Favorable outcomes of hydroxychloroquine in insulin resistance may be accomplished by adjustment of the endothelial dysfunction as well as the skewed balance of adipokines

Deciphering the immunological interactions: targeting preeclampsia with Hydroxychloroquine's biological mechanisms

Preeclampsia (PE) is a complex pregnancy-related disorder characterized by hypertension, followed by organ dysfunction and uteroplacental abnormalities. It remains a major cause of maternal and neonatal morbidity and mortality worldwide. Although the pathophysiology of PE has not been fully elucidated, a two-stage model has been proposed. In this model, a poorly perfused placenta releases various factors into the maternal circulation during the first stage, including pro-inflammatory cytokines, anti-angiogenic factors, and damage-associated molecular patterns into the maternal circulation. In the second stage, these factors lead to a systemic vascular dysfunction with consecutive clinical maternal and/or fetal manifestations. Despite advances in feto-maternal management, effective prophylactic and therapeutic options for PE are still lacking. Since termination of pregnancy is the only curative therapy, regardless of gestational age, new treatment/prophylactic options are urgently needed. Hydroxychloroquine (HCQ) is mainly used to treat malaria as well as certain autoimmune conditions such as systemic lupus and rheumatoid arthritis. The exact mechanism of action of HCQ is not fully understood, but several mechanisms of action have been proposed based on its pharmacological properties. Interestingly, many of them might counteract the proposed processes involved in the development of PE. Therefore, based on a literature review, we aimed to investigate the interrelated biological processes of HCQ and PE and to identify potential molecular targets in these processes.

Dominance of Pro-Inflammatory Cytokines Over Anti-Inflammatory Ones in Placental Bed of Creta Cases

Objective

The objective of the study is to investigate changes occurring in key inflammatory cytokines at molecular level (including genetic and protein) in placental bed of placenta creta compared to that of normal placenta and their correlation to interstitial extravillous trophoblasts (EVT) number.

Subjects and Methods

Case-control study including placentas of patients with invasive placentation (creta placentas, n = 19) compared with those of normal placentation (n = 19). Besides routine histology and immunocytochemistry detection (cytokeratin-7 [CK-7]), addition to biochemical evaluation of expression of various cytokines including tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β), IL6, IL-1RA, IL-8, IL-10, and IL-13 was carried out.

Results

Routine histological examination of placentas of creta cases revealed CK-7+ extravillous trophoblasts (EVT) penetrating deeply the myometrium with various histopathological arrangements and trophoblastic vascular invasion of the deep myometrial blood vessels. A significant increase (P < 0.05) in the mRNA expression of TNF-α, IL-1 β, and IL6 with an insignificant decrease in placental bed IL-1RA, IL-8, IL-10, and IL-13 was observed in creta cases compared to the control ones. A corresponding significant increase was detected in the protein levels of TNF-α, IL-1 β, and IL-6 as well as an insignificant decrease in placental bed IL-1RA, IL-8, IL-10, and IL-13 in creta cases compared to the normal ones. Moreover, we displayed a significant positive correlation (P < 0.05) between interstitial EVT number and mRNA expression of almost all pro-inflammatory cytokines with negative but insignificant correlation with anti-inflammatory cytokines in creta cases.

Conclusion

The upregulated pro-inflammatory cytokines and the correlation of their expression with the increased interstitial EVT provide a supporting evidence of their potentially more relevant role in the development of placenta creta than the anti-inflammatory ones.

Oral nano-formulation improves pancreatic islets dysfunction via lymphatic transport for antidiabetic treatment

Type 2 diabetes mellitus (T2DM) therapy is facing the challenges of long-term medication and gradual destruction of pancreatic islet β-cells. Therefore, it is timely to develop oral prolonged action formulations to improve compliance, while restoring β-cells survival and function. Herein, we designed a simple nanoparticle with enhanced oral absorption and pancreas accumulation property, which combined apical sodium-dependent bile acid transporter-mediated intestinal uptake and lymphatic transportation. In this system, taurocholic acid (TCA) modified poly(lactic-co-glycolic acid) (PLGA) was employed to achieve pancreas location, hydroxychloroquine (HCQ) was loaded to execute therapeutic efficacy, and 1,2-dilauroyl-sn-glycero-3-phosphocholine (DLPC) was introduced as stabilizer together with synergist (PLGA-TCA/DLPC/HCQ). In vitro and in vivo results have proven that PLGA-TCA/DLPC/HCQ reversed the pancreatic islets damage and dysfunction, thus impeding hyperglycemia progression and restoring systemic glucose homeostasis via only once administration every day. In terms of mechanism PLGA-TCA/DLPC/HCQ ameliorated oxidative stress, remodeled the inflammatory pancreas microenvironment, and activated PI3K/AKT signaling pathway without obvious toxicity. This strategy not only provides an oral delivery platform for increasing absorption and pancreas targetability but also opens a new avenue for thorough T2DM treatment.

Supplemental hydroxychloroquine therapy regulates adipokines in patients with systemic lupus erythematosus with stable disease

BACKGROUND

In patients with systemic lupus erythematosus (SLE), a higher frequency of atherosclerotic lesions is associated with poor prognosis. Hydroxychloroquine (HCQ) has been reported to improve the lifespan and the prognosis of dyslipidaemia in patients with SLE, but the mechanism is unclear. We investigated the effect of supplemental HCQ treatment on the levels of serum cytokines associated with atherosclerosis in patients with stable SLE.

METHODS

Patients with SLE who received supplemental HCQ and maintained low disease activity between January 2016 and September 2020 were included in this study. Disease activity was assessed using Safety of Estrogens in Lupus National Assessment-SLE Disease Activity Index, Cutaneous Lupus Erythematous Disease Area and Severity Index, and Lupus Low Disease Activity State. Serum complement titres, anti-dsDNA antibodies, and serum cytokines (adiponectin, resistin, and leptin) were analyzed before and after HCQ treatment.

RESULTS

Forty-one patients (4 males and 37 females, mean age 41.3 ± 13.2 years) were included. Serum adiponectin levels were significantly increased after 3 months of HCQ treatment compared to baseline, and serum resistin levels were significantly reduced. The change in serum resistin level after HCQ administration was correlated with a significant reduction in serum TNF-α, interleukin (IL)-6, IL-8, and IL-1RA levels.

CONCLUSIONS

Supplemental HCQ treatment in patients with SLE improved adipokine levels. HCQ may improve prognosis by controlling disease activity in SLE and reducing risk factors for atherosclerosis. Key Points • Hydroxychloroquine has been reported to improve the prognosis of dyslipidaemia in patients with SLE, but the underlying mechanism is unclear. • In this study, hydroxychloroquine improved adipokine levels in patients with SLE, implicating adipokines as a potential mechanism underlying the benefit of hydroxychloroquine on dyslipidaemia. • Supplemental hydroxychloroquine should be considered in patients with SLE harboring lipid abnormalities and risk factors for atherosclerosis.

Molecular Changes in the Adipose Tissue Induced by Rheumatoid Arthritis: Effects of Disease-Modifying Anti-Rheumatic Drugs

Disease severity, progression and response to therapy might be worse in obese rheumatoid arthritis (RA) patients, but paradoxically, obesity also might protect from radiographic joint damage. Thus, the intricate relationship between obesity and RA needs urgent clarification. The aim of this study was to assess the influence of obesity on the onset and development of RA and to determine whether arthritis could modify the adipose tissue biology and whether conventional Disease Modifying Anti-Rheumatic Drugs (cDMARDs) can modulate these alterations. Two strategies were followed: (1) clinical profiling of two cohorts of RA: non-obese and obese patients; and (2) mechanistic studies carried out in both a collagen-induced arthritis (CIA) in an obese mouse model and 3T3-L1 adipocytes treated with cDMARDs (leflunomide, methotrexate, and hydroxychloroquine). In our cohort of RA patients with low-moderate disease activity, the presence of obesity was not related to a higher activity of the disease; actually, disease activity score 28-erythrocyte sedimentation rate (DAS28-ESR) was reduced in the obese RA patients. However, the induction of arthritis promoted transcriptomic changes in the adipose tissue under obesity condition in the obese CIA model. Treatment with hydroxychloroquine reduced weight and insulin resistance, accompanied by beneficial metabolic effects in the adipose tissue. These molecular changes in adipose tissue were also observed after methotrexate administration. In sum, arthritis might affect directly the inflammatory burden and metabolic alterations associated with obesity in adipose tissue. Clinicians should be cautious measuring the activity of the disease in obesity and managing the best therapeutic options for the metabolic comorbidities of these patients, where the combination of hydroxychloroquine and methotrexate should be considered to improve adipose tissue dysfunction in obese RA.

COVID-19, hydroxychloroquine and the importance of disease progression

The COVID-19 pandemic struck swiftly and forcefully. The medical response both commercial and clinical achieved what it could with the resources it had. In addition, society changed old habits and developed new behavior patterns. It is appropriate to identify what lessons were learned from COVID-19 for the future. The most important observation for managing SARS-CoV-2 infections was the identification, but not necessarily appreciation, of the manner in which the virus acts over time in the host that it infects. Based on population densities, the ease with which people are mobile and the way that SARS-CoV-2 infected humans, other infectious diseases can easily become pandemics in the future. This review is not focused on a xenobiotic and its toxicant properties. Rather, the review describes the relationship between a therapeutic (hydroxychloroquine) and the progression of a disease (SARS-CoV-2) along with the timing and sequence of the various pathologies that the disease causes. While at first glance, this may appear to beyond the scope of toxicology, it is not. Toxicology is capable to address disease-induced pathologies because it can use the same skills and tools that it uses for pathologies that xenobiotics cause. Assessing the pathology caused by a disease concurrently with the pathology caused by the drug used to treat the disease, puts toxicology in a position to make a greater contribution to drug development. Repurposing toxicology, just as drugs were repurposed for the COVID-19 pandemic, will avoid missing or misusing a useful therapeutic agent just because the disease-initiated pathology was ignored or unappreciated.

Repurposing New Use for Old Drug Chloroquine against Metabolic Syndrome: A Review on Animal and Human Evidence

Chloroquine (CQ) and hydroxychloroquine (HCQ) are traditional anti-malarial drugs that have been repurposed for new therapeutic uses in many diseases due to their simple usage and cost-effectiveness. The pleiotropic effects of CQ and HCQ in regulating blood pressure, glucose homeostasis, lipid, and carbohydrate metabolism have been previously described in vivo and in humans, thus suggesting their role in metabolic syndrome (MetS) prevention. The anti-hyperglycaemic, anti-hyperlipidaemic, cardioprotective, anti-hypertensive, and anti-obesity effects of CQ and HCQ might be elicited through reduction of inflammatory response and oxidative stress, improvement of endothelial function, activation of insulin signalling pathway, inhibition of lipogenesis and autophagy, as well as regulation of adipokines and apoptosis. In conclusion, the current state of knowledge supported the repurposing of CQ and HCQ usage in the management of MetS.

Recent Clinical and Preclinical Studies of Hydroxychloroquine on RNA Viruses and Chronic Diseases: A Systematic Review

The rapid spread of the new Coronavirus Disease 2019 (COVID-19) has actually become the newest challenge for the healthcare system since, to date, there is not an effective treatment. Among all drugs tested, Hydroxychloroquine (HCQ) has attracted significant attention. This systematic review aims to analyze preclinical and clinical studies on HCQ potential use in viral infection and chronic diseases. A systematic search of Scopus and PubMed databases was performed to identify clinical and preclinical studies on this argument; 2463 papers were identified and 133 studies were included. Regarding HCQ activity against COVID-19, it was noticed that despite the first data were promising, the latest outcomes highlighted the ineffectiveness of HCQ in the treatment of viral infection. Several trials have seen that HCQ administration did not improve severe illness and did not prevent the infection outbreak after virus exposure. By contrast, HCQ arises as a first-line treatment in managing autoimmune diseases such as rheumatoid arthritis, lupus erythematosus, and Sjögren syndrome. It also improves glucose and lipid homeostasis and reveals significant antibacterial activity.

Benefits and adverse effects of hydroxychloroquine, methotrexate and colchicine: searching for repurposable drug candidates

Repurposing of antirheumatic drugs has garnered global attention. The aim of this article is to overview available evidence on the use of widely used antirheumatic drugs hydroxychloroquine, methotrexate and colchicine for additional indications. Hydroxychloroquine has endothelial stabilizing and anti-thrombotic effects. Its use has been explored as an adjunctive therapy in refractory thrombosis in antiphospholipid syndrome. It may also prevent recurrent pregnancy losses in the absence of antiphospholipid antibodies. Hydroxychloroquine favourably modulates atherogenic lipid and glycaemic profiles. Methotrexate has been tried for modulation of cardiovascular events in non-rheumatic clinical conditions, although a large clinical trial failed to demonstrate a benefit. Colchicine has been shown to successfully reduce the risk of recurrent cardiovascular events in a large multicentric trial. Potential antifibrotic effects of colchicine require further exploration. Hydroxychloroquine, methotrexate and colchicine are also being tried at different stages of the ongoing Coronavirus Disease 19 (COVID-19) pandemic for prophylaxis and treatment. While the use of these agents is being diversified, their adverse effects should be timely diagnosed and prevented. Hydroxychloroquine can cause retinopathy and rarely cardiac and auditory toxicity, retinopathy being dose and time dependent. Methotrexate can cause transaminitis, cytopenias and renal failure, particularly in acute overdoses. Colchicine can rarely cause myopathies, cardiomyopathy, cytopenias and transaminitis. Strong evidence is warranted to keep balance between benefits of repurposing these old antirheumatic drugs and risk of their adverse effects.

Impact of liraglutide on microcirculation in experimental diabetic cardiomyopathy

Liraglutide is a new therapy used in diabetes and its effect on diabetic complications particularly cardiovascular ones is still under investigated. In our research, we tried to study the effect of liraglutide on experimental diabetic cardiomyopathy (DCM) induced by streptozotocin. We found that liraglutide nearly preserved normal myocardiac structure and significantly protected against myocardiac inflammation and fibrosis that was found in DCM group, p < 0.05. It also increased the density of coronary arteriolar vasculature markedly indicated by significant increase in α SMA (p < 0.05) compared to both DCM and non-diabetic (ND) groups. Moreover, liraglutide decreased TNFα and increased VEGF proteins expression (P < 0.05) compared to DCM group. Conclusion, liraglutide may have a very important role in protecting against experimentally induced diabetic cardiomyopathy by preventing the degenerative changes in the cardiomyocytes and the associated fibrosis, inflammation and decreased vasculature at structural and molecular levels.

Dysplastic urothelial changes accompany empagliflozin administration in urinary bladder of experimental diabetes

Empagliflozin (EMPA) is a promising novel antidiabetic drug; however, doubts have been raised regarding its use and the increased risk of urinary bladder carcinoma. In this study, we evaluated urothelium expression of cytokeratins (CKs) and Ki-67 proliferative activity in the urinary bladder of diabetic (DM + EMPA) and non-diabetic rats after EMPA administration. By routine histology, dysplastic changes were detected in the urothelium of diabetic as well as non-diabetic animals after EMPA administration. Moreover, the expression of CK-7 and CK-8 was significantly decreased (P < .05) while that of CK-20 as well as Ki-67 was significantly increased (P < .05) in EMPA per se and DM + EMPA urothelium groups compared to that of control and diabetics. The dysplastic changes together with the increased proliferative activity in urothelium after EMPA administration provide a cellular evidence that supports the former clinical concerns.

Impact of vildagliptin on vascular and fibrotic remodeling of myocardium in experimental diabetic cardiomyopathy

The effect of dipeptidyl peptidase-4 inhibitors (DPP-4is) on myocardium in diabetic cardiomyopathy (DCM) remains a matter of debate. In the current study we investigated the effect of vildagliptin (VILDA, 3 mg/kg/d) on myocardium of DCM focusing on coronary microcirculation as well as on endothelial stress markers (ICAM and VCAM). We divided animals equally into 4 groups; nondiabetic (ND), VILDA per se, DCM and DCM + VILDA and their myocardium was evaluated for the fibro-vascular remodeling immunohistochemically as well as for molecular changes. VILDA had reversed the histological changes occurred in DCM including the disintegration, degeneration, and steatosis of cardiomyocytes with disappearance of the edema fluid. In addition VILDA significantly increased (p < 0.05) density of the coronary microcirculation and relieved endothelial stress. However, it did not prevent the development of fibrotic remodeling including the increased collagen deposition and the significantly upregulated (p < 0.05) corresponding genes. Therefore VILDA may have a positive impact on the microvascular remodeling, but not on fibrotic changes, in DCM.

Potential Effect of Hydroxychloroquine in Diabetes Mellitus: A Systematic Review on Preclinical and Clinical Trial Studies

BACKGROUND

Diabetes mellitus is a chronic metabolic disorder characterized by persistent hyperglycemia. It affects millions of people globally. In spite of many antidiabetic drugs that are available, an adequate level of control remains challenging. Hydroxychloroquine is an immunomodulatory drug that has been used for the treatment of malaria and autoimmune diseases. There is an emerging evidence that suggests its beneficial effect against diabetes mellitus. Therefore, this systematic review is aimed at discoursing the role of hydroxychloroquine against diabetes mellitus and its potential mechanisms of actions.

METHODS

A systematic and manual searching was carried out to retrieve relevant articles (preclinical and clinical studies) published from January 2014 to July 2019. Electronic databases including PubMed and Scopus as well as clinicaltrials.gov have been searched using different searching terms: "hydroxychloroquine," "diabetes mellitus," "hyperglycemia," and "insulin resistance." The MeSH terms (PubMed) and text words were combined with "AND" or "OR." In addition, manual searching of Google Engine and Google Scholar was conducted. Quality assessment of all the included studies was performed using CAMARADES (preclinical studies) and the Newcastle-Ottawa Scale and Cochrane Collaboration's tools (clinical studies).

RESULTS

A total of eighteen studies (three experimental and fifteen clinical studies) were found to be eligible for the present systematic review. Among the included clinical studies (six randomized control trials, five observational studies, and four cohort studies), about 55,776 study participants were involved. Most of these studies showed significant improvement of lipid profile and insulin levels and substantial diminution of hemoglobin A1c, fasting plasma glucose, and postprandial blood glucose levels. Reduction in lysosomal degradation of the internal insulin-insulin receptor complex and enhancement in insulin sensitivity and adiponectin levels are some of the hypothesized mechanisms for the antidiabetic effect of hydroxychloroquine.

CONCLUSION

The current review provides preliminary evidence for potential antidiabetic properties of hydroxychloroquine. Though the provided available data were promising, further clinical trials and mechanistic studies are needed to determine its long-term effects.

Modulatory effect of empagliflozin on cellular parameters of endocrine pancreas in experimental pre-diabetes

The effect of empagliflozin (EMPA), a sodium-glucose cotransporter 2 inhibitor (SGLT2i), on the structure of endocrine pancreas in pre-diabetes (Pre-DM) is not yet elucidated. In the current study the relatively enlarged islets of Langerhans seen in the Pre-DM group was restored to control size by administration of EMPA. In addition the disbalance in the percentage of β-cells and α-cells in islets of the Pre-DM was corrected in the Pre-DM + EMPA group with reversal of the significantly increased islet mass, β-cell mass and neogenesis. Administrating EMPA in Pre-DM decreased level of caspase-3, increased that of Bcl-2 to control level and reduced the significantly increased inflammatory cytokines to levels approximated to those of the control group. In Pre-DM + EMPA group, EMPA had efficiently restored the significantly impaired glucose hemostasis to levels nearly similar to those of the control animals. This may indicate that the modulatory effect of EMPA on cells of the islets in Pre-DM is associated with a local pleotropic effect on inflammatory cytokines.

Increased mast cell number is associated with a decrease in beta-cell mass and regeneration in type 2 diabetic rats

The role of mast cells (MCs) in type 2 diabetes (T2D) is not thoroughly studied as much as in T1D. Therefore in the current study we investigated correlation between these cells and various parameters of islets of Langerhans (IOL) in rats which were equally divided (n = 40) into; control and diabetic groups. We detected a significantly increased (p < 0.05) MC count (MCC) in the diabetic IOL compared to the control, together with a noticeable intra-islet seeding of these cells which displayed a tryptase positive immunostaining. A significant positive correlation (p < 0.05) between MCC and the % of glucagon cells per islet was detected in DM, unlike mass of the islets, mass of β-cells, and % of β-cells per islet which were negatively correlated with MCC. Similarly, there was a negative correlation between MCC with β-cell proliferation and neogenesis frequency in DM. This highlights the potential association between the increased MC number and the diminished islet`s mass as well as regeneration which may fasten the progression of T2D.

Real-World Clinical Effectiveness and Tolerability of Hydroxychloroquine 400 Mg in Uncontrolled Type 2 Diabetes Subjects who are not Willing to Initiate Insulin Therapy (HYQ-Real-World Study)

OBJECTIVE

The epidemic of T2DM is rising across the globe. Systemic inflammation plays a pivotal role in the pathogenesis and complications of T2DM. Combination of two or more oral hypoglycemic agents (OHA) is widely prescribed in patients with T2DM, however many patients have poor glycemic control despite receiving combination therapy. The new antidiabetic drugs are relatively costly or many patients have anxiety over the use of injectable insulin. The objective of this observational study was to investigate the effectiveness and tolerability of hydroxychloroquine (HCQ) in T2DM patients uncontrolled on multiple OHA and despite high sugar level not willing to initiate insulin therapy in a real-world clinical setting.

METHODS

A prospective, investigator-initiated, observational, single-centred study was conducted where 250 patients (18-65 years) with T2DM for more than 5 years, with uncontrolled glycemia despite on a combination of multiple OHA, HbA1c between ≥7% and <10.5%, FPG >130 mg/dL or PPG >180 mg/dL and BMI between >25 and <39 kg/m2, were prescribed hydroxychloroquine sulphate 400 mg once daily for 48 weeks. Percentage of drugs used at the baseline were as follows: metformin 2000 mg (100%), glimepiride 4 mg (100%), pioglitazone 30 mg (100%), sitagliptin 100 mg (100%), canagliflozin 300 mg (52.4%), empagliflozin 25 mg (22.8%), dapagliflozin 10 mg (17.6%) and voglibose 0.3 mg (62%). Mean change in HbA1c, blood glucose and hs-CRP at baseline, week 12, 24 and 48 were assessed using the paired t-test.

RESULTS

After 48 weeks of add-on treatment with HCQ, almost all SGLT-2 inhibitors were withdrawn; metformin dose was reduced to 1000 mg, glimepiride reduced to 1 mg and sitagliptin reduced to 50 mg OD. Patients continued to have good glycemic control. HbA1c was reduced from 8.83% to 6.44%. Reduction in FPG was 40.78% (baseline 177.30 mg/dL) and PPG was reduced by 58.95% (baseline 329.86 mg/dL). Change in mean body weight was -4.66 Kg. The reduction in glycemic parameters and mean body weight was significant (p < 0.0001). Hs-CRP was significantly reduced from 2.70±1.98 mg/L to 0.71±0.30 mg/L 9 (p < 0.0001). More reduction in glycemic parameters and body weight was observed among the patients with higher hs-CRP (> 3 mg/L) as compared to patients with baseline hs- CRP ≤ 3 mg/L. Most common adverse events reported with the drug therapy were GI irritation (3.6%) and hypoglycemia (2%). None of the patients required medical assistance for hypoglycemia.

CONCLUSION

Add-on treatment of HCQ effectively improved glycemic control in T2DM patients uncontrolled on multiple antidiabetic drugs. By virtue of its antidiabetic and anti-inflammatory properties, it may emerge as a valuable therapeutic intervention for the patients with T2DM.

Correlation between pancreatic mast cells and the low grade inflammation in adipose tissue of experimental prediabetes

The role of mast cells (MCs) in prediabetes (Pre-DM) is not clearly elucidated. In the current study rats (n = 22 each) were divided equally into; control and Pre-DM (received high fat diet, HFD) groups. Samples from pancreas as well as from visceral adipose tissue (VAT) were studied for the consequent changes. We detected a significantly increased mast cell count (MCC) in the pancreas of Pre-DM compared to that of control. Frequent degranulation of MC granules was observed in Pre-DM. VAT of the Pre-DM had significantly increased (p < 0.05) macrophages (CD68⁺) and mast cells (tryptase⁺) compared to that of the control. A significant increase (p < 0.05) in CD68 mRNA expression as well as in the level of IL-1 β, IL-6, TNF-α and TGF- β1 was detected in VAT of Pre-DM with a significant positive correlation (p < 0.05) with the MCC. All these findings may indicate a potential role of MC in the low grade inflammation of VAT in Pre-DM.

The Proposal of Molecular Mechanisms of Weak Organic Acids Intake-Induced Improvement of Insulin Resistance in Diabetes Mellitus via Elevation of Interstitial Fluid pH

Blood contains powerful pH-buffering molecules such as hemoglobin (Hb) and albumin, while interstitial fluids have little pH-buffering molecules. Thus, even under metabolic disorder conditions except severe cases, arterial blood pH is kept constant within the normal range (7.35~7.45), but the interstitial fluid pH under metabolic disorder conditions becomes lower than the normal level. Insulin resistance is one of the most important key factors in pathogenesis of diabetes mellitus, nevertheless the molecular mechanism of insulin resistance occurrence is still unclear. Our studies indicate that lowered interstitial fluid pH occurs in diabetes mellitus, causing insulin resistance via reduction of the binding affinity of insulin to its receptor. Therefore, the key point for improvement of insulin resistance occurring in diabetes mellitus is development of methods or techniques elevating the lowered interstitial fluid pH. Intake of weak organic acids is found to improve the insulin resistance by elevating the lowered interstitial fluid pH in diabetes mellitus. One of the molecular mechanisms of the pH elevation is that: (1) the carboxyl group (R-COO⁻) but not H⁺ composing weak organic acids in foods is absorbed into the body, and (2) the absorbed the carboxyl group (R-COO⁻) behaves as a pH buffer material, elevating the interstitial fluid pH. On the other hand, high salt intake has been suggested to cause diabetes mellitus; however, the molecular mechanism is unclear. A possible mechanism of high salt intake-caused diabetes mellitus is proposed from a viewpoint of regulation of the interstitial fluid pH: high salt intake lowers the interstitial fluid pH via high production of H⁺ associated with ATP synthesis required for the Na⁺,K⁺-ATPase to extrude the high leveled intracellular Na⁺ caused by high salt intake. This review article introduces the molecular mechanism causing the lowered interstitial fluid pH and insulin resistance in diabetes mellitus, the improvement of insulin resistance via intake of weak organic acid-containing foods, and a proposal mechanism of high salt intake-caused diabetes mellitus.

Favorable outcomes of metformin on coronary microvasculature in experimental diabetic cardiomyopathy

Although metformin is widely prescribed in diabetes, its use with associated cardiac dysfunction remains debatable. In the current study, we investigated the effect of metformin on coronary microvasculature in experimental diabetic cardiomyopathy (DCM) induced by streptozotocin. Administration of metformin after induction of DCM, reversed almost all cardiomyocyte degenerative changes induced by DCM. Metformin diminished the significantly increased (p < 0.05) collagen deposited in the DCM. In addition metformin had improved the density of the significantly decreased arteriolar (αSMA⁺) and capillary (CD31⁺) coronary microvasculature compared to that of the DCM and non-diabetics (ND) with downregulation of the significantly increased expression (p < 0.05) of COL-I, III, TGF-β, CTGF, ICAM and VCAM genes. Therefore metformin may be beneficial in limiting the fibrotic and the vascular remodeling occurring in DCM at the genetic as well as the structural levels.

Correlation between testicular mast cell count and spermatogenic epithelium in non-obstructive azoospermia

Although there is emerging evidence that mast cells are involved in infertility, their exact role has not been elucidated clearly. Here we carried out a retrospective case-control study to find out whether there is a correlation between mast cell (MC) count and proliferation (Ki67 index) of the spermatogenic epithelium as well as of the Sertoli cells (vimentin-positive) in non-obstructive azoospermia (NOA). We assessed MCs, Ki67 and vimentin expression in Sertoli cells in testicular biopsies of germ cell aplasia (GCA, n = 14) and maturation arrest (MA, n = 14) vs. normal spermatogenesis (n = 14) cases. There was a significant decrease in the spermatogonial Ki67 index (1.25 ± 0.91, 4.21 ± 1.81 vs. 39.57 ± 3.92) and Johnsen score (2.48 ± 0.65, 4.89 ± 1.05 vs. 9.75 ± 0.30) as well as a significant increase (P < 0.001) in MC count (29.00 ± 4.11, 7.57 ± 1.95 vs. 3.00 ± 1.30) in seminiferous tubules of infertile cases with GCA and MA vs. controls. On the other hand, the percentage of vimentin-expressing Sertoli cells was significantly decreased (P < 0.001) in biopsies of cases with MA (35.50 ± 15.62) compared to those of cases with GCA and controls (72.64 ± 10.67 and 98.57 ± 1.45 respectively). Additionally, a significant negative correlation was detected between MC count and Ki67 index as well as Johnsen score in the MA group which became more significant in the GCA group. The significant increase in MC count in the GCA group and to a lesser extent in the MA group indicates their possible role in NOA particularly at the spermatogonial proliferation level and this is supported by the significant negative correlation with the Ki67 index.

Vascular and cellular changes accompany altered expression of angiopoietins in placenta of non-complicated ART pregnancies

BACKGROUND

ART is steadily performed for infertility cases and most of the previous researches have focused on complicated pregnancies. Nonetheless, few ones have concerned with placenta of ART in non-complicated pregnancies.

OBJECTIVES

To investigate the expression of angiopoietins (ANG) and their receptor, TIE-2, in placenta of full-term non-complicated pregnancies having ART (n=28) versus those with spontaneous conception (n=28) together with the histological as well as morphometric analysis.

RESULTS

While no prominent changes were noticed in the histological structure of the placenta ART pregnancies, it showed a significant decrease (p<0.05) in the percentage of syncytial area and numbers of syncytial knots with insignificant reduction in the placental villous area. Vascular changes in the form of significant decrease (p<0.05) in the chorionic vessel diameter and significant increase (p<0.05) in percentage of vessel area were detected in the ART placenta. In addition, the levels ANG-1, ANG-2 and TIE-2 were significantly increased (p<0.05) in the ART placentas compared with those of SC.

CONCLUSIONS

We demonstrated that there is an altered expression of angiopoietins accompanying the morphometric changes occurring in placenta of ART pregnancies. These changes may indicate vascular and cellular adaptation mechanism for a potential subclinical hypoxia in placenta of ART even in non-complicated pregnancies.