear. In this study, we used a chemical proteomics approach to search for targets of NBP and identified cytochrome C oxidase 7c (Cox7c) as a key interacting target of NBP. Our findings indicated that NBP inhibits mitochondrial apoptosis and reactive oxygen species (ROS) release and increases ATP production through upregulation of Cox7c. Subsequently, mitochondrial respiratory capacity was improved and the HIF-1α/VEGF pathway was upregulated, which contributed to the maintenance of mitochondrial membrane potential and blood brain barrier integrity and promoting angiogenesis. Therefore, our findings provided a novel insight into the mechanisms underlying the neuroprotective effects of NBP, and also proposed for the first time that Cox7c exerts a critical role by protecting mitochondrial function.

Dapagliflozin as an autophagic enhancer via LKB1/AMPK/SIRT1 pathway in ovariectomized/D-galactose Alzheimer's rat model

Autophagy and mitochondrial deficits are characteristics of early phase of Alzheimer's disease (AD). Sodium-glucose cotransporter-2 inhibitors have been nominated as a promising class against AD hallmarks. However, there are no available data yet to discuss the impact of gliflozins on autophagic pathways in AD. Peripherally, dapagliflozin's (DAPA) effect is mostly owed to autophagic signals. Thus, the goal of this study is to screen the power of DAPA centrally on LKB1/AMPK/SIRT1/mTOR signaling in the ovariectomized/D-galactose (OVX/D-Gal) rat model. Animals were arbitrarily distributed between 5 groups; the first group undergone sham operation, while remaining groups undergone OVX followed by D-Gal (150 mg/kg/day; i.p.) for 70 days. After 6 weeks, the third, fourth, and fifth groups received DAPA (1 mg/kg/day; p.o.); concomitantly with the AMPK inhibitor dorsomorphin (DORSO, 25 µg/rat, i.v.) in the fourth group and the SIRT1 inhibitor EX-527 (10 µg/rat, i.v.) in the fifth group. DAPA mitigated cognitive deficits of OVX/D-Gal rats, as mirrored in neurobehavioral task with hippocampal histopathological examination and immunohistochemical aggregates of p-Tau. The neuroprotective effect of DAPA was manifested by elevation of energy sensors; AMP/ATP ratio and LKB1/AMPK protein expressions along with autophagic markers; SIRT1, Beclin1, and LC3B expressions. Downstream the latter, DAPA boosted mTOR and mitochondrial function; TFAM, in contrary lessened BACE1. Herein, DORSO or EX-527 co-administration prohibited DAPA's actions where DORSO elucidated DAPA's direct effect on LKB1 while EX-527 mirrored its indirect effect on SIRT1. Therefore, DAPA implied its anti-AD effect, at least in part, via boosting hippocampal LKB1/AMPK/SIRT1/mTOR signaling in OVX/D-Gal rat model.

Empagliflozin protects against renal ischemia/reperfusion injury in mice

Renal ischemia/reperfusion (I/R) can induce acute kidney injury. Empagliflozin is a newly developed inhibitor of sodium-glucose cotransporter-2 (SGLT2) approved as an antidiabetic medication for patients with type 2 diabetes mellitus. Despite the established cardioprotective functions of empagliflozin, its protective role in renal I/R is unclear. Here, the present study evaluated the renoprotective effects of empagliflozin in a mouse model of renal I/R injury. Male C57/BL6 mice were allocated to sham-operated, I/R, and empagliflozin groups. Kidney pedicles on both sides were clamped for 45 min and were reperfused for 24 h. Empagliflozin (1 mg/kg) was administered to the mice for 2 days preischemia. The GSK-3β inhibitor SB216763 was administered intravenously at the beginning of reperfusion (0.1 mg/kg). Renal function and histological scores were evaluated. The kidneys were taken for immunohistochemical analysis, western blotting and apoptosis measurements. We found that empagliflozin decreased serum levels of creatinine and urea, reduced the average kidney weight-to-tibia length ratio, attenuated tubular damage, reduced renal proinflammatory cytokine expression and inhibited apoptosis in injured kidneys. Furthermore, empagliflozin increased renal glycogen synthase kinase 3β (GSK-3β) phosphorylation post I/R. Pharmacological inhibition of GSK-3β activity mimicked the renal protective effects offered by empagliflozin. In summary, these results support a protective role of empagliflozin against renal I/R injury.

Effect of Empagliflozin on Thioacetamide-Induced Liver Injury in Rats: Role of AMPK/SIRT-1/HIF-1α Pathway in Halting Liver Fibrosis

Hepatic fibrosis causes severe morbidity and death. No viable treatment can repair fibrosis and protect the liver until now. We intended to discover the empagliflozin's (EMPA) hepatoprotective efficacy in thioacetamide (TAA)-induced hepatotoxicity by targeting AMPK/SIRT-1 activity and reducing HIF-1α. Rats were treated orally with EMPA (3 or 6 mg/kg) with TAA (100 mg/kg, IP) thrice weekly for 6 weeks. EMPA in both doses retracted the serum GGT, ALT, AST, ammonia, triglycerides, total cholesterol, and increased serum albumin. At the same time, EMPA (3 or 6 mg/kg) replenished the hepatic content of GSH, ATP, AMP, AMPK, or SIRT-1 and mitigated the hepatic content of MDA, TNF-α, IL-6, NF-κB, or HIF-1α in a dose-dependent manner. Likewise, hepatic photomicrograph stained with hematoxylin and eosin or Masson trichrome stain of EMPA (3 or 6 mg/kg) revealed marked regression of the hepatotoxic effect of TAA with minimal injury. Similarly, in rats given EMPA (3 or 6 mg/kg), the immunohistochemically of hepatic photomicrograph revealed minimal stain of either α-SMA or caspase-3 compared to the TAA group. Therefore, we concluded that EMPA possessed an antifibrotic effect by targeting AMPK/SIRT-1 activity and inhibiting HIF-1α. The present study provided new insight into a novel treatment of liver fibrosis.

Repurposing SGLT2 Inhibitors for Neurological Disorders: A Focus on the Autism Spectrum Disorder

Autism spectrum disorder (ASD) is a neurodevelopmental disorder with a substantially increasing incidence rate. It is characterized by repetitive behavior, learning difficulties, deficits in social communication, and interactions. Numerous medications, dietary supplements, and behavioral treatments have been recommended for the management of this condition, however, there is no cure yet. Recent studies have examined the therapeutic potential of the sodium-glucose cotransporter 2 (SGLT2) inhibitors in neurodevelopmental diseases, based on their proved anti-inflammatory effects, such as downregulating the expression of several proteins, including the transforming growth factor beta (TGF-β), interleukin-6 (IL-6), C-reactive protein (CRP), nuclear factor κB (NF-κB), tumor necrosis factor alpha (TNF-α), and the monocyte chemoattractant protein (MCP-1). Furthermore, numerous previous studies revealed the potential of the SGLT2 inhibitors to provide antioxidant effects, due to their ability to reduce the generation of free radicals and upregulating the antioxidant systems, such as glutathione (GSH) and superoxide dismutase (SOD), while crossing the blood brain barrier (BBB). These properties have led to significant improvements in the neurologic outcomes of multiple experimental disease models, including cerebral oxidative stress in diabetes mellitus and ischemic stroke, Alzheimer's disease (AD), Parkinson's disease (PD), and epilepsy. Such diseases have mutual biomarkers with ASD, which potentially could be a link to fill the gap of the literature studying the potential of repurposing the SGLT2 inhibitors' use in ameliorating the symptoms of ASD. This review will look at the impact of the SGLT2 inhibitors on neurodevelopmental disorders on the various models, including humans, rats, and mice, with a focus on the SGLT2 inhibitor canagliflozin. Furthermore, this review will discuss how SGLT2 inhibitors regulate the ASD biomarkers, based on the clinical evidence supporting their functions as antioxidant and anti-inflammatory agents capable of crossing the blood-brain barrier (BBB).

Sodium-Glucose Cotransporter-2 Inhibition Exacerbates Hepatic Encephalopathy in Biliary Cirrhotic Rats

In liver cirrhosis, hepatic inflammation and abundant portal-systemic collaterals are indicated for the development of hepatic encephalopathy. Sodium-glucose cotransporter-2 (SGLT-2) inhibitors are a type of anti-diabetic agent which exert pleiotropic and anti-inflammatory effects. Diabetes and chronic liver disease often coexist, but the influence of SGLT-2 inhibition on liver cirrhosis and hepatic encephalopathy remains unknown. This study investigated the effect of SGLT-2 inhibition on cirrhotic rats. Biliary cirrhosis was induced in Sprague-Dawley rats via common bile duct ligation. A total of two weeks of treatment with the SGLT-2 inhibitor, empagliflozin 30 mg/kg/d, was applied. The motor activities, hemodynamics, biochemistry parameters, plasma levels of vascular endothelial growth factor (VEGF), and the severity of portal-systemic collateral shunts were measured. The hepatic histopathology and protein expressions were examined. We found that empagliflozin treatment did not affect hemodynamics, liver biochemistry, or blood glucose levels in cirrhotic rats. Empagliflozin did not affect hepatic inflammation and fibrosis. The protein expression of factors related to liver injury were not influenced by empagliflozin. However, empagliflozin decreased motor activities in cirrhotic rats and increased portal-systemic collateral shunts and VEGF plasma levels. In summary, SGLT-2 inhibition by empagliflozin did not ameliorate portal hypertension and hepatic inflammation in cirrhotic rats. In contrast, it exacerbated hepatic encephalopathy, which was evidenced by a decrease in motor activity. A possible mechanism could be an increase of portal-systemic shunts related to VEGF upregulation. Therefore, empagliflozin use should be cautious in cirrhotic patients regarding the development of hepatic encephalopathy. SIGNIFICANCE STATEMENT: Sodium-glucose cotransporter-2 inhibition by empagliflozin did not ameliorate portal hypertension and hepatic inflammation in cirrhotic rats. In contrast, it exacerbated hepatic encephalopathy through increased portal-systemic shunts related to VEGF up-regulation.

A review of potential mechanisms and uses of SGLT2 inhibitors in ischemia-reperfusion phenomena

Recently added to the therapeutic arsenal against chronic heart failure as a first intention drug, the antidiabetic drug-class sodium-glucose cotransporter-2 inhibitors (SGLT2i) showed efficacy in decreasing overall mortality, hospitalization, and sudden death in patients of this very population, in whom chronic or acute ischemia count among the first cause. Remarkably, this benefit was observed independently from diabetic status, and benefited both preserved and altered ventricular ejection fraction. This feature, observed in several large randomized controlled trials, suggests additional effects from SGLT2i beyond isolated glycemia control. Indeed, both in-vitro and animal models suggest that inhibiting the Na⁺/H⁺ exchanger (NHE) may be key to preventing ischemia/ reperfusion injuries, and by extension may hold a similar role in ischemic damage control and ischemic preconditioning. Yet, several other mechanisms may be explored which may help better target those who may benefit most from SGLT2i molecules. Because of a large therapeutic margin with few adverse events, ease of prescription and potential pharmacological efficacity, SGLT2i could be candidate for wider indications. In this review, we aim to summarize all evidence which link SGLT2i and ischemia/reperfusion injuries modulation, by first listing known mechanisms, including metabolic switch, prevention of lethal arrythmias and others, which portend the latter, and second, hypothesize how the former may interact with these mechanisms.

Further Evidence of Neuroprotective Effects of Recombinant Human Erythropoietin and Growth Hormone in Hypoxic Brain Injury in Neonatal Mice

Experimental in vivo data have recently shown complementary neuroprotective actions of rhEPO and growth hormone (rhGH) in a neonatal murine model of hypoxic brain injury. Here, we hypothesized that rhGH and rhEPO mediate stabilization of the blood−brain barrier (BBB) and regenerative vascular effects in hypoxic injury to the developing brain. Using an established model of neonatal hypoxia, neonatal mice (P7) were treated i.p. with rhGH (4000 µg/kg) or rhEPO (5000 IU/kg) 0/12/24 h after hypoxic exposure. After a regeneration period of 48 h or 7 d, cerebral mRNA expression of Vegf-A, its receptors and co-receptors, and selected tight junction proteins were determined using qRT-PCR and ELISA. Vessel structures were assessed by Pecam-1 and occludin (Ocln) IHC. While Vegf-A expression increased significantly with rhGH treatment (p < 0.01), expression of the Vegfr and TEK receptor tyrosine kinase (Tie-2) system remained unchanged. RhEPO increased Vegf-A (p < 0.05) and Angpt-2 (p < 0.05) expression. While hypoxia reduced the mean vessel area in the parietal cortex compared to controls (p < 0.05), rhGH and rhEPO prevented this reduction after 48 h of regeneration. Hypoxia significantly reduced the Ocln+ fraction of cortical vascular endothelial cells. Ocln signal intensity increased in the cortex in response to rhGH (p < 0.05) and in the cortex and hippocampus in response to rhEPO (p < 0.05). Our data indicate that rhGH and rhEPO have protective effects on hypoxia-induced BBB disruption and regenerative vascular effects during the post-hypoxic period in the developing brain.

Empagliflozin attenuates cardiac microvascular ischemia/reperfusion through activating the AMPKα1/ULK1/FUNDC1/mitophagy pathway

Mitophagy preserves microvascular structure and function during myocardial ischemia/reperfusion (I/R) injury. Empagliflozin, an anti-diabetes drug, may also protect mitochondria. We explored whether empagliflozin could reduce cardiac microvascular I/R injury by enhancing mitophagy. In mice, I/R injury induced luminal stenosis, microvessel wall damage, erythrocyte accumulation and perfusion defects in the myocardial microcirculation. Additionally, I/R triggered endothelial hyperpermeability and myocardial neutrophil infiltration, which upregulated adhesive factors and endothelin-1 but downregulated vascular endothelial cadherin and endothelial nitric oxide synthase in heart tissue. In vitro, I/R impaired the endothelial barrier function and integrity of cardiac microvascular endothelial cells (CMECs), while empagliflozin preserved CMEC homeostasis and thus maintained cardiac microvascular structure and function. I/R activated mitochondrial fission, oxidative stress and apoptotic signaling in CMECs, whereas empagliflozin normalized mitochondrial fission and fusion, neutralized supraphysiologic reactive oxygen species concentrations and suppressed mitochondrial apoptosis. Empagliflozin exerted these protective effects by activating FUNDC1-dependent mitophagy through the AMPKα1/ULK1 pathway. Both in vitro and in vivo, genetic ablation of AMPKα1 or FUNDC1 abolished the beneficial effects of empagliflozin on the myocardial microvasculature and CMECs. Taken together, the preservation of mitochondrial function through an activation of the AMPKα1/ULK1/FUNDC1/mitophagy pathway is the working mechanism of empagliflozin in attenuating cardiac microvascular I/R injury.

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Empagliflozin reduces I/R-induced microvascular damage.

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Empagliflozin suppresses I/R-induced endothelial cell damage.

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Empagliflozin activates FUNDC1-dependent mitophagy through the AMPKα1/ULK1 pathway.

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Ablation of FUNDC1 or AMPKα1 abolishes the protective effects of empagliflozin against I/R-induced microvascular damage.

Empagliflozin alleviates endoplasmic reticulum stress and augments autophagy in rotenone-induced Parkinson's disease in rats: Targeting the GRP78/PERK/eIF2α/CHOP pathway and miR-211-5p

Empagliflozin, a selective sodium-glucose co-transporter-2 inhibitor, has been demonstrated to provide additional non-glycemic benefits, including neuroprotection. Endoplasmic reticulum (ER) stress is a key player in neurodegeneration and occurs at the crossroads of other pathologic mechanisms; however, its role in the pathogenesis of Parkinson's disease (PD) is still elusive. miR-211-5p regulates neuronal differentiation and viability and was predicted to target CHOP, a downstream effector in the ER stress pathway. For the first time, this study investigated the possible neuroprotective effect of empagliflozin in a rotenone-induced rat model of PD from the perspective of ER stress. Rotenone (1.5 mg/kg) was administered subcutaneously every other day for 3 weeks. Meanwhile, the treated group received empagliflozin 10 mg/kg/day orally for 15 consecutive days post-PD induction. On the molecular level, the ER stress pathway components; GRP78, total and phosphorylated PERK, eIF2α and CHOP, along with miR-211-5p expression were upregulated in the striatum of rotenone-injected rats. Concurrently, the untreated rats showed elevated striatal α-synuclein levels along with diminished autophagy and the proteasome system as evidenced by reduced beclin-1 protein and ELF2/NERF mRNA expression levels. The rotenone-induced striatal oxidative stress and neuroinflammation were expressed by reduced catalase activity and elevated interleukin (IL)-1β levels. miR-211-5p was positively correlated with PERK/eIF2α/CHOP, IL-1β and α-synuclein, while negatively correlated with ELF2/NERF, beclin-1 and catalase activity. Empagliflozin treatment showed a restorative effect on all biochemical alterations and improved the motor function of rats tested by open field, grip strength and footprint gait analysis. In the histopathological examination, empagliflozin increased the intact neuron count and attenuated astrogliosis and microgliosis by reducing the glial fibrillary protein and ionized calcium-binding adaptor protein 1 immunostaining. Conclusively, these results emphasize the neurotherapeutic impact of empagliflozin in PD by moderating the GRP78/PERK/eIF2α/CHOP ER stress pathway, downregulating miR-211-5p, resolving oxidative stress, lessening astrocyte/microglial activation and neuroinflammation, along with augmenting autophagy.

Role of Sodium-Glucose Co-Transporter 2 Inhibitors in the Regulation of Inflammatory Processes in Animal Models

Sodium-glucose co-transporter 2 inhibitors, also known as gliflozins, were developed as a novel class of anti-diabetic agents that promote glycosuria through the prevention of glucose reabsorption in the proximal tubule by sodium-glucose co-transporter 2. Beyond the regulation of glucose homeostasis, they resulted as being effective in different clinical trials in patients with heart failure, showing a strong cardio-renal protective effect in diabetic, but also in non-diabetic patients, which highlights the possible existence of other mechanisms through which gliflozins could be exerting their action. So far, different gliflozins have been approved for their therapeutic use in T2DM, heart failure, and diabetic kidney disease in different countries, all of them being diseases that have in common a deregulation of the inflammatory process associated with the pathology, which perpetuates and worsens the disease. This inflammatory deregulation has been observed in many other diseases, which led the scientific community to have a growing interest in the understanding of the biological processes that lead to or control inflammation deregulation in order to be able to identify potential therapeutic targets that could revert this situation and contribute to the amelioration of the disease. In this line, recent studies showed that gliflozins also act as an anti-inflammatory drug, and have been proposed as a useful strategy to treat other diseases linked to inflammation in addition to cardio-renal diseases, such as diabetes, obesity, atherosclerosis, or non-alcoholic fatty liver disease. In this work, we will review recent studies regarding the role of the main sodium-glucose co-transporter 2 inhibitors in the control of inflammation.

Sodium-glucose cotransporter 2 inhibitors and neurological disorders: a scoping review

Background

Sodium-glucose cotransporter 2 inhibitors (SGLT2i) are a group of antidiabetic medications with a favourable cardiovascular, renal and overall safety profile. Given the limited treatment options available for neurological disorders, it is important to determine whether the pleiotropic effects of SGLT2i can be utilised in their prevention and management.

Methods

All articles published before 20 March 2021 were systematically searched in MEDLINE, EMBASE, Scopus, Web of Science, APA PsycINFO and ClinicalTrials.gov. Overall, 1395 titles were screened, ultimately resulting in 160 articles being included in the qualitative analysis. Screening and data extraction were conducted by two independent authors and studies were excluded if they were not an original research study.

Findings

Of the 160 studies, 134 addressed stroke, 19 cognitive impairment, 4 epilepsy and 4 movement disorders, encompassing a range from systematic reviews and randomised controlled trials to bioinformatic and animal studies. Most animal studies demonstrated significant improvements in behavioural and neurological deficits, which were reflected in beneficial changes in neurovascular units, synaptogenesis, neurotransmitter levels and target receptors' docking energies. The evidence from the minority clinical literature was conflicting and many studies did not reach statistical significance.

Interpretation

SGLT2i may exert neurological benefits through three mechanisms: reduction in cardiovascular risk factors, augmentation of ketogenesis and anti-inflammatory pathways. Most clinical studies were observational, meaning that a causal relationship could not be established, while randomised controlled trials were heterogeneous and powered to detect cardiovascular or renal outcomes. We suggest that a longitudinal study should be conducted and specifically powered to detect neurological outcomes.

Cardamonin attenuates cerebral ischemia/reperfusion injury by activating the HIF-1α/VEGFA pathway

Cardamonin is a chalcone with neuroprotective activity. The aim of our study was to explore the functions and mechanism of action of cardamonin in ischemic stroke. Oxygen-glucose deprivation and reperfusion (OGD/R)-induced human brain microvascular endothelial cells (HBMECs) and middle cerebral artery occlusion (MCAO) mouse model were utilized to mimic ischemic stroke. Cell viability was analyzed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide. Permeability was investigated via fluorescein isothiocyanate-dextran assay. Apoptosis was detected by TdT-Mediated dUTP Nick End Labeling staining. Hypoxia-inducible factor (HIF)-1α and vascular endothelial growth factor A (VEGFA) protein levels were measured using Western blotting. Brain injury was evaluated by 2,3,5-triphenyltetrazolium chloride staining, neurological score and brain water content. The 37 overlapping targets of ischemic stroke and cardamonin were predicted to be associated with the HIF-1/VEGFA signaling. Cardamonin alleviated OGD/R-induced viability reduction and increase of permeability and apoptosis in HBMECs. Cardamonin increased OGD/R-induced activation of the HIF-1α/VEGFA pathway. Inhibition of the HIF-1α/VEGFA signaling using inhibitor relieved the effect of cardamonin on cell viability, permeability and apoptosis in HBMECs under OGD/R. Cardamonin mitigated brain injury and promoted activation of the HIF-1α/VEGFA signaling in MCAO-treated mice. Overall, cardamonin protected against OGD/R-induced HBMEC damage and MACO-induced brain injury through activating the HIF-1α/VEGFA pathway.

New treatment approaches for Alzheimer's disease: preclinical studies and clinical trials centered on antidiabetic drugs

INTRODUCTION

Alzheimer's disease (AD) and type 2 diabetes mellitus (T2DM) represent two major chronic diseases that affect a large percentage of the population and share common pathogenetic mechanisms, including oxidative stress and inflammation. Considering their common mechanistic aspects, and given the current lack of effective therapies for AD, accumulating research has focused on the therapeutic potential of antidiabetic drugs in the treatment or prevention of AD.

AREAS COVERED

This review examines the latest preclinical and clinical evidence on the potential of antidiabetic drugs as candidates for AD treatment. Numerous approved drugs for T2DM, including insulin, metformin, glucagon-like peptide-1 receptor agonists (GLP-1 RA), and sodium glucose cotransporter 2 inhibitors (SGLT2i), are in the spotlight and may constitute novel approaches for AD treatment.

EXPERT OPINION

Among other pharmacologic agents, GLP-1 RA and SGLT2i have so far exhibited promising results as novel treatment approaches for AD, while current research has centered on deciphering their action on the central nervous system (CNS). Further investigation is crucial to reveal the most effective pharmacological agents and their optimal combinations, maximize their beneficial effects on neurons, and find ways to increase their distribution to the CNS.

F-box and WD repeat domain-containing 7 (FBXW7) mediates the hypoxia inducible factor-1α (HIF-1α)/vascular endothelial growth factor (VEGF) signaling pathway to affect hypoxic-ischemic brain damage in neonatal rats

The aim of this study was to determine whether F-box and WD repeat domain-containing 7 (FBXW7) can mediate the hypoxia inducible factor-1α (HIF-1α)/vascular endothelial growth factor (VEGF) signaling pathway to affect neonatal hypoxic-ischemic brain damage (HIBD) in neonatal rats. HIBD rats were treated with LV-shFBXW7. Cerebral infarct size was determined by 2,3,5-triphenyltetrazolium chloride (TTC) staining, while microvessel density (MVD) was evaluated by immunohistochemistry. Learning and memory were tested using the Morris water maze (MWM) test. FBXW7 and HIF-1α/VEGF signaling pathway proteins were measured by Western blotting. Brain microvascular endothelial cells (BMECs) were isolated to establish an oxygen-glucose deprivation (OGD) model to evaluate treatment with FBXW7 siRNA. Cell viability was detected using a 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) assay, while cell migration was evaluated using a wound healing assay. The tube formation of BMECs was also assessed. The results demonstrated that HIBD rats exhibited increased protein expression of FBXW7, HIF-1α, and VEGF. HIBD rats also displayed increased cerebral infarct size, prolonged escape latency and a decreased number of platform crossings. However, HIBD rats treated with LV-shFBXW7 exhibited reversal of these changes. In vitro experiments showed that BMECs in the OGD group had significantly decreased cell viability, shorter vascular lumen length, and shorter migration distance than cells in the control group. Moreover, silencing FBXW7 promoted proliferation, tube formation and migration of BMECs. Taken together, silencing FBXW7 upregulates the HIF-1α/VEGF signaling pathway to promote the angiogenesis of neonatal HIBD rats after brain injury, reducing infarct volume and improving recovery of nerve function in HIBD rats.

Biological Functions and Regulatory Mechanisms of Hypoxia-Inducible Factor-1α in Ischemic Stroke

Ischemic stroke is caused by insufficient cerebrovascular blood and oxygen supply. It is a major contributor to death or disability worldwide and has become a heavy societal and clinical burden. To date, effective treatments for ischemic stroke are limited, and innovative therapeutic methods are urgently needed. Hypoxia inducible factor-1α (HIF-1α) is a sensitive regulator of oxygen homeostasis, and its expression is rapidly induced after hypoxia/ischemia. It plays an extensive role in the pathophysiology of stroke, including neuronal survival, neuroinflammation, angiogenesis, glucose metabolism, and blood brain barrier regulation. In addition, the spatiotemporal expression profile of HIF-1α in the brain shifts with the progression of ischemic stroke; this has led to contradictory findings regarding its function in previous studies. Therefore, unveiling the Janus face of HIF-1α and its target genes in different type of cells and exploring the role of HIF-1α in inflammatory responses after ischemia is of great importance for revealing the pathogenesis and identifying new therapeutic targets for ischemic stroke. Herein, we provide a succinct overview of the current approaches targeting HIF-1α and summarize novel findings concerning HIF-1α regulation in different types of cells within neurovascular units, including neurons, endothelial cells, astrocytes, and microglia, during the different stages of ischemic stroke. The current representative translational approaches focused on neuroprotection by targeting HIF-1α are also discussed.