Function of the GABAergic System in Diabetic Encephalopathy.

Diabetes is a common metabolic disease characterized by loss of blood sugar control and a high rate of complications. γ-Aminobutyric acid (GABA) functions as the primary inhibitory neurotransmitter in the adult mammalian brain. The normal function of the GABAergic system is affected in diabetes. Herein, we summarize the role of the GABAergic system in diabetic cognitive dysfunction, diabetic blood sugar control disorders, diabetes-induced peripheral neuropathy, diabetic central nervous system damage, maintaining diabetic brain energy homeostasis, helping central control of blood sugar and attenuating neuronal oxidative stress damage. We show the key regulatory role of the GABAergic system in multiple comorbidities in patients with diabetes and hope that further studies elucidating the role of the GABAergic system will yield benefits for the treatment and prevention of comorbidities in patients with diabetes.

Differential Modulators of NG2-Glia Differentiation into Neurons and Glia and Their Crosstalk.

As the fifth main cell population in the brain, NG2-glia are also known as oligodendrocyte precursor cells. NG2-glia express receptors and ion channels for fast modulation of neuronal activities and signaling with neuronal synapses, which are of functional significance in both physiological and pathological states. NG2-glia also participate in fast signaling with peripheral neurons via direct synaptic contacts in the brain. These distinctive glia have the unique capability of proliferating and differentiating into oligodendrocytes, which are critical for axonal myelination in the early developing brain. In neurodegenerative diseases, NG2-glia play an important role and undergo morphological modification, adapt the expression of their membrane receptors and ion channels, and display gene-modulated cell reprogramming and excitotoxicity-caused cell death. These modifications directly and indirectly influence populations of neurons and other glial cells. NG2-glia regulate their action and dynamics in response to neuronal behavior and disease, indicating a critical function to preserve and remodel myelin in physiological states and to repair it in pathological states. Here, we review in detail the differential modulators of NG2-glia into neurons and astrocytes, as well as interactions of NG2-glia with neurons, astrocytes, and microglia. We will also summarize a future potential exploitation of NG2-glia.

Development proposals of Human Research Protection Program.

BACKGROUND: China's ethics committees alone are unable to meet the growing need for human participant protection. Several scandals in recent years indicate weaknesses in the protection of human participants in China. OBJECTIVES: The aim of the study is to summarize the status and problems of human research protection program in China and to explore its establishment proposals at national and hospital levels. RESEARCH DESIGN: To conduct literature retrieval, Chinese National Knowledge Infrastructure, Chinese Biomedical Document Database, and English databases Web of Science and PubMed were searched; laws, guidelines, and regulations were also searched on web by Google and Chinese search engine Baidu. ETHICAL CONSIDERATIONS: No data were collected from human participants, and ethical review was not required. FINDINGS: There are problems for China's Human Research Protection Program, such as weak relevant legal systems, insufficient administrative supervision, and incompetent ethics committee capacities. To fully protect human participants, China should promote the development of Human Research Protection Program, which can formulate ethics-related laws, improve regulations for the protection of the safety and rights of human participants, strengthen supervision, and enforce compensation for human participants. Owing to the frequency with which human participants are recruited in hospitals in China, hospitals can utilize existing ethics committees and establish data and safety monitoring committees, quality control, fund and contract management, and conflict of interest management offices. DISCUSSION: As a growing program, it remains necessary to learn from the experience of developed countries with high ethics standards and reformulate them to fit China's conditions to explore potential future development. The program will also be an experience for other developing countries. CONCLUSION: Human Research Protection Program can strengthen communication and coordination among various hospital departments to effectively protect the rights and welfare of human participants.

Problems and development strategies for research ethics committees in China's higher education institutions.

The establishment of research ethics committees (REC) in China's higher education institutions (HEI) is lagging far behind western developed countries. This has at least partly directly led to anomie in scientific research ethics, as seen in the recent controversies involving a proposed human head transplant and gene-edited babies. At present, the problems for REC in China's HEI include lack of regulation, informal ethics reviews, lack of supervision and insufficient ethics review capacity. To counteract these problems, suggested measures include mandatory formation of formal ethics committee, administrative support from HEI, ethics approval letter prior to funding application, formulation of regulations and standard operating procedures, selecting and training for members and independent consultants, training for secretaries and staff, ethics training for investigators, and learning from the experience of HEI outside of China, such as the USA and Canada. The establishment of REC in China's HEI will greatly enhance the overall quality of ethics reviews in China. In addition to better protecting the rights and welfare of human participants, it is also conducive to maintaining the reputation of China's HEI.

Neuropathy and inflammation in diabetic bone marrow.

Diabetes impairs the bone marrow (BM) architecture and function as well as the mobilization of immature cells into the bloodstream and number of potential regenerative cells. Circadian regulation of bone immature cell migration is regulated by ß-adrenergic receptors, which are expressed on haematopoietic stem cells, mesenchymal stem cells, and osteoblasts in the BM. Diabetes is associated with a substantially lower number of sympathetic nerve terminal endings in the BM; thus, diabetic neuropathy plays a critical role in BM dysfunction. Treatment with mesenchymal stem cells, BM mononuclear cells, haematopoietic stem cells, and stromal cells ameliorates the dysfunction of diabetic neuropathy, which occurs, in part, through secreted neurotrophic factors, growth factors, adipokines, and polarizing macrophage M2 cells and inhibiting inflammation. Inflammation may be a therapeutic target for BM stem cells to improve diabetic neuropathy. Given that angiogenic and neurotrophic effects are two major barriers to effective diabetic neuropathy therapy, targeting BM stem cells may provide a novel approach to develop these types of treatments.

Trigonelline Inhibits Inflammation and Protects ß Cells to Prevent Fetal Growth Restriction during Pregnancy in a Mouse Model of Diabetes.

BACKGROUND: As an active component from traditional Chinese medicine, trigonelline has a protective effect on diabetes. This study evaluated the protective effects of trigonelline on diabetic mice during pregnancy. METHODS: Diabetes was induced in female mice by intraperitoneal injection for continuous 5-day of 40 mg/kg/day streptozotocin. Female mice were divided into 4 groups after they were allowed to mate with normal male mice: nondiabetic, nondiabetic treated with trigonelline (70 mg/kg) for 18 days, diabetic, and diabetic treated with trigonelline (70 mg/kg). RESULTS: Diabetic pregnant mice had significantly higher levels of blood glucose, serum total cholesterol, triglyceride, insulin, and leptin but lower serum omentin-1 level and insulin sensitivity index than the nondiabetic ones. Trigonelline improved the hyperglycemia, dyslipidemia, insulin resistance, and adipocytokine of diabetic pregnant mice. Diabetic pregnant mice had significantly reduced fetus numbers, fetal weight, and fetal/placental ratio, which were reversed by trigonelline. Trigonelline prevented the increase in proinflammatory cytokines and reduced interleukin-10 level in placenta of diabetic pregnant mice. Trigonelline increased ß-cell replication and the decreased ß-cell mass, and decreased the ß-cell apoptosis of diabetic pregnant mice. CONCLUSION: These findings suggest that trigonelline protects diabetic pregnancy partly by suppressing inflammation, regulating the secretion of adipocytokines, increasing ß-cell mass, replication, and decreasing ß-cell apoptosis.

Effectiveness of problem-based learning in Chinese pharmacy education: a meta-analysis.

BACKGROUND: This review provides a critical overview of problem-based learning (PBL) practices in Chinese pharmacy education. PBL has yet to be widely applied in pharmaceutical education in China. The results of those studies that have been conducted are published in Chinese and thus may not be easily accessible to international researchers. Therefore, this meta-analysis was carried out to review the effectiveness of PBL. METHODS: Databases were searched for studies in accordance with the inclusion criteria. Two reviewers independently performed the study identification and data extraction. A meta-analysis was conducted using Revman 5.3 software. RESULTS: Sixteen randomized controlled trials were included. The meta-analysis revealed that PBL had a positive association with higher theoretical scores (SMD = 1.17, 95% CI [0.77, 11.57], P < 0.00001). The questionnaire results show that PBL methods are superior to conventional teaching methods in improving students' learning interest, independent analysis skills, scope of knowledge, self-study, team spirit, and oral expression. CONCLUSIONS: This meta-analysis indicates that PBL pedagogy is superior to traditional lecture-based teaching in Chinese pharmacy education. PBL methods could be an optional, supplementary method of pharmaceutical teaching in China. However, Chinese pharmacy colleges and universities should revise PBL curricula according to their own needs, which would maximize the effectiveness of PBL.

Resveratrol protects against hyperglycemia-induced oxidative damage to mitochondria by activating SIRT1 in rat mesangial cells.

Oxidative stress and mitochondrial dysfunction are involved in the pathogenesis of diabetic nephropathy (DN). Resveratrol has potent protective effects on diabetes and diabetic complications including diabetic nephropathy. We aimed to investigate the protective effects of resveratrol on mitochondria and the underlying mechanisms by using an in vitro model of hyperglycemia. We exposed primary cultured rat mesangial cells to high glucose (30mM) for 48h. We found that pretreatment with resveratrol (10µM) 6h prior to high glucose treatment significantly reduced hyperglycemia-induced increase in reactive oxygen species (ROS) production and mitochondrial superoxide generation, as well as stimulated MnSOD activity. In addition, resveratrol pretreatment significantly reversed the decrease of mitochondrial complex III activity in glucose-treated mesangial cells, which is considered to be the major source of mitochondrial oxidative stress in glucose-treated cells. Furthermore, resveratrol pretreatment efficiently restored the hyperpolarization of ∆Ψm, increased ATP production and preserved the mtDNA content. All of these protective effects of resveratrol were successfully blocked by siRNA targeting SIRT1 and EX-527, a specific inhibitor of SIRT1 activity. Our results indicated that resveratrol efficiently reduced oxidative stress and maintained mitochondrial function related with activating SIRT1 in glucose-treated mesangial cells. It suggested that resveratrol is pharmacologically promising for treating diabetic nephropathy.

Protection of trigonelline on experimental diabetic peripheral neuropathy.

The mechanisms leading to diabetic peripheral neuropathy are complex and there is no effective drug to treat it. As an active component of several traditional Chinese medicines, trigonelline has beneficial effects on diabetes with hyperlipidemia. The protective effects and the mechanism of trigonelline on diabetic peripheral neuropathy were evaluated in streptozotocin- and high-carbohydrate/high-fat diet-induced diabetic rats. Rats were divided into four groups at the end of week 2: control, diabetes, diabetes + trigonelline (40 mg/kg), and diabetes + sitagliptin (4 mg/kg). After 48-week treatment, technologies of nerve conduction, cold and hot immersion test, transmission electron microscopy, real-time PCR, and Western blotting were applied. Serum glucose, serum insulin, insulin sensitivity index, lipid parameters, body weight, sciatic nerve conduction velocity, nociception, glucagon-like peptide-1 receptor mRNA and protein, total and phosphorylated p38 mitogen-activated protein kinases protein expression, malonaldehyde content, and superoxide dismutase activity were altered in diabetic rats, and were near control levels treated with trigonelline. Slight micropathological changes existed in sciatic nerve of trigonelline-treated diabetic rats. These findings suggest that trigonelline has beneficial effects for diabetic peripheral neuropathy through glucagon-like peptide-1 receptor/p38 mitogen-activated protein kinases signaling pathway, nerve conduction velocity, antioxidant enzyme activity, improving micropathological changes of sciatic nerve and decreasing lipid peroxidation.

Hypoglycemic and Hypolipidemic Effects of Ethanolic Extract of Mirabilis jalapa L. Root on Normal and Diabetic Mice.

The present study investigated the insulin sensitivity, hypoglycemic, and hypolipidemic activities of ethanolic extract of Mirabilis jalapa L. root (EEM) in normal and diabetic mice. After induction of diabetes with streptozotocin, both normal and diabetic mice were singly or repeatedly for 28 days administrated with EEM at doses of 2, 4, 8 g/kg, respectively. Before induction of diabetes, mice were administrated with EEM at doses of 2, 4, 8 g/kg for 14 days and were injected with streptozotocin and continued on EEM administration for another 28 days. Both after and before induction of diabetes, repeated administration with 4, 8 g/kg EEM continually lowered blood glucose level, decreased serum insulin level and improved insulin sensitivity index, and lowered serum total cholesterol, triglyceride levels and triglyceride content in liver and skeletal muscle, and increased glycogen content in these tissues; but repeated administration had no influence on those indexes of normal mice. Single administration with EEM (4, 8 g/kg) showed hypoglycemic effect in oral glucose tolerance test in normal and diabetic mice. Single administration with EEM had no hypoglycemic and hypolipidemic effects on normal and diabetic mice. These results suggest that EEM possesses both potential insulin sensitivity, hypoglycemic, and hypolipidemic effects on diabetes.

Protective effect of total flavonoids of seabuckthorn (Hippophae rhamnoides) in simulated high-altitude polycythemia in rats.

Seabuckthorn (Hippophae rhamnoides L.) has been used to treat high altitude diseases. The effects of five-week treatment with total flavonoids of seabuckthorn (35, 70, 140 mg/kg, ig) on cobalt chloride (5.5 mg/kg, ip)- and hypobaric chamber (simulating 5,000 m)-induced high-altitude polycythemia in rats were measured. Total flavonoids decreased red blood cell number, hemoglobin, hematocrit, mean corpuscular hemoglobin levels, span of red blood cell electrophoretic mobility, aggregation index of red blood cell, plasma viscosity, whole blood viscosity, and increased deformation index of red blood cell, erythropoietin level in serum. Total flavonoids increased pH, pO2, Sp(O2), pCO2 levels in arterial blood, and increased Na⁺, HCO3⁻, Cl⁻, but decreased K⁺ concentrations. Total flavonoids increased mean arterial pressure, left ventricular systolic pressure, end-diastolic pressure, maximal rate of rise and decrease, decreased heart rate and protected right ventricle morphology. Changes in hemodynamic, hematologic parameters, and erythropoietin content suggest that administration of total flavonoids from seabuckthorn may be useful in the prevention of high altitude polycythaemia in rats.

Glial and Vascular Cell Regulation of the Blood-Brain Barrier in Diabetes.

As a structural barrier, the blood-brain barrier (BBB) is located at the interface between the brain parenchyma and blood, and modulates communication between the brain and blood microenvironment to maintain homeostasis. The BBB is composed of endothelial cells, basement membrane, pericytes, and astrocytic end feet. BBB impairment is a distinguishing and pathogenic factor in diabetic encephalopathy. Diabetes causes leakage of the BBB through downregulation of tight junction proteins, resulting in impaired functioning of endothelial cells, pericytes, astrocytes, microglia, nerve/glial antigen 2-glia, and oligodendrocytes. However, the temporal regulation, mechanisms of molecular and signaling pathways, and consequences of BBB impairment in diabetes are not well understood. Consequently, the efficacy of therapies diabetes targeting BBB leakage still lags behind the requirements. This review summarizes the recent research on the effects of diabetes on BBB composition and the potential roles of glial and vascular cells as therapeutic targets for BBB disruption in diabetic encephalopathy.

The serotonergic system dysfunction in diabetes mellitus.

Most peripheral serotonin (5-HT) is synthesized in enterochromaffin cells, and most circulating 5-HT is stored in platelets. As a monoamine, 5-HT has several functions in various non-neuronal and neuronal systems. In the central nervous system, it functions as a neurotransmitter to modulate feeding behavior and mood. Numerous clinical trials have focused on increasing 5-HT activation in the central nervous system, including those involving anti-obesity drugs currently in the market, although severe side effects on peripheral system can lead to the withdrawal of certain drugs. Recent studies have revealed that both the peripheral and central serotonergic systems play a vital role in diabetes and its complications. This review summarizes the roles of the serotonergic system in blood glucose regulation, diabetic macroangiopathy, diabetic peripheral neuropathy, and diabetic encephalopathy, indicating its potential clinical significance as a therapeutic target for the treatment of diabetes and its complications.

Neuritin Promotes Bone Marrow-Derived Mesenchymal Stem Cell Migration to Treat Diabetic Peripheral Neuropathy.

The purpose of this study is to explore the effect and mechanism of neuritin overexpression in the bone marrow on peripheral neuropathy in type 2 diabetic (db/db) mice. We analyzed the impact of bone marrow neuritin overexpression on diabetic peripheral neuropathy and migration of bone marrow mesenchymal stem cells in db/db mice. Antagonists were used to inhibit the stromal cell-derived factor (SDF)-1α/C-X-C chemokine receptor type 4 (CXCR4)-phosphoinositide 3-kinase (PI3K)/Akt signaling pathway in primary cultured bone marrow mesenchymal stem cells. Immunofluorescence, transmission electron microscopy, Oil Red O staining, and transwell migration assays were used. Bone marrow-specific overexpression of neuritin in db/db mice was successfully established. Overexpression of neuritin in the bone marrow ameliorated hyperglycemia, prevented diabetic peripheral neuropathy, protected the ultrastructure of the sciatic nerve and intra-epidermal nerve fiber density, and promoted Schwann cell proliferation and remyelination in the sciatic nerve. Moreover, it ameliorated fat accumulation, adipocyte number, and vascular and nerve densities; decreased glutamate content in serum and bone marrow; restored gradient SDF-1α contents between bone marrow, blood, and sciatic nerve; and promoted impaired diabetic bone marrow mesenchymal stem cell migration. Neuritin improves bone marrow mesenchymal stem cell migration via the SDF-1α/CXCR4-PI3K/Akt signaling pathway in vitro. Overexpression of neuritin in the bone marrow can locally ameliorate neuropathy in the bone marrow. This improves the migration capability of bone marrow mesenchymal stem cells and repairs diabetic peripheral neuropathy, at least partly by activating the PI3K/Akt pathway through the SDF-1α/CXCR4 axis.

NG2-glia crosstalk with microglia in health and disease.

Neurodegenerative diseases are increasingly becoming a global problem. However, the pathological mechanisms underlying neurodegenerative diseases are not fully understood. NG2-glia abnormalities and microglia activation are involved in the development and/or progression of neurodegenerative disorders, such as multiple sclerosis, Alzheimer's disease, Parkinson's disease, and cerebrovascular diseases. In this review, we summarize the present understanding of the interaction between NG2-glia and microglia in physiological and pathological states and discuss unsolved questions concerning their fate and potential fate. First, we introduce the NG2-glia and microglia in health and disease. Second, we formulate the interaction between NG2-glia and microglia. NG2-glia proliferation, migration, differentiation, and apoptosis are influenced by factors released from the microglia. On the other hand, NG2-glia also regulate microglia actions. We conclude that NG2-glia and microglia are important immunomodulatory cells in the brain. Understanding the interaction between NG2-glia and microglia will help provide a novel method to modulate myelination and treat neurodegenerative disorders.

Neuritin inhibits astrogliosis to ameliorate diabetic cognitive dysfunction.

Earlier, it was shown that reversing the downregulation of neuritin expression in the brain improves central neuropathy in diabetic rats. We investigated the protective mechanism of neuritin in diabetic cognitive dysfunction via astrocytes. Further, the impact of the overexpression of neuritin in the cortex and the hippocampus on diabetic cognitive dysfunction and astrogliosis in type 2 diabetic (db/db) mice was assessed. Antagonists were used to inhibit the JAK2/STAT3 signaling pathway in U-118MG, an astrocyte cell line. Immunofluorescence, Western blotting, and real-time PCR were performed. Neuritin overexpression in the hippocampus of db/db mice significantly ameliorated cognitive dysfunction, hippocampal neuronal impairment, and synaptic plasticity deterioration, and inhibited astrogliosis and the JAK2/STAT3 signaling pathway in the hippocampus. Neuritin suppressed the JAK2/STAT3 signaling pathway to inhibit lipopolysaccharide-induced gliosis in U-118MG cells. It was observed that neuritin regulates the JAK2/STAT3 signaling pathway in astrocytes to inhibit astrogliosis and improve diabetic cognitive dysfunction.

Orexigenic effect of cocaine- and amphetamine-regulated transcript (CART) after injection into hypothalamic nuclei in streptozotocin-diabetic rats.

1. The aim of the present study was to investigate the orexigenic effect of cocaine- and amphetamine-regulated transcript (CART) peptide on feeding regulation following its injection into discrete nuclei of the hypothalamus. 2. Male Sprague-Dawley diabetic rats were injected with 0.06 or 0.2 nmol CART (55-102) or an equal volume of saline into various hypothalamic areas and food intake was then measured 1, 2, 4, 8 and 24 h after injection. Changes in hypothalamic CART mRNA expression in response to dietary intervention (2 weeks feeding of a high-fat diet) were assessed using quantitative real-time reverse transcription-polymerase chain reaction. Possible interactions between neuropeptide Y (NPY), agouti-related protein (AGRP), α-melanocyte-stimulating hormone (MSH) and corticotropin-releasing hormone (CRH) were evaluated in an in vitro hypothalamic explant system. Neuropeptide immunoreactivities (IR) were determined using radioimmunoassays (RIAs). 3. At 0.2 nmol, CART (55-102) significantly increased feeding in fasted diabetic rats after injection into the dorsomedial hypothalamic nucleus and arcuate nucleus (ARC). Injection of 0.2 nmol CART (55-102) into the ARC of satiated diabetic rats also increased food intake that was similar in both magnitude and time-course to the response seen in fasted diabetic rats. Food intake in diabetic rats on a high-fat diet was clearly increased after injection of 0.2 nmol CART (55-102) into the ARC, as was CART mRNA expression. Incubation of hypothalamic explants with 0.4, 4 and 40 nmol/L CART (55-102) for 45 min significantly increased NPY IR, whereas exposure of explants to 4 nmol/L CART (55-102) increased AGRP IR and CRH IR. None of the concentrations of CART (55-102) tested had any effect on α-MSH IR. 4. Together, these data provide further evidence that hypothalamic CART has an orexigenic effect, which, in the ARC, may stimulate the release of hypothalamic orexigenic neuropeptides.

Omentin-1 attenuates adipose tissue inflammation via restoration of TXNIP/NLRP3 signaling in high-fat diet-induced obese mice.

Omentin-1 is an adipokine expressed by the adipose tissue and is reduced in obesity. This study was designed to calculate the protective efficiency and mechanism of omentin-1 against inflammation of the adipose tissue in obese mice. A transgenic mouse model with omentin-1 protein overexpression was established by crossing omentin-1 transgenic mice with Fabp4-Cre mice. Obesity was induced in the mice by feeding them a high-fat diet for 10 weeks. Fabp4-Cre-mediated overexpression of omentin-1 significantly increased serum omentin-1 level, serum anti-inflammatory factor levels, and expression of M2-specific mRNAs; inhibited body weight and adipose tissue weight gain; improved glucose tolerance, insulin tolerance, and insulin sensitivity; decreased serum levels of insulin and proinflammatory factors, adipocyte size, and expression of M1-specific mRNAs; suppressed macrophage infiltration; downregulated expression of proinflammatory factors; upregulated expression of anti-inflammatory factors; and inhibited thioredoxin-interacting protein (TXNIP)/NOD-like receptor 3 (NLRP3) signaling in the adipose tissue of obese mice. An NLRP3 inhibitor (20 mg/kg MCC950) exhibited the same effects as overexpression of omentin-1. Pretreatment with omentin-1 inhibited lipopolysaccharide-induced inflammation via TXNIP/NLRP3 signaling in RAW 264.7 macrophages. These findings suggest that omentin-1 suppresses adipose tissue inflammation in obese mice, at least partly, via inhibiting the TXNIP/NLRP3 signaling pathway.

Heterogeneity and Proliferative and Differential Regulators of NG2-glia in Physiological and Pathological States.

NG2-glia, also called Oligodendrocyte Precursor Cells (OPCs), account for approximately 5%-10% of the cells in the developing and adult brain and constitute the fifth major cell population in the central nervous system. NG2-glia express receptors and ion channels involved in rapid modulation of neuronal activities and signaling with neuronal synapses, which have functional significance in both physiological and pathological states. NG2-glia participate in quick signaling with peripheral neurons via direct synaptic touches in the developing and mature central nervous system. These distinctive glia perform the unique function of proliferating and differentiating into oligodendrocytes in the early developing brain, which is critical for axon myelin formation. In response to injury, NG2-glia can proliferate, migrate to the lesions, and differentiate into oligodendrocytes to form new myelin sheaths, which wrap around damaged axons and result in functional recovery. The capacity of NG2-glia to regulate their behavior and dynamics in response to neuronal activity and disease indicate their critical role in myelin preservation and remodeling in the physiological state and in repair in the pathological state. In this review, we provide a detailed summary of the characteristics of NG2-glia, including their heterogeneity, the regulators of their proliferation, and the modulators of their differentiation into oligodendrocytes.

Diabetic Cognitive Dysfunction: From Bench to Clinic.

Type 2 diabetes increases the risk of developing cognitive dysfunction in the elderly in the form of short-term memory and executive function impairment. Genetic and diet-induced models of type 2 diabetes further support this link, displaying deficits in working memory, learning, and memory performance. The risk factors for diabetic cognitive dysfunction include vascular disease, hypoglycaemia, hyperlipidaemia, adiposity, insulin resistance, lifestyle factors, and genetic factors. Using neuronal imaging technologies, diabetic patients with cognitive dysfunction show atrophy of the whole brain, particularly the grey matter, hippocampus and amygdala; increased volume of the ventricular and white matter; brain infarcts; impaired network integrity; abnormal microstructure; and reduced cerebral blood flow and amplitude of low-frequency fluctuations. The pathogenesis of type 2 diabetes with cognitive dysfunction involves hyperglycaemia, macrovascular and microvascular diseases, insulin resistance, inflammation, apoptosis, and disorders of neurotransmitters. Large clinical trials may offer further proof of biomarkers and risk factors for diabetic cognitive dysfunction. Advanced neuronal imaging technologies and novel disease animal models will assist in elucidating the precise pathogenesis and to provide better therapeutic interventions and treatment.