A Novel Nonsense INS Mutation Causes Inefficient Preproinsulin Translocation Into the Endoplasmic Reticulum

Preproinsulin (PPI) translocation across the membrane of the endoplasmic reticulum (ER) is the first and critical step of insulin biosynthesis. Inefficient PPI translocation caused by signal peptide (SP) mutations can lead to β-cell failure and diabetes. However, the effect of proinsulin domain on the efficiency of PPI translocation remains unknown. With whole exome sequencing, we identified a novel INS nonsense mutation resulting in an early termination at the 46th residue of PPI (PPI-R46X) in two unrelated patients with early-onset diabetes. We examined biological behaviors of the mutant and compared them to that of an established neonatal diabetes causing mutant PPI-C96Y. Although both mutants were retained in the cells, unlike C96Y, R46X did not induce ER stress or form abnormal disulfide-linked proinsulin complexes. More importantly, R46X did not interact with co-expressed wild-type (WT) proinsulin in the ER, and did not impair proinsulin-WT folding, trafficking, and insulin production. Metabolic labeling experiments established that, despite with an intact SP, R46X failed to be efficiently translocated into the ER, suggesting that proinsulin domain downstream of SP plays an important unrecognized role in PPI translocation across the ER membrane. The study not only expends the list of INS mutations associated with diabetes, but also provides genetic and biological evidence underlying the regulation mechanism of PPI translocation.

SGC-CK2-1 Is an Efficient Inducer of Insulin Production and Secretion in Pancreatic β-Cells

The pyrazolopyrimidine based compound SGC-CK2-1 is a potent and highly specific CK2 inhibitor and a new tool to study the biological functions of protein kinase CK2 irrespective from off-target effects. We used this compound in comparison with the well-established CK2 inhibitor CX-4945 to analyze the importance of CK2 for insulin production and secretion from pancreatic β-cells. Both inhibitors affected the proliferation and viability of MIN6 cells only marginally and downregulated the endogenous CK2 activity to a similar level. Furthermore, both inhibitors increased the message for insulin and boosted the secretion of insulin from storage vesicles. Thus, regarding the high specificity of SGC-CK2-1, we can clearly attribute the observed effects to biological functions of protein kinase CK2.

Association of Fatty Liver (Non-Alcoholic), Metabolic Syndrome and Subclinical Inflammation on Mild Renal Inadequacy

Background: Non-alcoholic liver disease causes liver damage and influences the insulin production, metabolic and inflammatory pathways and renal sufficiency. Aim: To find an association of fatty liver, metabolic syndrome and subclinical inflammation on mild renal inadequacy. Study design: Comparative analytical study Place and duration of study: Department of Medicine, Bolan Medical College Quetta from 1st January 2020 to 30th June 2021. Methodology: One hundred and twenty patients were enrolled. They were divided in two groups; 60 controls and 60 non-alcoholic fatty liver disease patients age between 30-55 years of age included. Their demographic, ultrasonography, anthropometric measurements and biochemical details were recorded. Results: There were 34 men out of 60 having NA fatty liver with a mean age of 45±5.8 years. Mild renal inadequacy was seen in 21, metabolic syndrome in 27, hypertension in 18 and diabetes in 8 of non-alcoholic fatty liver patients with a mean raised CRP as 1.5±0.8mg/L. Conclusion: Non-alcoholic fatty liver presence in addition to metabolic syndrome and subclinical inflammation effect on mild renal inadequacy Key words: Fatty liver, Metabolic syndrome, Subclinical inflammation, Mild renal inadequacy

Antioxidative Activity of Wakouba, a Salt Extracted from Elaeis guineensis Jacq in Streptozotocin-Induced Diabetic Rats

Background: Oxidative stress plays a major role in the chronic complications of diabetes, high blood pressure, cancer etc. free radicals such as superoxyde anions, hydrogen peroxides cause severe cell damage. The use of plants is increasingly recommended to treat diseases related to oxidative stress. Aims: This work aims to evaluate the antioxidant properties of Wakouba, a salt extracted from Elaeis guineensis Jacq on biochemical markers of oxidative stress. Place and Duration of Study: Pharmacodynamie-biochemical UPR, Biology and Health Laboratory and Department of Radiology, Services Institute of Medical Sciences (SIMS), Services Hospital Lahore, between March 2017 and July 2018. Materials and Methods: Diabetes was induced in Wistar rats (Rattus norvegicus) by streptozotocin 55 mg / kg bw. The biochemical parameters such as insulin and glycemia, the activities and the level of markers of oxidative stress such as superoxide dismutase (SOD), Catalase (CAT) and Malondialdehyde (MDA) in the aorta, heart and the kidney were determined in the absence and presence of different doses of WAKOUBA (1000 and 2500 mg / kg bw) and GLIBENCLAMIDE, a reference product at 10 and 20 mg / kg bw. Results: The results showed that the administration of streptozotocin at 55 mg / kg bw in rats caused a significant drop (P<0.05) in insulin production followed by a significant increase (P < 0.05) in blood glucose. Similarly, during diabetes, the activities, and levels of oxidative stress markers (SOD, CAT and MDA) increased significantly (P < 0.05). WAKOUBA, at 1000 and 2500 mg / kg bw, significantly normalized insulin production, blood sugar levels, SOD and CAT activities and MDA levels in the aorta, heart, and kidneys in diabetic rats. The same results were obtained with GLIBENCLAMIDE at 10 and 20 mg / kg bw. Conclusion: This study showed that WAKOUBA, a salt extracted from Elaeis guineensis Jacq, lowered and normalized the activities of SOD, CAT and the level of MDA which are markers of oxidative stress in rats made diabetic by streptozocin. WAKOUBA also normalized insulin production and blood sugar levels in diabetic rats. WAKOUBA would have antioxidant properties coupled with antidiabetic properties, which might support its use in traditional medicine to treat diabetes.

N-3 PUFA and Pregnancy Preserve C-Peptide in Women with Type 1 Diabetes Mellitus

Type 1 diabetes (T1DM) is an autoimmune disease characterized by the gradual loss of β-cell function and insulin secretion. In pregnant women with T1DM, endogenous insulin production is absent or minimal, and exogenous insulin is required to control glycemia and prevent ketoacidosis. During pregnancy, there is a partial decrease in the activity of the immune system, and there is a suppression of autoimmune diseases. These changes in pregnant women with T1DM are reflected by Langerhans islet enlargement and improved function compared to pre-pregnancy conditions. N-3 polyunsaturated fatty acids (n-3 PUFA) have a protective effect, affect β-cell preservation, and increase endogenous insulin production. Increased endogenous insulin production results in reduced daily insulin doses, better metabolic control, and adverse effects of insulin therapy, primarily hypoglycemia. Hypoglycemia affects most pregnant women with T1DM and is several times more common than that outside of pregnancy. Strict glycemic control improves the outcome of pregnancy but increases the risk of hypoglycemia and causes maternal complications, including coma and convulsions. The suppression of the immune system during pregnancy increases the concentration of C-peptide in women with T1DM, and n-3 PUFA supplements serve as the additional support for a rise in C-peptide levels through its anti-inflammatory action.

REVIEW OF POTENTIAL PLANTS IN INDONESIA AS AN ANTIDIABETIC WITH HYPOGLYCEMIC ACTIVITIES

Background: Diabetes mellitus which is characterized by hyperglycemia is a metabolic disease due to insulin action, defects in insulin secretion, or both. Various studies have shown that herbs that have a hypoglycemic effect can be used in the treatment of diabetes mellitus. Generally, herbs can slow down the complications of diabetes mellitus and improve metabolism. The ability of plants to restore the function of pancreatic tissue to increase insulin production or make it easier for insulin to process glucose is related to the effects of hypoglycemia. Objective: Comparing plants that have a hypoglycemic activity that can be used in the treatment of diabetes mellitus in Indonesia. Methods: studying literature from various databases, websites, national journals, and relevant international journals to identify plants that have hypoglycemic activity. Results: The mechanism A. sativum as a hypoglycemic involves different fiber viscosities; A. vera involved as a hypoglycemic by protecting pancreatic? cells; Asiatic acid in C. asiatica increasing glycolysis by restoring the activity of key enzymes; G. max inhibiting ?-amylase and the stigmasterol increasing the absorption of blood glucose and reducing insulin resistance; P. macrocarpa exert their antidiabetic action via ?-glucosidase modulation, an extra distinctive pancreatic mechanism; S. arvensis has the potential to inhibit ?-amylase enzymes. Conclusions: This review article has presented 6 detailed comparisons of plants that have a hypoglycemic activity that can be used in the treatment of diabetes mellitus in Indonesia and we believe can be useful for students, researchers, or practitioners. Keywords: Diabetes mellitus, hypoglycemia, Indonesian plants

Transformation and characterization of human insulin precursor gene in Pichiapastoris X-33

The case of diabetes increases significantly and has been projected to reach 592 million people in 2035. Consequently, the necessity of insulin will rise manifold and an efficient production system for insulin production is required to meet the market demands. The human insulin precursors that enzymatically converted to human insulin can be produced using Escherichia coli, Saccharomyces cerevisiae, or Pichia pastoris. In this study, Pichia pastoris is used for production human insulin precursor because the resulting recombinant protein can be folded accordingly and secreted to the external environment of the cell that simplifies the purification process. The study was initiated with the insertion of a synthetic gene of human insulin precursor into the pPICZaA to create recombinant pPICZaA-IP plasmid. The recombinant plasmid was transformed into Escherichia coli Top10 which then isolated and digested by the SacI enzyme. The linearize pPICZaA-IP plasmid was transfected into Pichia pastoris X-33 by electroporator. The result of transformation process, a total of 20 colonies of P pastoris X-33 were selected and inoculated in YPD agar medium containing Zeocin. The two colonies of P pastoris were characterized by PCR and sequencing showed that the recombinant pPICZaA-IP plasmid was successfully integrated into selected colonies of P pastoris.

Excessive Blood Glucose in Diabetic Ketoacidosis and Hyperosmolar Hyperglycemia: A Rare Case Report

Type 1 diabetes (T1D) is an autoimmune assault on pancreatic β-cells characterized by a decrease in insulin production. The worldwide incidence rate of T1D is reportedly increasing. In parallel with the increase of T1D, diabetic ketoacidosis (DKA) and hyperosmolar hyperglycemic state (HHS) also appear as two risk factors for hyperglycemia. This case report presents a T1D patient with DKA and HHS who was finally discharged after recovery.