Ekspresi Gen CHOP sebagai Biomarker Stres Retikulum Endoplasma pada Optimasi Sulfo-N-Succinimidyl Oleate Sodium sebagai Inhibitor CD36 pada Sel HepG2

Shabrina Farras Tsany, dr. Widya Wasityastuti, M.Sc., M.Med.Ed., Ph.D.; dr. Dwi Aris Agung Nugrahaningsih, M.Sc., Ph.D.

2025 | Skripsi | PENDIDIKAN DOKTER

Latar belakang: Diet tinggi lemak dapat mengakibatkan dislipidemia, yakni ketidakseimbangan penyerapan dan pemanfaatan asam lemak yang dapat mengakibatkan akumulasi lemak. Reseptor CD36 memfasilitasi translokasi ambilan asam lemak bebas (ALB) oleh hepatosit. Akumulasi ALB dilaporkan terlibat dalam mekanisme terjadinya stress retikulum endoplasma melalui regulasi ekspresi CHOP (C/EBP homologous protein). Sulfo-N-succinimidyl Oleate Sodium (SSO) diketahui merupakan salah satu inhibitor CD36. Namun, penelitian terkait analisis konsentrasi optimum SSO dalam inhibisi CD36 masih terbatas.

Tujuan: Menentukan konsentrasi optimum SSO dalam penghambatan CD36 melalui analisis ekspresi gen CHOP yang mengindikasikan stres RE pada sel HepG2.

Metode: Penelitian ini merupakan kajian in vitro berbentuk posttest only controlled group design menggunakan sel HepG2. Terdapat 4 kelompok perlakuan berdasarkan nilai IC50 yang diperoleh melalui MTT assay, yaitu kelompok SSO dengan konsentrasi IC50, ½ IC50, ¼ IC50, ? IC50, beserta kontrol tanpa pemberian SSO (0 IC50). Dilakukan inkubasi menggunakan asam palmitat sebagai ALB setelah proses inhibisi dengan SSO. Ekspresi relatif gen CHOP dianalisis dengan RT-qPCR sebagai acuan untuk menentukan konsentrasi optimum SSO dalam inhibisi CD36.

Hasil: IC50 SSO pada sel HepG2 sebesar 59,11 ?M diperoleh melalui uji MTT assay. Intervensi pre-treatment SSO pada sel HepG2 yang diinkubasi asam palmitat menunjukkan nilai ekspresi relatif CHOP yang lebih rendah dibandingkan kelompok kontrol (p<0>

Kesimpulan: Pemberian SSO pada sel HepG2 yang diinkubasi asam palmitat dapat menekan ekspresi relatif CHOP yang merupakan biomarker stres retikulum endoplasma. Konsentrasi SSO pada rentang ?IC50 (7,38875 ?M) sampai dengan IC50 (59,11 ?M) optimal dalam menghambat ekspresi gen CHOP.

Background: A high-fat diet can lead to dyslipidemia, characterized by an imbalance in the uptake and utilization of fatty acids, resulting in fat accumulation. The CD36 receptor facilitates the translocation of free fatty acid (FFA) uptake by hepatocytes. FFA accumulation has been reported to play a role in the mechanism of endoplasmic reticulum (ER) stress through the regulation of CHOP (C/EBP homologous protein) expression. Sulfo-N-succinimidyl Oleate Sodium (SSO) is known as a CD36 inhibitor. However, studies analyzing the optimal concentration of SSO in CD36 inhibition remain limited.

Objective: To determine the optimal concentration of SSO for CD36 inhibition by analyzing CHOP gene expression, which indicates ER stress in HepG2 cells.

Method: This is an in vitro post-test only controlled group design study using HepG2 cells. There were four treatment groups based on the IC50 value obtained from the MTT assay, namely SSO groups with concentrations of IC50, ½ IC50, ¼ IC50, and ? IC50, along with a control group without SSO treatment (0 IC50). Palmitic acid was used as FFA incubation following the inhibition process with SSO. CHOP gene expression was analyzed using RT-qPCR to determine the optimal SSO concentration for CD36 inhibition.

Results: The IC50 of SSO in HepG2 cells was determined to be 59,11 ?M through the MTT assay. Pre-treatment intervention with SSO in HepG2 cells incubated with palmitic acid showed lower level of CHOP expression compared to the control group (p<0>

Conclusion: SSO treatment in HepG2 cells that incubated with palmitic acid had supressed the relative expression of CHOP as an endoplasmic reticulum stress biomarker. The concentration of SSO in the range of ?IC50 (7.38875 ?M) to IC50 (59.11 ?M) was optimal in inhibiting CHOP gene expression.

Kata Kunci : CD36, Sulfo-N-succinimidyl oleate sodium (SSO), CHOP, stres RE, HepG2, ambilan asam lemak bebas (ALB)