Potential role of human umbilical cord stem cells-derived exosomes as novel molecular inhibitors of hepatocellular carcinoma growth.

Hepatocellular carcinoma (HCC) is one of the most critical cancers; thus, novel therapeutical regimens are of great need. In this study, we investigated the effects of umbilical cord mesenchymal stem cells (UC-MSCs) derived exosomes on HepG2 cell line, and the underlying mechanism to control HCC proliferation, to identify the potential clinical role of exosomes as a novel molecular therapeutic target. Proliferation, apoptosis, and angiogenesis effects were assessed together with the cell viability evaluation by MTT assay in HepG2 cells at 24/48 h. with or without UC-MSCs-derived exosomes. Gene expressions of TNF-α, caspase-3, VEGF, stromal cell-derived factor-1 (SDF-1), and CX chemokine receptor-4 (CXCR-4) were measured by quantitative real-time PCR technique. Expression of sirtuin-1 (SIRT-1) protein was detected by western blot. Treatment of HepG2 cells with UC-MSCs-derived exosomes for 24 and 48 h. demonstrated a significant reduction of cells survival compared to the control group (p < 0.05). The SIRT-1 protein, and VEGF, SDF-1, CXCR-4 expression levels were significantly lower, TNF-α and caspase-3 expression levels were significantly higher in exosomal-treated HepG2 cells for 24 and 48 h. than those in the control group. Moreover, our findings documented that the anti-proliferative, apoptotic, and anti-angiogenic effects were achieved in a time-dependent manner in which more effects were determined after 48 h supplementation compared to 24 h (p < 0.05). UC-MSCs-derived exosomes exert anticarcinogenic molecular effects on HepG2 cells through the involvement of SIRT-1, SDF-1, and CXCR-4. Hence, exosomes would be a potential novel therapy regimen against HCC. Large-scale studies are recommended to verify this conclusion.

Prevalence and Some Possible Mechanisms of Colistin Resistance Among Multidrug-Resistant and Extensively Drug-Resistant Pseudomonas aeruginosa.

BACKGROUND AND AIM: The emergence of colistin-resistant strains is considered a great threat for patients with severe infections. Here, we investigate the prevalence and some possible mechanisms of colistin resistance among multidrug-resistant (MDR) and extensively drug-resistant (XDR) Pseudomonas aeruginosa (P. aeruginosa). METHODS: Antimicrobial susceptibility was performed using disc diffusion methods while colistin resistance was detected by agar dilution method. Possible mechanisms for colistin resistance were studied by detection of mcr-1 and mcr-2 genes by conventional PCR, detection of efflux mechanisms using Carbonyl Cyanide 3-Chlorophenylhydrazone (CCCP), studying outer membrane protein profile and Lipopolysaccharide (LPS) profile of resistant isolates. RESULTS: It was found that MDR and XDR represented 96% and 87% of the isolated P. aeruginosa, respectively, and colistin resistance represented 21.3%. No isolates were positive for mcr-2 gene while 50% of colistin-resistant isolates were positive for mcr-1. Efflux mechanisms were detected in 3 isolates. Protein profile showed the presence of a band of 21.4 KDa in the resistant strains which may represent OprH while LPS profile showed differences among colistin-resistant mcr-1 negative strains, colistin-resistant mcr-1 positive strains and susceptible strains. CONCLUSION: The current study reports a high prevalence of colistin resistance and mcr-1 gene in P. aeruginosa strains isolated from Egypt that may result in untreatable infections. Our finding makes it urgent to avoid unnecessary clinical use of colistin.

Effect of single and repeated administration of amitriptyline on neuropathic pain model in rats: Focus on glutamatergic and upstream nitrergic systems.

AIMS: Few studies have compared the interaction of single and repeated administration of amitriptyline (amit) with the nitrergic system and glutamatergic system in the experimental model of neuropathic pain. We aimed to evaluate the antinociceptive effect of single and repeated administration of amit and to assess whether glutamate preceded inducible nitric oxide synthase (iNOS) inhibition as a mechanism of the analgesic effect of amit in the neuropathic model of pain. MATERIALS AND METHODS: Male Wistar rats were subjected to left sciatic nerve ligation. The effect of single (25 mg kg-1) and repeated (10 mg kg-1 daily for 3 weeks) administration of amit intraperitoneally (i.p.) alone or in combination with aminoguanidine (AG i.p., 100 mg kg-1 for 3 days, a selective iNOS inhibitor) and MK-801 (0.05 mg kg-1 i.p., NMDA antagonist) on resting paw posture and mechanical hyperalgesia were studied. Glutamate level and iNOS protein expression in hippocampus were detected. KEY FINDINGS: Single and repeated administration of amit alone or in combination with AG or MK-801 demonstrated a significant decrease in resting pain score and increase in the pain threshold. Both glutamate and nitrite levels decreased in the hippocampi of single and repeated amit + MK-801 groups. Immunohistochemistry showed a marked decrease in iNOS immunoreactivity in rats treated with single and repeated amit + MK-801. SIGNIFICANCE: Our results suggest that glutamate-dependent mechanisms are involved in the analgesic responses to amit administration. Importantly, glutamatergic system and its upstream nitrergic system play an important role in the antinociceptive action of amit.

Does vitamin D status correlate with insulin resistance in obese prediabetic patients? An Egyptian multicenter study.

BACKGROUND: The link between Vitamin-D deficiency and type 2 diabetes (T2D) is well-established. Since prediabetic obese populations have the greatest risk to develop to T2D, it was important in our study to examine serum 25(OH) D3 concentration among prediabetic obese patients and to evaluate the correlation between serum level of vitamin D and BMI, FBS, HOMA IR and HbA1c among prediabetes patients. METHODS: A multicenter case control study was carried out among 101 prediabetic persons & 50 controls, after obtaining consent from subjects and clearance from institutional ethics committee. Serum vitamin D level, Plasma levels of glycosylated hemoglobin (HbA1c) and fasting insulin levels were measured by ELISA in both groups enrolled in the study. RESULTS: The prevalence of vitamin-D deficiency/insufficiency was (73.3%) (n = 74) among 101 prediabetic obese individuals. Also, A significant inverse correlation was observed between vitamin D levels & body mass index(r = - 0.28, P = 0.004); fasting blood sugar (r = - 0.22, P = 0.002); HOMA insulin resistance (r = - 0.25 P = 0.01); HbA1C (r = - 0.2, P= 0.004). CONCLUSIONS: High prevalence of vitamin D deficiency exists among obese prediabetic individuals and there is significant inverse correlation between BMI, FBS, HOMA IR, HbA1c and vitamin D level.

Uses of fluoxetine in nociceptive pain management: A literature overview.

Fluoxetine is one of the top ten prescribed antidepressants. Other therapeutic applications were approved for fluoxetine including, anxiety disorders, bulimia nervosa, and premature ejaculation. However, the role of fluoxetine in nociceptive pain management is still unclear. In this review, we discuss an overview of five possible roles of fluoxetine in pain management: intrinsic antinociceptive effect, enhancement of acute opioid analgesia, attenuation of tolerance development to opioid analgesia, attenuation of dependence development and abstinence syndrome, and attenuation of opioid induced hyperalgesia. Conflicting data were reported about fluoxetine intrinsic anti-nociceptive effect in preclinical and clinical studies except for inflammatory pain. Similar controversy was described in preclinical and clinical studies which explored the possible enhancement of opioid analgesia by fluoxetine co-administration. However, fluoxetine was found to have a promising effect on opioid tolerance and dependence in animal and human studies. Regarding opioid induced hyperalgesia, no studies examined fluoxetine effects in this regard. Our literature review revealed that, the most likely beneficial use of fluoxetine in nociceptive pain management is for alleviation of inflammatory pain and attenuation of opioid tolerance and dependence. Non-steroidal anti-inflammatory and corticosteroids carry many adverse effects and toxicities. Effective alleviation of opioid tolerance and dependence represents a huge health burden and growing unmet medical need. Moreover, most agents used to attenuate these phenomena are either experimental or poorly tolerable drugs which limit their transitional value. Fluoxetine offers an effective, safe, and tolerable alternative for management of both inflammatory pain and opioid tolerance and dependence presently available to clinicians.

Fluoxetine uses in nociceptive pain management: a promising adjuvant to opioid analgesics.

Fluoxetine, a commonly prescribed antidepressant, use in nociceptive pain management represents one of the unsettled issues of fluoxetine therapeutics. By reviewing the literature about fluoxetine's possible roles in this setting, those could be solitary antinociceptive effect, enhancement of acute morphine analgesia, blocking morphine tolerance development, and blocking dependence development and associated abstinence syndrome. In this study, we examined those four alleged roles of fluoxetine. Moreover, as effective alleviation of morphine tolerance, dependence, and abstinence syndrome represents one of the most challenging medical needs, we biochemically analyzed fluoxetine effect on these phenomena. Fluoxetine (10 mg/kg, IP) was examined in hot plate test for assessment of possible analgesic activity and enhancement of morphine acute analgesia (1 and 5 mg/kg, SC). Repeated morphine (5 mg/kg, SC) administration for 9 days developed tolerance and dependence; fluoxetine was co-administered to evaluate its potential to modulate these processes. We also determined concomitant changes in neurotransmitters (glutamate and noradrenaline), inflammatory status, and prooxidant-antioxidant balance. Our results indicated that fluoxetine did not possess significant analgesia solely and did not enhance acute morphine analgesia. However, fluoxetine administration with morphine significantly attenuated tolerance and dependence development and abstinence syndrome with corresponding suppression of morphine-induced changes in neurotransmitters (glutamate and noradrenaline), inflammatory status, and prooxidant-antioxidant balance. These biochemical results may reflect both direct and indirect effects of fluoxetine. Our conclusion is that despite fluoxetine possesses low - if any - analgesic activity, it significantly adds to opioids not via enhancing analgesic activity but through modulation of tolerance and dependence development.