Depression-induced cognitive impairment has recently been given more attention in research. However, the relationship between depression and different types of memory is still not clear. Chronic unpredictable mild stress (CUMS) is a commonly used animal model of depression in which animals are exposed to chronic unpredictable environmental and psychological stressors, which mimics daily human life stressors. This study investigated the impact of different durations of CUMS on various types of memory (short- and long-term spatial memory and recognition memory) and investigated CUMS’ impact on the ultrastructural level by histological assessment of the hippocampus and prefrontal cortex. Twenty male C57BL/J6 mice (6 weeks old, 21.8 ± 2 g) were randomly divided into two groups (n = 10): control and CUMS (8 weeks). A series of behavioral tasks were conducted twice at weeks 5–6 (early CUMS) and weeks 7–8 (late CUMS). A tail-suspension test (TST), forced swimming test (FST), elevated zero maze (EZM), elevated plus maze (EPM), open field test (OFT), and sucrose-preference test (SPT) were used to assess anxiety and depressive symptoms. The cognitive function was assessed by the novel object recognition test (NORT; for recognition memory), Y-maze (for short-term spatial memory), and Morris water maze (MWM: for long-term spatial memory) with a probe test (for reference memory). Our data showed that 8 weeks of CUMS increased the anxiety level, reported by a significant increase in anxiety index in both EPM and EZM and a significant decrease in central preference in OFT, and depression was reported by a significant increase in immobility in the TST and FST and sucrose preference in the SPT. Investigating the impact of CUMS on various types of memory, we found that reference memory is the first memory to be affected in early CUMS. In late CUMS, all types of memory were impaired, and this was consistent with the abnormal histological features of the memory-related areas in the brain (hippocampus and prefrontal cortex).
Diabetes mellitus (DM) is the leading cause of chronic kidney disease and diabetic nephropathy is widely studied. In contrast, the pathobiology of diabetic urinary bladder disease is less understood despite dysfunctional voiding being common in DM. We hypothesised that diabetic cystopathy has a characteristic molecular signature. We therefore studied bladders of hyperglycaemic and polyuric rats with streptozotocin (STZ)-induced DM. Sixteen weeks after induction of DM, as assessed by RNA arrays, wide-ranging changes of gene expression occurred in DM bladders over and above those induced in bladders of non-hyperglycaemic rats with sucrose-induced polyuria. The altered transcripts included those coding for extracellular matrix regulators and neural molecules. Changes in key genes deregulated in DM rat bladders were also detected in db/db mouse bladders. In DM rat bladders there was reduced birefringent collagen between detrusor muscle bundles, and atomic force microscopy showed a significant reduction in tissue stiffness; neither change was found in bladders of sucrose-treated rats. Thus, altered extracellular matrix with reduced tissue rigidity may contribute to voiding dysfunction in people with long-term DM. These results serve as an informative stepping stone towards understanding the complex pathobiology of diabetic cystopathy.
Fibromyalgia (FM) is a chronic and debilitating condition characterized by diffuse pain, often associated with symptoms such as fatigue, cognitive disturbances, and mood disorders. Metformin, an oral hypoglycemic agent, has recently gained attention for its potential benefits beyond glucose regulation. It has shown promise in alleviating neuropathic and inflammatory pain, suggesting that it could offer a novel approach to managing chronic pain conditions like FM. This study aimed to further explore metformin’s analgesic potential by evaluating its effects in an experimental FM model induced by reserpine in both male and female mice. After the administration of 200 mg/kg metformin to male and female mice, the FM-related symptoms were assessed, including mechanical allodynia, thermal hyperalgesia, and depressive-like behaviors. A histological examination of the thalamus, hippocampus, and spinal cord was conducted using haematoxylin and eosin staining. The neurotransmitter and proinflammatory cytokines levels were measured in the brains and spinal cords. Our results have shown that metformin treatment for seven days significantly reversed these FM-like symptoms, reducing pain sensitivity and improving mood-related behaviors in both the male and female mice. Additionally, metformin exhibited neuroprotective effects, mitigating reserpine-induced damage in the hippocampus, thalamus, and spinal cord. It also significantly lowered the levels of the proinflammatory cytokine interleukin 1-beta (IL-1β) in the brain and spinal cord. Notably, metformin modulated the neurotransmitter levels differently between the sexes, decreasing glutamate and increasing serotonin and norepinephrine in the male mice, but not in the females. These findings underscore metformin’s potential as an alternative therapy for FM, with sex-specific differences suggesting distinct mechanisms of action.
Background: Diabetes mellitus (DM) is one of the three most common chronic diseases worldwide. This study aimed to determine the prevalence of diabetic polyneuropathy (DPN) among patients with diabetes. Method: This cross-sectional study was carried out on DM patients who visited King Abdulaziz University Hospital (KAUH) between August 2021 and February 2022. We used the Michigan Neuropathy Screening Instrument (MNSI) questionnaire to determine if the patients had DN. In addition, we used the Global Physical Activity Questionnaire (GPAQ) to assess the level of physical activity (PA) in these DM patients. Results: A total of 336 patients consented to participate in the study. We found a DN prevalence of 23.8% amongst DM patients treated at the KAUH. In addition, the prevalence of DN amongst T1DM and T2DM patients was found to be 16% and 24.4%, respectively. Furthermore, we found that 65% of DM patients developed complications, with a significant correlation observed between the duration of DM and the development of complications. However, patient age and sex were non-statistically significantly correlated with the development of complications. Analysis of the GPAQ showed that among the 249 patients who completed the questionnaire, none had a high physical activity level, while 4% and 96% had moderate and low physical activity levels, respectively. No association was found between physical activity and patients’ age, sex, type of DM, duration of DM, and development of complications. Conclusion: DN prevalence amongst DM patients treated at KAUH was 23.8%. The duration of diabetes was found to be a risk factor for DN. However, patient age and sex were non-statistically significantly associated with DN.
Patients with peripheral neuropathy with type 2 diabetes mellitus (T2DM) are more likely to have functional impairments. Recently, the gene for serum sterile alpha and toll/interleukin receptor motif-containing protein 1 (SARM1), which may contribute to the pathogenesis of Wallerian degeneration, was discovered in mice models of peripheral neuropathy. We set out to assess serum SARM1’s activity as a potential biomarker for the early identification of diabetic peripheral neuropathy in T2DM patients while also examining the impact of the COVID-19 vaccine on SARM1 levels. We assessed the cross-sectional relationships between the SARM1 biomarker, clinical neuropathy scales, and nerve conduction parameters in 80 participants aged between 30 years and 60 years. The analysis was carried out after the patients were split into two groups since we discovered a significant increase in SARM1 levels following the second dose of the COVID-19 vaccination, where group A received one dose of the COVID-19 vaccine inoculation, and group B received two doses of the COVID-19 vaccine. SARM1 was correlated significantly (p < 0.05) with MNSIe and NSS in group A and showed a consistent positive correlation with the other neuropathy clinical scales in group A and group B without reaching statistical significance. Additionally, SARM1 was negatively correlated significantly (p < 0.05) with the median sensory amplitude in group A and showed a consistent negative correlation with the six other sensory and motor nerves’ potential amplitude in group A and group B without reaching statistical significance. In conclusion, SARM1 showed a consistent correlation with clinical neuropathy scales and nerve conduction parameters after accounting for the influence of COVID-19 vaccination doses.
Background: Etoricoxib is a widely used anti-inflammatory drug, but its safety profile concerning cardiovascular and renal health remains inadequately explored. This study aimed to assess the nephro- and cardiotoxic effects of etoricoxib in a murine model, with a focus on its impact on arachidonic acid-metabolizing enzymes and beta-adrenergic receptors associated with drug-induced toxicity. Methods: Thirty-five BALB/C mice were randomly assigned to five groups: control, low-dose etoricoxib, high-dose etoricoxib, low-dose celecoxib, and high-dose celecoxib (a well-known nephro- and cardiotoxic NSAID). The treatments were administered for 28 days, after which hearts and kidneys were excised for physical and histopathological analysis, and the expression of arachidonic acid-metabolizing enzymes (cytochrome P450s, lipoxygenases, cyclooxygenases) and beta-1 adrenergic receptor (adrb1) and angiotensin-converting enzyme (ace2) genes were quantified using quantitative reverse transcription PCR (qRT-PCR). Results: Etoricoxib administration resulted in dose-dependent nephro- and cardiotoxic effects. Renal histology revealed glomerular atrophy or hypertrophy and significant damage to the proximal and distal convoluted tubules, including epithelial flattening, cytoplasmic vacuolation, and luminal widening. Cardiac analysis showed disorganized muscle fibers and hyaline degeneration. These changes were associated with altered gene expression: the downregulation of cox2, cyp1a1, and cyp2c29 in the kidneys and the upregulation of cyp4a12, cox2, and adrb1, along with the downregulation of cyp2c29 and ace2 in the heart. Conclusions: Etoricoxib induces nephro- and cardiotoxicity, marked by alterations in arachidonic acid metabolism and beta-adrenergic signaling pathways. The drug affects the expression of arachidonic acid-metabolizing enzymes and adrb1 in the heart while downregulating cox2 and other related enzymes in the kidneys. These findings underscore the need for caution when prescribing etoricoxib, particularly in patients with pre-existing renal or cardiac conditions.